Science.gov

Sample records for impaired pmn migratory

  1. Hippocampal lesions do not impair the geomagnetic orientation of migratory savannah sparrows.

    PubMed

    Bingman, V P; Able, K P; Siegel, J J

    1999-12-01

    The avian hippocampal formation is known to participate in naturally occurring spatial behavior such as homing in pigeons and cache recovery in food storing passerines, but its participation in the often spectacular migrations of birds remains uncertain. As a first investigation into the possible role of hippocampal formation in migration, the effect of hippocampal formation lesions on the geomagnetic migratory orientation of Savannah sparrows was examined. When tested indoors, hippocampal formation-lesioned sparrows were able to orient in an appropriate migratory direction indicating no necessary role for hippocampal formation in geomagnetic migratory orientation. However, hippocampal formation-lesioned birds displayed significantly less migratory (nocturnal) activity, a result that inspires further study.

  2. Increased total number but impaired migratory activity and adhesion of endothelial progenitor cells in patients on long-term hemodialysis.

    PubMed

    Herbrig, Kay; Pistrosch, Frank; Oelschlaegel, Uta; Wichmann, Gunnar; Wagner, Andrea; Foerster, Sarah; Richter, Susanne; Gross, Peter; Passauer, Jens

    2004-11-01

    Endothelial progenitor cells (EPCs), derived from bone marrow, contribute to vessel repair and neovascularization. Because uremia is a state of endothelial dysfunction associated with high cardiovascular mortality, as well as a state of reduced hematopoiesis, we studied the number and function of EPCs in patients on long-term hemodialysis (HD) therapy. We counted the number of EPCs in 20 HD patients and 16 healthy volunteers. To assess EPC function, we measured migratory activity, adhesion to matrix proteins, and adhesion to endothelial cells. Furthermore, we measured blood levels of vascular endothelial growth factor (VEGF) and granulocyte-macrophage colony-stimulating factor, factors known to influence EPC kinetics. Circulating precursor cells (CD34+ , CD34+ /CD133+ , CD34+ /KDR+ cells) were counted by means of flow cytometric analysis. The number of EPCs in HD patients was significantly elevated compared with controls (459.7 +/- 92 versus 364.8 +/- 77.4 EPC/high-power field). However, migratory activity was markedly decreased in HD patients (47.5 +/- 27.7 versus 84.7 +/- 3.2 EPC/high-power field). EPCs of HD patients showed impaired adhesion to extracellular matrix and endothelial cells. VEGF blood levels in HD patients were 2-fold greater compared with controls. The number of circulating CD34+ and CD34+ /133+ cells was reduced in HD patients. There were no differences in total numbers of CD34+ /KDR+ cells. This study shows an elevated number, but pronounced functional impairment, of EPCs in patients on long-term HD therapy. The latter may result in limited endothelial repair, which, in turn, may contribute to endothelial dysfunction in this particular group of patients.

  3. Unconventional apoptosis of polymorphonuclear neutrophils (PMN): staurosporine delays exposure of phosphatidylserine and prevents phagocytosis by MΦ-2 macrophages of PMN

    PubMed Central

    Franz, S; Muñoz, L E; Heyder, P; Herrmann, M; Schiller, M

    2015-01-01

    Apoptosis of polymorphonuclear neutrophils (PMN) and subsequent ‘silent’ removal represents an important check-point for the resolution of inflammation. Failure in PMN clearance resulting in secondary necrosis-driven tissue damage has been implicated in conditions of chronic inflammation and autoimmunity. Apoptotic PMN undergo profound biophysical changes that warrant their efficient recognition and uptake by phagocytes before fading to secondary necrosis. In this study, we demonstrate that staurosporine (STS), a non-selective but potent inhibitor of cyclin-dependent kinase and protein kinase C, exerts a drastic impact on PMN apoptosis. PMN treated with STS underwent an unconventional form of cell death characterized by a delayed exposure of aminophospholipids, including phosphatidylserine (PS) and phosphatidylethanolamine and an increased exposure of neo-glycans. STS caused an impaired cellular fragmentation and accelerated DNA fragmentation. Phagocytosis of STS-treated PMN lacking PS on their surfaces was decreased significantly, which highlights the importance of PS for the clearance of apoptotic PMN. Specific opsonization with immune complexes completely restored phagocytosis of STS-treated PMN, demonstrating the efficiency of back-up clearance pathways in the absence of PS exposure. PMID:24995908

  4. 3D PMN Flextensional Stave Modeling

    DTIC Science & Technology

    2000-04-13

    WEIDLINGER ASSOCIATES, INC. 3D PMN Flextensional Stave Modeling** Greg Wojcik, John Mould, Paul Reynolds, Roger Richards* Weidlinger Associates Inc...2000 4. TITLE AND SUBTITLE 3D PMN Flextensional Stave Modeling 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...broadband • To address general needs of Navy Consider PMN-driven projector • Staves of butted Class IV flextensional shells • Array composed of

  5. Diabetes mellitus: polymorphonuclear leukocyte (PMN) filtration parameters and PMN membrane fluidity after chemotactic activation.

    PubMed

    LoPresti, R; Montana, M; Canino, B; Ventimiglia, G; Catania, A; Caimi, G

    1999-01-01

    The goal of this research was to determine leukocyte rheology at baseline and after chemotactic activation in type I and type II diabetics. In 19 normal subjects, 21 type I diabetics, and 16 type II diabetics at baseline and after in vitro chemotactic activation (prolonged for 5 and 15 minutes) with two stimulating agents (4-phorbol 12-myristate 13-acetate [PMA] and N-formyl-methionyl-leucyl-phenylalanine [fMLP]), we evaluated polymorphonuclear (PMN) filtration parameters (using a St. George filtrometer [Carri-Med, Dorking, UK] and considering the initial relative flow rate [IRFR] and the concentration of clogging particles [CP]) and PMN membrane fluidity (obtained by marking PMNs with the fluorescent probe 1-(4-[trimethylamino]phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). At baseline, there was a difference between normals and type I and II diabetics for PMN membrane fluidity only. After activation in normals and diabetics of both types, a significant variation was present in PMN filtration parameters (IRFR and CP) at both 5 and 15 minutes. In normals, no variation was present in PMN membrane fluidity after activation with PMA or fMLP. After PMN activation, only in type I diabetics was a significant decrease in PMN membrane fluidity present at both 5 and 15 minutes. After PMN activation with either PMA or fMLP in comparison to basal values, only the mean variation (delta%) of the IRFR was significantly different between normals, type I diabetics, and type II diabetics at both 5 and 15 minutes. From the data obtained, it is evident that after activation, the PMN filtration pattern shows a specific behavior in diabetics of both types, while PMN membrane fluidity changes only in type I diabetics. The latter finding may be the basis of a metabolic pattern present in PMNs of this type, revealed after in vitro activation.

  6. PMN-PT nanostructures for energy scavenging

    NASA Astrophysics Data System (ADS)

    Wu, Fan; Yao, Nan

    2017-06-01

    Piezoelectric nanocrystals have been used for self-powered nanosystems, implantable biodevices, wireless sensors and portable/wearable electronics. A profound way to increase the output voltage (or power) of the piezoelectric devices is to utilize a material with higher piezoelectric constants. (1 - x)Pb (Mg1/3Nb2/3)O3 - x PbTiO3 (PMN-PT) has been considered as the piezoelectric material of the next generation due to the high piezoelectric constant. The high flexibility, sensitivity and strain tolerance of PMN-PT nanostructures make them ideal for self-powered nanosystems. This article reviews the fabrication and structural characterization of different PMN-PT nanostructures, and their applications in various devices.

  7. Human dental stem cells suppress PMN activity after infection with the periodontopathogens Prevotella intermedia and Tannerella forsythia.

    PubMed

    Hieke, Cathleen; Kriebel, Katja; Engelmann, Robby; Müller-Hilke, Brigitte; Lang, Hermann; Kreikemeyer, Bernd

    2016-12-15

    Periodontitis is characterized by inflammation associated with the colonization of different oral pathogens. We here aimed to investigate how bacteria and host cells shape their environment in order to limit inflammation and tissue damage in the presence of the pathogen. Human dental follicle stem cells (hDFSCs) were co-cultured with gram-negative P. intermedia and T. forsythia and were quantified for adherence and internalization as well as migration and interleukin secretion. To delineate hDFSC-specific effects, gingival epithelial cells (Ca9-22) were used as controls. Direct effects of hDFSCs on neutrophils (PMN) after interaction with bacteria were analyzed via chemotactic attraction, phagocytic activity and NET formation. We show that P. intermedia and T. forsythia adhere to and internalize into hDFSCs. This infection decreased the migratory capacity of the hDFSCs by 50%, did not disturb hDFSC differentiation potential and provoked an increase in IL-6 and IL-8 secretion while leaving IL-10 levels unaltered. These environmental modulations correlated with reduced PMN chemotaxis, phagocytic activity and NET formation. Our results suggest that P. intermedia and T. forsythia infected hDFSCs maintain their stem cell functionality, reduce PMN-induced tissue and bone degradation via suppression of PMN-activity, and at the same time allow for the survival of the oral pathogens.

  8. Human dental stem cells suppress PMN activity after infection with the periodontopathogens Prevotella intermedia and Tannerella forsythia

    PubMed Central

    Hieke, Cathleen; Kriebel, Katja; Engelmann, Robby; Müller-Hilke, Brigitte; Lang, Hermann; Kreikemeyer, Bernd

    2016-01-01

    Periodontitis is characterized by inflammation associated with the colonization of different oral pathogens. We here aimed to investigate how bacteria and host cells shape their environment in order to limit inflammation and tissue damage in the presence of the pathogen. Human dental follicle stem cells (hDFSCs) were co-cultured with gram-negative P. intermedia and T. forsythia and were quantified for adherence and internalization as well as migration and interleukin secretion. To delineate hDFSC-specific effects, gingival epithelial cells (Ca9-22) were used as controls. Direct effects of hDFSCs on neutrophils (PMN) after interaction with bacteria were analyzed via chemotactic attraction, phagocytic activity and NET formation. We show that P. intermedia and T. forsythia adhere to and internalize into hDFSCs. This infection decreased the migratory capacity of the hDFSCs by 50%, did not disturb hDFSC differentiation potential and provoked an increase in IL-6 and IL-8 secretion while leaving IL-10 levels unaltered. These environmental modulations correlated with reduced PMN chemotaxis, phagocytic activity and NET formation. Our results suggest that P. intermedia and T. forsythia infected hDFSCs maintain their stem cell functionality, reduce PMN-induced tissue and bone degradation via suppression of PMN-activity, and at the same time allow for the survival of the oral pathogens. PMID:27974831

  9. Building Migratory Bridges

    ERIC Educational Resources Information Center

    Roy, Michael; Doss, Laurie K.

    2007-01-01

    The Building Migratory Bridges (BOMB) program--a collaboration between the Marvel wood School and Audubon Sharon in Connecticut and Conservation Research Education Action (CR EA), a U.S. not-for-profit in Panama--uses nontropical migratory bird research in the United States and Panama to demonstrate how negative environmental impacts in one…

  10. Building Migratory Bridges

    ERIC Educational Resources Information Center

    Roy, Michael; Doss, Laurie K.

    2007-01-01

    The Building Migratory Bridges (BOMB) program--a collaboration between the Marvel wood School and Audubon Sharon in Connecticut and Conservation Research Education Action (CR EA), a U.S. not-for-profit in Panama--uses nontropical migratory bird research in the United States and Panama to demonstrate how negative environmental impacts in one…

  11. Studies of Broadband PMN Transducers Based on Nonlinear Models

    DTIC Science & Technology

    1997-10-01

    Studies of Broadband PMN Transducers Based on Nonlinear Models G. Wojcik, J. Mould, D. Tennant, R. Richards†, H. Song, D. Vaughan, N. Abboud‡, D...here is a volume array of high-power, electrostrictive (PMN) flextensionals . Analysis and design of these complex arrays are clearly pushing the limits...finite element mod- eling of an icosahedral array of 12 electrostrictive flextensionals . Behavior of the PMN driver is illustrated with a 1D finite

  12. Type II diabetics with macrovascular complications: polymorphonuclear leukocyte (PMN) filtration, PMN membrane fluidity and cytosolic Ca2+ content after activation.

    PubMed

    Caimi, G; Lo Presti, R; Montana, M; Ferrara, F; Ventimiglia, G; Meli, F; Catania, A; Canino, B

    1998-02-01

    We evaluated polymorphonuclear (PMN) filtration parameters, membrane fluidity and cytosolic Ca2+ content in 21 normal subjects and in 18 type II diabetics with macrovascular complications (MVC). Evaluations were carried out at baseline and after in vitro activation prolonged for 5 and 15 min. PMA (4-phorbol 12-myristate 13-acetate) and fMLP (N-formyl-methionyl-leucyl-phenylalanine) were used as stimulating agents. TMA-DPH (1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene) was used as fluorescent probe for the membrane fluidity tests and Fura 2-AM for the cytosolic Ca2+ content. A significant variation was evident in PMN filtration parameters at 5 and 15 min. No variation was present in PMN membrane fluidity and cytosolic Ca2+ content in normals. In type II diabetics with MVC, we found an increase solely in PMN cytosolic Ca2+ content after PMA activation and an early decrease in PMN membrane fluidity and a late increase in PMN cytosolic Ca2+ content after fMLP activation. After PMA activation alone (at 15 min), PMN filtration distinguishes normals from type II diabetics with MVC. The PMN filtration parameters behave similarly in the two groups, but PMN membrane fluidity and cytosolic Ca2+ content behave differently.

  13. PMN-mediated immune reactions against Eimeria bovis.

    PubMed

    Behrendt, Jan Hillern; Hermosilla, Carlos; Hardt, Martin; Failing, Klaus; Zahner, Horst; Taubert, Anja

    2008-02-14

    For successful in vivo infection, Eimeria bovis sporozoites have to traverse the mucosal layer of the ileum to infect lymphatic endothelial cells and may, thereby, be exposed to the interstitial fluid and to the lymph representing potential targets for leukocytes. To mimic this situation in vitro, we exposed E. bovis sporozoites to bovine PMN and found enhanced elimination of the parasites. Addition of immune serum clearly increased these reactions, whereas neonatal calf serum had no effect, thus proposing a PMN-derived antibody-dependent cytotoxicity. Scanning and transmission electron microscopy showed PMN engulfing sporozoites or extending filopodia towards them and occasionally incorporating the parasites. PMN reacted with enhanced transcription of IL-6, MCP-1, GROalpha, TNF-alpha, and iNOS genes after exposure to sporozoites while stimulation with merozoite-antigen, in addition, upregulated IL-8, IP-10 and IL-12 gene transcription. Furthermore, enhanced in vitro oxidative burst and phagocytic activities were observed after contact of PMN with viable sporozoites. To verify the potential role of PMN in the in vivo situation, we analysed the general phagocytic and oxidative burst activities of PMN obtained ex vivo from E. bovis experimentally infected calves. Enhanced levels of both activities were found early p.i. (1-5 days) and towards the end of the first schizogony (days 13-22 p.i.) underlining the in vitro data. Our results suggest that PMN-mediated, innate immune reactions play an important role in the early immune response to E. bovis infections in calves.

  14. The ductus arteriosus migratory smooth muscle cell phenotype processes tropoelastin to a 52-kDa product associated with impaired assembly of elastic laminae.

    PubMed

    Hinek, A; Rabinovitch, M

    1993-01-15

    We established the identity of a 52-kDa protein secreted by fetal lamb ductus arteriosus (DA) smooth muscle cells (SMC) and suggest how it might be related to structural changes unique to DA development, i.e. reduced assembly of elastic laminae and associated formation of intimal cushions. We produced a monoclonal antibody (HI-20) to the 52-kDa protein and observed, by electron microscopy, immunogold labeling of elastin in both DA and aorta vessel walls. Western immunoblotting showed that HI-20, as well as antibodies to tropoelastin, reacted with the 52-kDa protein secreted by DA SMC, as well as with 68-kDa tropoelastin. The highly specific antibody to the carboxyl-terminal sequence of tropoelastin failed, however, to recognize the 52-kDa protein, although it reacted well with the 68-kDa tropoelastin. Amino acid analysis and sequencing data confirmed the identity of the affinity-purified 52-kDa protein as truncated tropoelastin with an intact amino terminus. Cell-free translation of mRNA extracted from DA and aorta SMC produced a 68-kDa, but not a 52-kDa, immunoprecipitated tropoelastin. When DA and aorta SMC were pulsed with [14C]valine, we immunoprecipitated, after only a 15-min chase, both 68-kDa and 52-kDa tropoelastin from cell extracts of DA SMC, but only the 68-kDa tropoelastin was present in aorta SMC. There was no evidence of proteolytic degradation of radiolabeled aorta 68-kDa tropoelastin to a 52-kDa species when mixed with DA SMC conditioned medium. This suggests that the 52-kDa tropoelastin is the result of cell-associated processing or degradation of an original 68-kDa product of translation. Furthermore, pulse-chase experiments showed initial secretion of equivalent amounts of 68-kDa and 52-kDa tropoelastins by cultured DA SMC with increasing accumulation of the 52-kDa species, suggesting its impaired insolubilization. The production, in high concentration, of a 52-kDa tropoelastin product that lacks the carboxyl terminus, may prevent its alignment

  15. PMN-PT/PVDF Nanocomposite for High Output Nanogenerator Applications.

    PubMed

    Li, Chuan; Luo, Wenbo; Liu, Xingzhao; Xu, Dong; He, Kai

    2016-04-11

    The 0.7Pb(Mg1/3Nb2/3)O₃-0.3PbTiO₃(0.7PMN-0.3PT) nanorods were obtained via hydrothermal method with high yield (over 78%). Then, new piezoelectric nanocomposites based on (1-x)Pb(Mg1/3Nb2/3)O₃-xPbTiO₃ (PMN-PT) nanorods were fabricated by dispersing the 0.7PMN-0.3PT nanorods into piezoelectric poly(vinylidene fluoride) (PVDF) polymer. The mechanical behaviors of the nanocomposites were investigated. The voltage and current generation of PMN-PT/PVDF nanocomposites were also measured. The results showed that the tensile strength, yield strength, and Young's modulus of nanocomposites were enhanced as compared to that of the pure PVDF. The largest Young's modulus of 1.71 GPa was found in the samples with 20 wt % nanorod content. The maximum output voltage of 10.3 V and output current of 46 nA were obtained in the samples with 20 wt % nanorod content, which was able to provide a 13-fold larger output voltage and a 4.5-fold larger output current than that of pure PVDF piezoelectric polymer. The current density of PMN-PT/PVDF nanocomposites is 20 nA/cm². The PMN-PT/PVDF nanocomposites exhibited great potential for flexible self-powered sensing applications.

  16. PMN-PT/PVDF Nanocomposite for High Output Nanogenerator Applications

    PubMed Central

    Li, Chuan; Luo, Wenbo; Liu, Xingzhao; Xu, Dong; He, Kai

    2016-01-01

    The 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3(0.7PMN-0.3PT) nanorods were obtained via hydrothermal method with high yield (over 78%). Then, new piezoelectric nanocomposites based on (1−x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) nanorods were fabricated by dispersing the 0.7PMN-0.3PT nanorods into piezoelectric poly(vinylidene fluoride) (PVDF) polymer. The mechanical behaviors of the nanocomposites were investigated. The voltage and current generation of PMN-PT/PVDF nanocomposites were also measured. The results showed that the tensile strength, yield strength, and Young’s modulus of nanocomposites were enhanced as compared to that of the pure PVDF. The largest Young’s modulus of 1.71 GPa was found in the samples with 20 wt % nanorod content. The maximum output voltage of 10.3 V and output current of 46 nA were obtained in the samples with 20 wt % nanorod content, which was able to provide a 13-fold larger output voltage and a 4.5-fold larger output current than that of pure PVDF piezoelectric polymer. The current density of PMN-PT/PVDF nanocomposites is 20 nA/cm2. The PMN-PT/PVDF nanocomposites exhibited great potential for flexible self-powered sensing applications. PMID:28335195

  17. Surfactant-Assisted Hydrothermal Synthesis of PMN-PT Nanorods.

    PubMed

    Li, Chuan; Liu, Xingzhao; Luo, Wenbo; Xu, Dong; He, Kai

    2016-12-01

    The effects of surfactant polyacrylate acid (PAA) on shape evolution of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (0.7PMN-0.3PT) nanorods were studied. The results revealed that the polyacrylic acid content had great influence on the morphology of 0.7PMN-0.3PT. With increasing PAA concentration from 0.45 to 0.82 g/ml, the ratio of perovskite phase (PMN-PT nanorod) increased, while the ratio of pyrochlore phase decreased. When the PAA concentration was 0.82 g/ml, pure 0.7PMN-0.3PT nanorods were obtained. However, when PAA concentration was higher than 0.82 g/ml, the excess of PAA would hindered their [100] orientation growth. The piezoelectric coefficient d 33 of 0.7PMN-0.3PT nanorod was obtained by linear fitting, and the d 33 value was 409 pm/V.

  18. Surfactant-Assisted Hydrothermal Synthesis of PMN-PT Nanorods

    NASA Astrophysics Data System (ADS)

    Li, Chuan; Liu, Xingzhao; Luo, Wenbo; Xu, Dong; He, Kai

    2016-02-01

    The effects of surfactant polyacrylate acid (PAA) on shape evolution of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (0.7PMN-0.3PT) nanorods were studied. The results revealed that the polyacrylic acid content had great influence on the morphology of 0.7PMN-0.3PT. With increasing PAA concentration from 0.45 to 0.82 g/ml, the ratio of perovskite phase (PMN-PT nanorod) increased, while the ratio of pyrochlore phase decreased. When the PAA concentration was 0.82 g/ml, pure 0.7PMN-0.3PT nanorods were obtained. However, when PAA concentration was higher than 0.82 g/ml, the excess of PAA would hindered their [100] orientation growth. The piezoelectric coefficient d 33 of 0.7PMN-0.3PT nanorod was obtained by linear fitting, and the d 33 value was 409 pm/V.

  19. Optimal Conservation of Migratory Species

    PubMed Central

    Martin, Tara G.; Chadès, Iadine; Arcese, Peter; Marra, Peter P.; Possingham, Hugh P.; Norris, D. Ryan

    2007-01-01

    Background Migratory animals comprise a significant portion of biodiversity worldwide with annual investment for their conservation exceeding several billion dollars. Designing effective conservation plans presents enormous challenges. Migratory species are influenced by multiple events across land and sea–regions that are often separated by thousands of kilometres and span international borders. To date, conservation strategies for migratory species fail to take into account how migratory animals are spatially connected between different periods of the annual cycle (i.e. migratory connectivity) bringing into question the utility and efficiency of current conservation efforts. Methodology/Principal Findings Here, we report the first framework for determining an optimal conservation strategy for a migratory species. Employing a decision theoretic approach using dynamic optimization, we address the problem of how to allocate resources for habitat conservation for a Neotropical-Nearctic migratory bird, the American redstart Setophaga ruticilla, whose winter habitat is under threat. Our first conservation strategy used the acquisition of winter habitat based on land cost, relative bird density, and the rate of habitat loss to maximize the abundance of birds on the wintering grounds. Our second strategy maximized bird abundance across the entire range of the species by adding the constraint of maintaining a minimum percentage of birds within each breeding region in North America using information on migratory connectivity as estimated from stable-hydrogen isotopes in feathers. We show that failure to take into account migratory connectivity may doom some regional populations to extinction, whereas including information on migratory connectivity results in the protection of the species across its entire range. Conclusions/Significance We demonstrate that conservation strategies for migratory animals depend critically upon two factors: knowledge of migratory

  20. [Necrolytic migratory erythema].

    PubMed

    Dandrifosse, J F; Dandrifosse, A C; Piérard, G; Scheen, A J; Dandrifosse, G

    1998-12-01

    Necrolytic migratory erythema (NME) is generally associated with glucagonoma. It waxes and wanes by successive relapses and remissions. The clinical and microscopical diagnosis is complex. In addition to glucagonoma treatments, the administration of corticoids, aminoacids, zinc or essential fatty acids can be helpful. There exist several etiological hypotheses for NME. These are based on modifications of pancreatic enzyme activities and on variations of aminoacids, fatty acids, zinc or glucagon concentrations.

  1. Design, production and testing of PMN-PT electrostrictive transducers.

    PubMed

    Coutte, J; Dubus, B; Debus, J C; Granger, C; Jones, D

    2002-05-01

    Lead magnesium niobate ceramics (PMN) are promising materials for application in the field of high power transducers. The advantage of PMN materials are the large strains generated under moderate electric field and the low hysteresis. The electrostrictive effect is non-linear, the corresponding physical constants depend on temperature and frequency and a DC electrical bias is required. These difficulties must be considered at the design stage. A finite element model has been developed and validated in the ATILA code for non-linear static and time-domain analyses. These numerical modelings are used to design and test two Langevin-type electrostrictive transducers. The first transducer is made of PMN-PT-La (90-10-1%) ceramics (TRS Ceramics), the second one of ESCI ceramics (Morgan Matroc). For given static mechanical prestresses, resonance frequencies and effective coupling coefficients are measured at different DC electric fields and temperatures.

  2. Misfit strain phase diagrams of epitaxial PMN-PT films

    NASA Astrophysics Data System (ADS)

    Khakpash, N.; Khassaf, H.; Rossetti, G. A.; Alpay, S. P.

    2015-02-01

    Misfit strain-temperature phase diagrams of three compositions of (001) pseudocubic (1 - x).Pb (Mgl/3Nb2/3)O3 - x.PbTiO3 (PMN-PT) thin films are computed using a phenomenological model. Two (x = 0.30, 0.42) are located near the morphotropic phase boundary (MPB) of bulk PMN-PT at room temperature (RT) and one (x = 0.70) is located far from the MPB. The results show that it is possible to stabilize an adaptive monoclinic phase over a wide range of misfit strains. At RT, the stability region of this phase is much larger for PMN-PT compared to barium strontium titanate and lead zirconate titanate films.

  3. PMN-PT nanowires with a very high piezoelectric constant.

    PubMed

    Xu, Shiyou; Poirier, Gerald; Yao, Nan

    2012-05-09

    A profound way to increase the output voltage (or power) of the piezoelectric nanogenerators is to utilize a material with higher piezoelectric constants. Here we report the synthesis of novel piezoelectric 0.72Pb(Mg(1/3)Nb(2/3))O(3)-0.28PbTiO(3) (PMN-PT) nanowires using a hydrothermal process. The unpoled single-crystal PMN-PT nanowires show a piezoelectric constant (d(33)) up to 381 pm/V, with an average value of 373 ± 5 pm/V. This is about 15 times higher than the maximum reported value of 1-D ZnO nanostructures and 3 times higher than the largest reported value of 1-D PZT nanostructures. These PMN-PT nanostructures are of good potential being used as the fundamental building block for higher power nanogenerators, high sensitivity nanosensors, and large strain nanoactuators.

  4. Design and fabrication of PIN-PMN-PT single-crystal high-frequency ultrasound transducers.

    PubMed

    Sun, Ping; Zhou, Qifa; Zhu, Benpeng; Wu, Dawei; Hu, Changhong; Cannata, Jonathan M; Tian, Jin; Han, Pengdi; Wang, Gaofeng; Shung, K Kirk

    2009-12-01

    High-frequency PIN-PMN-PT single crystal ultrasound transducers at center frequencies of 35 MHz and 60 MHz were successfully fabricated using lead indium niobate-lead magnesium niobate-lead titanate (0.23PIN- 0.5PMN-0.27PT) single crystal. The new PIN-PMN-PT single crystal has higher coercivity (6.0 kV/cm) and higher Curie temperature (160 degrees C) than PMN-PT crystal. Experimental results showed that the PIN-PMN-PT transducers have similar performance but better thermal stability compared with the PMN-PT transducers.

  5. Piezoelectric PMN-PT fibre hydrophone for ultrasonic transducer calibration

    NASA Astrophysics Data System (ADS)

    Lau, S. T.; Lam, K. H.; Chan, H. L. W.; Choy, C. L.; Luo, H. S.; Yin, Q. R.; Yin, Z. W.

    2005-01-01

    A newly developed ceramic fibre hydrophone with an active element as small as 0.25 mm in diameter is described in this work. Lead magnesium niobate-lead titanate (PMN-PT) ceramic fibre with a nominal composition of 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 was fabricated by an extrusion method. PMN-PT single crystals were ground to a powder form and then mixed with poly(acrylic) acid to form a homogenous slurry. The fibre was extruded by pressing the slurry through a spinneret and then sintering at 1250 °C for crystallization. The electrical characteristics of the PMN-PT fibre were evaluated by measuring the relative permittivity and the impedance spectrum. A piezoelectric PMN-PT fibre hydrophone was fabricated and its sensitivity, angular response, and spatial resolution were evaluated. The fibre hydrophone provides good spatial resolution, angular response and receiving sensitivity.

  6. 75 FR 53774 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-01

    ... Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain...-1231-9BPP-L2] RIN 1018-AX06 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain..., Interior. ACTION: Final rule. SUMMARY: This rule prescribes special early-season migratory bird hunting...

  7. High-performance PMN-PT thick films.

    PubMed

    Kosec, Marija; Ursic, Hana; Holc, Janez; Hrovat, Marko; Kuscer, Danjela; Malic, Barbara

    2010-10-01

    This article describes some of our work on ₀.₆₅Pb(Mg₁/₃Nb(₂/₃)O₃-₀.₃₅PbTiO₃ (0.65PMN-0.35PT) thick films printed on alumina substrates. These thick films, with the nominal composition ₀.₆₅Pb(Mg₁/₃Nb(₂/₃)O₃-₀.₃₅PbTiO₃, were produced by screen-printing and firing a paste prepared from an organic vehicle and pre-reacted fine particles of avery chemically homogeneous powder. To improve the adhesion of the 0.65PMN-0.35PT to the platinized alumina substrate,a Pb(Zr₀.₅₃Ti₀.₄₇)O₃ layer was deposited between the electrode and the substrate. The samples were then sintered at 950 °C for 2 h with various amounts of packing powder on the alumina (Al₂O₃) substrates. The sintering procedure was optimized to obtain dense 0.65PMN-0.35PT films. The films were then characterized using scanning electron microscopy as well as measurements of the dielectric and piezoelectric constants.The electrostrictive behavior of the 0.65PMN-0.35PT thick films was investigated using an atomic force microscope(AFM). Finally, substrate-free, large-displacement bending type actuators were prepared and characterized, and the normalized displacement (i.e., the displacement per unit length) of the actuators was determined to be 55 μm/cm at 3.6 kV/cm.

  8. The migratory fascia hypothesis.

    PubMed

    Lelean, Peter

    2009-10-01

    its possible implications for lumbo-pelvic function. Although a review of anatomy atlases has failed to reveal mention of migratory fascia, the author respectfully suggests that dissection, specifically aimed at this task, may demonstrate its presence. It is also suggested that a retrospective review of lumbo-pelvic MRI records be initiated to identify the presence of this proposed fascial feature in the general population. Finally, magnetic resonance elastography may be useful in defining areas of increased muscular tension, in order to test the migratory fascia hypothesis.

  9. Colloidal processing of PMN-PT thick films for piezoelectric sensor applications

    NASA Astrophysics Data System (ADS)

    Luo, Hongyu

    65%Pb(Mg1/3Nb2/3)O3-35%PbTiO3 (65PMN-35PT, or PMN-PT) is a highly piezoelectric ceramic with superior piezoelectric coefficients over the more popular Pb(Zr0.5Ti0.5)O 3 (PZT). Because of its complex chemistry and high volatility of lead above 1000°C, the perovskite phase of PMN-PT is hard to process and has prevented PMN-PT from various piezoelectric applications, especially in the new area of piezoelectric micro-electro-mechanical systems (PMEMS) involving thick or thin piezoelectric films. In this thesis, a novel precursor suspension method is introduced that substantially lowers the sintering temperature of PMN-PT to 850°C from a PMN precursor powder made by coating Mg(OH) 2 on Nb2O5 particles. The precursor suspension method entails suspending PMN powders in PT precursor and uses the reaction sintering capability of PMN with nano-sized PT in the temperature range of 800°C˜1000°C. Moreover, free-standing PMN-PT thick films were obtained by tape casting the PMN-PT powder. This new geometry of PMN-PT shows giant electric-field enhanced piezoelectric responses comparable with those of single crystals. As an example of application, the PMN-PT thick film is bonded to a thinner layer of copper by electroplating and made into piezoelectric cantilever sensors. In conclusion, the colloidal suspension processing method produces free-standing PMN-PT thick films with ultrahigh piezoelectric properties.

  10. Glaciation as a migratory switch

    PubMed Central

    Zink, Robert M.; Gardner, Aubrey S.

    2017-01-01

    Migratory behavior in birds is evolutionarily plastic, but it is unclear how this behavior responded during glacial cycles. One view is that at glacial maxima, species simply shifted their breeding ranges south of glacial ice and remained migratory. To test this hypothesis, we constructed ecological niche models for breeding and wintering ranges of 56 species, finding that 70% of currently long-distance North American migrant species likely lacked suitable breeding habitat in North America at the Last Glacial Maximum (LGM), and we hypothesized that they reverted to the ancestral state of being tropical sedentary residents. A smaller percentage of short-distance migrants (27%) experienced altered migratory behavior at the LGM, although the ranges of all species were shifted southward, as traditionally envisioned. We suggest that many species oscillate between sedentary and migratory strategies with each glacial cycle acting as an adaptive switch. Thus, range shifts occur more frequently than speciation events and are inadequately depicted by phylogenetic reconstructions. We suggest that reconstructing the evolutionary history of traits, such as migratory behavior, is best served by using ranges at glacial maxima. A phylogeny of warblers strongly predicted LGM, but not present distributions, and suggested that migration was re-expressed from three tropical centers of warbler diversity. Understanding of evolutionary history will be improved when reconstructions use distributions relevant to the time of character transitions. PMID:28948216

  11. Sol-Gel Preparation Of Lead Magnesium Ni Obate (Pmn) Powdersand Thin Films

    DOEpatents

    Boyle, Timothy J.

    1999-01-12

    A method of preparing a lead magnesium niobium oxide (PMN), Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3, precursor solution by a solvent method wherein a liquid solution of a lead-complex PMN precursor is combined with a liquid solution of a niobium-complex PMN precursor, the combined lead- and niobium-complex liquid solutions are reacted with a magnesium-alkyl solution, forming a PMN precursor solution and a lead-based precipitate, and the precipitate is separated from the reacted liquid PMN precursor solution to form a precipitate-free PMN precursor solution. This precursor solution can be processed to form both ferroelectric powders and thin films.

  12. Sol-gel preparation of lead magnesium niobate (PMN) powders and thin films

    DOEpatents

    Boyle, T.J.

    1999-01-12

    A method of preparing a lead magnesium niobium oxide (PMN), Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}, precursor solution by a solvent method wherein a liquid solution of a lead-complex PMN precursor is combined with a liquid solution of a niobium-complex PMN precursor, the combined lead- and niobium-complex liquid solutions are reacted with a magnesium-alkyl solution, forming a PMN precursor solution and a lead-based precipitate, and the precipitate is separated from the reacted liquid PMN precursor solution to form a precipitate-free PMN precursor solution. This precursor solution can be processed to form both ferroelectric powders and thin films. 3 figs.

  13. Tip-bias-induced domain evolution in PMN-PT transparent ceramics via piezoresponse force microscopy

    NASA Astrophysics Data System (ADS)

    Zhao, K. Y.; Zhao, W.; Zeng, H. R.; Yu, H. Z.; Ruan, W.; Xu, K. Q.; Li, G. R.

    2015-05-01

    Piezoresponse force microscopy (PFM) was employed to investigate ferroelectric domain structures and their dynamic behavior of lead magnesium niobate-lead titanate [Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT)] transparent ceramics under an tip-bias-induced electric field. A remarkable effect of fluctuation of PT content on the domain configurations and domain dynamic response in PMN-PT transparent ferroelectric ceramics were found by PFM. Comparing with PMN-10%PT and PMN-20%PT, the reversed polarization of macrodomain area in PMN-35%PT and PMN-25%PT exhibits a relatively higher response behavior and better polarization retention performance under the PFM tip-bias-induced electric field, which correspond to their unique macroscopic electro-optic properties.

  14. The Strength of PIN-PMN-PT Single Crystals under Bending with a Longitudinal Electric Field

    DTIC Science & Technology

    2011-04-06

    The strength of PIN– PMN – PT single crystals under bending with a longitudinal electric field This article has been downloaded from IOPscience. Please...COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE The Strength Of PIN- PMN - PT Single Crystals Under Bending With A Longitudinal Electric Field... PMN ? PT ) single crystals was measured using a four point bending apparatus with a longitudinal electric field applied to the bar during bending. The

  15. Neotropical Migratory Birds of the Southern Appalachians

    Treesearch

    Kathleen E. Franzreb; Ricky A. Phillips

    1996-01-01

    This publication describes Neotropical migratory birds in the Southern Appalachians, their general ecology and habitat associations, population status, possible reasons for declines and management needs. This paper concentrates on migratory landbirds, thus it does not include waterfowl or shorebirds.

  16. 77 FR 23093 - Migratory Bird Hunting; Proposed 2012-13 Migratory Game Bird Hunting Regulations (Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ... Bird Hunting; Proposed 2012-13 Migratory Game Bird Hunting Regulations (Preliminary) With Requests for... Migratory Bird Hunting; Proposed 2012-13 Migratory Game Bird Hunting Regulations (Preliminary) With Requests... to establish annual hunting regulations for certain migratory game birds for the 2012-13 hunting...

  17. 76 FR 19875 - Migratory Bird Hunting; Proposed 2011-12 Migratory Game Bird Hunting Regulations (Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-08

    ... Bird Hunting; Proposed 2011-12 Migratory Game Bird Hunting Regulations (Preliminary) With Requests for... Migratory Bird Hunting; Proposed 2011-12 Migratory Game Bird Hunting Regulations (Preliminary) With Requests... to establish annual hunting regulations for certain migratory game birds for the 2011-12 hunting...

  18. 77 FR 58657 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ... Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and Ceded Lands... Part 20 RIN 1018-AX97 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal..., Interior. ACTION: Final rule. SUMMARY: This rule prescribes special late-season migratory bird hunting...

  19. 77 FR 54451 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-05

    ... Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and Ceded.... SUMMARY: This rule prescribes special early-season migratory bird hunting regulations for certain tribes...: The Migratory Bird Treaty Act (MBTA) of July 3, 1918 (40 Stat. 755; 16 U.S.C. 703 et seq.), authorizes...

  20. 78 FR 47135 - Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-02

    ... Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and... 20 RIN 1018-AY87 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain...) proposes special migratory bird hunting regulations for certain Tribes on Federal Indian reservations, off...

  1. 76 FR 32224 - Migratory Birds; Take of Migratory Birds by the Armed Forces

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-03

    ... Fish and Wildlife Service Migratory Birds; Take of Migratory Birds by the Armed Forces AGENCY: Fish and... birds during approved military readiness activities without violating the Migratory Bird Treaty Act... the Armed Forces to incidentally take migratory birds. The Authorization Act also stated that the...

  2. 75 FR 47681 - Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ... Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Migratory Bird Hunting... INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX06 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and Ceded Lands for the 2010-11 Season...

  3. 75 FR 59041 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-24

    ... Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Migratory Bird Hunting...; ] DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX06 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and Ceded Lands for the 2010-11...

  4. 77 FR 49679 - Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-16

    ... August 16, 2012 Part V Department of the Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and Ceded... 20 RIN 1018-AX97 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain...

  5. 77 FR 29515 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-17

    ... Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for the 2012-13... RIN 1018-AX97 Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting... in an earlier document to establish annual hunting regulations for certain migratory game birds...

  6. Pennsylvania Migratory Labor Program Report.

    ERIC Educational Resources Information Center

    Governor's Committee on Migratory Labor, Harrisburg, PA.

    Operating for the 18th year, the Pennsylvania Governor's Committee on Migratory Labor, which is charged with coordinating and bringing into focus the activities of various governmental and nongovernmental agencies relating to Pennsylvania's migrant workers, submits the present document as an annual report. Some specific areas reported on by…

  7. Bacillus anthracis Edema Toxin Impairs Neutrophil Actin-Based Motility▿

    PubMed Central

    Szarowicz, Sarah E.; During, Russell L.; Li, Wei; Quinn, Conrad P.; Tang, Wei-Jen; Southwick, Frederick S.

    2009-01-01

    Inhalation anthrax results in high-grade bacteremia and is accompanied by a delay in the rise of the peripheral polymorphonuclear neutrophil (PMN) count and a paucity of PMNs in the infected pleural fluid and mediastinum. Edema toxin (ET) is one of the major Bacillus anthracis virulence factors and consists of the adenylate cyclase edema factor (EF) and protective antigen (PA). Relatively low concentrations of ET (100 to 500 ng/ml of PA and EF) significantly impair human PMN chemokinesis, chemotaxis, and ability to polarize. These changes are accompanied by a reduction in chemoattractant-stimulated PMN actin assembly. ET also causes a significant decrease in Listeria monocytogenes intracellular actin-based motility within HeLa cells. These defects in actin assembly are accompanied by a >50-fold increase in intracellular cyclic AMP and a >4-fold increase in the phosphorylation of protein kinase A. We have previously shown that anthrax lethal toxin (LT) also impairs neutrophil actin-based motility (R. L. During, W. Li, B. Hao, J. M. Koenig, D. S. Stephens, C. P. Quinn, and F. S. Southwick, J. Infect. Dis. 192:837-845, 2005), and we now find that LT combined with ET causes an additive inhibition of PMN chemokinesis, polarization, chemotaxis, and FMLP (N-formyl-met-leu-phe)-induced actin assembly. We conclude that ET alone or combined with LT impairs PMN actin assembly, resulting in paralysis of PMN chemotaxis. PMID:19349425

  8. An acoustic/thermal model for self-heating in PMN sonar projectors

    PubMed

    Shankar; Hom

    2000-11-01

    Dielectric hysteresis and a strong material temperature dependence uniquely couple the acoustic output and temperature of a sonar projector driven by electrostrictive Pb(Mg1/3, Nb2/3)O3 (PMN). Both the source level and the source of self-heating, i.e., dielectric hysteresis, dramatically decrease as the PMN driver heats. The final temperature delineates outstanding PMN transducers from mediocre PMN transducers, so accurate acoustic performance prediction requires accurate transducer temperature prediction. This study examined this self-heating phenomenon by combining an electro-acoustics model for a PMN flextensional transducer with a thermal finite element model. The sonar model calculated the source level and heat generation rate for the PMN driver as a function of temperature. This computed source level varied 12 dB over a 75 degrees C temperature range solely due to the temperature dependent ceramic. The heat transfer model used the computed heat rate to predict the transducer's transient thermal response. The results clearly demonstrate that the transducer reached a steady-state equilibrium temperature, where the heat generated by the PMN driver balanced the heat dissipated. While the transducer model predicted a significant temperature rise, the corresponding acoustic output still surpassed the output of an equivalent Pb(Zr,Ti)O3 (PZT) transducer by 8 dB. Good agreement with experiments made on a PMN flextensional transducer validated the model.

  9. Diffuse Scattering from Relaxor PMN-xPT

    NASA Astrophysics Data System (ADS)

    Krogstad, Matthew; Rosenkranz, Stephan; Osborn, Raymond; Wozniak, Justin; Ye, Feng; Ruff, Jacob; Gehring, Peter; Ye, Zuo-Guang; Phelan, Daniel

    Relaxor ferroelectrics possess intriguing electromechanical and dielectric properties, the microscopic physics of which is widely regarded to be related to local, correlated atomic displacements from long-range symmetry. However, despite numerous studies over the last few decades, the details of how short range correlations and disorder drive the relaxor behavior remain unresolved. Single crystal diffuse scattering provides a powerful probe of such deviations from an average structure correlated over varying length scales, and over the last few years, techniques and instruments for measuring diffuse scattering with both x-rays and neutrons have seen a dramatic improvement, allowing for large volumes of reciprocal space to be measured in little time. We present our recent complementary neutron and x-ray measurements on solid solutions of PMN-xPT which revealed new structure to the diffuse scattering of relaxors close to the morphotropic phase boundary.

  10. Fabrication of flexible piezoelectric PMN-PT based composite films for energy harvesting

    NASA Astrophysics Data System (ADS)

    Das, Satyabati; Biswal, Asutya Kumar; Roy, Amritendu

    2017-02-01

    Flexible piezoelectric composite films of lead magnesium niobate and lead titanate (PMN-PT) ceramic and multiwalled carbon nanotube (MW-CNT) in the matrix of polyvinyldene fluoride (PVDF) were fabricated for green energy harvesting and self-powered sensing. Compositions of PMN-PT was varied from 10-50 volume (vol. %) in PVDF matrix while a constant concentration of MW-CNT was maintained (1vol. %). Phase purity of the synthesized composites was confirm by X-ray diffraction (XRD) analysis. PMN-PT powder was found to be in single phase without the presence of any additional peak, which generally arises due to crystallization of another pyrochlore phase. Surface morphology study by scanning electron microscopy (SEM) revealed a well dispersed PMN-PT/CNT in PVDF matrix. The maximum measured output voltage and current during mechanical pressing and releasing conditions were found to be ∼ 3 volt and 30 nA, respectively in 30 vol. % PMN-PT composite.

  11. Isolation, In-111 labeling, and abscess detection efficiency of rabbit polymorphonuclear leukocytes (PMN) from blood and peritoneal fluid

    SciTech Connect

    Bettin, K.M.; Elson, M.K.; Gerding, D.N.; Bamberger, D.M.; Forstrom, L.A.; Shafer, R.B.

    1984-01-01

    In-111 labeled blood and peritoneal exudate PMN were compared for labeling efficiency and ability to migrate to sites of experimental abscesses using both direct sampling and visual imaging techniques. Blood PMN were prepared by combining heparinized blood with 6% Hetastarch for 1 hour and layering the plasma over a double density Ficoll-Hy-paque gradient (S.G. 1.076 over 1.141). The PMN layer (90-99% PMN) at the interface yielded 10/sup 6/-10/sup 7/ PMN from 80-120 ml of blood. Peritoneal PMN were obtained by infusion of 0.1% glycogen, followed by infusion of saline after 4 or 18 hours. The exudate yielded 10/sup 7/-10/sup 8/ PMN (80-99% PMN). PMN suspensions were labeled for 30 minutes by addition of 100 ..mu..Ci of In-111-oxine, then washed twice. Percent cell-associated radioactivity of the labeled blood, 4 hour, and 18 hour peritoneal PMN was 89%, 88%, and 86%. The labeled PMN were injected intravenously into rabbits which had two of three abdominal capsules (table tennis balls drilled with 250 1.5 mm holes) inoculated with Staphylococcus aureus 4 hours earlier. Peak venous recovery of circulating labeled PMN, for blood, 4 hour and 18 hour peritoneal PMN was 60%, 43%, and 19%. Gamma camera images 24 hours after infusion into infected rabbits were superior with 4 hour peritoneal PMN. The peritoneal PMN harvested 4 hours after glycogen stimulation are simple to prepare, are obtainable in greater numbers than blood PMN, and result in better abscess visualization.

  12. Dynamic conservation for migratory species

    PubMed Central

    Reynolds, Mark D.; Sullivan, Brian L.; Hallstein, Eric; Matsumoto, Sandra; Kelling, Steve; Merrifield, Matthew; Fink, Daniel; Johnston, Alison; Hochachka, Wesley M.; Bruns, Nicholas E.; Reiter, Matthew E.; Veloz, Sam; Hickey, Catherine; Elliott, Nathan; Martin, Leslie; Fitzpatrick, John W.; Spraycar, Paul; Golet, Gregory H.; McColl, Christopher; Morrison, Scott A.

    2017-01-01

    In an era of unprecedented and rapid global change, dynamic conservation strategies that tailor the delivery of habitat to when and where it is most needed can be critical for the persistence of species, especially those with diverse and dispersed habitat requirements. We demonstrate the effectiveness of such a strategy for migratory waterbirds. We analyzed citizen science and satellite data to develop predictive models of bird populations and the availability of wetlands, which we used to determine temporal and spatial gaps in habitat during a vital stage of the annual migration. We then filled those gaps using a reverse auction marketplace to incent qualifying landowners to create temporary wetlands on their properties. This approach is a cost-effective way of adaptively meeting habitat needs for migratory species, optimizes conservation outcomes relative to investment, and can be applied broadly to other conservation challenges. PMID:28845449

  13. Migratory journeys and tuberculosis risk.

    PubMed

    Ho, Ming-Jung

    2003-12-01

    After decades of decline, tuberculosis case rates in New York City more than tripled between 1978 and 1992. While the number of cases of those born in the United States declined after 1992, the proportion of immigrant tuberculosis cases continued to increase and reached 58 percent in 1999. This article questions the biomedical explanation of immigrant tuberculosis as being imported from immigrants' countries of origin. Illness narratives of illegal Chinese immigrants with tuberculosis detailing risks associated with migratory journeys are presented. The social and cultural nature of the concept of risk, as well as the adverse implication of biomedical identification of immigrants as being at higher risk of tuberculosis, are also discussed. The author concludes that the dominant biomedical explanation of immigrant tuberculosis could be modified with the incorporation of the migratory process as a risk factor.

  14. Social learning of migratory performance.

    PubMed

    Mueller, Thomas; O'Hara, Robert B; Converse, Sarah J; Urbanek, Richard P; Fagan, William F

    2013-08-30

    Successful bird migration can depend on individual learning, social learning, and innate navigation programs. Using 8 years of data on migrating whooping cranes, we were able to partition genetic and socially learned aspects of migration. Specifically, we analyzed data from a reintroduced population wherein all birds were captive bred and artificially trained by ultralight aircraft on their first lifetime migration. For subsequent migrations, in which birds fly individually or in groups but without ultralight escort, we found evidence of long-term social learning, but no effect of genetic relatedness on migratory performance. Social learning from older birds reduced deviations from a straight-line path, with 7 years of experience yielding a 38% improvement in migratory accuracy.

  15. Social learning of migratory performance

    USGS Publications Warehouse

    Mueller, Thomas; O'Hara, Robert B.; Converse, Sarah J.; Urbanek, Richard P.; Fagan, William F.

    2013-01-01

    Successful bird migration can depend on individual learning, social learning, and innate navigation programs. Using 8 years of data on migrating whooping cranes, we were able to partition genetic and socially learned aspects of migration. Specifically, we analyzed data from a reintroduced population wherein all birds were captive bred and artificially trained by ultralight aircraft on their first lifetime migration. For subsequent migrations, in which birds fly individually or in groups but without ultralight escort, we found evidence of long-term social learning, but no effect of genetic relatedness on migratory performance. Social learning from older birds reduced deviations from a straight-line path, with 7 years of experience yielding a 38% improvement in migratory accuracy.

  16. Strong magnetoelectric and spin phonon coupling in SmFeO3/PMN-PT composite

    NASA Astrophysics Data System (ADS)

    Ahlawat, Anju; Satapathy, S.; Sathe, V. G.; Choudhary, R. J.; Gupta, P. K.

    2016-08-01

    We have investigated spin phonon coupling in the strain coupled magnetoelectric SmFeO3/0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 (PMN-PT) composite in the temperature range of 300-650 K by Raman spectroscopy and magnetic measurements. The SmFeO3/PMN-PT composite shows sharp rise in magnetic moment across ferroelectric transition temperature (Tc) of PMN-PT. Around this transition temperature (Tc of PMN-PT), the temperature evolution of Raman spectra of the composite also shows anomalies in the phonon frequencies and line width corresponding to the SmFeO3 phase which indicate structural modifications in the SmFeO3 phase around Tc of PMN-PT. The observed structural, magnetic, and phonon anomalies of SmFeO3 around Tc of PMN-PT in SmFeO3/PMN-PT are attributed to spin-phonon coupling providing evidence of strong strain mediated magnetoelectric effects.

  17. High-performance energy harvester fabricated with aerosol deposited PMN-PT material

    NASA Astrophysics Data System (ADS)

    Chen, C. T.; Lin, S. C.; Lin, T. K.; Wu, W. J.

    2016-11-01

    This paper reports a high-performance piezoelectric energy harvester (EH) fabricated with xPb(Mg1/3Nb2/3)-(l-x)PbTiO3 (PMN-PT) by aerosol deposition method. The result indicates that PMN-PT based EH owns 1.8 times output power which is higher than traditional PbZrxTi1- xO3 (PZT) based EH. In order to compare the output performance of EH fabricated with PMN- PT compared with PZT, the similar thickness of PMN-PT and PZT thin film is deposited on stainless steel subtracted. The experimental results show that PZT-based EH had a maximum output power of 4.65 μW with 1.11 Vp-p output voltage excited at 94.4 Hz under 0.5g base excitation, while the PMN-PT based device has a maximum output power of 8.42 μW with 1.49 Vp-p output voltage at a vibration frequency of 94.8 Hz and the same base excitation level. The volumetric power density was 82.95 μW/mm3 and 48.05 μW/mm3 for the device based on PMN- PT and PZT materials, respectively. All the results demonstrate that PMN-PT has better output performance than PZT.

  18. Synthesis of novel precursors for PMN powders and the thin films obtained from them

    SciTech Connect

    Boyle, T.J.; Dimos, D.B.; Moore, G.J.

    1995-03-01

    Sol-gel processing has been widely used in the preparation of lead zirconate titanate (PZT) thin films. The authors have applied this methodology to the formation of lead magnesium niobate (PMN) spin-cast deposited thin films. Since there is a limited number of soluble, commercially available compounds, the authors have recently synthesized a series of novel metal alkoxides for use as precursors for generation of PMN thin films and powders. The process for generation of the perovskite phase of these PMN powders and films are reported.

  19. Nanodomain structures with hierarchical inhomogeneities in PMN-PT.

    PubMed

    Kurushima, Kosuke; Kobayashi, Keisuke; Mori, Shigeo

    2012-09-01

    The nanometric domain configuration of (1 - x) Pb(Mg(1/3)Nb(2/3))O(3-x)PbTiO(3) [(1 - x)PMN-xPT] single crystals in the monoclinic phase around a morphotropic phase boundary (MPB) has been examined thoroughly by means of transmission electron microscopy (TEM). Domain structures with hierarchically inhomogeneous configuration were found in the monoclinic phase near the MPB region around x ~ 0.32, which are characterized as nanoscaled lamella-type domain structures with ~10 nm width inside macroscopic-sized banded domains with 100 to 200 nm width. To elucidate formation processes of the domain structures with hierarchically inhomogeneous configuration, an in situ TEM observation of changes of the domain structures in the temperature window between 298K and 500K was carried out. It is revealed that these nanoscaled lamella-type domain structures with ~10 nm width appear inside the banded domains as a result of the tetragonal structure and are inherent to the monoclinic phase.

  20. 78 FR 35844 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-14

    ... Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AY87 Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for the 2013-14 Hunting Season; Notice of Meetings AGENCY... regulations for certain migratory game birds for the 2013-14 hunting season. This supplement to the proposed...

  1. 75 FR 27143 - Migratory Bird Hunting; Proposed 2010-11 Migratory Game Bird Hunting Regulations (Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-13

    ... Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed 2010-11 Migratory Game Bird Hunting Regulations (Preliminary) With Requests for Indian Tribal Proposals and Requests for 2011 Spring and Summer Migratory Bird Subsistence Harvest Proposals in Alaska; Proposed Rule...

  2. 76 FR 36508 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ... for Migratory Game Bird Hunting Regulations for the 2011-12 Hunting Season; Notice of Meetings AGENCY... regulations for certain migratory game birds for the 2011-12 hunting season. This supplement to the proposed..., and other regulations for hunting migratory game birds under Sec. Sec. 20.101 through 20.107, 20.109...

  3. 75 FR 32872 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-10

    ... for Migratory Game Bird Hunting Regulations for the 2010-11 Hunting Season; Notice of Meetings AGENCY... regulations for certain migratory game birds for the 2010-11 hunting season. This supplement to the proposed... addressed the establishment of seasons, limits, and other regulations for hunting migratory game birds under...

  4. 78 FR 21199 - Migratory Bird Hunting; Proposed 2013-14 Migratory Game Bird Hunting Regulations (Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ... Hunting; Proposed 2013-14 Migratory Game Bird Hunting Regulations (Preliminary) With Requests for Indian... Bird Hunting; Proposed 2013-14 Migratory Game Bird Hunting Regulations (Preliminary) With Requests for... to establish annual hunting regulations for certain migratory game birds for the 2013-14 hunting...

  5. 75 FR 3888 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ... Fish and Wildlife Service 50 CFR Part 92 RIN 1018-AW67 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2010 Season AGENCY: Fish and Wildlife Service... Wildlife Service, are reopening the public comment period on our proposed rule to establish migratory bird...

  6. 76 FR 68263 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... Department of the Interior Fish and Wildlife Service 50 CFR Part 92 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2012 Season; Proposed Rule #0;#0...-1231-9BPP-L2] RIN 1018-AX55 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for...

  7. 75 FR 29917 - Migratory Bird Permits; Changes in the Regulations Governing Migratory Bird Rehabilitation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX09 Migratory Bird Permits; Changes in the Regulations Governing Migratory Bird Rehabilitation AGENCY: Fish and Wildlife Service, Interior. ACTION: Final... on October 27, 2003, to create regulations governing migratory bird rehabilitation in the United...

  8. 77 FR 49867 - Migratory Bird Hunting; Proposed Frameworks for Late-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-17

    ... Bird Hunting; Proposed Frameworks for Late-Season Migratory Bird Hunting Regulations; Proposed Rule #0... OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX97 Migratory Bird Hunting; Proposed Frameworks for Late-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife Service...

  9. 78 FR 58123 - Migratory Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ... Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations; Final Rule #0;#0;Federal... INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AY87 Migratory Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife Service, Interior. ACTION...

  10. 75 FR 44855 - Migratory Bird Hunting; Proposed Frameworks for Early-Season Migratory Bird Hunting Regulations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ... Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Frameworks for Early-Season Migratory Bird Hunting Regulations; Notice of Meetings; Proposed Rule #0;#0;Federal Register / Vol... Wildlife Service 50 CFR Part 20 RIN 1018-AX06 Migratory Bird Hunting; Proposed Frameworks for Early-Season...

  11. 75 FR 52873 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX06 Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife Service, Interior. ACTION... migratory bird hunting seasons. Early seasons are those that generally open prior to October 1, and include...

  12. Fine grains ceramics of PIN-PT, PIN-PMN-PT and PMN-PT systems: drift of the dielectric constant under high electric field.

    PubMed

    Pham-Thi, M; Augier, C; Dammak, H; Gaucher, P

    2006-12-22

    Lead-based ferroelectric ceramics with (1-x)Pb(B1 B2)O3-xPbTiO3 formula have emerged as a group of promising materials for various applications like ultrasonic sonars or medical imaging transducers. (1-x)PMN-xPT, (1-x)PIN-xPT and ternary solutions xPIN-yPMN-zPT ceramics are synthesised using the solid state reaction method. Our objective is to achieve higher structural transition temperatures than those of PMN-PT ceramics with as good dielectric, piezoelectric and electromechanical properties. Ceramics capacitance and loss tangent are measured when the ac field of measurement increases up to E=500 V/mm. Behaviours of these materials under ac field are related to their coercive field and Curie temperature.

  13. Surface-effect enhanced magneto-electric coupling in FePt/PMN-PT multiferroic heterostructures

    NASA Astrophysics Data System (ADS)

    Yang, Y. T.; Li, J.; Peng, X. L.; Hong, B.; Wang, X. Q.; Ge, H. L.; Wang, D. H.; Du, Y. W.

    2017-05-01

    A series of FePt films with different film thickness are deposited on Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) substrates. A standard symmetric `Butterfly' shaped Δ M /M -Ed c loops is obtained in 8 nm FePt/PMN-PT heterostrucuture via strain mediated magnetoelectric coupling. For the 3 nm FePt/PMN-PT heterostructure, the loop-like in-plane magnetization (M) -E curve shares a similar shape with the electric polarization of PMN-PT as a function of electric field. The value of MS shows a dramatic change of 30.9% with Edc changing from 0 to 8 kV/cm, this giant magnetoelectric effect in 3 nm FePt/PMN-PT heterostructure results from the remnant polarization induced charge on FePt/PMN-PT interface via the screening charge effect. The enhanced magnetoelectric coupling in thin magnetic/ferroelectric heterostructures opens a promising avenue for the design of ultralow power magnetoelectric devices and information storage devices.

  14. Fabrication and properties of radially <001>C textured PMN-PT cylinders for transducer applications

    NASA Astrophysics Data System (ADS)

    Poterala, Stephen F.; Meyer, Richard J.; Messing, Gary L.

    2012-07-01

    <001>C Textured PMN-PT ceramics have electromechanical properties (d33 = 850-1050 pm/V, k33 = 0.79-0.83) between those of conventional PZT ceramics and relaxor PMN-PT crystals. In this work, we tailor crystallographic orientation in textured PMN-PT ceramics for transducer designs with non-planar poling surfaces. Specifically, omni-directional cylindrical transducer elements were fabricated using monolithic, radially <001>C textured and poled PMN-PT ceramic. Texture was produced by templated grain growth using NBT-PT templates, which were oriented radially by wrapping green ceramic tapes around a cylindrical mandrel. Finished transducer elements measure ˜5 cm in diameter by ˜2.5 cm in height and demonstrate scalability of textured ceramic fabrication techniques. The fabricated cylinders are ˜50 vol. % textured and show high 31-mode electromechanical properties compared to PZT ceramics (d31 = -259 pm/V, k31 = 0.43, ɛT33 = 3000, and Qm = 350). Frequency bandwidth is related to the square of the hoop mode coupling coefficient kh2, which is ˜60% higher in textured PMN-PT cylinders compared to PZT 5H. Finite element simulations show that this parameter may be further increased by improving texture quality to ≥90 vol. %. Radially textured PMN-PT may thus improve performance in omni-directional cylindrical transducers while avoiding the need for segmented single crystal designs.

  15. Micromachined PIN-PMN-PT Crystal Composite Transducer for High-Frequency Intravascular Ultrasound (IVUS) Imaging

    PubMed Central

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K. Kirk

    2015-01-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3–PbMg1/3Nb2/3O3–PbTiO3 (PIN-PMN-PT) single crystal 1–3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT. PMID:24960706

  16. Energy scavenging based on a single-crystal PMN-PT nanobelt

    NASA Astrophysics Data System (ADS)

    Wu, Fan; Cai, Wei; Yeh, Yao-Wen; Xu, Shiyou; Yao, Nan

    2016-03-01

    Self-powered nanodevices scavenging mechanical energy require piezoelectric nanostructures with high piezoelectric coefficients. Here we report the fabrication of a single-crystal (1 ‑ x)Pb(Mg1/3Nb2/3)O3 ‑ xPbTiO3 (PMN-PT) nanobelt with a superior piezoelectric constant (d33 = ~550 pm/V), which is approximately ~150%, 430%, and 2100% of the largest reported values for previous PMN-PT, PZT and ZnO nanostructures, respectively. The high d33 of the single-crystalline PMN-PT nanobelt results from the precise orientation control during its fabrication. As a demonstration of its application in energy scavenging, a piezoelectric nanogenerator (PNG) is built on the single PMN-PT nanobelt, generating a maximum output voltage of ~1.2 V. This value is ~4 times higher than that of a single-CdTe PNG, ~13 times higher than that of a single-ZnSnO3 PNG, and ~26 times higher than that of a single-ZnO PNG. The profoundly increased output voltage of a lateral PNG built on a single PMN-PT nanobelt demonstrates the potential application of PMN-PT nanostructures in energy harvesting, thus enriching the material choices for PNGs.

  17. Broadband ultrasonic linear array using ternary PIN-PMN-PT single crystal.

    PubMed

    Wang, Wei; Zhao, Xiangyong; Or, Siu Wing; Leung, Chung Ming; Zhang, Yaoyao; Jiao, Jie; Luo, Haosu

    2012-09-01

    Ternary Pb(In(1/2)Nb(1/2))O(3)-Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PIN-PMN-PT) single crystal was investigated for potential application in ultrasonic linear array. Orientation and temperature dependences of height extensional electromechanical coupling coefficient k'(33) for PIN-PMN-PT single crystal were studied. It was found that the [001] poled PIN-PMN-PT diced along the [100] direction would achieve a maximum k'(33) (~87%) and the service temperature was up to 110 °C. Ultrasonic linear arrays using PIN-PMN-PT single crystal and PZT ceramic were fabricated and compared. The bandwidth at -6 dB, two-way insertion loss and pulse length of the PIN-PMN-PT array were 98.6%, -45.1 dB, and 0.28 μs, respectively, which were about 25% broader, 3.7dB higher, and 0.08 μs shorter than those of the PZT array. The experimental results agreed well with the theoretical simulation. These superior performances were attributable to the excellent piezoelectric properties of PIN-PMN-PT single crystal.

  18. Energy scavenging based on a single-crystal PMN-PT nanobelt

    PubMed Central

    Wu, Fan; Cai, Wei; Yeh, Yao-Wen; Xu, Shiyou; Yao, Nan

    2016-01-01

    Self-powered nanodevices scavenging mechanical energy require piezoelectric nanostructures with high piezoelectric coefficients. Here we report the fabrication of a single-crystal (1 − x)Pb(Mg1/3Nb2/3)O3 − xPbTiO3 (PMN-PT) nanobelt with a superior piezoelectric constant (d33 = ~550 pm/V), which is approximately ~150%, 430%, and 2100% of the largest reported values for previous PMN-PT, PZT and ZnO nanostructures, respectively. The high d33 of the single-crystalline PMN-PT nanobelt results from the precise orientation control during its fabrication. As a demonstration of its application in energy scavenging, a piezoelectric nanogenerator (PNG) is built on the single PMN-PT nanobelt, generating a maximum output voltage of ~1.2 V. This value is ~4 times higher than that of a single-CdTe PNG, ~13 times higher than that of a single-ZnSnO3 PNG, and ~26 times higher than that of a single-ZnO PNG. The profoundly increased output voltage of a lateral PNG built on a single PMN-PT nanobelt demonstrates the potential application of PMN-PT nanostructures in energy harvesting, thus enriching the material choices for PNGs. PMID:26928788

  19. Energy scavenging based on a single-crystal PMN-PT nanobelt.

    PubMed

    Wu, Fan; Cai, Wei; Yeh, Yao-Wen; Xu, Shiyou; Yao, Nan

    2016-03-01

    Self-powered nanodevices scavenging mechanical energy require piezoelectric nanostructures with high piezoelectric coefficients. Here we report the fabrication of a single-crystal (1 - x)Pb(Mg1/3Nb2/3)O3 - xPbTiO3 (PMN-PT) nanobelt with a superior piezoelectric constant (d33 = ~550 pm/V), which is approximately ~150%, 430%, and 2100% of the largest reported values for previous PMN-PT, PZT and ZnO nanostructures, respectively. The high d33 of the single-crystalline PMN-PT nanobelt results from the precise orientation control during its fabrication. As a demonstration of its application in energy scavenging, a piezoelectric nanogenerator (PNG) is built on the single PMN-PT nanobelt, generating a maximum output voltage of ~1.2 V. This value is ~4 times higher than that of a single-CdTe PNG, ~13 times higher than that of a single-ZnSnO3 PNG, and ~26 times higher than that of a single-ZnO PNG. The profoundly increased output voltage of a lateral PNG built on a single PMN-PT nanobelt demonstrates the potential application of PMN-PT nanostructures in energy harvesting, thus enriching the material choices for PNGs.

  20. Ten years of International Migratory Bird Day

    Treesearch

    Jennifer Wheeler; Susan Bonfield

    2005-01-01

    Public awareness and concern are crucial components of migratory bird conservation. Citizens who are enthusiastic about birds, informed about threats, and empowered to become involved in addressing those threats can make a tremendous contribution to maintaining healthy bird populations. One of the most successful vehicles for public education on migratory birds is...

  1. Mapping global diversity patterns for migratory birds.

    PubMed

    Somveille, Marius; Manica, Andrea; Butchart, Stuart H M; Rodrigues, Ana S L

    2013-01-01

    Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world's birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes) where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective.

  2. Mapping Global Diversity Patterns for Migratory Birds

    PubMed Central

    Somveille, Marius; Manica, Andrea; Butchart, Stuart H. M.; Rodrigues, Ana S. L.

    2013-01-01

    Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world’s birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes) where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective. PMID:23951037

  3. Specificity of an HPETE peroxidase from rat PMN

    SciTech Connect

    Skoog, M.T.; Nichols, J.S.; Harrison, B.L.; Wiseman, J.S.

    1988-09-01

    The 15,000xg supernatant of sonicated rat PMN contains 5-lipoxygenase that converts arachidonic acid to 5-hydroperoxyeicosatetraenoic acid (5-HPETE) and leukotriene A4 and an HPETE peroxidase that catalyzes reduction of the 5-HPETE. The specificity of this HPETE peroxidase for peroxides, reducing agents, and inhibitors has been characterized to distinguish this enzyme from other peroxidase activities. In addition to 5-HPETE, the HPETE peroxidase will catalyze reduction of 15-hydroperoxyeicosatetraenoic acid, 13-hydroperoxyoctadecadienoic acid, and 15-hydroperoxy-8,11,13-eicosatrienoic acid, but not cumene or t-butylhydroperoxides. The HPETE peroxidase accepted 5 of 11 thiols tested as reducing agents. However, glutathione is greater than 15 times more effective than any other thiol tested. Other reducing agents, ascorbate, NADH, NADPH, phenol, p-cresol, and homovanillic acid, were not accepted by HPETE peroxidase. This enzyme is not inhibited by 10 mM KCN, 2 mM aspirin, 2 mM salicylic acid, or 0.5 mM indomethacin. When 5-(14C)HPETE is generated from (14C)arachidonic acid in the presence of unlabeled 5-HPETE and the HPETE peroxidase, the 5-(14C)HETE produced is of much lower specific activity than the (14C)arachidonic acid. This indicates that the 5-(14C)HPETE leaves the active site of 5-lipoxygenase and mixes with the unlabeled 5-HPETE in solution prior to reduction and is a kinetic demonstration that 5-lipoxygenase has no peroxidase activity. Specificity for peroxides, reducing agents, and inhibitors differentiates HPETE peroxidase from glutathione peroxidase, phospholipid-hydroperoxide glutathione peroxidase, a 12-HPETE peroxidase, and heme peroxidases. The HPETE peroxidase could be a glutathione S-transferase selective for fatty acid hydroperoxides.

  4. Impaired bactericidal but not fungicidal activity of polymorphonuclear neutrophils in patients with chronic lymphocytic leukemia.

    PubMed

    Kontoyiannis, Dimitrios P; Georgiadou, Sarah P; Wierda, William G; Wright, Susan; Albert, Nathaniel D; Ferrajoli, Alessandra; Keating, Michael; Lewis, Russell E

    2013-08-01

    We examined the qualitative polymorphonuclear neutrophil (PMN)-associated immune impairment in patients with chronic lymphocytic leukemia (CLL) by characterizing phagocytic killing of key non-opsonized bacterial (Staphylococcus aureus and Pseudomonas aeruginosa) and fungal (Candida albicans and Aspergillus fumigatus) pathogens. Neutrophils were collected from 47 non-neutropenic patients with CLL (PMN count > 1000/mm(3)) and age-matched and young healthy controls (five each). A subset of patients (13%) had prior or subsequent infections. We found that the patients with CLL had diminished PMN microbicidal response against bacteria but not against fungi compared with the controls. Compared to patients with effective PMN responses, we did not identify differences of basal PMN pathogen-associated molecular pattern receptor gene expression, soluble pathogen-associated molecular pattern gene expression or inflammatory cytokine signatures in patients with impaired PMN responses when PMNs were analyzed in multiplex real-time polymerase chain reaction assays. However, differences in PMN microbicidal response against A. fumigatus in patients with CLL were associated with the degree of hypogammaglobulinemia.

  5. Impaired bactericidal but not fungicidal activity of polymorphonuclear neutrophils in patients with chronic lymphocytic leukemia

    PubMed Central

    Kontoyiannis, Dimitrios P.; Georgiadou, Sarah P.; Wierda, William G.; Wright, Susan; Albert, Nathaniel D.; Ferrajoli, Alessandra; Keating, Michael; Lewis, Russell E.

    2013-01-01

    We examined the qualitative polymorphonuclear neutrophil (PMN)-associated immune impairment in patients with chronic lymphocytic leukemia (CLL) by characterizing phagocytic killing of key nonopsonized bacterial (Staphylococcus aureus and Pseudomonas aeruginosa) and fungal (Candida albicans and Aspergillus fumigatus) pathogens. Neutrophils were collected from 47 nonneutropenic CLL patients (PMN count > 1000/mm3), and age-matched and young healthy controls (five each). A subset of patients (13%) had prior or subsequent infections. We found that the CLL patients had diminished PMN microbicidal response against bacteria but not against fungi than did the controls. Compared to patients with effective PMN responses, we did not identify differences of basal PMN pathogen-associated molecular pattern receptor gene expression, soluble pathogen-associated molecular pattern gene expression, or inflammatory cytokine signatures in patients with impaired PMN responses when PMNs were analyzed in multiplex real-time polymerase chain reaction assays. However, differences in PMN microbicidal response against A. fumigatus in CLL patients were associated with the degree of hypogammaglobulinemia. PMID:23163595

  6. Clinical relevance of polymorphonuclear (PMN-) elastase determination in semen and serum during infertility investigation.

    PubMed

    Eggert-Kruse, W; Zimmermann, K; Geissler, W; Ehrmann, A; Boit, R; Strowitzki, T

    2009-08-01

    The polymorphonuclear (PMN) elastase is secreted by activated granulocytes and is widely used as a marker of male accessory gland infection. However, the clinical value of routine determination of seminal plasma (SP) PMN elastase in asymptomatic patients during infertility investigation has not clearly been established and not much is known about the significance of PMN-elastase levels in serum as a potential biochemical determinant associated with infection/inflammation of the male genital tract. This prospective study included a total of 221 asymptomatic males from unselected subfertile couples, to evaluate the relationship of (i) serum and (ii) same-day SP PMN elastase concentrations with established semen quality parameters, including sperm functional capacity, local antisperm antibodies (ASA), seminal leucocytes, and the outcome of semen cultures including typical sexually transmitted disease pathogens, and a potential association with patients' medical history and results of clinical andrological examination. Furthermore, couples were followed up for subsequent fertility (controlled for female infertility factors). The concentrations of PMN elastase in serum and in SP were not significantly related to semen quality [with regard to microscopic (e.g. count, motility, morphology) as well as biochemical parameters, and also to local ASA of the IgG- or IgA-class]. There was no strong relationship with sperm functional capacity. No significant relationship with the outcome of the microbial screening was found. PMN-elastase levels in serum and SP were not significantly correlated and there was no association with subsequent fertility. Therefore, the value of routine determination of PMN elastase in semen and/or serum samples, particularly when used as a single parameter to screen for subclinical infection/inflammation in males under infertility investigation is limited.

  7. LPS Responsiveness and Neutrophil Chemotaxis In Vivo Require PMN MMP-8 Activity

    PubMed Central

    Connor, Andrea R.; Starr, Amanda E.; Dean, Richard A.; Puente, Xose S.; López-Otín, Carlos; Overall, Christopher M.

    2007-01-01

    We identify matrix metalloproteinase (MMP)-8, the polymorphonuclear (PMN) leukocyte collagenase, as a critical mediator initiating lipopolysaccharide (LPS)-responsiveness in vivo. PMN infiltration towards LPS is abrogated in Mmp8-null mice. MMP-8 cleaves LPS-induced CXC chemokine (LIX) at Ser4∼Val5 and Lys79∼Arg80. LIX bioactivity is increased upon N-terminal cleavage, enhancing intracellular calcium mobilization and chemotaxis upon binding its cognate receptor, CXCR2. As there is no difference in PMN chemotaxis in Mmp8-null mice compared with wild-type mice towards synthetic analogues of MMP-8-cleaved LIX, MMP-8 is not essential for extravasation or cell migration in collagenous matrices in vivo. However, with biochemical redundancy between MMPs 1, 2, 9, and 13, which also cleave LIX at position 4∼5, it was surprising to observe such a markedly reduced PMN infiltration towards LPS and LIX in Mmp8-/- mice. This lack of physiological redundancy in vivo identifies MMP-8 as a key mediator in the regulation of innate immunity. Comparable results were found with CXCL8/IL-8 and CXCL5/ENA-78, the human orthologues of LIX. MMP-8 cleaves CXCL8 at Arg5-Ser6 and at Val7-Leu8 in CXCL5 to activate respective chemokines. Hence, rather than collagen, these PMN chemoattractants are important MMP-8 substrates in vivo; PMN-derived MMP-8 cleaves and activates LIX to execute an in cis PMN-controlled feed-forward mechanism to orchestrate the initial inflammatory response and promote LPS responsiveness in tissue. PMID:17375198

  8. 50 CFR 20.20 - Migratory Bird Harvest Information Program.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Migratory Bird Harvest Information Program... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.20 Migratory Bird Harvest... information will be used to provide a sampling frame for the national Migratory Bird Harvest Survey. Response...

  9. 50 CFR 20.20 - Migratory Bird Harvest Information Program.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Migratory Bird Harvest Information Program... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.20 Migratory Bird Harvest... information will be used to provide a sampling frame for the national Migratory Bird Harvest Survey. Response...

  10. 50 CFR 20.40 - Gift of migratory game birds.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Gift of migratory game birds. 20.40... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No person may receive, possess, or give to another, any freshly killed migratory game birds as a gift...

  11. 50 CFR 20.40 - Gift of migratory game birds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Gift of migratory game birds. 20.40... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No person may receive, possess, or give to another, any freshly killed migratory game birds as a gift...

  12. 50 CFR 20.40 - Gift of migratory game birds.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Gift of migratory game birds. 20.40... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No person may receive, possess, or give to another, any freshly killed migratory game birds as a gift...

  13. 50 CFR 20.40 - Gift of migratory game birds.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Gift of migratory game birds. 20.40... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No person may receive, possess, or give to another, any freshly killed migratory game birds as a gift...

  14. Micromachined PIN-PMN-PT crystal composite transducer for high-frequency intravascular ultrasound (IVUS) imaging.

    PubMed

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K Kirk

    2014-07-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3-PbMg1/3Nb2/3O3-PbTiO 3 (PIN-PMNPT) single crystal 1-3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT.

  15. Flexible piezoelectric PMN-PT nanowire-based nanocomposite and device.

    PubMed

    Xu, Shiyou; Yeh, Yao-wen; Poirier, Gerald; McAlpine, Michael C; Register, Richard A; Yao, Nan

    2013-06-12

    Piezoelectric nanocomposites represent a unique class of materials that synergize the advantageous features of polymers and piezoelectric nanostructures and have attracted extensive attention for the applications of energy harvesting and self-powered sensing recently. Currently, most of the piezoelectric nanocomposites were synthesized using piezoelectric nanostructures with relatively low piezoelectric constants, resulting in lower output currents and lower output voltages. Here, we report a synthesis of piezoelectric (1 - x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) nanowire-based nanocomposite with significantly improved performances for energy harvesting and self-powered sensing. With the high piezoelectric constant (d33) and the unique hierarchical structure of the PMN-PT nanowires, the PMN-PT nanowire-based nanocomposite demonstrated an output voltage up to 7.8 V and an output current up to 2.29 μA (current density of 4.58 μA/cm(2)); this output voltage is more than double that of other reported piezoelectric nanocomposites, and the output current is at least 6 times greater. The PMN-PT nanowire-based nanocomposite also showed a linear relationship of output voltage versus strain with a high sensitivity. The enhanced performance and the flexibility of the PMN-PT nanowire-based nanocomposite make it a promising building block for energy harvesting and self-powered sensing applications.

  16. Modeling and the management of migratory birds

    USGS Publications Warehouse

    Williams, B.K.; Nichols, J.D.

    1990-01-01

    Mathematical modeling of migratory bird populations is reviewed in the context of migratory bird management. We focus on dynamic models of waterfowl, since most management-oriented migratory bird models concern waterfowl species. We describe the management context for these modeling efforts, with a focus on large-scale operational data collection programs and on processes by which waterfowl harvest is regulated and waterfowl habitats are protected and managed. Through their impacts on key population parameters such as recruitment and survival rate, these activities can influence population dynamics, thereby providing managers some measure of control over the status of populations. Recent applications of the modeling of waterfowl are described in terms of objectives, mathematical structures, and contributions to management. Finally, we discuss research needs and data limitations in migratory bird modeling, and offer suggestions to increase the value to managers of future modeling efforts.

  17. Neurodegenerative changes are prevented by Erythropoietin in the pmn model of motoneuron degeneration.

    PubMed

    Ruiz, Marta; Martínez-Vidal, Ana Fe; Morales, José Manuel; Monleón, Daniel; Giménez Y Ribotta, Minerva

    2014-08-01

    Motoneuron diseases are fatal neurodegenerative disorders characterized by a progressive loss of motoneurons, muscle weakness and premature death. The progressive motor neuronopathy (pmn) mutant mouse has been considered a good model for the autosomal recessive childhood form of spinal muscular atrophy (SMA). Here, we investigated the therapeutic potential of Erythropoietin (Epo) on this mutant mouse. Symptomatic or pre-symptomatic treatment with Epo significantly prolongs lifespan by 84.6% or 87.2% respectively. Epo preserves muscle strength and significantly attenuates behavioural motor deficits of mutant pmn mice. Histological and metabolic changes in the spinal cord evaluated by immunohistochemistry, western blot, and high-resolution (1)H-NMR spectroscopy were also greatly prevented by Epo-treatment. Our results illustrate the efficacy of Epo in improving quality of life of mutant pmn mice and open novel therapeutic pathways for motoneuron diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. High Frequency PMN-PT 1–3 Composite Transducer for Ultrasonic Imaging Application

    PubMed Central

    SUN, PING; WANG, GAOFENG; WU, DAWEI; ZHU, BENPENG; HU, CHANGHONG; LIU, CHANGGENG; DJUTH, FRANK T.; ZHOU, QIFA; SHUNG, K. KIRK

    2011-01-01

    Development of PMN-PT single crystal/epoxy 1–3 composites for high-frequency ultrasonic transducers application is presented. The composite was fabricated by using a DRIE dry etching process with a 45% volume fraction of PMN-PT. A 35 MHz ultrasound flat transducer was fabricated with the composite, which was found to have an effective electromechanical coupling coefficient of 0.81, an insertion loss of 18 db, and a –6 dB bandwidth as high as 100%. Tungsten wire phantom image shows that the transducer had an axial resolution of 30 μm, which was in good agreement with the theoretical expectation. The initial results showed that the PMN-PT/epoxy 1–3 composite has many attractive properties over conventional piezoelectric materials for medical imaging applications. PMID:21869845

  19. High Frequency PMN-PT 1-3 Composite Transducer for Ultrasonic Imaging Application.

    PubMed

    Sun, Ping; Wang, Gaofeng; Wu, Dawei; Zhu, Benpeng; Hu, Changhong; Liu, Changgeng; Djuth, Frank T; Zhou, Qifa; Shung, K Kirk

    2010-01-01

    Development of PMN-PT single crystal/epoxy 1-3 composites for high-frequency ultrasonic transducers application is presented. The composite was fabricated by using a DRIE dry etching process with a 45% volume fraction of PMN-PT. A 35 MHz ultrasound flat transducer was fabricated with the composite, which was found to have an effective electromechanical coupling coefficient of 0.81, an insertion loss of 18 db, and a -6 dB bandwidth as high as 100%. Tungsten wire phantom image shows that the transducer had an axial resolution of 30 μm, which was in good agreement with the theoretical expectation. The initial results showed that the PMN-PT/epoxy 1-3 composite has many attractive properties over conventional piezoelectric materials for medical imaging applications.

  20. Electric-field-modulated nonvolatile resistance switching in VO₂/PMN-PT(111) heterostructures.

    PubMed

    Zhi, Bowen; Gao, Guanyin; Xu, Haoran; Chen, Feng; Tan, Xuelian; Chen, Pingfan; Wang, Lingfei; Wu, Wenbin

    2014-04-09

    The electric-field-modulated resistance switching in VO2 thin films grown on piezoelectric (111)-0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 (PMN-PT) substrates has been investigated. Large relative change in resistance (10.7%) was observed in VO2/PMN-PT(111) hererostructures at room temperature. For a substrate with a given polarization direction, stable resistive states of VO2 films can be realized even when the applied electric fields are removed from the heterostructures. By sweeping electric fields across the heterostructure appropriately, multiple resistive states can be achieved. These stable resistive states result from the different stable remnant strain states of substrate, which is related to the rearrangements of ferroelectric domain structures in PMN-PT(111) substrate. The resistance switching tuned by electric field in our work may have potential applications for novel electronic devices.

  1. Simultaneous measurement of electro-optical and converse-piezoelectric coefficients of PMN-PT ceramics.

    PubMed

    Xiao, Pingping; Wang, Xianping; Sun, Jingjing; Huang, Meizhen; Chen, Xianfeng; Cao, Zhuangqi

    2012-06-18

    A new scheme is proposed to measure the electro-optical (EO) and converse-piezoelectric (CPE) coefficients of the PMN-PT ceramics simultaneously, in which the PMN-PT ceramics acts as the guiding layer of a symmetrical metal-cladding waveguide. As the applied electric field exerts on the waveguide, the effective refractive index (RI) (or synchronous angle) can be effectively tuned from a selected mode to another adjacent mode owing to the high sensitivity and the small spacing of the ultra-high order modes. Subsequently, a correlation between EO and CPE coefficients is established. With this correlation and the measurement of the effective RI change to the applied voltage, the quadratic EO and CPE coefficients of PMN-PT ceramics are obtained simultaneously. The obtained results are further checked by fitting the variations of effective RI to a quadratic function. Our measurement method can be extended to a wide range of other materials.

  2. Application of PMN-32PT Piezoelectric Crystals for Novel Air-coupled Ultrasonic Transducers

    NASA Astrophysics Data System (ADS)

    Kazys, Rymantas Jonas; Sliteris, Reimondas; Sestoke, Justina

    Due to very high piezoelectric properties of PMN-PT crystals they may significantly improve performance of air-coupled ultrasonic transducers. For these purpose vibrations of PMN-PT rectangular plates and strips were investigated. An air-coupled ultrasonic transducer and array consisting of 8 single piezoelectric strips were designed. Operation of the transducer was simulated by the finite element method using ANSYS Mechanical APDL Product Launcher software. Spatial distributions of displacements inside piezoelectric elements and matching strip were obtained. Experimental investigations were carried out by the laser Doppler vibrometer Polytec OFV-5000 and the Bruel&Kjaer microphone 4138 with the measurement amplifier NEXUS WH 3219. It was found that performance of the ultrasonic transducer with PMN-32PT crystals was a few times better than of a PZT based ultrasonic transducer.

  3. Migratory diversity predicts population declines in birds.

    PubMed

    Gilroy, James J; Gill, Jennifer A; Butchart, Stuart H M; Jones, Victoria R; Franco, Aldina M A

    2016-03-01

    Declines in migratory species are a pressing concern worldwide, but the mechanisms underpinning these declines are not fully understood. We hypothesised that species with greater within-population variability in migratory movements and destinations, here termed 'migratory diversity', might be more resilient to environmental change. To test this, we related map-based metrics of migratory diversity to recent population trends for 340 European breeding birds. Species that occupy larger non-breeding ranges relative to breeding, a characteristic we term 'migratory dispersion', were less likely to be declining than those with more restricted non-breeding ranges. Species with partial migration strategies (i.e. overlapping breeding and non-breeding ranges) were also less likely to be declining than full migrants or full residents, an effect that was independent of migration distance. Recent rates of advancement in Europe-wide spring arrival date were greater for partial migrants than full migrants, suggesting that migratory diversity may also help facilitate species responses to climate change. © 2016 John Wiley & Sons Ltd/CNRS.

  4. The mouse mutation progressive motor neuronopathy (pmn) maps to chromosome 13

    SciTech Connect

    Brunialti, A.L.B.; Poirier, C.; Guenet, J.L.

    1995-09-01

    Analysis of polymorphic markers segregating in both intra- and interspecific crosses has allowed us to map the autosomal recessive mutation progressive motor neuronopathy (pmn) to mouse Chr 13. Although this mutation, based on its histological description, was reported as a model for infantile spinal muscular atrophy of the Werdig-Hoffman type, its localization to a region that is not homologous with human 5q makes it unlikely to be a homologue to SMA. The presence of the Extra-toe (Xt) locus in proximity to pmn will help in the detection of affected progenies before the onset of the degenerative process. 38 refs., 2 figs.

  5. Characterization of PMN-PT piezoelectric single crystal and PMN-PT 1-3 composite at elevated temperatures by electrical impedance resonance analysis.

    PubMed

    Wu, Zhengbin; Xi, Kui

    2014-07-01

    In this paper, lead magnesium niobate-lead titanate (PMN-PT) piezoelectric single crystal and its 1-3 composite counterpart were characterized and analyzed under different stable temperatures using both a Simulated Annealing (SA) optimization algorithm and the commercial software PRAP (Piezoelectric Resonance Analysis Program). Electrical impedance resonance characteristics of the two material samples over the range 25-125 °C were measured. The correlation between experimental data and numerical fits derived from both SA and PRAP is considered. Calculation of the determination coefficient (R1(2)) between numerically fitted and measured results is above 95% for both methods. Furthermore, variations in the number of data values used for the fit introduced no more than 3.1% uncertainty on the calculated material parameters. It is found that the complex material parameters of PMN-PT composite are more dependent on temperature than the single crystal. The phase transition of the PMN-PT, which is close to 90 °C, has an effect on the high temperature material characteristics of both piezoelectric materials. These calculated complex material parameters can be used for the design of ultrasonic transducers for elevated temperature applications.

  6. 76 FR 58681 - Migratory Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-21

    ... development of a harvest strategy for redheads is a priority for the Flyways, a conceptual framework for a... Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations; Final Rule #0;#0...; Final Frameworks for Late-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife...

  7. 76 FR 53535 - Migratory Bird Hunting; Proposed Frameworks for Late-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ... development of a harvest strategy for redheads is a priority for the Flyways, a conceptual framework for a... Bird Hunting; Proposed Frameworks for Late Season Migratory Bird Hunting Regulations; Proposed Rule #0...; Proposed Frameworks for Late-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife...

  8. 78 FR 65955 - Migratory Bird Permits; Control Order for Introduced Migratory Bird Species in Hawaii

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... Introduced Migratory Bird Species in Hawaii AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule. SUMMARY: Nonnative species in Hawaii displace, compete with, and consume native species, some of... alba), two introduced migratory bird species in Hawaii. We also make the supporting draft environmental...

  9. 78 FR 65578 - Migratory Bird Permits; Depredation Order for Migratory Birds in California

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-01

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AY65 Migratory Bird Permits; Depredation Order for Migratory Birds in California AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule. SUMMARY: We revise the regulations that allow control of depredating birds in California. We specify the counties in...

  10. 78 FR 67183 - Proposed Information Collection; Migratory Bird Harvest Information Program and Migratory Bird...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-08

    ... Fish and Wildlife Service Proposed Information Collection; Migratory Bird Harvest Information Program and Migratory Bird Surveys AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice; request for... Bird Treaty Act (16 U.S.C. 703-711) and the Fish and Wildlife Act of 1956 (16 U.S.C. 742d) designate...

  11. 78 FR 27927 - Migratory Bird Permits; Depredation Order for Migratory Birds in California

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-13

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AY65 Migratory Bird Permits; Depredation Order for Migratory Birds in California AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule. SUMMARY: We propose to revise the regulations that allow control of depredating birds in some counties...

  12. Single crystal PMN-PT/epoxy 1-3 composite for energy-harvesting application.

    PubMed

    Ren, Kailiang; Liu, Yiming; Geng, Xuecang; Hofmann, Heath F; Zhang, Qiming M

    2006-03-01

    One key parameter in using electroactive materials to harvest electric energy from mechanical sources is the energy conversion efficiency. Recently, it was shown that, in the relaxor ferroelectric PMN-PT single crystals, a very high longitudinal electromechanical coupling factor (>90%) can be obtained. This paper investigates energy harvesting using 1-3 composites of PMN-PT single crystals in a soft epoxy matrix. It is shown that 1-3 composites enable the single crystals operating in the longitudinal mode to achieve high efficiency for energy harvesting, and the soft-polymer, matrix-supported single-crystal rods maintain high mechanical integrity under different external loads. For comparison, 1-3 composites with piezoceramic PZT also are investigated in energy-harvesting applications, and the results show that the high coupling factor of single crystal PMN-PT 1-3 composites leads to much higher electric energy output for similar mechanical energy input. The harvested energy density of 1-3 composite with single crystal (22.1 mW/cm3 under a stress of 40.4 MPa) is about twice of that harvested with PZT ceramic 1-3 composite (12 mW/cm3 under a stress of 39 MPa). At a higher stress level, the harvested-energy density of 1-3 PMN-PT single crystal composite can reach 96 mW/cm3.

  13. PMN-PT-PZT composite films for high frequency ultrasonic transducer applications.

    PubMed

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Zheng, Fan; Chen, Rumin; Huang, Yuhong; Zhou, Qifa; Shung, K Kirk

    2012-06-01

    We have successfully fabricated x(0.65PMN-0.35PT)-(1 - x)PZT (xPMN-PT-(1 - x)PZT), where x is 0.1, 0.3, 0.5, 0.7 and 0.9, thick films with a thickness of approximately 9 µm on platinized silicon substrate by employing a composite sol-gel technique. X-ray diffraction analysis and scanning electron microscopy revealed that these films are dense and creak-free with well-crystallized perovskite phase in the whole composition range. The dielectric constant can be controllably adjusted by using different compositions. Higher PZT content of xPMN-PT-(1 - x)PZT films show better ferroelectric properties. A representative 0.9PMN-PT-0.1PZT thick film transducer is built. It has 200 MHz center frequency with a -6 dB bandwidth of 38% (76 MHz). The measured two-way insertion loss is 65 dB.

  14. Recent Developments on High Curie Temperature PIN-PMN-PT Ferroelectric Crystals.

    PubMed

    Zhang, Shujun; Li, Fei; Sherlock, Nevin P; Luo, Jun; Lee, Hyeong Jae; Xia, Ru; Meyer, Richard J; Hackenberger, Wesley; Shrout, Thomas R

    2011-03-01

    Pb(In(0.5)Nb(0.5))O(3)-Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PIN-PMN-PT) ferroelectric crystals attracted extensive attentions in last couple years, due to their higher usage temperatures range (> 30°C) and coercive fields (~5kV/cm), meanwhile maintaining similar electromechanical couplings (k(33)> 90%) and piezoelectric coefficients (d(33)~1500pC/N), when compared to their binary counterpart Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3). In this article, we reviewed recent developments on the PIN-PMN-PT single crystals, including the Bridgman crystal growth, dielectric, electromechanical, piezoelectric and ferroelectric behaviors as function of temperature and dc bias. Mechanical quality factor Q was studied as function of orientation and phase. Of particular interest is the dynamic strain, which related to the Q and d(33), was found to be improved when compared to binary system, exhibiting the potential usage of PIN-PMN-PT in high power application. Furthermore, PIN-PMN-PT crystals exhibit improved thickness dependent properties, due to their small domain size, being on the order of 1μm. Finally, the manganese acceptor dopant in the ternary crystals was investigated and discussed briefly in this paper.

  15. PMN-PT–PZT composite films for high frequency ultrasonic transducer applications

    PubMed Central

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Zheng, Fan; Chen, Rumin; Huang, Yuhong; Zhou, Qifa; Shung, K. Kirk

    2013-01-01

    We have successfully fabricated x(0.65PMN-0.35PT)–(1 − x)PZT (xPMN-PT–(1 − x)PZT), where x is 0.1, 0.3, 0.5, 0.7 and 0.9, thick films with a thickness of approximately 9 µm on platinized silicon substrate by employing a composite sol–gel technique. X-ray diffraction analysis and scanning electron microscopy revealed that these films are dense and creak-free with well-crystallized perovskite phase in the whole composition range. The dielectric constant can be controllably adjusted by using different compositions. Higher PZT content of xPMN-PT–(1 − x)PZT films show better ferroelectric properties. A representative 0.9PMN-PT–0.1PZT thick film transducer is built. It has 200 MHz center frequency with a −6 dB bandwidth of 38% (76 MHz). The measured two-way insertion loss is 65 dB. PMID:23750072

  16. Structure, frequency dependent dielectric properties and domain configuration of PMN-PFN-PT single crystal

    NASA Astrophysics Data System (ADS)

    Luo, Nengneng; Li, Qiang; Yan, Qingfeng; Zhang, Yiling; Xia, Zhiguo; Chu, Xiangcheng

    2014-09-01

    Pb(Mg1/3Nb2/3)O3-Pb(Fe1/2Nb1/2)O3-PbTiO3 (PMN-PFN-PT) single crystal was grown successfully from high temperature solution by slow cooling method. Structure, frequency dependent dielectric properties and domain configuration of [0 0 1]-oriented single crystal have been investigated. X-ray diffraction analysis showed that the as-grown single crystal had a pure perovskite structure with tetragonal symmetry at room temperature. The temperature dependent dielectric permittivity showed only one dielectric anomaly, indicating the ferroelectric-paraelectric phase transition. According to the modified Curie-Weiss relationship, as-grown PMN-PFN-PT single crystal was in an intermediate state between normal and relaxor ferroelectrics. Dielectric permittivity and loss of [0 0 1]-oriented PMN-PFN-PT single crystal at room temperature decreased sharply with increasing frequency, which were different from those of PMN-PT65/35 single crystal. Domain configuration of [0 0 1]-oriented PMN-PFN-PT single crystal was observed for the first time by using a polarized light microscopy (PLM). The extinction of 90° domains at P/A:0° revealed a tetragonal structure. Domains along (0 0 1) face exhibited a straight stripe-like morphology with domain size on the scale of 10 μm in average, combining with some much smaller domains about 3-5 μm in width at the intersection of domain blocks which helps to minimize its total energy.

  17. Electric field modification of magnetotransport in Ni thin films on (011) PMN-PT piezosubstrates

    NASA Astrophysics Data System (ADS)

    Tkach, Alexander; Kehlberger, Andreas; Büttner, Felix; Jakob, Gerhard; Eisebitt, Stefan; Kläui, Mathias

    2015-02-01

    This study reports the magnetotransport and magnetic properties of 20 nm-thick polycrystalline Ni films deposited by magnetron sputtering on unpoled piezoelectric (011) [PbMg1/3Nb2/3O3]0.68-[PbTiO3]0.32 (PMN-PT) substrates. The longitudinal magnetoresistance (MR) of the Ni films on (011) PMN-PT, measured at room temperature in the magnetic field range of -0.3 T < μ0H < 0.3 T, is found to depend on the crystallographic direction and polarization state of piezosubstrate. Upon poling the PMN-PT substrate, which results in a transfer of strain to the Ni film, the MR value decreases by factor of 20 for the current along [100] of PMN-PT and slightly increases for the [ 01 1 ¯ ] current direction. Simultaneously, a strong increase (decrease) in the field value, where the MR saturates, is observed for the [ 01 1 ¯ ] ([100]) current direction. The anisotropic magnetoresistance is also strongly affected by the remanent strain induced by the electric field pulses applied to the PMN-PT in the non-linear regime revealing a large (132 mT) magnetic anisotropy field. Applying a critical electric field of 2.4 kV/cm, the anisotropy field value changes back to the original value, opening a path to voltage-tuned magnetic field sensor or storage devices. This strain mediated voltage control of the MR and its dependence on the crystallographic direction is correlated with the results of magnetization reversal measurements.

  18. Unraveling navigational strategies in migratory insects

    PubMed Central

    Merlin, Christine; Heinze, Stanley; Reppert, Steven M.

    2011-01-01

    Long-distance migration is a strategy some animals use to survive a seasonally changing environment. To reach favorable grounds, migratory animals have evolved sophisticated navigational mechanisms that rely on a map and compasses. In migratory insects, the existence of a map sense (sense of position) remains poorly understood, but recent work has provided new insights into the mechanisms some compasses use for maintaining a constant bearing during long-distance navigation. The best-studied directional strategy relies on a time-compensated sun compass, used by diurnal insects, for which neural circuits have begun to be delineated. Yet, a growing body of evidence suggests that migratory insects may also rely on other compasses that use night sky cues or the Earth's magnetic field. Those mechanisms are ripe for exploration. PMID:22154565

  19. [France, the European migratory system, and globalization].

    PubMed

    Simon, G

    1996-01-01

    "The overwhelming trend of migratory flows to become globalized, which is manifesting itself in all the major immigrant countries and the planet's main pools of employment, henceforth concerns France and Europe. One of the main challenges confronting these two entities is related to the spatial expansion and rising diversity of their recruitment spaces, and the great difficulty involved in controlling mobility which increasingly tends to function on a global scale. It is essential to revise analytic paradigms based on a strictly national vision which is blind to and repressive of phenomena that are more planetary every day. The global approach will have to combine national management, the functioning of the community's migratory space, relations with increasingly distant and increasingly ¿foreign' lands of origin, and the globalization of migratory dynamics." (SUMMARY IN ENG AND SPA) excerpt

  20. 50 CFR 20.40 - Gift of migratory game birds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No... hunter who took the birds, stating such hunter's address, the total number and species of birds and the...

  1. Quantification of strain and charge co-mediated magnetoelectric coupling on ultra-thin Permalloy/PMN-PT interface.

    PubMed

    Nan, Tianxiang; Zhou, Ziyao; Liu, Ming; Yang, Xi; Gao, Yuan; Assaf, Badih A; Lin, Hwaider; Velu, Siddharth; Wang, Xinjun; Luo, Haosu; Chen, Jimmy; Akhtar, Saad; Hu, Edward; Rajiv, Rohit; Krishnan, Kavin; Sreedhar, Shalini; Heiman, Don; Howe, Brandon M; Brown, Gail J; Sun, Nian X

    2014-01-14

    Strain and charge co-mediated magnetoelectric coupling are expected in ultra-thin ferromagnetic/ferroelectric multiferroic heterostructures, which could lead to significantly enhanced magnetoelectric coupling. It is however challenging to observe the combined strain charge mediated magnetoelectric coupling, and difficult in quantitatively distinguish these two magnetoelectric coupling mechanisms. We demonstrated in this work, the quantification of the coexistence of strain and surface charge mediated magnetoelectric coupling on ultra-thin Ni0.79Fe0.21/PMN-PT interface by using a Ni0.79Fe0.21/Cu/PMN-PT heterostructure with only strain-mediated magnetoelectric coupling as a control. The NiFe/PMN-PT heterostructure exhibited a high voltage induced effective magnetic field change of 375 Oe enhanced by the surface charge at the PMN-PT interface. Without the enhancement of the charge-mediated magnetoelectric effect by inserting a Cu layer at the PMN-PT interface, the electric field modification of effective magnetic field was 202 Oe. By distinguishing the magnetoelectric coupling mechanisms, a pure surface charge modification of magnetism shows a strong correlation to polarization of PMN-PT. A non-volatile effective magnetic field change of 104 Oe was observed at zero electric field originates from the different remnant polarization state of PMN-PT. The strain and charge co-mediated magnetoelectric coupling in ultra-thin magnetic/ferroelectric heterostructures could lead to power efficient and non-volatile magnetoelectric devices with enhanced magnetoelectric coupling.

  2. Strong magnetoelectric and spin phonon coupling in SmFeO{sub 3}/PMN-PT composite

    SciTech Connect

    Ahlawat, Anju E-mail: anju@rrcat.gov.in; Satapathy, S.; Gupta, P. K.; Sathe, V. G.; Choudhary, R. J.

    2016-08-22

    We have investigated spin phonon coupling in the strain coupled magnetoelectric SmFeO{sub 3}/0.65Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–0.35PbTiO{sub 3} (PMN-PT) composite in the temperature range of 300–650 K by Raman spectroscopy and magnetic measurements. The SmFeO{sub 3}/PMN-PT composite shows sharp rise in magnetic moment across ferroelectric transition temperature (T{sub c}) of PMN-PT. Around this transition temperature (T{sub c} of PMN-PT), the temperature evolution of Raman spectra of the composite also shows anomalies in the phonon frequencies and line width corresponding to the SmFeO{sub 3} phase which indicate structural modifications in the SmFeO{sub 3} phase around T{sub c} of PMN-PT. The observed structural, magnetic, and phonon anomalies of SmFeO{sub 3} around T{sub c} of PMN-PT in SmFeO{sub 3}/PMN-PT are attributed to spin-phonon coupling providing evidence of strong strain mediated magnetoelectric effects.

  3. 50 CFR 20.20 - Migratory Bird Harvest Information Program.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.20 Migratory Bird Harvest... is required from licensed hunters to obtain the benefit of hunting migratory game birds. Public... hunter and given his or her name, address, and date of birth to the respective State hunting licensing...

  4. Stopover ecology and habitat use of migratory Wilson's Warblers

    Treesearch

    Wang Yong; Deborah M. Finch; Frank R. Moore; Jeffrey F. Kelly

    1998-01-01

    The conservation of long-distance migratory songbirds is complicated by their life-history characteristics and the spatial scales that they traverse. Events during migratory stopovers may have significant consequences in determining the population status of migratory songbirds. Using Wilson's Warbler (Wilsonia pusilla) as a focal species, we investigated effects...

  5. 77 FR 60381 - Migratory Bird Conservation; Executive Order 13186

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... National Oceanic and Atmospheric Administration RIN 0648-XC148 Migratory Bird Conservation; Executive Order... the U.S. Fish and ] Wildlife Service (FWS) to promote the conservation of migratory birds. DATES: This... Migratory Birds''. One of the requirements of E.O. 13186 is that each Federal agency taking actions that...

  6. 78 FR 3446 - Migratory Bird Hunting; Service Regulations Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-16

    ... Fish and Wildlife Service Migratory Bird Hunting; Service Regulations Committee Meeting AGENCY: Fish... issues concerning the 2013-14 migratory bird hunting regulations. DATES: The meeting will be held..., Division of Migratory Bird Management, U.S. Fish and Wildlife Service, Department of the Interior, ms-4107...

  7. 77 FR 1718 - Migratory Bird Hunting; Service Regulations Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-11

    ... Fish and Wildlife Service Migratory Bird Hunting; Service Regulations Committee Meeting AGENCY: Fish... issues concerning the 2012-13 migratory bird hunting regulations. DATES: The meeting will be held... CONTACT: Chief, Division of Migratory Bird Management, U.S. Fish and Wildlife Service, Department of the...

  8. 78 FR 78377 - Migratory Bird Hunting; Service Regulations Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-26

    ... Fish and Wildlife Service RIN 1018-AZ80 Migratory Bird Hunting; Service Regulations Committee Meeting... preliminary issues concerning the 2014-15 migratory bird hunting regulations. DATES: The meeting will be held..., Division of Migratory Bird Management, U.S. Fish and Wildlife Service, Department of the Interior,...

  9. Effect of manganese doping on PIN-PMN-PT single crystals for high power applications

    NASA Astrophysics Data System (ADS)

    Sahul, Raffi

    Single crystals based on relaxor-lead titanate (relaxor-PT) solid solutions have advanced the world of piezoelectric materials for the past two decades with their giant piezoelectric properties achieved by domain engineered configurations. When single crystals of lead magnesium niobate-lead titanate (PMN-PT) solid solution in the rhombohedral phase were poled along [001]c direction with "4R" domain configuration, they exhibited high piezoelectric charge coefficient (d33 >2000 pC/N) and high electromechanical coupling (k33 >0.9) which led to their widespread use in advanced medical imaging systems and underwater acoustic devices. However, PMN-PT crystals suffer from low phase transition temperature (Trt ˜85-95 °C) and lower coercive field (depolarizing electric field, Ec ˜2-3 kV/cm). Lead indium niobate - lead magnesium niobate - lead titanate (PIN-PMN-PT) ternary single crystals formed by adding indium as another constituent exhibit higher coercive field (E c ˜5kV/cm) and higher Curie temperature (Tc >210 °C) than the binary PMN-PT crystals (Ec ˜2.5 kV/cm and Tc <140 °C). When these ternary PIN-PMN-PT crystals are doped with manganese (Mn:PIN-PMN-PT), they behave like hard piezoelectric materials demonstrating an internal bias field (Ei ˜0.8-1.6 kV/cm), leading to low elastic losses and high mechanical Q-factor (Qm >600) compared to the undoped binary crystals (Qm of PMN-PT <150). Although the spontaneous polarization directions for these rhombohedral crystals are in the c directions, the giant piezoelectric effect (d33 >2000 pC/N for PMN-PT) occurs in the [001]c poled crystals, which is attributed to the polarization rotation mechanisms. Hence, domain engineering configurations induced by poling these crystals in orientations other than their polarization axis are critical for achieving large piezoelectric effects. Based on the phase diagram of these solid solutions, with the increase in PT content beyond the rhombohedral phase region, orthorhombic

  10. Suggestions for Teaching the Migratory Pupil.

    ERIC Educational Resources Information Center

    Blanton, Dolly; And Others

    Suggestions for teachers of migrant children are offered in seven individual teaching guides which were developed as part of a research and curriculum development project to improve the teaching of migratory pupils. Levels of study include grades four, five, six, and seven, and one general unit deals with providing an effective learning…

  11. STOPOVER ECOLOGY OF NEOTROPICAL MIGRATORY BIRDS

    EPA Science Inventory

    The distribution of intact stopovers may be as important as the condition of individual stopover. We modeled migratory flights based on flight distance and direction to examine how nightly flights link stopovers into flyways. The resulting maps highlight portions of the landsca...

  12. MIGRATORY AGRICULTURAL WORKERS IN THE UNITED STATES.

    ERIC Educational Resources Information Center

    JORGENSON, JANET M.; AND OTHERS

    FIELD STUDIES WERE CONDUCTED IN 1960 IN THE LOWER RIO GRANDE VALLEY OF TEXAS AND IN IOWA TO AUGMENT INFORMATION ON MIGRATORY WORKERS. FACULTY-STUDENT TEAM FIELD TRIPS FOUND MANY FACTORS TO CONSIDER IN PROVIDING A CONSTRUCTIVE APPROACH TO THE PROBLEMS OF THE MIGRANT WORKER. CHILDREN OF THE MIGRANTS ARE NOT GETTING THE EDUCATION THEY NEED TO BREAK…

  13. MIGRATORY WORKERS IN THE UNITED STATES.

    ERIC Educational Resources Information Center

    1965

    THE NEED FOR LARGE NUMBERS OF FARM WORKERS FOR SHORT PERIODS DURING THE CULTIVATION AND HARVESTING OF CROPS IN WIDELY SEPARATED AREAS RESULTS IN A MIGRATORY WORK FORCE OF APPROXIMATELY 400,000 PERSONS EACH YEAR. MIGRANTS ARE EMPLOYED TO AVOID LOSSES OF PERISHABLE CROPS IN THE FIELDS, TO TAKE ADVANTAGE OF GOOD WEATHER OR TO FORESTALL LOSSES DUE TO…

  14. MIGRATORY AGRICULTURAL WORKERS IN THE UNITED STATES.

    ERIC Educational Resources Information Center

    JORGENSON, JANET M.; AND OTHERS

    FIELD STUDIES WERE CONDUCTED IN 1960 IN THE LOWER RIO GRANDE VALLEY OF TEXAS AND IN IOWA TO AUGMENT INFORMATION ON MIGRATORY WORKERS. FACULTY-STUDENT TEAM FIELD TRIPS FOUND MANY FACTORS TO CONSIDER IN PROVIDING A CONSTRUCTIVE APPROACH TO THE PROBLEMS OF THE MIGRANT WORKER. CHILDREN OF THE MIGRANTS ARE NOT GETTING THE EDUCATION THEY NEED TO BREAK…

  15. MIGRATORY LABOR IN COLORADO. PROGRESS REPORT.

    ERIC Educational Resources Information Center

    SIMPSON, RAY; AND OTHERS

    DEVELOPMENTS, FROM 1950 THROUGH 1960, ARE TRACED CONCERNING MIGRATORY LABOR IN COLORADO IN THE AREAS OF EMPLOYMENT, WAGE RATES, MINIMUM WAGE LEGISLATION, EMPLOYMENT OF MEXICAN NATIONALS, EDUCATION, HEALTH, HOUSING, SANITATION, WELFARE, UNEMPLOYMENT COMPENSATION, WORKMEN'S COMPENSATION COVERAGE, AND THE LICENSING AND REGULATION OF LABOR CONTRACTORS…

  16. Silvicultural options for neotropical migratory birds

    Treesearch

    Frank R. Thompson; John R. Probst; Martin G. Raphael

    1993-01-01

    We review: factors that affect forest bird populations; basic concepts of silvicultural systems; potential impacts of these systems on neotropical migratory birds (NTMBs); and conclude with management recommendations for integrating NTMB conservation with forest management. We approach this topic from a regional-landscape scale to a forest stand-habitat scale, rather...

  17. MIGRATORY LABOR IN COLORADO. PROGRESS REPORT.

    ERIC Educational Resources Information Center

    SIMPSON, RAY; AND OTHERS

    DEVELOPMENTS, FROM 1950 THROUGH 1960, ARE TRACED CONCERNING MIGRATORY LABOR IN COLORADO IN THE AREAS OF EMPLOYMENT, WAGE RATES, MINIMUM WAGE LEGISLATION, EMPLOYMENT OF MEXICAN NATIONALS, EDUCATION, HEALTH, HOUSING, SANITATION, WELFARE, UNEMPLOYMENT COMPENSATION, WORKMEN'S COMPENSATION COVERAGE, AND THE LICENSING AND REGULATION OF LABOR CONTRACTORS…

  18. 76 FR 54657 - Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game Birds in the Contiguous... Bag and Possession Limits for Certain Migratory Game Birds in the Contiguous United States, Alaska...; migratory game birds in Alaska, Hawaii, Puerto Rico, and the Virgin Islands; and some extended falconry...

  19. Cryptochrome expression in the eye of migratory birds depends on their migratory status.

    PubMed

    Fusani, Leonida; Bertolucci, Cristiano; Frigato, Elena; Foà, Augusto

    2014-03-15

    Most passerine birds are nocturnal migrants. When kept in captivity during the migratory periods, these species show a migratory restlessness, or Zugunruhe. Recent studies on Sylvia warblers have shown that Zugunruhe is an excellent proxy of migratory disposition. Passerine birds can use the Earth's geomagnetic field as a compass to keep their course during their migratory flight. Among the candidate magnetoreceptive mechanisms are the cryptochromes, flavoproteins located in the retina that are supposed to perceive the magnetic field through a light-mediated process. Previous work has suggested that expression of Cryptochrome 1 (Cry1) is increased in migratory birds compared with non-migratory species. Here we tested the hypothesis that Cry1 expression depends on migratory status. Blackcaps Sylvia atricapilla were caught before fall migration and held in registration cages. When the birds were showing robust Zugunruhe, we applied a food deprivation protocol that simulates a long migratory flight. When the birds were refed after 2 days, their Zugunruhe decreased substantially, as is expected from birds that would interrupt migration for a refuelling stopover. We found that Cry1 expression was higher at night than during daytime in birds showing Zugunruhe, whereas in birds that underwent the fasting-and-refeeding protocol and reduced their levels of Zugunruhe, night Cry1 expression decreased to daytime levels. Our work shows that Cry1 expression is dependent on the presence of Zugunruhe and not on species-specific or seasonal factors, or on the birds being active versus inactive. These results support the hypothesis that cryptochromes underlie magnetoreceptive mechanisms in birds.

  20. The response of migratory populations to phenological change: a Migratory Flow Network modelling approach.

    PubMed

    Taylor, Caz M; Laughlin, Andrew J; Hall, Richard J

    2016-05-01

    Declines in migratory species have been linked to anthropogenic climate change through phenological mismatch, which arises due to asynchronies between the timing of life-history events (such as migration) and the phenology of available resources. Long-distance migratory species may be particularly vulnerable to phenological change in their breeding ranges, since the timing of migration departure is based on environmental cues at distant non-breeding sites. Migrants may, however, be able to adjust migration speed en route to the breeding grounds, and thus, ability of migrants to update their timing of migration may depend critically on stopover frequency during migration; however, understanding how migratory strategy influences population dynamics is hindered by a lack of predictive models explicitly linking habitat quality to demography and movement patterns throughout the migratory cycle. Here, we present a novel modelling framework, the Migratory Flow Network (MFN), in which the seasonally varying attractiveness of breeding, winter and stopover regions drives the direction and timing of migration based on a simple general flux law. We use the MFN to investigate how populations respond to shifts in breeding site phenology based on their frequency of stopover and ability to detect and adapt to these changes. With perfect knowledge of advancing phenology, 'jump' migrants (low-frequency stopover) require more adaptation for populations to recover than 'hop' and 'skip' (high or medium frequency stopover) migrants. If adaptation depends on proximity, hop and skip migrants' populations can recover but jump migrants cannot adjust and decline severely. These results highlight the importance of understanding migratory strategies and maintaining high-quality stopover habitat to buffer migratory populations from climate-induced mismatch. We discuss how MFNs could be applied to diverse migratory taxa and highlight the potential of MFNs as a tool for exploring how migrants

  1. The July 2010 Outburst of the NLS1 PMN J0948+0022

    NASA Technical Reports Server (NTRS)

    Foschini, L.; Ghisellini, G.; Marashi, L.; Tagliaferri, G.; Tavecchio, F.; Kovalev, Y. Y.; Kovalev, Yu. A.; Lister, M. L.; Richards, J. L.; D'Ammando, F.; hide

    2011-01-01

    We report about the multiwavelength campaign on the Narrow-Line Seyfert 1 (NLS1) Galaxy PMN J0948+0022 (z = 0.5846) performed in 2010 July-September and triggered by high activity as measured by Fermi/LAT. The peak luminosity in the 0.1 - 100 GeV energy band exceeded, for the first time in this type of source, the value of 1048 erg/s, a level comparable to the most powerful blazars. The comparison of the spectral energy distribution of the NLS1 PMN J0948+0022 with that of a typical blazar like 3C 273 shows that the power emitted at gamma rays is extreme.

  2. Electric-field tunable spin diode FMR in patterned PMN-PT/NiFe structures

    NASA Astrophysics Data System (ADS)

    Zietek, Slawomir; Ogrodnik, Piotr; Skowroński, Witold; Stobiecki, Feliks; van Dijken, Sebastiaan; Barnaś, Józef; Stobiecki, Tomasz

    2016-08-01

    Dynamic properties of NiFe thin films on PMN-PT piezoelectric substrate are investigated using the spin-diode method. Ferromagnetic resonance (FMR) spectra of microstrips with varying width are measured as a function of magnetic field and frequency. The FMR frequency is shown to depend on the electric field applied across the substrate, which induces strain in the NiFe layer. Electric field tunability of up to 100 MHz per 1 kV/cm is achieved. An analytical model based on total energy minimization and the Landau-Lifshitz-Gilbert equation, taking into account the magnetostriction effect, is used to explain the measured dynamics. Based on this model, conditions for optimal electric-field tunable spin diode FMR in patterned NiFe/PMN-PT structures are derived.

  3. Lift-off PMN-PT Thick Film for High Frequency Ultrasonic Biomicroscopy.

    PubMed

    Zhu, Benpeng; Han, Jiangxue; Shi, Jing; Shung, K Krik; Wei, Q; Huang, Yuhong; Kosec, M; Zhou, Qifa

    2010-10-01

    Piezoelectric 0.65Pb(Mg(1/3)Nb(2/3))O(3)-0.35PbTiO(3) (PMN-35PT) thick film with a thickness of approximately 12 µm has been deposited on the platinum buffered Si substrate via a sol-gel composite method. The separation of the film from the substrate was achieved using a wet chemical method. The lifted-off PMN-35PT thick film exhibited good dielectric and ferroelectric properties. At 1 kHz, the dielectric constant and the dielectric loss were 3,326 and 0.037, respectively, while the remnant polarization was 30.0 µC/cm(2). A high frequency single element acoustic transducer fabricated with this film showed a bandwidth at -6 dB of 63.6% at 110 MHz.

  4. Switching of 800 nm femtosecond laser pulses using a compact PMN-PT modulator.

    PubMed

    Adany, Peter; Price, E Shane; Johnson, Carey K; Zhang, Run; Hui, Rongqing

    2009-03-01

    A voltage-controlled birefringent cell based on ceramic PMN-PT material is used to enable fast intensity modulation of femtosecond laser pulses in the 800 nm wavelength window. The birefringent cell based on a PMN-PT compound has comparatively high electro-optic response, allowing for a short interaction length of 3 mm and thus very small size, low attenuation of 0.16 dB, and negligible broadening for 100 fs optical pulses. As an application example, agile wavelength tuning of optical pulses is demonstrated using the soliton self-frequency shift in a photonic crystal fiber. By dynamically controlling the optical power into the fiber, this system switches the wavelength of 100 fs pulses from 900 nm to beyond 1120 nm with less than 5 micros time. In addition, a feedback system stabilizes the wavelength drift against external conditions resulting in high wavelength stability.

  5. Refractive index modulating Raman spectroscopy based on perovskite PMN-PT ceramics.

    PubMed

    Wei, Danzhu; Xu, Tian; Yuan, Li; Tian, Shu; Fang, Jinghuai; Jin, Yonglong; Wang, Chaonan; Ma, Xinxiang; Shi, Jianzhen

    2016-04-01

    A three-layer planar waveguide structure comprising a perovskite (1-x)Pb(Mg1/3Nb2/3Nb2/3)O3-xPbTiO3 (PMN-PT) ceramic sandwiched by two silver films is designed and called PMPW. Using the high sensitivity of ultrahigh-order modes, theoretical analysis is performed to calculate the effective refractive index (ERI) of the PMPW. A detailed analysis of the Raman spectrum of PMN-PT at 795  cm-1 is performed. A comparison of the numerical analysis and experimental results reveals that the nonlinear change in ERI plays a primary role in the Raman signal variation. Analysis of the Raman spectrum of a sample deposited on PMPW confirms that it is effective for modulating Raman signals.

  6. Electric-field tunable spin diode FMR in patterned PMN-PT/NiFe structures

    SciTech Connect

    Ziętek, Slawomir Skowroński, Witold; Stobiecki, Tomasz; Ogrodnik, Piotr; Stobiecki, Feliks; Dijken, Sebastiaan van; Barnaś, Józef

    2016-08-15

    Dynamic properties of NiFe thin films on PMN-PT piezoelectric substrate are investigated using the spin-diode method. Ferromagnetic resonance (FMR) spectra of microstrips with varying width are measured as a function of magnetic field and frequency. The FMR frequency is shown to depend on the electric field applied across the substrate, which induces strain in the NiFe layer. Electric field tunability of up to 100 MHz per 1 kV/cm is achieved. An analytical model based on total energy minimization and the Landau-Lifshitz-Gilbert equation, taking into account the magnetostriction effect, is used to explain the measured dynamics. Based on this model, conditions for optimal electric-field tunable spin diode FMR in patterned NiFe/PMN-PT structures are derived.

  7. The role of PMN-leucocyte lysosomes in tissue injury, inflammation and hypersensitivity

    PubMed Central

    Movat, H. Z.; Uriuhara, T.; Taichman, N. S.; Rowsell, H. C.; Mustard, J. F.

    1968-01-01

    Anaphylaxis due to intravascular interaction of hyperimmune antibody with antigen was studied in rabbits, swine and rats. Obstruction of the pulmonary vessels by the immune precipitates was found to initiate the process. This is followed by aggregation of PMN-leucocytes and platelets in pulmonary vessels and phagocytosis of the precipitates by these blood elements. During this process degranulation of the cells takes place with release of lysosomal contents. As a concomitant a rise in plasma acid protease and other hydrolases was demonstrated, presumably derived from the degranulating PMN-leucocytes and platelets. Unlike leukopaenic animals, normal ones showed a more marked hypotension, a greater tendency to protracted shock and developed focal and confluent haemorrhagic pulmonary lesions. It is suggested that anaphylaxis due to intravascular antigen—antibody interaction or aggregate anaphylaxis is a systemic or pulmonary Arthus reaction, rather than a `true' anaphylaxis. ImagesFIG. 5FIG. 6FIG. 3FIG. 4 PMID:4231971

  8. North American migratory bird management issues

    USGS Publications Warehouse

    Wilson, M.H.; Ryan, D.A.

    1995-01-01

    As human population and industry have grown in North America, land-use practices have greatly altered the landscape. As a result of this changed landscape, several migratory bird populations have declined in recent years. For waterbirds, there have been several milestones: the 1986 North American Waterfowl Management Plan (NAWMP) and the 1989 North American Wetlands Conservation Act. As a result, the United States and Canada have established 12 habitat and 2 species joint ventures. The primary emphasis of waterfowl management in Canada-U.S. has been land purchase and lease, wetland restoration, and coordination of harvest rates. Because of its different biological and cultural context, Mexico has established other conservation priorities. Mexico has had a long-standing concern to conserve its biodiversity and, in addition, conservation of Mexican resources goes hand in hand with human community development. Unlike Canada-U.S., wetland conservation projects in'Mexico include information gathering, environmental education, and management planning for its 32 priority wetlands. For migratory landbirds' scientists attribute declines in several migrant populations to forest fragmentation on the breeding grounds, deforestation on the wintering grounds, pesticide poisoning, or the cumulative effects of habitat changes. In 1990, the Neotropical Migratory Bird Conservation Program, commonly known as Partners in Flight-Aves de las Americas-was initiated. The next step that is being proposed is the formation of a habitat conservation plan for landbirds modeled after the NAWMP. Management of migratory birds requires a strong international approach in order to coordinate actions for the benefit of migratory birds, their habitats, and the uses they provide.

  9. Low level exposure to crude oil impacts avian flight performance: The Deepwater Horizon oil spill effect on migratory birds.

    PubMed

    Perez, Cristina R; Moye, John K; Cacela, Dave; Dean, Karen M; Pritsos, Chris A

    2017-06-05

    In 2010, the Deepwater Horizon oil spill released 134 million gallons of crude oil into the Gulf of Mexico making it the largest oil spill in US history. The three month oil spill left tens of thousands of birds dead; however, the fate of tens of thousands of other migratory birds that were affected but did not immediately die is unknown. We used the homing pigeon as a surrogate species for migratory birds to investigate the effects of a single external oiling event on the flight performance of birds. Data from GPS data loggers revealed that lightly oiled pigeons took significantly longer to return home and spent more time stopped en route than unoiled birds. This suggests that migratory birds affected by the oil spill could have experienced long term flight impairment and delayed arrival to breeding, wintering, or crucial stopover sites and subsequently suffered reductions in survival and reproductive success. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Magnetic field-induced ferroelectric domain structure evolution and magnetoelectric coupling for [110]-oriented PMN-PT/Terfenol-D multiferroic composites

    NASA Astrophysics Data System (ADS)

    Fang, F.; Jing, W. Q.

    2016-01-01

    Magnetic field-induced polarization rotation and magnetoelectric coupling effects are studied for [110]-oriented (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3/Tb0.3Dy0.7Fe2(PMN-xPT/Terfenol-D) multiferroic composites. Two compositions of the [110]-oriented relaxor ferroelectric single crystals, PMN-28PT and PMN-33PT, are used. In [110]-oriented PMN-28PT, domains of rhombohedral (R) and monoclinic (MB) phases coexist prior to the magnetic loadings. Upon the applied magnetic loadings, phase transition from monoclinic MB to R phase occurs. In [110]-oriented PMN-33PT, domains are initially of mixed orthorhombic (O) and MB phases, and the phase transition from O to MB phase takes place upon the external magnetic loading. Compared to PMN-28PT, the PMN-33PT single crystal exhibits much finer domain boundary structure prior to the magnetic loadings. Upon the magnetic loadings, more domain variants are induced via the phase transition in PMN-33PT than that in PMN-28PT single crystal. The finer domain band structure and more domain variants contribute to stronger piezoelectric activity. As a result, the composite of PMN-33PT/Terfenol-D manifests a stronger ME coupling than PMN-28PT/Terfenol-D composite.

  11. Self-powered cardiac pacemaker enabled by flexible single crystalline PMN-PT piezoelectric energy harvester.

    PubMed

    Hwang, Geon-Tae; Park, Hyewon; Lee, Jeong-Ho; Oh, SeKwon; Park, Kwi-Il; Byun, Myunghwan; Park, Hyelim; Ahn, Gun; Jeong, Chang Kyu; No, Kwangsoo; Kwon, HyukSang; Lee, Sang-Goo; Joung, Boyoung; Lee, Keon Jae

    2014-07-23

    A flexible single-crystalline PMN-PT piezoelectric energy harvester is demonstrated to achieve a self-powered artificial cardiac pacemaker. The energy-harvesting device generates a short-circuit current of 0.223 mA and an open-circuit voltage of 8.2 V, which are enough not only to meet the standard for charging commercial batteries but also for stimulating the heart without an external power source.

  12. High-power characterization of a microcutter actuated by PMN-PT piezocrystals.

    PubMed

    Kuang, Yang; Sadiq, Muhammad; Cochran, Sandy; Huang, Zhihong

    2015-11-01

    An ultrasonic microcutter is an alternative approach to conventional ultrasonic instruments actuated by sandwich piezoelectric transducers for surgery. This paper reports high-power behavior of a microcutter actuated by the piezocrystal lead magnesium niobate-lead titanate (PMN-PT), defining its practical performance and the feasibility of PMNPT actuation for surgical applications. The microcutter was driven at resonance with constant current amplitudes, either unloaded or loaded by poultry breast tissue, until its behavior achieved a steady state. During this driving process, its electric impedance, resonant frequency, and vibration velocity, along with the temperature increase of the PMN-PT, were recorded in real time. The microcutter produced a maximum vibration velocity >2.8 m/s with an excitation current of 0.11 A(rms). The mechanical loss increased significantly with current amplitude, resulting in a maximum temperature increase approaching 50°C around the interface between the PMN-PT and the blade, where they were bonded together with epoxy. Because of the low phase-transition temperature of PMN-PT, this temperature rise prevented the microcutter from working at higher current amplitudes. Along with the high vibration velocity, it also caused a frequency shift downward by 3 kHz at the same current amplitude. During tests with poultry breast tissue, radiation reactance increased the resonant frequency and the radiation resistance increased the loss of the microcutter. However, the loss did not further increase the temperature of the piezoelectric material. The maximum force and the overall work required to penetrate the microcutter into poultry breast tissue were reduced by 47.1 ± 8% and 53.5 ± 6%, respectively, when the microcutter was actuated at a current of 0.07 A(rms).

  13. Fermi-LAT Detection of Gamma-ray Emission from PMN J1747-5236

    NASA Astrophysics Data System (ADS)

    Ojha, Roopesh; Carpenter, Bryce; Valverd, Janeth

    2017-09-01

    The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope has observed a gamma-ray flare from a source positionally consistent with the radio source PMN J1747-5236 with coordinates RA: 17h47m05.68s, Dec: -52d36m32.5s, J2000, (Healey et al. 2007, ApJS, 171, 61). This source is not in any published LAT catalog and was not detected by AGILE or EGRET.

  14. PMN-PT Single-Crystal High-Frequency Kerfless Phased Array

    PubMed Central

    Chen, Ruimin; Cabrera-Munoz, Nestor E.; Lam, Kwok Ho; Hsu, Hsiu-sheng; Zheng, Fan; Zhou, Qifa; Shung, K. Kirk

    2015-01-01

    This paper reports the design, fabrication, and characterization of a miniature high-frequency kerfless phased array prepared from a PMN-PT single crystal for forward-looking intravascular or endoscopic imaging applications. After lapping down to around 40 μm, the PMN-PT material was utilized to fabricate 32-element kerfless phased arrays using micromachining techniques. The aperture size of the active area was only 1.0 × 1.0 mm. The measured results showed that the array had a center frequency of 40 MHz, a bandwidth of 34% at −6 dB with a polymer matching layer, and an insertion loss of 20 dB at the center frequency. Phantom images were acquired and compared with simulated images. The results suggest that the feasibility of developing a phased array mounted at the tip of a forward-looking intravascular catheter or endoscope. The fabricated array exhibits much higher sensitivity than PZT ceramic-based arrays and demonstrates that PMN-PT is well suited for this application. PMID:24859667

  15. Effects of oxygen ion irradiation on PMN-PT ferroelectric materials for space applications

    NASA Astrophysics Data System (ADS)

    Guggilla, Padmaja; Batra, A. K.; Powell, Rachel

    2016-09-01

    Lead magnesium niobate-lead titanate (PMN-PT) is an important and high performance piezoelectric and pyroelectric relaxor material having wide range of applications in infrared sensor devices. Present work studies the fabrication and dielectric characteristics of PMN-PT in the bulk form. The PMN-PT bulk material was prepared in sol-gel method and subsequently irradiated with heavy ion oxygen. The materials were analyzed and determined that the relaxorferroelectric material indicated changes in its dielectric constant and pyroelectric coefficient after irradiation. Due to the radiation fluent of 1×1016 ions/cm2, the dielectric constant of the material increased uniformly, while its pyroelectric coefficient showed a sharp increased to the value of 5×10-9 μC/cm2 °C with increase in temperature. Its dielectric constants showed increase in values of 527 μC/cm2 °C at 50°C, 635 μC/cm2 °C at 60°C and 748 μC/cm2 °C at 70°C. Properties such as the material impedance, admittance and modulus were investigated for changes in properties which became evident after irradiation.

  16. Influence of the polarization anisotropy on the electrocaloric effect in epitaxial PMN-PT thin films

    NASA Astrophysics Data System (ADS)

    Mietschke, M.; Chekhonin, P.; Molin, C.; Gebhardt, S.; Fähler, S.; Nielsch, K.; Schultz, L.; Hühne, R.

    2016-09-01

    Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) compounds, which are typically used for high performance actuator applications due to their outstanding piezoelectric properties, show, in addition, a pronounced electrocaloric (EC) effect. The study of epitaxial films is a useful tool to analyze the correlation between the microstructure and EC properties in order to optimize the performance of these materials. Therefore, the 0.9PMN-0.1PT films were grown by a pulsed laser deposition on (001) as well as (111) oriented SrTiO3 single crystalline substrates using a La0.7Sr0.3CoO3 buffer as the bottom electrode and additional Au top electrodes. The structural properties determined by a high resolution X-ray and electron microscopy techniques indicated an undisturbed epitaxial growth. The anisotropy of the ferroelectric domain structure was investigated by a vertical and lateral piezoresponse force microscopy showing clear differences between the two orientations. A significant reduction of the thermal hysteresis was observed in the T-dependent polarization measurements for (111) oriented PMN-PT films, whereas the indirectly determined EC properties yield a maximum ΔT of around 15 K at 40 °C for a field of about 400 kV/cm for both film orientations.

  17. 80-MHz intravascular ultrasound transducer using PMN-PT free-standing film.

    PubMed

    Li, Xiang; Wu, Wei; Chung, Youngsoo; Shih, Wan Y; Shih, Wei-Heng; Zhou, Qifa; Shung, K Kirk

    2011-11-01

    [Pb(Mg(1/3)Nb(2/3))O(3)](0.63)[PbTiO(3)](0.37) (PMN-PT) free-standing film of comparable piezoelectric properties to bulk material with thickness of 30 μm has been fabricated using a modified precursor coating approach. At 1 kHz, the dielectric permittivity and loss were 4364 and 0.033, respectively. The remnant polarization and coercive field were 28 μC/cm(2) and 18.43 kV/cm. The electromechanical coupling coefficient k(t) was measured to be 0.55, which was close to that of bulk PMN-PT single-crystal material. Based on this film, high-frequency (82 MHz) miniature ultrasonic transducers were fabricated with 65% bandwidth and 23 dB insertion loss. Axial and lateral resolutions were determined to be as high as 35 and 176 μm. In vitro intravascular imaging on healthy rabbit aorta was performed using the thin film transducers. In comparison with a 35-MHz IVUS transducer, the 80-MHz transducer showed superior resolution and contrast with satisfactory penetration depth. The imaging results suggest that PMN-PT free-standing thin film technology is a feasible and efficient way to fabricate very-high-frequency ultrasonic transducers.

  18. Self-Powered Ultrabroadband Photodetector Monolithically Integrated on a PMN-PT Ferroelectric Single Crystal.

    PubMed

    Fang, Huajing; Xu, Chao; Ding, Jie; Li, Qiang; Sun, Jia-Lin; Dai, Ji-Yan; Ren, Tian-Ling; Yan, Qingfeng

    2016-12-07

    Photodetectors capable of detecting two or more bands simultaneously with a single system have attracted extensive attentions because of their critical applications in image sensing, communication, and so on. Here, we demonstrate a self-powered ultrabroadband photodetector monolithically integrated on a 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 (PMN-28PT) single crystal. By combining the optothermal and pyroelectric effect, the multifunctional PMN-28PT single crystal can response to a wide wavelength range from UV to terahertz (THz). At room temperature, the photodetector could generate a pyroelectric current under the intermittent illumination of incident light in absence of external bias. A systematic study of the photoresponse was investigated. The pyroelectric current shows an almost linear relationship to illumination intensity. Benefiting from the excellent pyroelectric property of PMN-28PT single crystal and the optimized device architecture, the device exhibited a dramatic improvement in operation frequency up to 3 kHz without any obvious degradation in sensitivity. Such a self-powered photodetector with ultrabroadband response may open a window for the novel application of ferroelectric materials in optoelectronics.

  19. PMN-PT single-crystal high-frequency kerfless phased array.

    PubMed

    Chen, Ruimin; Cabrera-Munoz, Nestor E; Lam, Kwok Ho; Hsu, Hsiu-sheng; Zheng, Fan; Zhou, Qifa; Shung, K Kirk

    2014-06-01

    This paper reports the design, fabrication, and characterization of a miniature high-frequency kerfless phased array prepared from a PMN-PT single crystal for forward-looking intravascular or endoscopic imaging applications. After lapping down to around 40 μm, the PMN-PT material was utilized to fabricate 32-element kerfless phased arrays using micromachining techniques. The aperture size of the active area was only 1.0 × 1.0 mm. The measured results showed that the array had a center frequency of 40 MHz, a bandwidth of 34% at -6 dB with a polymer matching layer, and an insertion loss of 20 dB at the center frequency. Phantom images were acquired and compared with simulated images. The results suggest that the feasibility of developing a phased array mounted at the tip of a forward-looking intravascular catheter or endoscope. The fabricated array exhibits much higher sensitivity than PZT ceramic-based arrays and demonstrates that PMN-PT is well suited for this application.

  20. High frequency ultrasonic dispersion of single crystal PMN-28%PT with engineered domain structures

    NASA Astrophysics Data System (ADS)

    Jiang, Wenhua; Cao, Wenwu

    2002-03-01

    The ultrasonic spectroscopy was performed on single crystal 0.72Pb(Mg_1/3Nb_2/3)O_3-0.28PbTiO3 [PMN-28%PT] with engineered domain structures in the frequency range of 50-110 MHz.The sample (H. C. Materials Corporation, Urbana, IL) has the dimensions of 18x13x2.35 mm with [100]/[010]/[001] orientations in the cubic reference frame and is poled along the dimension of 2.35 mm. The frequency dispersions of ultrasonic phase velocity and attenuation for the longitudinal wave propagating along the poling direction were obtained from the spectra analysis of the through ultrasonic signals. For comparison, the ultrasonic spectroscopy were also performed on PZT-4 ceramic and a z-cut LiNbO3 single crystal. It is found that the frequency dispersion of ultrasonic phase velocity and attenuation of the multi-domain PMN-28%PT single crystal is comparable with that of single crystal LiNbO3 and is much smaller than that of PZT-4 ceramic. The measured velocity dispersion is also compared with the one derived from the Kramers-Kronig relationship based on the measured frequency-dependent attenuation. The agreement is fairly good. Our results indicate that the new multi-domain PMN-PT single crystals have great potential for high frequency applications due to its low dispersion and extremely large piezoelectric effect.

  1. Guidance Documents and Sample Forms for Central Data Exchange (CDX) Registration and e-PMN Software (Thin Client)

    EPA Pesticide Factsheets

    For users submitting electronic notices through CDX, this page contains guidance documents and sample forms to help you, submit Premanufacture Notices (PMN), Bona Fide and biotechnology notices, among others.

  2. Eimeria bovis modulates adhesion molecule gene transcription in and PMN adhesion to infected bovine endothelial cells.

    PubMed

    Hermosilla, Carlos; Zahner, Horst; Taubert, Anja

    2006-04-01

    Eimeria bovis is an important coccidian parasite of cattle causing severe diarrhea in young animals. Its first schizogony takes place in endothelial cells of the ileum resulting in the formation of macroschizonts 14-18 days p.i. This longlasting development suggests a particular immune evasion strategy of the parasite. Here, we analyse early innate immune reactions to E. bovis by determining the adhesion of polymorphonuclear neutrophils (PMN) to infected endothelial cell layers under flow conditions and the transcription of adhesion molecule genes in infected host cells. Bovine umbilical vein endothelial cells (BUVEC) were infected with E. bovis sporozoites. Sporozoites invaded BUVEC within 1h and the first mature macroschizonts occurred 14 days p.i. PMN adhesion was enhanced in E. bovis-infected BUVEC layers as early as 8h p.i.; maximum adhesion occurred 48 h p.i. Increased adhesion rates persisted until the end of the observation period at 14 days p.i. PMN adhered to both infected and uninfected cells within monolayers, suggesting paracrine cell activation. E. bovis infection upregulated the transcription of genes encoding for P-selectin, E-selectin, vascular cellular adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1). Most marked effects concerned E-selectin followed by P-selectin, VCAM-1 and ICAM-1. Increased transcript levels were found beginning 30 min p.i. and maximum values occurred 1-2h p.i. (P-selectin) and 2-4h p.i. (E-selectin, VCAM-1, ICAM-1). By 12-24h p.i. levels had decreased to those of uninfected controls. Tumor necrosis factor alpha (TNFalpha)-induced PMN adhesion was significantly reduced in infected vs. uninfected BUVEC. Eimeria bovis also had suppressive effects on TNFalpha-mediated upregulation of adhesion molecule gene transcription. The data presented here suggest that infection of BUVEC with E. bovis on one hand induces proinflammatory reactions resulting in enhanced PMN adhesion mediated by upregulated adhesion

  3. Freshwater to seawater transitions in migratory fishes

    USGS Publications Warehouse

    Zydlewski, Joseph; Michael P. Wilkie,

    2012-01-01

    The transition from freshwater to seawater is integral to the life history of many fishes. Diverse migratory fishes express anadromous, catadromous, and amphidromous life histories, while others make incomplete transits between freshwater and seawater. The physiological mechanisms of osmoregulation are widely conserved among phylogenetically diverse species. Diadromous fishes moving between freshwater and seawater develop osmoregulatory mechanisms for different environmental salinities. Freshwater to seawater transition involves hormonally mediated changes in gill ionocytes and the transport proteins associated with hypoosmoregulation, increased seawater ingestion and water absorption in the intestine, and reduced urinary water losses. Fishes attain salinity tolerance through early development, gradual acclimation, or environmentally or developmentally cued adaptations. This chapter describes adaptations in diverse taxa and the effects of salinity on growth. Identifying common strategies in diadromous fishes moving between freshwater and seawater will reveal the ecological and physiological basis for maintaining homeostasis in different salinities, and inform efforts to conserve and manage migratory euryhaline fishes.

  4. Migratory Birds as Global Dispersal Vectors.

    PubMed

    Viana, Duarte S; Santamaría, Luis; Figuerola, Jordi

    2016-10-01

    Propagule dispersal beyond local scales has been considered rare and unpredictable. However, for many plants, invertebrates, and microbes dispersed by birds, long-distance dispersal (LDD) might be regularly achieved when mediated by migratory movements. Because LDD operates over spatial extents spanning hundreds to thousands of kilometers, it can promote rapid range shifts and determine species distributions. We review evidence supporting this widespread LDD service and propose a conceptual framework for estimating LDD by migratory birds. Although further research and validation efforts are still needed, we show that current knowledge can be used to make more realistic estimations of LDD mediated by regular bird migrations, thus refining current predictions of its ecological and evolutionary consequences.

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

    USGS Publications Warehouse

    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

  6. Migratory decisions in birds: extent of genetic versus environmental control.

    PubMed

    Ogonowski, Mark S; Conway, Courtney J

    2009-08-01

    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

  7. Catalytic migratory oxidative coupling of nitrones.

    PubMed

    Hashizume, Shogo; Oisaki, Kounosuke; Kanai, Motomu

    2011-08-19

    A Cu(I)-catalyzed migratory oxidative coupling between nitrones and heterocycles or a methylamine is described. Selective C-C bond-formation proceeds through cleavage of two C(sp(3))-H bonds concomitant with C═N double bond-migration. The reaction provides an alternating nitrone moiety, allowing for further synthetically useful transformations. Radical clock studies suggest that the nucleophilic addition of nitrones to an oxidatively generated carbocation is a key step.

  8. Overseas seed dispersal by migratory birds

    PubMed Central

    2016-01-01

    Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has never been directly observed nor quantified. By sampling birds caught while in migratory flight by GPS-tracked wild falcons, we show that migratory birds transport seeds over hundreds of kilometres and mediate dispersal from mainland to oceanic islands. Up to 1.2% of birds that reached a small island of the Canary Archipelago (Alegranza) during their migration from Europe to Sub-Saharan Africa carried seeds in their guts. The billions of birds making seasonal migrations each year may then transport millions of seeds. None of the plant species transported by the birds occurs in Alegranza and most do not occur on nearby Canary Islands, providing a direct example of the importance of environmental filters in hampering successful colonization by immigrant species. The constant propagule pressure generated by these LDD events might, nevertheless, explain the colonization of some islands. Hence, migratory birds can mediate rapid range expansion or shifts of many plant taxa and determine their distribution. PMID:26740610

  9. Necrolytic migratory erythema and pancreatic glucagonoma.

    PubMed

    Rodríguez, Gerzaín; Vargas, Elga; Abaúnza, Claudia; Cáceres, Sergio

    2016-06-03

    Necrolytic migratory erythema is a rare paraneoplastic dermatosis that may be the first clinical manifestation of the glucagonoma syndrome, a disorder characterized by mucocutaneous rash, glucose intolerance, hypoaminoacidemia, hyperglucagonaemia and pancreatic glucagonoma. The clinical case of a 45-year-old woman is presented. She had been experiencing weight loss, polydipsia, polyphagia, postprandial emesis, excessive hair loss and abdominal pain for two months. Erythematous, scaly and migratory plaques with 20 days of evolution were found on her trunk, perineum, elbows, hands, feet, inframammary and antecubital folds. The skin biopsy revealed noticeable vacuolar changes in high epidermal cells, extensive necrosis and thin orthokeratotic cornified layer. These findings pointed to a diagnosis of necrolytic migratory erythema. A suggestion was made to investigate a pancreatic glucagonoma. Laboratory tests showed moderate anemia, hyperglycemia and marked hyperglucagonaemia. Abdominal ultrasound revealed a mass in the tail of the pancreas measuring 6 x 5 x 5 cm which was resected. The histopathological findings were compatible with a diagnosis of glucagonoma, as confirmed by immunohistochemistry. Skin symptoms disappeared 10 days after the tumor resection. We can conclude that the histological changes defined may be clues that can lead the search for a distant skin disease and allow for its diagnosis. The histological pattern of vacuolation and epidermal necrosis should arouse suspicion of pancreatic glucagonoma.

  10. Overseas seed dispersal by migratory birds.

    PubMed

    Viana, Duarte S; Gangoso, Laura; Bouten, Willem; Figuerola, Jordi

    2016-01-13

    Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has never been directly observed nor quantified. By sampling birds caught while in migratory flight by GPS-tracked wild falcons, we show that migratory birds transport seeds over hundreds of kilometres and mediate dispersal from mainland to oceanic islands. Up to 1.2% of birds that reached a small island of the Canary Archipelago (Alegranza) during their migration from Europe to Sub-Saharan Africa carried seeds in their guts. The billions of birds making seasonal migrations each year may then transport millions of seeds. None of the plant species transported by the birds occurs in Alegranza and most do not occur on nearby Canary Islands, providing a direct example of the importance of environmental filters in hampering successful colonization by immigrant species. The constant propagule pressure generated by these LDD events might, nevertheless, explain the colonization of some islands. Hence, migratory birds can mediate rapid range expansion or shifts of many plant taxa and determine their distribution.

  11. Abrupt switch to migratory night flight in a wild migratory songbird

    PubMed Central

    Zúñiga, Daniel; Falconer, Jade; Fudickar, Adam M.; Jensen, Willi; Schmidt, Andreas; Wikelski, Martin; Partecke, Jesko

    2016-01-01

    Every year, billions of wild diurnal songbirds migrate at night. To do so, they shift their daily rhythm from diurnality to nocturnality. In captivity this is observed as a gradual transition of daytime activity developing into nocturnal activity, but how wild birds prepare their daily rhythms for migration remains largely unknown. Using an automated radio-telemetry system, we compared activity patterns of free-living migrant and resident European blackbirds (Turdus merula) in a partially migratory population during the pre-migratory season. We found that activity patterns between migrant and resident birds did not differ during day and night. Migrants did not change their daily rhythm in a progressive manner as has been observed in captivity, but instead abruptly became active during the night of departure. The rapid shift in rhythmicity might be more common across migratory songbird species, but may not have been observed before in wild animals due to a lack of technology. PMID:27666200

  12. Quantification of strain and charge co-mediated magnetoelectric coupling on ultra-thin Permalloy/PMN-PT interface

    PubMed Central

    Nan, Tianxiang; Zhou, Ziyao; Liu, Ming; Yang, Xi; Gao, Yuan; Assaf, Badih A.; Lin, Hwaider; Velu, Siddharth; Wang, Xinjun; Luo, Haosu; Chen, Jimmy; Akhtar, Saad; Hu, Edward; Rajiv, Rohit; Krishnan, Kavin; Sreedhar, Shalini; Heiman, Don; Howe, Brandon M.; Brown, Gail J.; Sun, Nian X.

    2014-01-01

    Strain and charge co-mediated magnetoelectric coupling are expected in ultra-thin ferromagnetic/ferroelectric multiferroic heterostructures, which could lead to significantly enhanced magnetoelectric coupling. It is however challenging to observe the combined strain charge mediated magnetoelectric coupling, and difficult in quantitatively distinguish these two magnetoelectric coupling mechanisms. We demonstrated in this work, the quantification of the coexistence of strain and surface charge mediated magnetoelectric coupling on ultra-thin Ni0.79Fe0.21/PMN-PT interface by using a Ni0.79Fe0.21/Cu/PMN-PT heterostructure with only strain-mediated magnetoelectric coupling as a control. The NiFe/PMN-PT heterostructure exhibited a high voltage induced effective magnetic field change of 375 Oe enhanced by the surface charge at the PMN-PT interface. Without the enhancement of the charge-mediated magnetoelectric effect by inserting a Cu layer at the PMN-PT interface, the electric field modification of effective magnetic field was 202 Oe. By distinguishing the magnetoelectric coupling mechanisms, a pure surface charge modification of magnetism shows a strong correlation to polarization of PMN-PT. A non-volatile effective magnetic field change of 104 Oe was observed at zero electric field originates from the different remnant polarization state of PMN-PT. The strain and charge co-mediated magnetoelectric coupling in ultra-thin magnetic/ferroelectric heterostructures could lead to power efficient and non-volatile magnetoelectric devices with enhanced magnetoelectric coupling. PMID:24418911

  13. Polarized light cues underlie compass calibration in migratory songbirds.

    PubMed

    Muheim, Rachel; Phillips, John B; Akesson, Susanne

    2006-08-11

    Migratory songbirds use the geomagnetic field, stars, the Sun, and polarized light patterns to determine their migratory direction. To prevent navigational errors, it is necessary to calibrate all of these compass systems to a common reference. We show that migratory Savannah sparrows use polarized light cues from the region of sky near the horizon to recalibrate the magnetic compass at both sunrise and sunset. We suggest that skylight polarization patterns are used to derive an absolute (i.e., geographic) directional system that provides the primary calibration reference for all of the compasses of migratory songbirds.

  14. 76 FR 38598 - Atlantic Highly Migratory Species; Vessel Monitoring Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ... Species; Vessel Monitoring Systems AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... modifications to vessel monitoring system (VMS) requirements in Atlantic Highly Migratory Species...

  15. Escaping peril: perceived predation risk affects migratory propensity

    PubMed Central

    Hulthén, Kaj; Chapman, Ben B.; Nilsson, P. Anders; Vinterstare, Jerker; Hansson, Lars-Anders; Skov, Christian; Brodersen, Jakob; Baktoft, Henrik; Brönmark, Christer

    2015-01-01

    Although migratory plasticity is increasingly documented, the ecological drivers of plasticity are not well understood. Predation risk can influence migratory dynamics, but whether seasonal migrants can adjust their migratory behaviour according to perceived risk is unknown. We used electronic tags to record the migration of individual roach (Rutilus rutilus), a partially migratory fish, in the wild following exposure to manipulation of direct (predator presence/absence) and indirect (high/low roach density) perceived predation risk in experimental mesocosms. Following exposure, we released fish in their lake summer habitat and monitored individual migration to connected streams over an entire season. Individuals exposed to increased perceived direct predation risk (i.e. a live predator) showed a higher migratory propensity but no change in migratory timing, while indirect risk (i.e. roach density) affected timing but not propensity showing that elevated risk carried over to alter migratory behaviour in the wild. Our key finding demonstrates predator-driven migratory plasticity, highlighting the powerful role of predation risk for migratory decision-making and dynamics. PMID:26311158

  16. Virus investigation in ticks from migratory birds in Italy.

    PubMed

    Mancini, Fabiola; Toma, Luciano; Ciervo, Alessandra; Di Luca, Marco; Faggioni, Giovanni; Lista, Forigio; Rezza, Giovanni

    2013-10-01

    The role of migratory birds in circulation tick-borne viruses needs to be better defined. In order to assess the potential role of migratory birds in exotic virus spread, we conducted a study to identify ticks collected from migratory birds in the Central Region of Italy, and performed molecular investigation for Crimea-Congo Hemorrhagic Fever (CCHFV), West Nile fever (WNFV) and Usutu (USUV) in the vectors. A total of 137 competent ticks were collected with predominance of Hyalomma species. Although, negative results were obtained for all viruses considered, the high proportion of Hyalomma ticks highlights the potential risk for the dissemination of tick-borne viruses through infested migratory birds.

  17. Importance of reservoir tributaries to spawning of migratory fish in the upper Paraná River

    USGS Publications Warehouse

    da Silva, P.S.; Makrakis, Maristela Cavicchioli; Miranda, Leandro E.; Makrakis, Sergio; Assumpcao, L.; Paula, S.; Dias, João Henrique Pinheiro; Marques, H.

    2015-01-01

    Regulation of rivers by dams transforms previously lotic reaches above the dam into lentic ones and limits or prevents longitudinal connectivity, which impairs access to suitable habitats for the reproduction of many migratory fish species. Frequently, unregulated tributaries can provide important habitat heterogeneity to a regulated river and may mitigate the influence of impoundments on the mainstem river. We evaluated the importance of tributaries to spawning of migratory fish species over three spawning seasons, by comparing several abiotic conditions and larval fish distributions in four rivers that are tributaries to an impounded reach of the Upper Parana River, Brazil. Our study confirmed reproduction of at least 8 long-distance migrators, likely nine, out of a total of 19 occurring in the Upper Parana River. Total larval densities and percentage species composition differed among tributaries, but the differences were not consistent among spawning seasons and unexpectedly were not strongly related to annual differences in temperature and hydrology. We hypothesize that under present conditions, densities of larvae of migratory species may be better related to efficiency of fish passage facilities than to temperature and hydrology. Our study indicates that adult fish are finding suitable habitat for spawning in tributaries, fish eggs are developing into larvae, and larvae are finding suitable rearing space in lagoons adjacent to the tributaries. Our findings also suggest the need for establishment of protected areas in unregulated and lightly regulated tributaries to preserve essential spawning and nursery habitats.

  18. Pulmonary alveolar macrophages (PAM) engulf and regain elastin particles and do not respond to some stimuli of neutrophil (PMN) elastinolysis

    SciTech Connect

    Tricomi, S.M.; Hyers, T.M.; Yu, S.Y.; Liao, J.J.

    1986-03-05

    Elastin degradation by PMN and by PAM differs in the proteinases produced and in the method of cellular attack on the substrate. To further characterize the elastinolytic mechanisms of these two cells, /sup 14/C-labelled bovine ligament elastin was dried onto 24-well culture plates and live cells were placed on the substrate in culture medium. Incubation times were 4 hours for PMN and 20 hours for PAM. Elastinolytic activity was determined by counting /sup 14/C-elastin peptides in the supernatant. By lidocaine release of PAM from the surface, /sup 14/C-elastin retained by the cell was measured. Studies on rabbit PAM showed that 40% of dpm remain associated with the cell at 20 hours. Transmission electron microscopy of human PAM confirmed that PAM can engulf and retain elastin particles at 4 and 24 hours of incubation when in close contact with the substrate. Of the number of dpm released by PMN in 4 hours, PAM in 20 hours released only 23% of that number into supernatant and retained 17% closely associated with the cell after lidocaine treatment. Platelet factor 4, a protein released by platelets upon aggregation which stimulates activity of PMN elastase on elastin, was shown to enhance elastinolysis by whole PMN by 57% at 10 ..mu..g/ml in this assay. Platelet factor 4 did not enhance elastinolysis by PAM at concentrations up to 100 ..mu..g/ml.

  19. 78 FR 65576 - Migratory Bird Permits; Definition of “Hybrid” Migratory Bird

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-01

    ... and Wildlife Service (FWS), revise the definition of ``hybrid'' as it relates to birds protected under the Migratory Bird Treaty Act. We revise the definition to make it clear that it applies to all... created difficulties because it differs from the longstanding Service interpretation of ``hybrid'' as...

  20. A SCHOOL AND HEALTH RECORD TRANSFER SYSTEM FOR MIGRATORY CHILDREN OF MIGRATORY AGRICULTURAL WORKERS (CALIFORNIA).

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento.

    THE CALIFORNIA STATE DEPARTMENT OF EDUCATION HAS ADOPTED A UNIFORM TRANSFER SYSTEM FOR CHILDREN OF MIGRATORY AGRICULTURAL WORKERS. EACH SCHOOL DISTRICT ENROLLING MIGRANT CHILDREN MUST COMPLETE A STANDARDIZED FORM FOR EACH MIGRANT CHILD AND FORWARD IT WITH THE PUPIL WHEN HE WITHDRAWS FROM SCHOOL. A COPY ALSO MUST BE FORWARDED TO THE STATE…

  1. 78 FR 78322 - Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-26

    ...On August 22, 2013, NMFS published a notice of public hearings for Draft Amendment 7 to the 2006 Consolidated Highly Migratory Species (HMS) Fishery Management Plan (2006 Consolidated HMS FMP), which included 10 public hearings. Due to the government shut down and NMFS' inability to respond to constituents on this complex rule during that time frame and based on the comments received to date......

  2. 75 FR 19369 - Atlantic Highly Migratory Species; Meeting of the Atlantic Highly Migratory Species Advisory Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-14

    ...: NMFS will hold a 3-day Atlantic Highly Migratory Species (HMS) Advisory Panel (AP) meeting in May 2010.... The meeting is open to the public. DATES: The AP meeting will be held from 1 p.m. to 6 p.m. on Tuesday... establishment of an AP to assist in the collection and evaluation of information relevant to the development...

  3. 76 FR 7547 - Atlantic Highly Migratory Species; Meeting of the Atlantic Highly Migratory Species Advisory Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-10

    ... meeting. SUMMARY: NMFS will hold a 3-day Atlantic Highly Migratory Species (HMS) Advisory Panel (AP... management of Atlantic HMS. The meeting is open to the public. DATES: The AP meeting will be held on April 5... by the Sustainable Fisheries Act, Public Law 104-297, provided for the establishment of an AP...

  4. 76 FR 45781 - Atlantic Highly Migratory Species; Meeting of the Atlantic Highly Migratory Species Advisory Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-01

    ... meeting. SUMMARY: NMFS will hold a 3-day Atlantic Highly Migratory Species (HMS) Advisory Panel (AP... management of Atlantic HMS. The meeting is open to the public. DATES: The AP meeting will be held Sept. 20... by the Sustainable Fisheries Act, Public Law 104-297, provided for the establishment of an AP...

  5. 75 FR 43928 - Atlantic Highly Migratory Species; Meeting of the Atlantic Highly Migratory Species Advisory Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ...: NMFS will hold a 3-day Atlantic Highly Migratory Species (HMS) Advisory Panel (AP) meeting in September... HMS. The meeting is open to the public. DATES: The AP meeting will be held on September 21, 2010... Sustainable Fisheries Act, Public Law 104 297, provided for the establishment of an AP to assist in...

  6. Migratory connectivity and population-specific migration routes in a long-distance migratory bird.

    PubMed

    Trierweiler, Christiane; Klaassen, Raymond H G; Drent, Rudi H; Exo, Klaus-Michael; Komdeur, Jan; Bairlein, Franz; Koks, Ben J

    2014-03-07

    Knowledge about migratory connectivity, the degree to which individuals from the same breeding site migrate to the same wintering site, is essential to understand processes affecting populations of migrants throughout the annual cycle. Here, we study the migration system of a long-distance migratory bird, the Montagu's harrier Circus pygargus, by tracking individuals from different breeding populations throughout northern Europe. We identified three main migration routes towards wintering areas in sub-Saharan Africa. Wintering areas and migration routes of different breeding populations overlapped, a pattern best described by 'weak (diffuse) connectivity'. Migratory performance, i.e. timing, duration, distance and speed of migration, was surprisingly similar for the three routes despite differences in habitat characteristics. This study provides, to our knowledge, a first comprehensive overview of the migration system of a Palaearctic-African long-distance migrant. We emphasize the importance of spatial scale (e.g. distances between breeding populations) in defining patterns of connectivity and suggest that knowledge about fundamental aspects determining distribution patterns, such as the among-individual variation in mean migration directions, is required to ultimately understand migratory connectivity. Furthermore, we stress that for conservation purposes it is pivotal to consider wintering areas as well as migration routes and in particular stopover sites.

  7. 77 FR 24161 - Atlantic Highly Migratory Species; Amendment 7 to the 2006 Consolidated Atlantic Highly Migratory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-23

    ... Species; Amendment 7 to the 2006 Consolidated Atlantic Highly Migratory Species Fishery Management Plan... the development of a proposed Amendment 7. The types of management measures under consideration for Amendment 7 will include those described in the scoping document, as well as alternative measures that...

  8. Migratory connectivity and population-specific migration routes in a long-distance migratory bird

    PubMed Central

    Trierweiler, Christiane; Klaassen, Raymond H. G.; Drent, Rudi H.; Exo, Klaus-Michael; Komdeur, Jan; Bairlein, Franz; Koks, Ben J.

    2014-01-01

    Knowledge about migratory connectivity, the degree to which individuals from the same breeding site migrate to the same wintering site, is essential to understand processes affecting populations of migrants throughout the annual cycle. Here, we study the migration system of a long-distance migratory bird, the Montagu's harrier Circus pygargus, by tracking individuals from different breeding populations throughout northern Europe. We identified three main migration routes towards wintering areas in sub-Saharan Africa. Wintering areas and migration routes of different breeding populations overlapped, a pattern best described by ‘weak (diffuse) connectivity’. Migratory performance, i.e. timing, duration, distance and speed of migration, was surprisingly similar for the three routes despite differences in habitat characteristics. This study provides, to our knowledge, a first comprehensive overview of the migration system of a Palaearctic-African long-distance migrant. We emphasize the importance of spatial scale (e.g. distances between breeding populations) in defining patterns of connectivity and suggest that knowledge about fundamental aspects determining distribution patterns, such as the among-individual variation in mean migration directions, is required to ultimately understand migratory connectivity. Furthermore, we stress that for conservation purposes it is pivotal to consider wintering areas as well as migration routes and in particular stopover sites. PMID:24430850

  9. MIGRATORY LABOR IN THE WEST, BACKGROUND INFORMATION FOR THE WESTERN INTERSTATE CONFERENCE ON MIGRATORY LABOR.

    ERIC Educational Resources Information Center

    Council of State Governments, Chicago, IL.

    THE MIGRATORY FARM LABOR FORCE IN THE UNITED STATES IS GENERALLY COMPOSED OF UNDEREMPLOYED WORKERS WHO ARE PRIMARILY FROM THE NEGRO, SPANISH-AMERICAN, AND INDIAN MINORITY GROUPS OF RURAL AREAS. THESE WORKERS MIGRATE IN SEARCH OF EMPLOYMENT BECAUSE OF THEIR LOW EARNING POTENTIAL IN THEIR HOME AREAS. ALTHOUGH THEY HELP SATISFY THE CRITICAL DEMAND…

  10. Assessing allowable take of migratory birds

    USGS Publications Warehouse

    Runge, M.C.; Sauer, J.R.; Avery, M.L.; Blackwell, B.F.; Koneff, M.D.

    2009-01-01

    Legal removal of migratory birds from the wild occurs for several reasons, including subsistence, sport harvest, damage control, and the pet trade. We argue that harvest theory provides the basis for assessing the impact of authorized take, advance a simplified rendering of harvest theory known as potential biological removal as a useful starting point for assessing take, and demonstrate this approach with a case study of depredation control of black vultures (Coragyps atratus) in Virginia, USA. Based on data from the North American Breeding Bird Survey and other sources, we estimated that the black vulture population in Virginia was 91,190 (95% credible interval = 44,520?212,100) in 2006. Using a simple population model and available estimates of life-history parameters, we estimated the intrinsic rate of growth (rmax) to be in the range 7?14%, with 10.6% a plausible point estimate. For a take program to seek an equilibrium population size on the conservative side of the yield curve, the rate of take needs to be less than that which achieves a maximum sustained yield (0.5 x rmax). Based on the point estimate for rmax and using the lower 60% credible interval for population size to account for uncertainty, these conditions would be met if the take of black vultures in Virginia in 2006 was < 3,533 birds. Based on regular monitoring data, allowable harvest should be adjusted annually to reflect changes in population size. To initiate discussion about how this assessment framework could be related to the laws and regulations that govern authorization of such take, we suggest that the Migratory Bird Treaty Act requires only that take of native migratory birds be sustainable in the long-term, that is, sustained harvest rate should be < rmax. Further, the ratio of desired harvest rate to 0.5 x rmax may be a useful metric for ascertaining the applicability of specific requirements of the National Environmental Protection Act.

  11. Assessing allowable take of migratory birds

    USGS Publications Warehouse

    Runge, M.C.; Sauer, J.R.; Avery, M.L.; Blackwell, B.F.; Koneff, M.D.

    2009-01-01

    Legal removal of migratory birds from the wild occurs for several reasons, including subsistence, sport harvest, damage control, and the pet trade. We argue that harvest theory provides the basis for assessing the impact of authorized take, advance a simplified rendering of harvest theory known as potential biological removal as a useful starting point for assessing take, and demonstrate this approach with a case study of depredation control of black vultures (Coragyps atratus) in Virginia, USA. Based on data from the North American Breeding Bird Survey and other sources, we estimated that the black vulture population in Virginia was 91,190 (95% credible interval = 44,520?212,100) in 2006. Using a simple population model and available estimates of life-history parameters, we estimated the intrinsic rate of growth (rmax) to be in the range 7?14%, with 10.6% a plausible point estimate. For a take program to seek an equilibrium population size on the conservative side of the yield curve, the rate of take needs to be less than that which achieves a maximum sustained yield (0.5 x rmax). Based on the point estimate for rmax and using the lower 60% credible interval for population size to account for uncertainty, these conditions would be met if the take of black vultures in Virginia in 2006 was <3,533 birds. Based on regular monitoring data, allowable harvest should be adjusted annually to reflect changes in population size. To initiate discussion about how this assessment framework could be related to the laws and regulations that govern authorization of such take, we suggest that the Migratory Bird Treaty Act requires only that take of native migratory birds be sustainable in the long-term, that is, sustained harvest rate should be

  12. Are Migratory Animals Superspreaders of Infection?

    PubMed

    Fritzsche McKay, Alexa; Hoye, Bethany J

    2016-08-01

    Migratory animals are simultaneously challenged by the physiological demands of long-distance movements and the need to avoid natural enemies including parasites and pathogens. The potential for animal migrations to disperse pathogens across large geographic areas has prompted a growing body of research investigating the interactions between migration and infection. However, the phenomenon of animal migration is yet to be incorporated into broader theories in disease ecology. Because migrations may expose animals to a greater number and diversity of pathogens, increase contact rates between hosts, and render them more susceptible to infection via changes to immune function, migration has the potential to generate both "superspreader species" and infection "hotspots". However, migration has also been shown to reduce transmission in some species, by facilitating parasite avoidance ("migratory escape") and weeding out infected individuals ("migratory culling"). This symposium was convened in an effort to characterize more broadly the role that animal migrations play in the dynamics of infectious disease, by integrating a range of approaches and scales across host taxa. We began with questions related to within-host processes, focusing on the consequences of nutritional constraints and strenuous movement for individual immune capability, and of parasite infection for movement capacity. We then scaled-up to between-host processes to identify what types, distances, or patterns of host movements are associated with the spread of infectious agents. Finally, we discussed landscape-scale relationships between migration and infectious disease, and how these may be altered as a result of anthropogenic changes to climate and land use. We are just beginning to scratch the surface of the interactions between infection and animal migrations; yet, with so many migrations now under threat, there is an urgent need to develop a holistic understanding of the potential for migrations to

  13. Micromachined High Frequency PMN-PT/Epoxy 1-3 Composite Ultrasonic Annular Array

    PubMed Central

    Liu, Changgeng; Djuth, Frank; Li, Xiang; Chen, Ruimin; Zhou, Qifa; Shung, K. Kirk

    2013-01-01

    This paper reports the design, fabrication, and performance of miniature micromachined high frequency PMN-PT/epoxy 1-3 composite ultrasonic annular arrays. The PMN-PT single crystal 1-3 composites were made with micromachining techniques. The area of a single crystal pillar was 9 μm × 9 μm. The width of the kerf among pillars was ~ 5 μm and the kerfs were filled with a polymer. The composite thickness was 25 μm. A six-element annular transducer of equal element area of 0.2 mm2 with 16 μm kerf widths between annuli was produced. The aperture size the array transducer is about 1.5 mm in diameter. A novel electrical interconnection strategy for high density array elements was implemented. After the transducer was attached to the electric connection board and packaged, the array transducer was tested in a pulse/echo arrangement, whereby the center frequency, bandwidth, two-way insertion loss (IL), and cross talk between adjacent elements were measured for each annulus. The center frequency was 50 MHz and -6 dB bandwidth was 90%. The average insertion loss was 19.5 dB at 50 MHz and the crosstalk between adjacent elements was about -35 dB. The micromachining techniques described in this paper are promising for the fabrication of other types of high frequency transducers e.g. 1D and 2D arrays. PMID:22119324

  14. Air-Coupled Low Frequency Ultrasonic Transducers and Arrays with PMN-32%PT Piezoelectric Crystals

    PubMed Central

    Kazys, Rymantas J.; Sliteris, Reimondas; Sestoke, Justina

    2017-01-01

    Air-coupled ultrasonic techniques are being increasingly used for material characterization, non-destructive evaluation of composite materials using guided waves as well as for distance measurements. Application of those techniques is mainly limited by the big losses of ultrasonic signals due to attenuation and mismatch of the acoustic impedances of ultrasonic transducers and air. One of the ways to solve this problem is by application of novel more efficient piezoelectric materials like lead magnesium niobate-lead titanate (PMN-PT) type crystals. The objective of this research was the development and investigation of low frequency (<50 kHz) wide band air-coupled ultrasonic transducers and arrays with an improved performance using PMN-32%PT crystals. Results of finite element modelling and experimental investigations of the developed transducers and arrays are presented. For improvement of the performance strip-like matching elements made of low acoustic impedance, materials such as polystyrene foams were applied. It allowed to achieve transduction losses for one single element transducer −11.4 dB, what is better than of commercially available air-coupled ultrasonic transducers. Theoretical and experimental investigations of the acoustic fields radiated by the eight element ultrasonic array demonstrated not only a good performance of the array in a pulse mode, but also very good possibilities to electronically focus and steer the ultrasonic beam in space. PMID:28067807

  15. Air-Coupled Low Frequency Ultrasonic Transducers and Arrays with PMN-32%PT Piezoelectric Crystals.

    PubMed

    Kazys, Rymantas J; Sliteris, Reimondas; Sestoke, Justina

    2017-01-06

    Air-coupled ultrasonic techniques are being increasingly used for material characterization, non-destructive evaluation of composite materials using guided waves as well as for distance measurements. Application of those techniques is mainly limited by the big losses of ultrasonic signals due to attenuation and mismatch of the acoustic impedances of ultrasonic transducers and air. One of the ways to solve this problem is by application of novel more efficient piezoelectric materials like lead magnesium niobate-lead titanate (PMN-PT) type crystals. The objective of this research was the development and investigation of low frequency (<50 kHz) wide band air-coupled ultrasonic transducers and arrays with an improved performance using PMN-32%PT crystals. Results of finite element modelling and experimental investigations of the developed transducers and arrays are presented. For improvement of the performance strip-like matching elements made of low acoustic impedance, materials such as polystyrene foams were applied. It allowed to achieve transduction losses for one single element transducer -11.4 dB, what is better than of commercially available air-coupled ultrasonic transducers. Theoretical and experimental investigations of the acoustic fields radiated by the eight element ultrasonic array demonstrated not only a good performance of the array in a pulse mode, but also very good possibilities to electronically focus and steer the ultrasonic beam in space.

  16. Micromachined high frequency PMN-PT/epoxy 1-3 composite ultrasonic annular array.

    PubMed

    Liu, Changgeng; Djuth, Frank; Li, Xiang; Chen, Ruimin; Zhou, Qifa; Shung, K Kirk

    2012-04-01

    This paper reports the design, fabrication, and performance of miniature micromachined high frequency PMN-PT/epoxy 1-3 composite ultrasonic annular arrays. The PMN-PT single crystal 1-3 composites were made with micromachining techniques. The area of a single crystal pillar was 9×9 μm. The width of the kerf among pillars was ∼5 μm and the kerfs were filled with a polymer. The composite thickness was 25 μm. A six-element annular transducer of equal element area of 0.2 mm(2) with 16 μm kerf widths between annuli was produced. The aperture size the array transducer is about 1.5 mm in diameter. A novel electrical interconnection strategy for high density array elements was implemented. After the transducer was attached to the electric connection board and packaged, the array transducer was tested in a pulse/echo arrangement, whereby the center frequency, bandwidth, two-way insertion loss (IL), and cross talk between adjacent elements were measured for each annulus. The center frequency was 50 MHz and -6 dB bandwidth was 90%. The average insertion loss was 19.5 dB at 50 MHz and the crosstalk between adjacent elements was about -35 dB. The micromachining techniques described in this paper are promising for the fabrication of other types of high frequency transducers, e.g. 1D and 2D arrays.

  17. Magnetoelectric properties of epitaxial Fe3O4 thin films on (011) PMN-PT piezosubstrates

    NASA Astrophysics Data System (ADS)

    Tkach, Alexander; Baghaie Yazdi, Mehrdad; Foerster, Michael; Büttner, Felix; Vafaee, Mehran; Fries, Maximilian; Kläui, Mathias

    2015-01-01

    We determine the magnetic and magnetotransport properties of 33 nm thick Fe3O4 films epitaxially deposited by rf-magnetron sputtering on unpoled (011) [PbMg1/3Nb2/3O3] 0.68-[PbTiO3]0.32 (PMN-PT) substrates. The magnetoresistance (MR), as well as the magnetization reversal, strongly depend on the in-plane crystallographic direction of the epitaxial (011) Fe3O4 film and strain. When the magnetic field is applied along [100], the magnetization loops are slanted and the sign of the longitudinal MR changes from positive to negative around the Verwey transition at 125 K on cooling. Along the [01 1 ¯] direction, the loops are square shaped and the MR is negative above the switching field across the whole temperature range, just increasing in absolute value when cooling from 300 K to 150 K. The value of the MR is found to be strongly affected by poling the PMN-PT substrate, decreasing in the [100] direction and slightly increasing in the [01 1 ¯] direction upon poling, which results in a strained film.

  18. Mechanical confinement for tuning ferroelectric response in PMN-PT single crystal

    NASA Astrophysics Data System (ADS)

    Patel, Satyanarayan; Chauhan, Aditya; Vaish, Rahul

    2015-02-01

    Ferroelectrics form an important class of materials and are employed for a variety of applications. However, specific applications dictate the need of tailored ferroelectric response. This creates a requirement to obtain ferroelectric materials with tunable properties. Generally, chemical modifications or domain engineering are employed to this effect. This study attempts to shed light on the use of compressive pre-stresses for tuning and enhancing the ferroelectric properties. For the purpose, polarization versus electric field hysteresis data for 68Pb(Mn1/3Nb2/3)O3-32PbTiO3 (PMN-PT) single crystals were obtained as a function of uniaxial compressive stresses and operating temperatures. These data were utilized to investigate the effects of mechanical confinement for four individual case studies of electrocaloric effect, electrical energy storage, pyroelectric, and piezoelectric effect. A significant improvement was obtained for all case studies. The adiabatic temperature change was improved by ≈80% (28 MPa, 353 K); energy storage density increased by a factor of five (28 MPa, 353 K); pyroelectric figure of merits improved by an order of magnitude (21 MPa) and the piezoelectric coefficient was tailored (variable stress). The results offer promising insight into the use of directional confinement for improving application specific ferroelectric properties in PMN-PT single crystal.

  19. Growth and piezo-/ferroelectric properties of PIN-PMN-PT single crystals

    NASA Astrophysics Data System (ADS)

    Li, Xiuzhi; Wang, Zujian; He, Chao; Long, Xifa; Ye, Zuo-Guang

    2012-02-01

    Ternary solid solution crystals of 0.19Pb(In1/2Nb1/2)O3- 0.46Pb(Mg1/3Nb2/3)O3- 0.35PbTiO3 [PIMNT(19/46/35)] with dimensions of 35 × 38 × 15 mm3 were grown by the top-seeded solution growth (TSSG) method. The dielectric, piezo- and ferroelectric properties of the grown crystals were characterized. The ternary piezocrystals exhibit a Curie temperature TC = 190 °C and a tetragonal-rhombohedral phase transition temperature TR-T = 130 °C, which are increased significantly compared with TC ≈ 155 °C and TR-T ≈ 80 °C of PMN-PT crystals. The dielectric constant (ɛ') and dielectric loss tangent (tan δ) are 4300 and 0.40 at room temperature. The piezoelectric coefficient d33 is found to be 2380 pC/N. The longitudinal electromechanical coupling factor k33 reaches 90% at room temperature. A peak-to-peak bipolar strain value of 0.13% is obtained at E ≈ ± 14 kV/cm. The coercive field Ec and remanent polarization Pr are 5.50 kV/cm and 27.10 μC/cm2, respectively, which are also improved from the vales of PMN-PT crystals.

  20. Links between worlds: Unraveling migratory connectivity

    USGS Publications Warehouse

    Webster, M.; Marra, P.P.; Haig, Susan M.; Bensch, S.; Holmes, Richard T.

    2002-01-01

    Migration is the regular seasonal movement of animals from one place to another, often from a breeding site to a nonbreeding site and back. Because the act of migration makes it difficult to follow individuals and populations year round, our understanding of the ecology and evolution of migrating organisms, particularly birds, has been severely impeded. Exciting new advances in satellite telemetry, genetic analyses and stable isotope chemistry are now making it possible to determine the population and geographical origin of individual birds. Here, we review these new approaches and consider the relevance of understanding migratory connectivity to ecological, evolutionary and conservation issues.

  1. [New migratory flows of the Brazilian population].

    PubMed

    Sales, T

    1991-01-01

    "This article focuses [on] the recent emigration of Brazilians abroad. In the post World War II period, a new type of international migration was observed, caused by demands for labor in the receiving countries, where immigrants are integrated into the secondary labor market. The programs created to stimulate temporary foreign migrations resulted in the recent illegal migrations of Brazilians, most of them working in unskilled jobs. The study is based on data from a preliminary survey on the migratory flow from the city of Governador Valadares in the State of Minas Gerais, to Boston, in the U.S." (SUMMARY IN ENG)

  2. Migratory connectivity of a Neotropical migratory songbird revealed by archival light-level geolocators.

    PubMed

    Hallworth, Michael T; Sillett, T Scott; Van Wilgenburg, Steven L; Hobson, Keith A; Marra, Peter P

    2015-03-01

    Understanding migratory connectivity is critical for interpreting population dynamics, seasonal interactions, and for the implementation of conservation strategies of migratory species. We evaluated the migratory connectivity of a Neotropical migratory songbird, the Ovenbird (Seiurus aurocapilla) using archival light-level geolocators deployed at two breeding and four nonbreeding locations while incorporating Ovenbird abundance as prior information using Bayes' Rule. We also included band recoveries submitted to the United States Geological Survey's Bird Banding Laboratory to assess connectivity of areas where geolocators were not deployed. We created a probabilistic map of origin for each capture site and mapped spring migration routes between nonbreeding and breeding locations. We found a complete separation of eastern and western populations of Ovenbirds throughout the annual cycle. Breeding Ovenbirds from western Canada spent the nonbreeding season throughout Central America and migrated through central North America during spring migration. Birds breeding in the northeastern United States were distributed throughout the central Greater Antilles in the Caribbean and migrated through eastern North America during spring migration. Fall migration routes were not included because the timing of migration coincided with fall equinox when latitudinal estimates are unreliable. However, longitudinal estimates suggest no overlap between eastern and western populations during fall migration. Ovenbirds with geolocators attached in Jamaica bred in the northeastern United States with the highest posterior probability of origin found in Massachusetts, while Ovenbirds captured in Florida and Puerto Rico bred primarily in the mid-Atlantic. Incorporating Ovenbird abundance as a prior into geolocator estimates decreased the area of origin by 90.37% ± 1.05% (mean ± SE) for the breeding season and 62.30% ± 1.69% for the nonbreeding season, compared to geolocator estimates alone

  3. Climate and the complexity of migratory phenology: sexes, migratory distance, and arrival distributions

    NASA Astrophysics Data System (ADS)

    Macmynowski, Dena P.; Root, Terry L.

    2007-05-01

    The intra- and inter-season complexity of bird migration has received limited attention in climatic change research. Our phenological analysis of 22 species collected in Chicago, USA, (1979 2002) evaluates the relationship between multi-scalar climate variables and differences (1) in arrival timing between sexes, (2) in arrival distributions among species, and (3) between spring and fall migration. The early migratory period for earliest arriving species (i.e., short-distance migrants) and earliest arriving individuals of a species (i.e., males) most frequently correlate with climate variables. Compared to long-distance migrant species, four times as many short-distance migrants correlate with spring temperature, while 8 of 11 (73%) of long-distance migrant species’ arrival is correlated with the North Atlantic Oscillation (NAO). While migratory phenology has been correlated with NAO in Europe, we believe that this is the first documentation of a significant association in North America. Geographically proximate conditions apparently influence migratory timing for short-distance migrants while continental-scale climate (e.g., NAO) seemingly influences the phenology of Neotropical migrants. The preponderance of climate correlations is with the early migratory period, not the median of arrival, suggesting that early spring conditions constrain the onset or rate of migration for some species. The seasonal arrival distribution provides considerable information about migratory passage beyond what is apparent from statistical analyses of phenology. A relationship between climate and fall phenology is not detected at this location. Analysis of the within-season complexity of migration, including multiple metrics of arrival, is essential to detect species’ responses to changing climate as well as evaluate the underlying biological mechanisms.

  4. Climate and the complexity of migratory phenology: sexes, migratory distance, and arrival distributions.

    PubMed

    MacMynowski, Dena P; Root, Terry L

    2007-05-01

    The intra- and inter-season complexity of bird migration has received limited attention in climatic change research. Our phenological analysis of 22 species collected in Chicago, USA, (1979-2002) evaluates the relationship between multi-scalar climate variables and differences (1) in arrival timing between sexes, (2) in arrival distributions among species, and (3) between spring and fall migration. The early migratory period for earliest arriving species (i.e., short-distance migrants) and earliest arriving individuals of a species (i.e., males) most frequently correlate with climate variables. Compared to long-distance migrant species, four times as many short-distance migrants correlate with spring temperature, while 8 of 11 (73%) of long-distance migrant species' arrival is correlated with the North Atlantic Oscillation (NAO). While migratory phenology has been correlated with NAO in Europe, we believe that this is the first documentation of a significant association in North America. Geographically proximate conditions apparently influence migratory timing for short-distance migrants while continental-scale climate (e.g., NAO) seemingly influences the phenology of Neotropical migrants. The preponderance of climate correlations is with the early migratory period, not the median of arrival, suggesting that early spring conditions constrain the onset or rate of migration for some species. The seasonal arrival distribution provides considerable information about migratory passage beyond what is apparent from statistical analyses of phenology. A relationship between climate and fall phenology is not detected at this location. Analysis of the within-season complexity of migration, including multiple metrics of arrival, is essential to detect species' responses to changing climate as well as evaluate the underlying biological mechanisms.

  5. Electrical switching of the magnetic vortex circulation in artificial multiferroic structure of Co/Cu/PMN-PT(011)

    NASA Astrophysics Data System (ADS)

    Li, Q.; Tan, A.; Scholl, A.; Young, A. T.; Yang, M.; Hwang, C.; N'Diaye, A. T.; Arenholz, E.; Li, J.; Qiu, Z. Q.

    2017-06-01

    Co films and micron sized disks were grown on top of piezoelectric PMN-PT(011) and Cu/PMN-PT(001) substrates and investigated by the Magneto-Optic Kerr Effect and Photoemission Electron Microscopy. By applying an electric field in the surface normal direction, we find that the strain of the ferroelectric PMN-PT(011) substrate induces an in-plane uniaxial magnetic anisotropy in the Co overlayer. Under specific conditions, the Co magnetic vortex could be switched between clockwise and counter-clockwise circulations. The variations of the Co vortex switching were attributed to the variations of the ferroelectric domains under the Co disks. We speculate that the switching of the magnetic vortex circulation is a dynamical process which may involve pulses of appropriate magnitude and duration of the uniaxial magnetic anisotropy delivered to the magnetic vortex.

  6. Thermal-independent properties of PIN-PMN-PT single-crystal linear-array ultrasonic transducers.

    PubMed

    Chen, Ruimin; Wu, Jinchuan; Ho Lam, Kwok; Yao, Liheng; Zhou, Qifa; Tian, Jian; Han, Pengdi; Shung, K Kirk

    2012-12-01

    In this paper, low-frequency 32-element linear-array ultrasonic transducers were designed and fabricated using both ternary Pb(In(1/2)Nb(1/2))-Pb(Mg(1/3)Nb(2/3))-PbTiO(3) (PIN-PMN-PT) and binary Pb(Mg(1/3)Nb(2/3))-PbTiO(3) (PMNPT) single crystals. Performance of the array transducers was characterized as a function of temperature ranging from room temperature to 160°C. It was found that the array transducers fabricated using the PIN-PMN-PT single crystal were capable of satisfactory performance at 160°C, having a -6-dB bandwidth of 66% and an insertion loss of 37 dB. The results suggest that the potential of PIN-PMN-PT linear-array ultrasonic transducers for high-temperature ultrasonic transducer applications is promising.

  7. Sensory neuropathy in progressive motor neuronopathy (pmn) mice is associated with defects in microtubule polymerization and axonal transport.

    PubMed

    Schäfer, Michael K; Bellouze, Sarah; Jacquier, Arnaud; Schaller, Sébastien; Richard, Laurence; Mathis, Stéphane; Vallat, Jean-Michel; Haase, Georg

    2016-08-04

    Motor neuron diseases such as amyotrophic lateral sclerosis (ALS) are now recognized as multi-system disorders also involving various non-motor neuronal cell types. The precise extent and mechanistic basis of non-motor neuron damage in human ALS and ALS animal models remain however unclear. To address this, we here studied progressive motor neuronopathy (pmn) mice carrying a missense loss-of-function mutation in tubulin binding cofactor E (TBCE). These mice manifest a particularly aggressive form of motor axon dying back and display a microtubule loss, similar to that induced by human ALS-linked TUBA4A mutations. Using whole nerve confocal imaging of pmn × thy1.2-YFP16 fluorescent reporter mice and electron microscopy, we demonstrate axonal discontinuities, bead-like spheroids and ovoids in pmn suralis nerves indicating prominent sensory neuropathy. The axonal alterations qualitatively resemble those in phrenic motor nerves but do not culminate in the loss of myelinated fibers. We further show that the pmn mutation decreases the level of TBCE, impedes microtubule polymerization in dorsal root ganglion (DRG) neurons and causes progressive loss of microtubules in large and small caliber suralis axons. Live imaging of axonal transport using GFP-tagged tetanus toxin C-fragment (GFP-TTC) demonstrates defects in microtubule-based transport in pmn DRG neurons, providing a potential explanation for the axonal alterations in sensory nerves. This study unravels sensory neuropathy as a pathological feature of mouse pmn, and discusses the potential contribution of cytoskeletal defects to sensory neuropathy in human motor neuron disease.

  8. Limitations and mechanisms influencing the migratory performance of soaring birds

    Treesearch

    Tricia A. Miller; Brooks Robert P.; Michael J. Lanzone; David Brandes; Jeff Cooper; Junior A. Tremblay; Jay Wilhelm; Adam Duerr; Todd E. Katzner

    2016-01-01

    Migration is costly in terms of time, energy and safety. Optimal migration theory suggests that individual migratory birds will choose between these three costs depending on their motivation and available resources. To test hypotheses about use of migratory strategies by large soaring birds, we used GPS telemetry to track 18 adult, 13 sub-adult and 15 juvenile Golden...

  9. The Migratory Farm Labor Problem in the United States.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on Labor and Public Welfare.

    Migratory farm workers employed in 688 countries in 46 states in 1965 represent a 9 percent increase over 1964. Average earnings for the migratory farm worker in 1965 were $1,737. In spite of the new legislation, which is described, there are additional needs in the areas of wages, child labor, health, education, day care, housing, sanitation, and…

  10. REPORT TO THE PRESIDENT ON DOMESTIC MIGRATORY FARM LABOR.

    ERIC Educational Resources Information Center

    MITCHELL, JAMES P.

    THE OBJECTIVES OF THE PRESIDENT'S COMMITTEE ON MIGRATORY LABOR ARE TO BRING ABOUT IMPROVED CONDITIONS FOR MIGRATORY WORKERS TO MIGRATE BY STABILIZING AGRICULTURAL EMPLOYMENT. EFFORTS HAVE BEEN DIRECTED TOWARD RESOLVING PROBLEMS OF CAMP HOUSING, SAFE TRANSPORTATION, ADEQUATE EDUCATION AND HEALTH SERVICES, EXTENSION OF LABOR LAWS TO AGRICULTURAL…

  11. 76 FR 67650 - Migratory Bird Permits; Abatement Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-02

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AW75 Migratory Bird Permits; Abatement Regulations... and suggestions on migratory bird permit regulations for a permit to use raptors (birds of prey) in abatement activities. Abatement means the use of trained raptors to flush, scare (haze), or take birds or...

  12. 76 FR 39368 - Migratory Bird Permits; Abatement Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AW75 Migratory Bird Permits; Abatement Regulations... are considering promulgating migratory bird permit regulations for a permit to use raptors (birds of... take birds or other wildlife to mitigate damage or other problems, including risks to human health and...

  13. Totipotent migratory stem cells in a hydroid.

    PubMed

    Müller, Werner A; Teo, Regina; Frank, Uri

    2004-11-01

    Hydroids, members of the most ancient eumetazoan phylum, the Cnidaria, harbor multipotent, migratory stem cells lodged in interstitial spaces of epithelial cells and are therefore referred to as interstitial cells or i-cells. According to traditional understanding, based on studies in Hydra, these i-cells give rise to several cell types such as stinging cells, nerve cells, and germ cells, but not to ectodermal and endodermal epithelial cells; these are considered to constitute separate cell lineages. We show here that, in Hydractinia, the developmental potential of these migratory stem cells is wider than previously anticipated. We eliminated the i-cells from subcloned wild-type animals and subsequently introduced i-cells from mutant clones and vice versa. The mutant donors and the wild-type recipients differed in their sex, growth pattern, and morphology. With time, the recipient underwent a complete conversion into the phenotype and genotype of the donor. Thus, under these experimental conditions the interstitial stem cells of Hydractinia exhibit totipotency.

  14. 75 FR 53226 - Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ..., or from the Division of Migratory Bird Management's Web site at http://www.fws.gov/migratorybirds/ or...: Robert Blohm, Chief, or Ron W. Kokel, Division of Migratory Bird Management, U.S. Fish and Wildlife.... Executive Order 12866 The Office of Management and Budget has determined that this rule is significant...

  15. Current selection for lower migratory activity will drive the evolution of residency in a migratory bird population

    PubMed Central

    Pulido, Francisco; Berthold, Peter

    2010-01-01

    Global warming is impacting biodiversity by altering the distribution, abundance, and phenology of a wide range of animal and plant species. One of the best documented responses to recent climate change is alterations in the migratory behavior of birds, but the mechanisms underlying these phenotypic adjustments are largely unknown. This knowledge is still crucial to predict whether populations of migratory birds will adapt to a rapid increase in temperature. We monitored migratory behavior in a population of blackcaps (Sylvia atricapilla) to test for evolutionary responses to recent climate change. Using a common garden experiment in time and captive breeding we demonstrated a genetic reduction in migratory activity and evolutionary change in phenotypic plasticity of migration onset. An artificial selection experiment further revealed that residency will rapidly evolve in completely migratory bird populations if selection for shorter migration distance persists. Our findings suggest that current alterations of the environment are favoring birds wintering closer to the breeding grounds and that populations of migratory birds have strongly responded to these changes in selection. The reduction of migratory activity is probably an important evolutionary process in the adaptation of migratory birds to climate change, because it reduces migration costs and facilitates the rapid adjustment to the shifts in the timing of food availability during reproduction. PMID:20368446

  16. 77 FR 58627 - Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ... Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds; Final Rule...; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds AGENCY: Fish and Wildlife..., and daily bag and possession limits for general waterfowl seasons and those early seasons for which...

  17. 78 FR 58204 - Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-23

    ... Possession Limits for Certain Migratory Game Birds AGENCY: Fish and Wildlife Service, Interior. ACTION: Final... limits for general waterfowl seasons and those early seasons for which States previously deferred... the migratory bird hunting regulations process, and addressed the establishment of seasons, limits...

  18. 75 FR 58993 - Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-24

    ... Possession Limits for Certain Migratory Game Birds; Final Rule #0;#0;Federal Register / Vol. 75 , No. 185... Service 50 CFR Part 20 RIN 1018-AX06 Migratory Bird Hunting; Late Seasons and Bag and Possession Limits.... SUMMARY: This rule prescribes the hunting seasons, hours, areas, and daily bag and possession limits for...

  19. The Parkes-MIT-NRAO (PMN) survey of the southern sky

    NASA Astrophysics Data System (ADS)

    Griffith, Mark Robert

    1993-01-01

    We describe a radio survey covering the sky from -87.5 deg to +10 deg declination made using the Parkes 64 m radio telescope with the NRAO multi-beam receiver at a frequency of 4850 MHz during 1990. We have fully reduced the data from the Southern Survey (-87.5 deg is less than delta is less than -37 deg) and Tropical Survey (-29 deg is less than delta is less than -9.5 deg). Together, these surveys cover 4.51 sr and contain 36,640 sources to a flux limit that is, typically, about 35 mJy but varies as a function of declination. In this thesis, we describe the overall PMN Survey, including equipment, observations, and the data reduction techniques adopted. We assess the quality of the source list resulting from the Southern and Tropical Surveys by estimating the completeness and reliability. We analyze the resulting source list for clustering on three distinct distance scales. We examine the extent of the Galactic plane in the radio and show that the 'rule of thumb' value of +/- 10 deg Galactic latitude is appropriate, but conservative. We also show that the distribution of sources in Galactic longitude is consistent with previous work. We check for clustering of radio sources toward the super-galactic plane and find no significant clustering. We analyze the data for large scale structure and show that our weighted differential source counts are consistent with the Northern Hemisphere counts. We use the 2-point angular correlation function to show that there is no significant large scale clustering of sources in the PMN Survey. We construct luminosity and visibility functions from a comparison of our data with an IRAS sample of galaxies and from other data. We use these luminosity functions along with the radio 2-point spatial correlation function to predict the angular correlation function. We determine which luminosity functions are consistent with our data. We use the luminosity and visibility functions to predict statistically the composition of the PMN Survey

  20. Unique role for ATG5 in PMN-mediated immunopathology during M. tuberculosis infection

    PubMed Central

    Kimmey, Jacqueline M.; Huynh, Jeremy P.; Weiss, Leslie A.; Park, Sunmin; Kambal, Amal; Debnath, Jayanta; Virgin, Herbert W.; Stallings, Christina L.

    2015-01-01

    Summary Paragraph Mycobacterium tuberculosis (Mtb), a major global health threat, replicates in macrophages (MΦ) in part by inhibiting phagosome-lysosome fusion, until IFN-γ activates the MΦ to traffic Mtb to the lysosome. How IFN-γ elicits this effect is unknown, but many studies suggest a role for macroautophagy (autophagy herein), a cellular process by which cytoplasmic contents are sequestered into an autophagosome and targeted for lysosomal degradation1. The involvement of autophagy has been defined based on studies in cultured MΦ or dendritic cells (DC) where Mtb colocalizes with autophagy (ATG) factors ATG5, ATG12, ATG16L1, p62, NDP52, Beclin1 and LC32–6, stimulation of autophagy increases bacterial killing6–8, and inhibition of autophagy allows for increased bacterial survival1,2,4,6,7. Notably, these studies reveal modest (e.g. 1.5- to 3-fold change) effects on Mtb replication. In contrast, Atg5fl/fl-LysM-Cre mice lacking ATG5 in monocyte-derived cells and neutrophils (polymorphic mononuclear cells, PMN) succumb to Mtb within 30 days4,9, an extremely severe phenotype similar to mice lacking IFN-γ signaling10,11. Importantly, ATG5 is the only ATG factor that has been studied during Mtb infection in vivo and autophagy-independent functions of ATG5 have been described12–18. For this reason, we used a genetic approach to elucidate the role for multiple ATG genes and the requirement for autophagy in resistance to Mtb infection in vivo. We have discovered that, contrary to expectation, autophagic capacity does not correlate with the outcome of Mtb infection. Instead, ATG5 plays a unique role in protection against Mtb by preventing PMN-mediated immunopathology. Furthermore, while ATG5 is dispensable in alveolar MΦ during Mtb infection, loss of Atg5 in PMN can sensitize mice to Mtb. These findings shift our understanding of the role of ATG5 during Mtb infection, reveal a new outcome of ATG5 activity, and shed light on early events in innate immunity

  1. EGF receptor-dependent mechanism may be involved in the Tamm-Horsfall glycoprotein-enhanced PMN phagocytosis via activating Rho family and MAPK signaling pathway.

    PubMed

    Li, Ko-Jen; Siao, Sue-Cien; Wu, Cheng-Han; Shen, Chieh-Yu; Wu, Tsai-Hung; Tsai, Chang-Youh; Hsieh, Song-Chou; Yu, Chia-Li

    2014-01-21

    Our previous studies showed that urinary Tamm-Horsfall glycoprotein (THP) potently enhanced polymorphonuclear neutrophil (PMN) phagocytosis. However, the domain structure(s), signaling pathway and the intracellular events responsible for THP-enhanced PMN phagocytosis remain to be elucidated. THP was purified from normal human urine. The human promyelocytic leukemia cell line HL-60 was induced to differentiate into PMNs by all-trans retinoid acid. Pretreatment with different MAPK and PI3K inhibitors was used to delineate signaling pathways in THP-enhanced PMN phagocytosis. Phosphorylation of molecules responsible for PMN phagocytosis induced by bacterial lipopolysaccharide (LPS), THP, or human recombinant epidermal growth factor (EGF) was evaluated by western blot. A p38 MAPK inhibitor, SB203580, effectively inhibited both spontaneous and LPS- and THP-induced PMN phagocytosis. Both THP and LPS enhanced the expression of the Rho family proteins Cdc42 and Rac that may lead to F-actin re-arrangement. Further studies suggested that THP and EGF enhance PMN and differentiated HL-60 cell phagocytosis in a similar pattern. Furthermore, the EGF receptor inhibitor GW2974 significantly suppressed THP- and EGF-enhanced PMN phagocytosis and p38 and ERK1/2 phosphorylation in differentiated HL-60 cells. We conclude that EGF receptor-dependent signaling may be involved in THP-enhanced PMN phagocytosis by activating Rho family and MAP kinase.

  2. Integration, electrical, and electromechanical properties of PZT and PMN-PT thin films for MEMS applications

    NASA Astrophysics Data System (ADS)

    Kuegeler, Carsten; Hoffmann, Marcus; Boettger, Ulrich; Waser, Rainer

    2002-07-01

    Piezoelectric and electrostrictive thin films are potential candidates for actuator functions in micro-electro-mechanical systems (MEMS) offering displacements and forces which outperform standard solutions, e.g. in micro mirrors and micro relays. Within this context the paper reports on the preparation and the integration processes of chemical solution deposited (CSD) PZT and PMN-PT thin films in combination with silicon bulk micro machining technique. The operativeness of the processes is demonstrated by the development of an integrated micro actuator for a micro switch application. Furthermore, the work deals also with the characterization of the integrated materials. For fabrication control and electrical characterizations microscopy, SEM, hysteresis- and CV-, and degradation measurements were performed. Laser interferometry and resonance frequency measurements were used to characterize the electromechanical performance of both materials in comparison to the behavior of the developed micro actuator.

  3. PMN-PT single crystal focusing transducer fabricated using a mechanical dimpling technique.

    PubMed

    Lam, K H; Chen, Y; Cheung, K F; Dai, J Y

    2012-01-01

    A ∼5MHz focusing PMN-PT single crystal ultrasound transducer has been fabricated utilizing a mechanical dimpling technique, where the dimpled crystal wafer was used as an active element of the focusing transducer. For the dimpled focusing transducer, the effective electromechanical coupling coefficient was enhanced significantly from 0.42 to 0.56. The dimpled transducer also yields a -6dB bandwidth of 63.5% which is almost double the bandwidth of the plane transducer. An insertion loss of the dimpled transducer (-18.1dB) is much lower than that of the plane transducer. Finite element simulation also reveals specific focused beam from concave crystal surface. These promising results show that the dimpling technique can be used to develop high-resolution focusing single crystal transducers.

  4. High frequency PMN-PT single crystal focusing transducer fabricated by a mechanical dimpling technique.

    PubMed

    Chen, Y; Lam, K H; Zhou, D; Cheng, W F; Dai, J Y; Luo, H S; Chan, H L W

    2013-02-01

    High frequency (∼30MHz and ∼80MHz) focusing ultrasound transducers were fabricated using a PMN-0.28PT single crystal by a mechanical dimpling technique. The dimpled single crystal was used as an active element for the focusing transducer. Compared with a plane transducer, the focusing transducer fabricated with a dimpled active element exhibits much broader bandwidth and higher sensitivity. Besides, a high quality image can be obtained by the 30MHz focusing transducer, in which the -6dB axial and lateral resolution is 27μm and 139μm, respectively. These results prove that the dimpling technique is capable to fabricate the high frequency focusing transducers with excellent performance for imaging applications.

  5. Giant isothermal entropy change In (111)-oriented PMN-PT thin film

    NASA Astrophysics Data System (ADS)

    Hamad, Mahmoud A.

    2014-11-01

    An isothermal entropy change of 240 nm (111)-oriented PMN-PT 65/35 film near the ferroelectric Curie temperature, relative cooling power (RCP) and change of heat capacity have been investigated. The extracted data characterized giant isothermal entropy change of more than 16 J/kg K in electric field shift ΔE of 455 kV cm-1, which is nearly twice than that found for PbZr0.95Ti0.05O3 thin film at 492 kV cm-1 near the Curie point. Furthermore, the RCP ≈ 700 J/kg and change of heat capacity ≈ 233 J/kg K in electric field shift ΔE of 747 kV cm-1.

  6. Design and Characterization of an Ultrasonic Surgical Tool Using d31 PMN-PT Plate

    NASA Astrophysics Data System (ADS)

    Kuang, Y.; Sadiq, M.; Cochran, S.; Huang, Z.

    An ultrasonic surgical tool for tissue incision and dissection has been designed and characterized. The surgical tool is based on a simple geometry to which PMN-PT d31 plates are bonded directly. The performance of the surgical tool has been defined numerically with the Abaqus finite element analysis (FEA) package and practically with laser vibrometer and impedance spectroscopy. The results show the ability of FEA to accurately predict the behaviors of an ultrasonic device as numerical and practical analysis were found to be in a good agreement. The design of the tool presented has the ability to generate displacement amplitude high enough to carry out soft tissue incision with relatively low driving voltage.

  7. Blocking force of a piezoelectric stack actuator made of single crystal layers (PMN-29PT)

    NASA Astrophysics Data System (ADS)

    Tran, K. S.; Phan, H. V.; Lee, H. Y.; Kim, Yongdae; Park, H. C.

    2016-09-01

    In this study, we fabricated and characterized a stack actuator made of forty layers of 1 mm thick PMN-29PT with a cross-sectional area of 10 × 10 mm2. From the measurement of actuation displacement, we confirmed that the piezoelectric strain constant in the direction of thickness of the material is 2000 pm V-1, as suggested by the manufacturer. The blocking forces of the actuator are measured to be 230 N, 369 N, and 478 N for 100 V, 200 V, and 300 V, respectively. The measured blocking forces showed large discrepancies from the estimated blocking forces calculated using linear models, especially for a high voltage application. An empirical equation acquired by fitting the measured blocking forces indicates that the blocking force has a nonlinear relationship with the applied voltage. The measured hysteresis showed a slight nonlinear voltage-stroke relationship and small energy loss.

  8. The Flight Apparatus of Migratory and Sedentary Individuals of a Partially Migratory Songbird Species

    PubMed Central

    Fudickar, Adam M.; Partecke, Jesko

    2012-01-01

    Variations in the geometry of the external flight apparatus of birds are beneficial for different behaviors. Long-distance flight is less costly with more pointed wings and shorter tails; however these traits decrease maneuverability at low speeds. Selection has led to interspecific differences in these and other flight apparatuses in relation to migration distance. If these principles are general, how are the external flight apparatus within a partially migratory bird species shaped in which individuals either migrate or stay at their breeding grounds? We resolved this question by comparing the wing pointedness and tail length (relative to wing length) of migrant and resident European blackbirds (Turdus merula) breeding in the same population. We predicted that migrant blackbirds would have more pointed wings and shorter tails than residents. Contrary to our predictions, there were no differences between migrants and residents in either measure. Our results indicate that morphological differences between migrants and residents in this partially migratory population may be constrained. PMID:23284817

  9. Neurotensin Modulates the Migratory and Inflammatory Response of Macrophages under Hyperglycemic Conditions

    PubMed Central

    Moura, Liane I. F.; Silva, Lucília; Leal, Ermelindo C.; Tellechea, Ana; Cruz, Maria Teresa; Carvalho, Eugénia

    2013-01-01

    Diabetic foot ulcers (DFUs) are characterized by an unsatisfactory inflammatory and migratory response. Skin inflammation involves the participation of many cells and particularly macrophages. Macrophage function can be modulated by neuropeptides; however, little is known regarding the role of neurotensin (NT) as a modulator of macrophages under inflammatory and hyperglycemic conditions. RAW 264.7 cells were maintained at 10/30 mM glucose, stimulated with/without LPS (1 μg/mL), and treated with/without NT(10 nM). The results show that NT did not affect macrophage viability. However, NT reverted the hyperglycemia-induced impair in the migration of macrophages. The expression of IL-6 and IL-1β was significantly increased under 10 mM glucose in the presence of NT, while IL-1β and IL-12 expression significantly decreased under inflammatory and hyperglycemic conditions. More importantly, high glucose modulates NT and NT receptor expression under normal and inflammatory conditions. These results highlight the effect of NT on cell migration, which is strongly impaired under hyperglycemic conditions, as well as its effect in decreasing the proinflammatory status of macrophages under hyperglycemic and inflammatory conditions. These findings provide new insights into the potential therapeutic role of NT in chronic wounds, such as in DFU, characterized by a deficit in the migratory properties of cells and a chronic proinflammatory status. PMID:24000330

  10. Role of membrane depolarization and extracellular calcium in increased complement receptor expression during neutrophil (PMN) activation

    SciTech Connect

    Berger, M.; Wetzler, E.; Birx, D.L.

    1986-03-05

    During PMN activation the surface expression of receptors (R) for C3b and C3bi increases rapidly. This is necessary for optimal cell adhesion, migration, and phagocytosis. Following stimulation with fMLP or LTB-4, the increased expression of C3bR depends only on the Ca/sup + +/ released from intracellular stores and is not inhibited by 5mM EDTA, while the increase in C3biR also requires extracellular Ca/sup + +/. CR expression also increases when the PMN are depolarized with 140 mM K/sup +/, but with this stimulus, EDTA inhibits C3bR by 67% and C3biR 100%, suggesting that intracellular Ca/sup + +/ stores may not be released. Pertussis toxin caused dose-dependent inhibition of both CR responses to fMLP and also inhibited the increases in both CR induced by K/sup +/. Membrane depolarization (monitored by di-O-C5 fluorescence) due to fMLP was similarly inhibited by toxin but the depolarization due to K/sup +/ was not. The dose of phorbol myristate acetate that maximally increased CR expression, 0.1 ng/ml, did not depolarize the membrane. These results suggest that membrane depolarization is neither necessary nor sufficient for increased CR expression. A Ca/sup + +/ and GTP binding protein-dependent enzyme such as phospholipase C is necessary to the amplify initial signals generated either by release of Ca/sup + +/ stores or by opening voltage dependent Ca/sup + +/ channels following membrane depolarization.

  11. Field stability of piezoelectric shear properties in PIN-PMN-PT crystals under large drive field.

    PubMed

    Zhang, Shujun; Li, Fei; Luo, Jun; Xia, Ru; Hackenberger, Wesley; Shrout, Thomas

    2011-02-01

    The coercive fields (E(C)) of Pb(In₀.₅Nb₀.₅)O₃-Pb(Mg(¹/₃)Nb(²/₃)O₃-PbTiO₃ (PIN-PMN-PT) ternary single crystals were found to be 5 kV/cm, double the value of binary Pb(Mg(¹/₃)Nb(²/₃)O₃-PbTiO₃ (PMNT) crystals, further increased to 6 to 9 kV/cm using Mn modifications. In addition to an increased EC, the acceptor modification resulted in the developed internal bias (E(int)), on the order of ~1 kV/cm. The piezoelectric shear properties of unmodified and Mn-modified PIN-PMN-PT crystals with various domain configurations were investigated. The shear piezoelectric coefficients and electromechanical coupling factors for different domain configurations were found to be >2000 pC/N and >0.85, respectively, with slightly reduced properties observed in Mn-modified tetragonal crystals. Fatigue/cycling tests performed on shearmode samples as a function of ac drive field level demonstrated that the allowable ac field levels (the maximum applied ac field before the occurrence of depolarization) were only ~2 kV/cm for unmodified crystals, less than half of their coercive field. Allowable ac drive levels were on the order of 4 to 6 kV/cm for Mn-modified crystals with rhombohedral/orthorhombic phase, further increased to 5 to 8 kV/cm in tetragonal crystals, because of their higher coercive fields. It is of particular interest that the allowable ac drive field level for Mn-modified crystals was found to be ≥ 60% of their coercive fields, because of the developed E(int), induced by the acceptor-oxygen vacancy defect dipoles.

  12. Measurements along the growth direction of PMN-PT crystals: dielectric, piezoelectric, and elastic properties.

    PubMed

    Tian, Jian; Han, Pengdi; Payne, David A

    2007-09-01

    Property measurements are reported for Pb(Mg1/3Nb2/3)03-PbTiO3 (PMN-PT) single crystals grown along (001) by a seeded-melt method. Chemical segregation occurs during crystal growth, leading to property changes along the growth direction. Variations in dielectric, piezoelectric, and elastic properties were evaluated for specimens selected from the crystals. Room-temperature data are correlated with Tc and composition that ranged from 27 to 32% PT, i.e., in the vicinity of the morphotropic phase boundary (MPB). While there was little change in the high electromechanical coupling factor k33 (0.87-0.92), both the piezoelectric charge coefficient d33 (1100-1800 pC/N) and the free dielectric constant K3 (4400-7000) were found to vary significantly with position. Increases in d33 and KT33 were relatively offsetting in that the ratio yielded a relatively stable piezoelectric voltage coefficient g33 (27-31 x 10(-3) Vm/N). Values are also reported for the elastic compliance (3.3-6.3 x 10(-11) m2/N) determined from resonance measurements. Enhancements in d33 and K(T)33 were associated with lattice softening (increasing sE33) as the composition approached the MPB. Details are reported for the piezoelectric, dielectric, and elastic properties as a function of growth direction, Tc, and composition. The results are useful for an understanding of properties in PMN-PT crystals and for the design of piezoelectric devices.

  13. Field Stability of Piezoelectric Shear Properties in PIN-PMN-PT Crystals Under Large Drive Field

    PubMed Central

    Zhang, Shujun; Li, Fei; Luo, Jun; Xia, Ru; Hackenberger, Wesley; Shrout, Thomas R.

    2013-01-01

    The coercive fields (EC) of Pb(In0.5Nb0.5)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) ternary single crystals were found to be 5 kV/cm, double the value of binary Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMNT) crystals, further increased to 6 to 9 kV/cm using Mn modifications. In addition to an increased EC, the acceptor modification resulted in the developed internal bias (Eint), on the order of ~1 kV/cm. The piezoelectric shear properties of unmodified and Mn-modified PIN-PMN-PT crystals with various domain configurations were investigated. The shear piezoelectric coefficients and electromechanical coupling factors for different domain configurations were found to be >2000 pC/N and >0.85, respectively, with slightly reduced properties observed in Mn-modified tetragonal crystals. Fatigue/cycling tests performed on shear-mode samples as a function of ac drive field level demonstrated that the allowable ac field levels (the maximum applied ac field before the occurrence of depolarization) were only ~2 kV/cm for unmodified crystals, less than half of their coercive field. Allowable ac drive levels were on the order of 4 to 6 kV/cm for Mn-modified crystals with rhombohedral/orthorhombic phase, further increased to 5 to 8 kV/cm in tetragonal crystals, because of their higher coercive fields. It is of particular interest that the allowable ac drive field level for Mn-modified crystals was found to be ≥60% of their coercive fields, because of the developed Eint, induced by the acceptor-oxygen vacancy defect dipoles. PMID:21342812

  14. Neuronal migration in the murine rostral migratory stream requires serum response factor

    PubMed Central

    Alberti, Siegfried; Krause, Sven M.; Kretz, Oliver; Philippar, Ulrike; Lemberger, Thomas; Casanova, Emilio; Wiebel, Franziska F.; Schwarz, Heinz; Frotscher, Michael; Schütz, Günther; Nordheim, Alfred

    2005-01-01

    The central nervous system is fundamentally dependent on guided cell migration, both during development and in adulthood. We report an absolute requirement of the transcription factor serum response factor (SRF) for neuronal migration in the mouse forebrain. Conditional, late-prenatal deletion of Srf causes neurons to accumulate ectopically at the subventricular zone (SVZ), a prime neurogenic region in the brain. SRF-deficient cells of the SVZ exhibit impaired tangential chain migration along the rostral migratory stream into the olfactory bulb. SVZ explants display retarded chain migration in vitro. Regarding target genes, SRF deficiency impairs expression of the β-actin and gelsolin genes, accompanied by reduced cytoskeletal actin fiber density. At the posttranslational level, cofilin, a key regulator of actin dynamics, displays dramatically elevated inhibitory phosphorylation at Ser-3. Our studies indicate that SRF-controlled gene expression directs both the structure and dynamics of the actin microfilament, thereby determining cell-autonomous neuronal migration. PMID:15837932

  15. 77 FR 58443 - Migratory Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ...The Fish and Wildlife Service (Service or we) prescribes final late-season frameworks from which States may select season dates, limits, and other options for the 2012-13 migratory bird hunting seasons. These late seasons include most waterfowl seasons, the earliest of which commences on September 22, 2012. The effect of this final rule is to facilitate the States' selection of hunting seasons......

  16. 78 FR 52337 - Migratory Bird Hunting; Proposed Frameworks for Late-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-22

    ...The Fish and Wildlife Service (hereinafter Service or we) is proposing to establish the 2013-14 late-season hunting regulations for certain migratory game birds. We annually prescribe frameworks, or outer limits, for dates and times when hunting may occur and the number of birds that may be taken and possessed in late seasons. These frameworks are necessary to allow State selections of seasons......

  17. 75 FR 58249 - Migratory Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ...The Fish and Wildlife Service (Service or we) prescribes final late-season frameworks from which States may select season dates, limits, and other options for the 2010-11 migratory bird hunting seasons. These late seasons include most waterfowl seasons, the earliest of which commences on September 25, 2010. The effect of this final rule is to facilitate the States' selection of hunting seasons......

  18. 77 FR 53117 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-30

    ...This rule prescribes final early-season frameworks from which the States, Puerto Rico, and the Virgin Islands may select season dates, limits, and other options for the 2012-13 migratory bird hunting seasons. Early seasons are those that generally open prior to October 1, and include seasons in Alaska, Hawaii, Puerto Rico, and the Virgin Islands. The effect of this final rule is to facilitate......

  19. 78 FR 52657 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-23

    ...This rule prescribes final early-season frameworks from which the States, Puerto Rico, and the Virgin Islands may select season dates, limits, and other options for the 2013-14 migratory bird hunting seasons. Early seasons are those that generally open prior to October 1, and include seasons in Alaska, Hawaii, Puerto Rico, and the Virgin Islands. The effect of this final rule is to facilitate......

  20. 77 FR 42919 - Migratory Bird Hunting; Proposed Frameworks for Early-Season Migratory Bird Hunting Regulations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    ...The U.S. Fish and Wildlife Service (hereinafter Service or we) is proposing to establish the 2012-13 early-season hunting regulations for certain migratory game birds. We annually prescribe frameworks, or outer limits, for dates and times when hunting may occur and the maximum number of birds that may be taken and possessed in early seasons. Early seasons may open as early as September 1, and......

  1. Thermal-Independent Properties of PIN-PMN-PT Single-Crystal Linear-Array Ultrasonic Transducers

    PubMed Central

    Chen, Ruimin; Wu, Jinchuan; Lam, Kwok Ho; Yao, Liheng; Zhou, Qifa; Tian, Jian; Han, Pengdi; Shung, K. Kirk

    2013-01-01

    In this paper, low-frequency 32-element linear-array ultrasonic transducers were designed and fabricated using both ternary Pb(In1/2Nb1/2)–Pb(Mg1/3Nb2/3)–PbTiO3 (PIN-PMN-PT) and binary Pb(Mg1/3Nb2/3)–PbTiO3 (PMN-PT) single crystals. Performance of the array transducers was characterized as a function of temperature ranging from room temperature to 160°C. It was found that the array transducers fabricated using the PIN-PMN-PT single crystal were capable of satisfactory performance at 160°C, having a −6-dB bandwidth of 66% and an insertion loss of 37 dB. The results suggest that the potential of PIN-PMN-PT linear-array ultrasonic transducers for high-temperature ultrasonic transducer applications is promising. PMID:23221227

  2. Neutrophil (PMN) surface contact with keratocytes following corneal epithelial abrasion in the mouse: a novel role for ICAM-1

    USDA-ARS?s Scientific Manuscript database

    Corneal epithelial abrasion is associated with an inflammatory response that involves PMN recruitment from the limbal vessels into the corneal stroma. Previously, in the injured mouse cornea, we showed that migrating PMNs not only make contact with collagen, but they also make extensive surface cont...

  3. Migratory double breeding in Neotropical migrant birds

    PubMed Central

    Rohwer, Sievert; Hobson, Keith A.; Rohwer, Vanya G.

    2009-01-01

    Neotropical migratory songbirds typically breed in temperate regions and then travel long distances to spend the majority of the annual cycle in tropical wintering areas. Using stable-isotope methodology, we provide quantitative evidence of dual breeding ranges for 5 species of Neotropical migrants. Each is well known to have a Neotropical winter range and a breeding range in the United States and Canada. However, after their first bout of breeding in the north, many individuals migrate hundreds to thousands of kilometers south in midsummer to breed a second time during the same summer in coastal west Mexico or Baja California Sur. They then migrate further south to their final wintering areas in the Neotropics. Our discovery of dual breeding ranges in Neotropical migrants reveals a hitherto unrealized flexibility in life-history strategies for these species and underscores that demographic models and conservation plans must consider dual breeding for these migrants. PMID:19858484

  4. Science support for managing migratory waterfowl.

    USGS Publications Warehouse

    Fleskes, Joseph P.; Miller, Michael R.; Takekawa, John Y.

    2003-01-01

    Migratory birds in North America are an international resource shared by Canada, the United States, and Mexico. Ultimate population management authority in the U.S. lies with the U.S. Fish and Wildlife Service (FWS), but states participate in development of management decisions through the Flyway system. The FWS, state wildlife agencies, and nongovernmental organizations participate through independent actions and cooperative Joint Ventures under the North American Waterfowl Management Plan (NAWMP) to acquire, protect, restore, and enhance wetlands and other habitats critical to the long-term conservation of breeding, migrating, and wintering waterfowl. A thorough base of scientific information is required to support and evaluate waterfowl populations and habitat management in North America.

  5. Migratory double breeding in Neotropical migrant birds.

    PubMed

    Rohwer, Sievert; Hobson, Keith A; Rohwer, Vanya G

    2009-11-10

    Neotropical migratory songbirds typically breed in temperate regions and then travel long distances to spend the majority of the annual cycle in tropical wintering areas. Using stable-isotope methodology, we provide quantitative evidence of dual breeding ranges for 5 species of Neotropical migrants. Each is well known to have a Neotropical winter range and a breeding range in the United States and Canada. However, after their first bout of breeding in the north, many individuals migrate hundreds to thousands of kilometers south in midsummer to breed a second time during the same summer in coastal west Mexico or Baja California Sur. They then migrate further south to their final wintering areas in the Neotropics. Our discovery of dual breeding ranges in Neotropical migrants reveals a hitherto unrealized flexibility in life-history strategies for these species and underscores that demographic models and conservation plans must consider dual breeding for these migrants.

  6. Development of migratory behavior in northern white-tailed deer

    USGS Publications Warehouse

    Nelson, M.E.

    1998-01-01

    I examined the development of migratory behavior in northern white-tailed deer (Odocoileus virginianus) from 1975 to 1996 by radio-tracking adult females and their fawns. Of 40 migratory fawns with radio-collared mothers, all returned from winter ranges to their mothers' summer ranges, as did 36 fawns with unknown mothers. Of 1.5- to 3.0-year-old daughters with radio-collared mothers, 67-80% continued migrating with mothers to their traditional summer ranges. Eighty-four percent (16/19) of yearling dispersers continued migratory behavior after replacing their natal summer ranges with their dispersal ranges, and 88% (14/16) of these continued migrating to their natal winter ranges, some through at least 6.5 years of age. Twenty percent (4/20) of nonmigratory fawns dispersed as yearlings, and two became migratory between their dispersal summer ranges and new winter ranges, one through 4.9 years of age and another through 6.5 years. Seven fawns changed their movement behavior from migratory to nonmigratory or vice versa as yearlings or when older, indicating that migratory behavior is not under rigid genetic control. Thus, the adaptiveness of migration must depend upon natural selection operating upon varying capacities and propensities to learn and mimic long-distance movements and not upon migratory behavior directly.

  7. Migratory Prostitution with Emphasis on Europe.

    PubMed

    M&oring;rdh; Genç

    1995-03-01

    In many European countries, foreigners constitute the majority of certain groups of prostitutes, e.g., approximately 90% of the window prostitutes in the red light district of Amsterdam are not native to the Netherlands. The same is true for prostitutes working in bars in Vienna. In cities where registered prostitution is legal, unregistered prostitutes, most of whom are foreigners, often outnumber the registered ones. Central European countries often receive "sex workers" from eastern Europe, e.g., from Bulgaria, the Czech Republic, Slovakia, Hungary, and Romania, whereas the majority of migratory prostitutes in Great Britain and continental western Europe come from Africa, the Caribbean, and South America. In northern Europe, women from Russia, the Czech Republic, Slovakia, Poland, and the Baltic states are prostituting themselves in increasing numbers. Scandinavia has so far been affected relatively less by this mobility. In Spain, France, and Italy, women from Arabic and subSaharan countries are common among prostitutes. Foreign prostitutes move into Turkey along two main routes: women from the Balkan countries come to the western part of the country, whereas those from the former Soviet Union cross the border from Georgia, where they usually operate at resorts along the eastern Black Sea coast. Prostitutes are also mobile within the former communist bloc. For instance, women from Russia prostitute themselves in Lithuania, the Czech Republic, Slovakia, and Hungary. the customers are locals, particularly those with "hard currency", such as businessmen and "sex tourists" from the West. Following the outbreak of civil war in the former Yugoslavia, women from that country are now more frequently seen among the population of migratory prostitutes in Europe.

  8. 78 FR 907 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-07

    ... reduces the commercial trip limit of Atlantic migratory group Spanish mackerel in or from the exclusive... coastal migratory pelagic fish (king mackerel, Spanish mackerel, and cobia) is managed under the Fishery... million lb (1.42 million kg) for the Atlantic migratory group of Spanish mackerel. Atlantic migratory...

  9. 76 FR 39367 - Migratory Bird Permits; Changes in the Regulations Governing Raptor Propagation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX78 Migratory Bird Permits; Changes in the... primary responsibility for managing migratory birds. Our authority is based on the Migratory Bird Treaty... take and possession of migratory birds for many purposes. The BGEPA allows bald eagles and golden...

  10. 50 CFR 20.25 - Wanton waste of migratory game birds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Wanton waste of migratory game birds. 20... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.25 Wanton waste of migratory game birds. No person shall kill or cripple any migratory game bird pursuant to this part without...

  11. 50 CFR 20.25 - Wanton waste of migratory game birds.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Wanton waste of migratory game birds. 20... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.25 Wanton waste of migratory game birds. No person shall kill or cripple any migratory game bird pursuant to this part without...

  12. 50 CFR 20.25 - Wanton waste of migratory game birds.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Wanton waste of migratory game birds. 20... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.25 Wanton waste of migratory game birds. No person shall kill or cripple any migratory game bird pursuant to this part without...

  13. 50 CFR 20.25 - Wanton waste of migratory game birds.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Wanton waste of migratory game birds. 20... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.25 Wanton waste of migratory game birds. No person shall kill or cripple any migratory game bird pursuant to this part without...

  14. Using radar to advance migratory bird management: An interagency collaboration

    USGS Publications Warehouse

    Sojda, R.; Ruth, J.M.; Barrow, W.C.; Dawson, D.K.; Diehl, R.H.; Manville, A.; Green, M.T.; Krueper, D.J.; Johnston, S.

    2005-01-01

    Migratory birds face many changes to the landscapes they traverse and the habitats they use. Wind turbines and communications towers, which pose hazards to birds and bats in flight, are being erected across the United States and offshore. Human activities can also destroy or threaten habitats critical to birds during migratory passage, and climate change appears to be altering migratory patterns. The U.S. Fish and Wildlife Service (USFWS) and other agencies are under increasing pressure to identify and evaluate movement patterns and habitats used during migration and other times.

  15. Tracking Migratory Animals: Going Online for Environmental Education.

    ERIC Educational Resources Information Center

    Coulter, Bob

    1997-01-01

    Describes a project in which students pick a migratory animal and track it during migration using internet resources. Employs background readings, authentic research data, and questions to experts to enable students to have meaningful learning experiences. (DDR)

  16. Tracking Migratory Animals: Going Online for Environmental Education.

    ERIC Educational Resources Information Center

    Coulter, Bob

    1997-01-01

    Describes a project in which students pick a migratory animal and track it during migration using internet resources. Employs background readings, authentic research data, and questions to experts to enable students to have meaningful learning experiences. (DDR)

  17. 78 FR 53397 - Atlantic Highly Migratory Species; Vessel Monitoring Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... National Oceanic and Atmospheric Administration 50 CFR Part 635 RIN 0648-BD24 Atlantic Highly Migratory Species; Vessel Monitoring Systems AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION: Proposed rule; request for comments. SUMMARY:...

  18. Life history correlates of alternative migratory strategies in American Dippers.

    PubMed

    Gillis, Elizabeth A; Green, David J; Middleton, Holly A; Morrissey, Christy A

    2008-06-01

    Partial migration is thought to be a critical step in the evolution of avian migration, but data on the life history correlates of alternative migratory strategies are extremely limited. We have studied a partially migratory population of American Dippers since 1999. This population is composed of sedentary individuals (residents) that maintain the same territory year round and altitudinal migrants that share winter grounds with residents, but move to higher elevations to breed. We used seven years of data on individually marked birds to (1) determine if individuals consistently use the same migratory strategy, (2) determine if offspring have the same strategy as their parents, and (3) estimate reproductive and survival rates of the two migratory strategies. We evaluate hypotheses for the persistence of partial migration and discuss their implication for the evolution of migration in sedentary populations. Individual American Dippers rarely switched migratory strategy (4/169 monitored more than one year). An individual's strategy, however, was not always that of its parents, indicating that, while migratory behavior may have a genetic component, environmental or social conditions probably influence the migratory strategy that an individual adopts. Sedentary dippers consistently had higher annual productivity (approximately 1.4 more fledglings/year) than migratory dippers, but mark-recapture models suggested that migratory dippers may have slightly higher survival than residents (approximately 3.4%). Migrants were estimated to have lower lifetime reproductive success than residents because their higher survival was insufficient to offset their lower productivity. Our data suggest that alternative migratory strategies in American Dippers are unlikely to be a fixed genetic dimorphism that persists because the two strategies have equal fitness, or because the relative fitness of the two strategies fluctuates over time. Migratory strategies in American Dippers are more

  19. Applying metapopulation theory to conservation of migratory birds

    USGS Publications Warehouse

    Esler, Daniel N.

    2000-01-01

    Metapopulation theory has proven useful for understanding the population structure and dynamics of many species of conservation concern. The metapopulation concept has been applied almost exclusively to nonmigratory species, however, for which subpopulation demographic independence—a requirement for a classically defined metapopulation - is explicitly related to geographic distribution and dispersal probabilities. Defining the degree of demographic independence among subpopulations of migratory animals, and thus the applicability of metapopulation theory as a conceptual framework for understanding population dynamics, is much more difficult. Unlike nonmigratory species, subpopulations of migratory animals cannot be defined as synonymous with geographic areas. Groups of migratory birds that are geographically separate at one part of the annual cycle may occur together at others, but co-occurrence in time and space does not preclude the demographic independence of subpopulations. I suggest that metapopulation theory can be applied to migratory species but that understanding the degree of subpopulation independence may require information about both spatial distribution throughout the annual cycle and behavioral mechanisms that may lead to subpopulation demographic independence. The key for applying metapopulation theory to migratory animals lies in identifying demographically independent subpopulations, even as they move during the annual cycle and potentially co-occur with other subpopulations. Using examples of migratory bird species, I demonstrate that spatial and temporal modes of subpopulation independence can interact with behavioral mechanisms to create demographically independent subpopulations, including cases in which subpopulations are not spatially distinct in some parts of the annual cycle.

  20. PMN-PT piezoelectric-electrostrictive bi-layer composite actuators

    NASA Astrophysics Data System (ADS)

    Ngernchuklin, Piyalak

    In the past few decades, significant advances have been achieved to replace the conventional actuators, including hydraulic, shape memory alloy, electromagnetic and linear induction, with piezoelectric actuators since they are light weight and small in size, have precision positioning capabilities, offer a wide range of generative force, consume less power, and provide higher durability and reliability. The strain produced by bulk polycrystalline piezoelectric ceramics and single crystals are typically in the range of 0.1 to 1%, respectively, which is still low for many applications. Therefore, various strain amplification designs including multilayer, bimorph, unimorph, flextensional actuators (Moonie and cymbal), co-fired and functionally graded ceramics have been proposed to enhance the displacement. In this investigation, Piezoelectric/Electrostrictive Bi-Layer Monolithic Composites (PE-MBLC) were fabricated by co-pressing and co-sintering of the piezoelectric (PMN-PT 65/35: P) and electrostrictive (PMN/PT 90/10: E) powders. Flat and dome shaped of PE-MBLCs were obtained by optimizing processing conditions such as pressing pressure and sintering temperature. In addition, poling conditions of bilayer composite actuators were thoroughly studied to maximize their electromechanical properties. It was found that composites had lower d33eff and Keff values than the calculated values. This was attributed to a significant difference between relative permittivities of P and E materials as well as the presence of induced stresses in both P and E layers after sintering that hindered domain switching within piezoelectric layer during poling. The shape change (planar to dome), electromechanical properties, and actuation performance of PE-MBLC actuators were examined as a function of volume percent of piezoelectric phase. The highest displacement ˜15 mum was obtained from PE-MBLC actuator with 50 volume % piezoelectric phase due to the transverse strain response of

  1. Bulk Crystal Growth of Piezoelectric PMN-PT Crystals Using Gradient Freeze Technique for Improved SHM Sensors

    NASA Technical Reports Server (NTRS)

    Aggarwal, Mohan D.; Kochary, F.; Penn, Benjamin G.; Miller, Jim

    2007-01-01

    There has been a growing interest in recent years in lead based perovskite ferroelectric and relaxor ferroelectric solid solutions because of their excellent dielectric, piezoelectric and electrostrictive properties that make them very attractive for various sensing, actuating and structural health monitoring (SHM) applications. We are interested in the development of highly sensitive and efficient PMN-PT sensors based on large single crystals for the structural health monitoring of composite materials that may be used in future spacecrafts. Highly sensitive sensors are needed for detection of defects in these materials because they often tend to fail by distributed and interacting damage modes and much of the damage occurs beneath the top surface of the laminate and not detectable by visual inspection. Research is being carried out for various combinations of solid solutions for PMN-PT piezoelectric materials and bigger size crystals are being sought for improved sensor applications. Single crystals of this material are of interest for sensor applications because of their high piezoelectric coefficient (d33 greater than 1700 pC/N) and electromechanical coefficients (k33 greater than 0.90). For comparison, the commonly used piezoelectric ceramic lead zirconate titanate (PZT) has a d33 of about 600 pC/N and electromechanical coefficients k33 of about 0.75. At the present time, these piezoelectric relaxor crystals are grown by high temperature flux growth method and the size of these crystals are rather small (3x4x5 mm(exp 3). In the present paper, we have attempted to grow bulk single crystals of PMN-PT in a 2 inch diameter platinum crucible and successfully grown a large size crystal of 67%PMN-33%PT using the vertical gradient freeze technique with no flux. Piezoelectric properties of the grown crystals are investigated. PMN-PT plates show excellent piezoelectric properties. Samples were poled under an applied electric field of 5 kV/cm. Dielectric properties at a

  2. Comparison of Navigation-Related Brain Regions in Migratory versus Non-Migratory Noctuid Moths.

    PubMed

    de Vries, Liv; Pfeiffer, Keram; Trebels, Björn; Adden, Andrea K; Green, Ken; Warrant, Eric; Heinze, Stanley

    2017-01-01

    Brain structure and function are tightly correlated across all animals. While these relations are ultimately manifestations of differently wired neurons, many changes in neural circuit architecture lead to larger-scale alterations visible already at the level of brain regions. Locating such differences has served as a beacon for identifying brain areas that are strongly associated with the ecological needs of a species-thus guiding the way towards more detailed investigations of how brains underlie species-specific behaviors. Particularly in relation to sensory requirements, volume-differences in neural tissue between closely related species reflect evolutionary investments that correspond to sensory abilities. Likewise, memory-demands imposed by lifestyle have revealed similar adaptations in regions associated with learning. Whether this is also the case for species that differ in their navigational strategy is currently unknown. While the brain regions associated with navigational control in insects have been identified (central complex (CX), lateral complex (LX) and anterior optic tubercles (AOTU)), it remains unknown in what way evolutionary investments have been made to accommodate particularly demanding navigational strategies. We have thus generated average-shape atlases of navigation-related brain regions of a migratory and a non-migratory noctuid moth and used volumetric analysis to identify differences. We further compared the results to identical data from Monarch butterflies. Whereas we found differences in the size of the nodular unit of the AOTU, the LX and the protocerebral bridge (PB) between the two moths, these did not unambiguously reflect migratory behavior across all three species. We conclude that navigational strategy, at least in the case of long-distance migration in lepidopteran insects, is not easily deductible from overall neuropil anatomy. This suggests that the adaptations needed to ensure successful migratory behavior are found in the

  3. Comparison of Navigation-Related Brain Regions in Migratory versus Non-Migratory Noctuid Moths

    PubMed Central

    de Vries, Liv; Pfeiffer, Keram; Trebels, Björn; Adden, Andrea K.; Green, Ken; Warrant, Eric; Heinze, Stanley

    2017-01-01

    Brain structure and function are tightly correlated across all animals. While these relations are ultimately manifestations of differently wired neurons, many changes in neural circuit architecture lead to larger-scale alterations visible already at the level of brain regions. Locating such differences has served as a beacon for identifying brain areas that are strongly associated with the ecological needs of a species—thus guiding the way towards more detailed investigations of how brains underlie species-specific behaviors. Particularly in relation to sensory requirements, volume-differences in neural tissue between closely related species reflect evolutionary investments that correspond to sensory abilities. Likewise, memory-demands imposed by lifestyle have revealed similar adaptations in regions associated with learning. Whether this is also the case for species that differ in their navigational strategy is currently unknown. While the brain regions associated with navigational control in insects have been identified (central complex (CX), lateral complex (LX) and anterior optic tubercles (AOTU)), it remains unknown in what way evolutionary investments have been made to accommodate particularly demanding navigational strategies. We have thus generated average-shape atlases of navigation-related brain regions of a migratory and a non-migratory noctuid moth and used volumetric analysis to identify differences. We further compared the results to identical data from Monarch butterflies. Whereas we found differences in the size of the nodular unit of the AOTU, the LX and the protocerebral bridge (PB) between the two moths, these did not unambiguously reflect migratory behavior across all three species. We conclude that navigational strategy, at least in the case of long-distance migration in lepidopteran insects, is not easily deductible from overall neuropil anatomy. This suggests that the adaptations needed to ensure successful migratory behavior are found in

  4. Epidermal loss of Gαq confers a migratory and differentiation defect in keratinocytes

    PubMed Central

    Callejas-Valera, Juan Luis; Hansen, Karina K.; Molinolo, Alfredo A.; Inoue, Asuka; Offermanns, Stefan; Gutkind, J. Silvio

    2017-01-01

    G-protein coupled receptors (GPCRs), which activate heterotrimeric G proteins, are an essential class of transmembrane receptors that are responsible for a myriad of signaling events in normal and pathologic conditions. Two members of the G protein family, Gαq and Gα11, activate one of the main GPCR pathways and function as oncogenes by integrating mitogen-stimulated signaling cascades that are active under malignant conditions. Recently, it has been shown that targeted deletion of Gα11 and Gαq from endothelial cells impairs the Rho-mediated formation of focal adherens junctions, suggesting that Gα11/q signaling may also play a significant role in cytoskeletal-mediated cellular responses in epithelial cells. Indeed, combined deletion of Gα11 and Gαq confers a significant migratory defect in keratinocytes that delays cutaneous wound healing in an in vivo setting. This delay can be attributed to a defect during the reepithelialization phase due to significantly attenuated migratory capacity of Gαq-null keratinocytes under combined Gα11 deficiency. In fact, cells lacking Gα11/q demonstrate a severely reduced ability to respond to mitogenic and migratory signals in the microenvironment, leading to inappropriate and premature terminal differentiation. These results suggest that Gα11/q signaling pathways may be critical for integrating mitogenic signals and cytoskeletal function to achieve normal physiological responses. Emergence of a malignant phenotype may therefore arise from both under- and overexpression of Gα11/q signaling, implicating its upstream regulation as a potential therapeutic target in a host of pathologic conditions. PMID:28301547

  5. Specialization and evolutionary branching within migratory populations

    PubMed Central

    Torney, Colin J.; Levin, Simon A.; Couzin, Iain D.

    2010-01-01

    Understanding the mechanisms that drive specialization and speciation within initially homogeneous populations is a fundamental challenge for evolutionary theory. It is an issue of relevance for significant open questions in biology concerning the generation and maintenance of biodiversity, the origins of reciprocal cooperation, and the efficient division of labor in social or colonial organisms. Several mathematical frameworks have been developed to address this question and models based on evolutionary game theory or the adaptive dynamics of phenotypic mutation have demonstrated the emergence of polymorphic, specialized populations. Here we focus on a ubiquitous biological phenomenon, migration. Individuals in our model may evolve the capacity to detect and follow an environmental cue that indicates a preferred migration route. The strategy space is defined by the level of investment in acquiring personal information about this route or the alternative tendency to follow the direction choice of others. The result is a relation between the migratory process and a game theoretic dynamic that is generally applicable to situations where information may be considered a public good. Through the use of an approximation of social interactions, we demonstrate the emergence of a stable, polymorphic population consisting of an uninformed subpopulation that is dependent upon a specialized group of leaders. The branching process is classified using the techniques of adaptive dynamics. PMID:21059935

  6. Orientation of migratory birds under ultraviolet light.

    PubMed

    Wiltschko, Roswitha; Munro, Ursula; Ford, Hugh; Stapput, Katrin; Thalau, Peter; Wiltschko, Wolfgang

    2014-05-01

    In view of the finding that cryptochrome 1a, the putative receptor molecule for the avian magnetic compass, is restricted to the ultraviolet single cones in European Robins, we studied the orientation behaviour of robins and Australian Silvereyes under monochromatic ultraviolet (UV) light. At low intensity UV light of 0.3 mW/m(2), birds showed normal migratory orientation by their inclination compass, with the directional information originating in radical pair processes in the eye. At 2.8 mW/m(2), robins showed an axial preference in the east-west axis, whereas silvereyes preferred an easterly direction. At 5.7 mW/m(2), robins changed direction to a north-south axis. When UV light was combined with yellow light, robins showed easterly 'fixed direction' responses, which changed to disorientation when their upper beak was locally anaesthetised with xylocaine, indicating that they were controlled by the magnetite-based receptors in the beak. Orientation under UV light thus appears to be similar to that observed under blue, turquoise and green light, albeit the UV responses occur at lower light levels, probably because of the greater light sensitivity of the UV cones. The orientation under UV light and green light suggests that at least at the level of the retina, magnetoreception and vision are largely independent of each other.

  7. Remarkable spatial memory in a migratory cardinalfish.

    PubMed

    Fukumori, Kayoko; Okuda, Noboru; Yamaoka, Kosaku; Yanagisawa, Yasunobu

    2010-03-01

    The ability to orient and navigate within a certain environment is essential for all animals, and spatial memory enables animals to remember the locations of such markers as predators, home, and food. Here we report that the migratory marine cardinalfish Apogon notatus has the potential to retain long-term spatial memory comparable to that of other animals. Female A. notatus establish a small territory on a shallow boulder bottom to pair and spawn with males. We carried out field research in two consecutive breeding seasons on territory settlement by individually marked females. Females maintained a territory at the same site throughout one breeding season. After overwintering in deep water, many of them (82.1%) returned to their breeding ground next spring and most occupied the same site as in the previous season, with only a 0.56 m shift on average. Our results suggest that female A. notatus have long-distance homing ability to pinpoint the exact location of their previous territory, and retain spatial memory for as long as 6 months.

  8. Specialization and evolutionary branching within migratory populations.

    PubMed

    Torney, Colin J; Levin, Simon A; Couzin, Iain D

    2010-11-23

    Understanding the mechanisms that drive specialization and speciation within initially homogeneous populations is a fundamental challenge for evolutionary theory. It is an issue of relevance for significant open questions in biology concerning the generation and maintenance of biodiversity, the origins of reciprocal cooperation, and the efficient division of labor in social or colonial organisms. Several mathematical frameworks have been developed to address this question and models based on evolutionary game theory or the adaptive dynamics of phenotypic mutation have demonstrated the emergence of polymorphic, specialized populations. Here we focus on a ubiquitous biological phenomenon, migration. Individuals in our model may evolve the capacity to detect and follow an environmental cue that indicates a preferred migration route. The strategy space is defined by the level of investment in acquiring personal information about this route or the alternative tendency to follow the direction choice of others. The result is a relation between the migratory process and a game theoretic dynamic that is generally applicable to situations where information may be considered a public good. Through the use of an approximation of social interactions, we demonstrate the emergence of a stable, polymorphic population consisting of an uninformed subpopulation that is dependent upon a specialized group of leaders. The branching process is classified using the techniques of adaptive dynamics.

  9. Fishing out collective memory of migratory schools

    PubMed Central

    De Luca, Giancarlo; Mariani, Patrizio; MacKenzie, Brian R.; Marsili, Matteo

    2014-01-01

    Animals form groups for many reasons, but there are costs and benefits associated with group formation. One of the benefits is collective memory. In groups on the move, social interactions play a crucial role in the cohesion and the ability to make consensus decisions. When migrating from spawning to feeding areas, fish schools need to retain a collective memory of the destination site over thousands of kilometres, and changes in group formation or individual preference can produce sudden changes in migration pathways. We propose a modelling framework, based on stochastic adaptive networks, that can reproduce this collective behaviour. We assume that three factors control group formation and school migration behaviour: the intensity of social interaction, the relative number of informed individuals and the strength of preference that informed individuals have for a particular migration area. We treat these factors independently and relate the individuals’ preferences to the experience and memory for certain migration sites. We demonstrate that removal of knowledgeable individuals or alteration of individual preference can produce rapid changes in group formation and collective behaviour. For example, intensive fishing targeting the migratory species and also their preferred prey can reduce both terms to a point at which migration to the destination sites is suddenly stopped. The conceptual approaches represented by our modelling framework may therefore be able to explain large-scale changes in fish migration and spatial distribution. PMID:24647905

  10. Fishing out collective memory of migratory schools.

    PubMed

    De Luca, Giancarlo; Mariani, Patrizio; MacKenzie, Brian R; Marsili, Matteo

    2014-06-06

    Animals form groups for many reasons, but there are costs and benefits associated with group formation. One of the benefits is collective memory. In groups on the move, social interactions play a crucial role in the cohesion and the ability to make consensus decisions. When migrating from spawning to feeding areas, fish schools need to retain a collective memory of the destination site over thousands of kilometres, and changes in group formation or individual preference can produce sudden changes in migration pathways. We propose a modelling framework, based on stochastic adaptive networks, that can reproduce this collective behaviour. We assume that three factors control group formation and school migration behaviour: the intensity of social interaction, the relative number of informed individuals and the strength of preference that informed individuals have for a particular migration area. We treat these factors independently and relate the individuals' preferences to the experience and memory for certain migration sites. We demonstrate that removal of knowledgeable individuals or alteration of individual preference can produce rapid changes in group formation and collective behaviour. For example, intensive fishing targeting the migratory species and also their preferred prey can reduce both terms to a point at which migration to the destination sites is suddenly stopped. The conceptual approaches represented by our modelling framework may therefore be able to explain large-scale changes in fish migration and spatial distribution.

  11. Angled-focused 45 MHz PMN-PT single element transducer for intravascular ultrasound imaging

    PubMed Central

    Yoon, Sangpil; Williams, Jay; Kang, Bong Jin; Yoon, Changhan; Cabrera-Munoz, Nestor; Jeong, Jong Seob; Lee, Sang Goo; Shung, K. Kirk; Kim, Hyung Ham

    2015-01-01

    A transducer with an angled and focused aperture for intravascular ultrasound imaging has been developed. The acoustic stack for the angled-focused transducer was made of PMN-PT single crystal with one matching layer, one protective coating layer, and a highly damped backing layer. It was then press-focused to a desired focal length and inserted into a thin needle housing with an angled tip. A transducer with an angled and unfocused aperture was also made, following the same fabrication procedure, to compare the performance of the two transducers. The focused and unfocused transducers were tested to measure their center frequencies, bandwidths, and spatial resolutions. Lateral resolution of the angled-focused transducer (AFT) improved more than two times compared to that of the angled-unfocused transducer (AUT). A tissue-mimicking phantom in water and a rabbit aorta tissue sample in rabbit blood were scanned using AFT and AUT. Imaging with AFT offered improved contrast, over imaging with AUT, of the tissue-mimicking phantom and the rabbit aorta tissue sample by 23 dB and 8 dB, respectively. The results show that AFT has strong potential to provide morphological and pathological information of coronary arteries with high resolution and high contrast. PMID:25914443

  12. Resonant frequency and hysteresis of a stack actuator made of single crystal (PMN-29PT) layers

    NASA Astrophysics Data System (ADS)

    Tran, K. S.; Lee, H. Y.; Kim, Y.; Park, H. C.

    2016-12-01

    In this study, we have presented the dynamic behavior of a piezoelectric stack actuator made of forty layers of single-crystal (PMN-29PT) with an area of 10 × 10 mm2 and thickness of 1 mm. To conduct a dynamic test of the actuator, we built a test apparatus with dummy weights that was placed over the top of the actuator to measure the actuation displacement. The resonant frequencies of the actuator with and without the dummy weight were determined as the excitation frequencies where a significant increase in the actuation displacement could be observed. We also proposed an analytical multi-degree-of-freedom (MDOF) model of the actuator to analytically predict the resonant frequency. Finite element analyses were conducted to validate the analytically predicted and measured resonant frequencies. With no dummy weight, the resonant frequency of the actuator was measured at 730.00 Hz, which was 0.70% higher than the one calculated by the MDOF model and 0.10% smaller than that of the finite element model. With a dummy weight, the measured resonant frequency was lower than 730.00 Hz and close enough to those computed by the MDOF model and the finite element model. The hysteresis curves of the actuator at various frequencies indicated that the actuator might incur a small energy loss.

  13. Angled-focused 45 MHz PMN-PT single element transducer for intravascular ultrasound imaging.

    PubMed

    Yoon, Sangpil; Williams, Jay; Kang, Bong Jin; Yoon, Changhan; Cabrera-Munoz, Nestor; Jeong, Jong Seob; Lee, Sang Goo; Shung, K Kirk; Kim, Hyung Ham

    2015-06-01

    A transducer with an angled and focused aperture for intravascular ultrasound imaging has been developed. The acoustic stack for the angled-focused transducer was made of PMN-PT single crystal with one matching layer, one protective coating layer, and a highly damped backing layer. It was then press-focused to a desired focal length and inserted into a thin needle housing with an angled tip. A transducer with an angled and unfocused aperture was also made, following the same fabrication procedure, to compare the performance of the two transducers. The focused and unfocused transducers were tested to measure their center frequencies, bandwidths, and spatial resolutions. Lateral resolution of the angled-focused transducer (AFT) improved more than two times compared to that of the angled-unfocused transducer (AUT). A tissue-mimicking phantom in water and a rabbit aorta tissue sample in rabbit blood were scanned using AFT and AUT. Imaging with AFT offered improved contrast, over imaging with AUT, of the tissue-mimicking phantom and the rabbit aorta tissue sample by 23 dB and 8 dB, respectively. The results show that AFT has strong potential to provide morphological and pathological information of coronary arteries with high resolution and high contrast.

  14. Elastic, dielectric and piezoelectric characterization of single domain PIN-PMN-PT: Mn crystals.

    PubMed

    Huo, Xiaoqing; Zhang, Shujun; Liu, Gang; Zhang, Rui; Luo, Jun; Sahul, Raffi; Cao, Wenwu; Shrout, Thomas R

    2012-12-15

    Mn modified 0.26Pb(In(1/2)Nb(1/2))O(3)-0.42Pb(Mg(1/3)Nb(2/3))O(3)-0.32PbTiO(3) (PIN-PMN-PT:Mn) single crystals with orthorhombic perovskite crystal structure were polarized along [011] direction, resulting in the single domain state "1O." The complete set of material constants was determined using the combined resonance and ultrasonic methods. The thickness shear piezoelectric coefficient d(15) and electromechanical coupling factor k(15) were found to be on the order of 3100 pC/N and 94%, respectively, much higher than longitudinal d(33) ∼ 270 pC/N and k(33) ∼ 70%. Using the single domain data, the rotated value of d(33)* along [001] direction was found to be 1230 pC/N, in agreement with the experimentally determined d(33) value of 1370 pC/N, conferring extrinsic contributions being about 10%, which was also confirmed using the Rayleigh analysis. In addition, the mechanical quality factors Q(m) were evaluated for different "1O" vibration modes, where the longitudinal Q(m) was found to be ∼1200, much higher than the value for "4O" crystals, ∼300.

  15. Implementation of a PMN-PT piezocrystal-based focused array with geodesic faceted structure.

    PubMed

    Qiu, Zhen; Qiu, Yongqiang; Demore, Christine E M; Cochran, Sandy

    2016-07-01

    The higher performance of relaxor-based piezocrystals compared with piezoceramics is now well established, notably including improved gain-bandwidth product, and these materials have been adopted widely for biomedical ultrasound imaging. However, their use in other applications, for example as a source of focused ultrasound for targeted drug delivery, is hindered in several ways. One of the issues, which we consider here, is in shaping the material into the spherical geometries used widely in focused ultrasound. Unlike isotropic unpoled piezoceramics that can be shaped into a monolithic bowl then poled through the thickness, the anisotropic structure of piezocrystals make it impossible to machine the bulk crystalline material into a bowl without sacrificing performance. Instead, we report a novel faceted array, inspired by the geodesic dome structure in architecture, which utilizes flat piezocrystal material and maximizes fill factor. Aided by 3D printing, a prototype with f#≈ 1.2, containing 96 individually addressable elements was manufactured using 1-3 connectivity PMN-PT piezocrystal-epoxy composite. The fabrication process is presented and the array was connected to a 32-channel controller to shape and steer the beam for preliminary performance demonstration. At an operating frequency of 1MHz, a focusing gain around 30 was achieved and the side lobe intensities were all at levels below -12dB compared to main beam. We conclude that, by taking advantage of contemporary fabrication techniques and driving instrumentation, the geodesic array configuration is suitable for focused ultrasound devices made with piezocrystal.

  16. Electric-field tunable spin waves in PMN-PT/NiFe heterostructure: Experiment and micromagnetic simulations

    NASA Astrophysics Data System (ADS)

    Ziȩtek, Slawomir; Chȩciński, Jakub; Frankowski, Marek; Skowroński, Witold; Stobiecki, Tomasz

    2017-04-01

    We present a comprehensive theoretical and experimental study of voltage-controlled standing spin waves resonance (SSWR) in PMN-PT/NiFe multiferroic heterostructures patterned into microstrips. A spin-diode technique was used to observe ferromagnetic resonance (FMR) mode and SSWR in NiFe strip mechanically coupled with a piezoelectric substrate. Application of an electric field to a PMN-PT creates a strain in permalloy and thus shifts the FMR and SSWR fields due to the magnetostriction effect. The experimental results are compared with micromagnetic simulations and a good agreement between them is found for dynamics of FMR and SSWR with and without electric field. Moreover, micromagnetic simulations enable us to discuss the amplitude and phase spatial distributions of FMR and SSWR modes, which are not directly observable by means of spin diode detection technique.

  17. Development of Matched (migratory Analytical Time Change Easy Detection) Method for Satellite-Tracked Migratory Birds

    NASA Astrophysics Data System (ADS)

    Doko, Tomoko; Chen, Wenbo; Higuchi, Hiroyoshi

    2016-06-01

    Satellite tracking technology has been used to reveal the migration patterns and flyways of migratory birds. In general, bird migration can be classified according to migration status. These statuses include the wintering period, spring migration, breeding period, and autumn migration. To determine the migration status, periods of these statuses should be individually determined, but there is no objective method to define 'a threshold date' for when an individual bird changes its status. The research objective is to develop an effective and objective method to determine threshold dates of migration status based on satellite-tracked data. The developed method was named the "MATCHED (Migratory Analytical Time Change Easy Detection) method". In order to demonstrate the method, data acquired from satellite-tracked Tundra Swans were used. MATCHED method is composed by six steps: 1) dataset preparation, 2) time frame creation, 3) automatic identification, 4) visualization of change points, 5) interpretation, and 6) manual correction. Accuracy was tested. In general, MATCHED method was proved powerful to identify the change points between migration status as well as stopovers. Nevertheless, identifying "exact" threshold dates is still challenging. Limitation and application of this method was discussed.

  18. Electric field mediated non-volatile tuning magnetism in CoPt/PMN-PT heterostructure for magnetoelectric memory devices

    NASA Astrophysics Data System (ADS)

    Yang, Y. T.; Li, J.; Peng, X. L.; Wang, X. Q.; Wang, D. H.; Cao, Q. Q.; Du, Y. W.

    2016-02-01

    We report a power efficient non-volatile magnetoelectric memory in the CoPt/(011)PMN-PT heterostructure. Two reversible and stable electric field induced coercivity states (i.e., high-HC or low-HC) are obtained due to the strain mediated converse magnetoelectric effect. The reading process of the different coercive field information written by electric fields is demonstrated by using a magnetoresistance read head. This result shows good prospects in the application of novel multiferroic devices.

  19. Fermi LAT Detection of a Gamma-ray Flare from the FSRQ PMN J1703-6212

    NASA Astrophysics Data System (ADS)

    Ojha, Roopesh; Carpen, Bryce

    2015-03-01

    The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope has observed increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar (FSRQ) PMN J1703-6212 (RA: 255.9022550 deg, Dec: -62.2111133 deg, J2000, Fey et al., 2004, AJ, 127, 1791) at z = 1.755 (Titov et al., 2011, AJ, 142, 165).

  20. Migratory patterns and developmental potential of trunk neural crest cells in the axolotl embryo.

    PubMed

    Epperlein, Hans-Henning; Selleck, Mark A J; Meulemans, Daniel; Mchedlishvili, Levan; Cerny, Robert; Sobkow, Lidia; Bronner-Fraser, Marianne

    2007-02-01

    Using cell markers and grafting, we examined the timing of migration and developmental potential of trunk neural crest cells in axolotl. No obvious differences in pathway choice were noted for DiI-labeling at different lateral or medial positions of the trunk neural folds in neurulae, which contributed not only to neural crest but also to Rohon-Beard neurons. Labeling wild-type dorsal trunks at pre- and early-migratory stages revealed that individual neural crest cells migrate away from the neural tube along two main routes: first, dorsolaterally between the epidermis and somites and, later, ventromedially between the somites and neural tube/notochord. Dorsolaterally migrating crest primarily forms pigment cells, with those from anterior (but not mid or posterior) trunk neural folds also contributing glia and neurons to the lateral line. White mutants have impaired dorsolateral but normal ventromedial migration. At late migratory stages, most labeled cells move along the ventromedial pathway or into the dorsal fin. Contrasting with other anamniotes, axolotl has a minor neural crest contribution to the dorsal fin, most of which arises from the dermomyotome. Taken together, the results reveal stereotypic migration and differentiation of neural crest cells in axolotl that differ from other vertebrates in timing of entry onto the dorsolateral pathway and extent of contribution to some derivatives.

  1. Moving across the border: Modeling migratory bat populations

    USGS Publications Warehouse

    Ruscena, Wiederholt; López-Hoffman, Laura; Cline, Jon; Medellin, Rodrigo; Cryan, Paul M.; Russell, Amy; McCracken, Gary; Diffendorfer, Jay; Semmens, Darius J.

    2013-01-01

    The migration of animals across long distances and between multiple habitats presents a major challenge for conservation. For the migratory Mexican free-tailed bat (Tadarida brasiliensis mexicana), these challenges include identifying and protecting migratory routes and critical roosts in two countries, the United States and Mexico. Knowledge and conservation of bat migratory routes is critical in the face of increasing threats from climate change and wind turbines that might decrease migratory survival. We employ a new modeling approach for bat migration, network modeling, to simulate migratory routes between winter habitat in southern Mexico and summer breeding habitat in northern Mexico and the southwestern United States. We use the model to identify key migratory routes and the roosts of greatest conservation value to the overall population. We measure roost importance by the degree to which the overall bat population declined when the roost was removed from the model. The major migratory routes—those with the greatest number of migrants—were between winter habitat in southern Mexico and summer breeding roosts in Texas and the northern Mexican states of Sonora and Nuevo Leon. The summer breeding roosts in Texas, Sonora, and Nuevo Leon were the most important for maintaining population numbers and network structure – these are also the largest roosts. This modeling approach contributes to conservation efforts by identifying the most influential areas for bat populations, and can be used as a tool to improve our understanding of bat migration for other species. We anticipate this approach will help direct coordination of habitat protection across borders.

  2. Linear Thermal Expansion Measurements of Lead Magnesium Niobate (PMN) Electroceramic Material for the Terrestrial Planet Finder Coronagraph

    NASA Technical Reports Server (NTRS)

    Karlmann, Paul B.; Halverson, Peter G.; Peters, Robert D.; Levine, Marie B.; VanBuren, David; Dudik, Matthew J.

    2005-01-01

    Linear thermal expansion measurements of nine samples of Lead Magnesium Niobate (PMN) electroceramic material were recently performed in support of NASA's Terrestrial Planet Finder Coronagraph (TPF-C) mission. The TPF-C mission is a visible light coronagraph designed to look at roughly 50 stars pre- selected as good candidates for possessing earth-like planets. Upon detection of an earth-like planet, TPF-C will analyze the visible-light signature of the planet's atmosphere for specific spectroscopic indicators that life may exist there. With this focus, the project's primary interest in PMN material is for use as a solid-state actuator for deformable mirrors or compensating optics. The nine test samples were machined from three distinct boules of PMN ceramic manufactured by Xinetics Inc. Thermal expansion measurements were performed in 2005 at NASA Jet Propulsion Laboratory (JPL) in their Cryogenic Dilatometer Facility. All measurements were performed in vacuum with sample temperature actively controlled over the range of 270K to 3 10K. Expansion and contraction of the test samples with temperature was measured using a JPL developed interferometric system capable of sub-nanometer accuracy. Presented in this paper is a discussion of the sample configuration, test facilities, test method, data analysis, test results, and future plans.

  3. Multiple receptors mobilize calcium through a pertussis toxin (PT) sensitive GTP-binding protein in human neutrophils (PMN's)

    SciTech Connect

    Lad, P.M.; Olson, C.V.; Grewal, I.S.; Frolich, M.; Scott, S.J.

    1986-03-05

    Treatment of PMN's with PT causes an abolition of chemotaxis, enzyme release, superoxide generation and aggregation caused by f-met-leu-phe (FMLP),C5a and platelet activating factor (PAF). Lectin (Con-A) induced capping and receptor induced shape change are abolished, but phagocytosis is unaltered. In whole cells, calcium mobilization induced by FMLP, PAF and Con-A inhibited by PT although the FMLP-mediated effect is more susceptible to PT's effects. Treatment of PMN's with phorbol 12-myristate 13 acetate (PMA) causes an abolition of calcium mobilization by all agents in a range which also inhibits cap formation. Investigation of calcium uptake reveals PT sensitive and insensitive components. Reciprocal interactions between Ns and Ni proteins are also observed since pretreatment with FMLP and PAF causes a stimulation of Ns-mediated cyclic AMP enhancement while pretreatment with Ns linked receptors (PGE/sub 1/ and beta receptor agonists) inhibits calcium mobilization. Comparative peptide mapping studies indicate substantial similarity between Ni proteins in PMN's, platelets and human erythrocytes. The authors results suggest that the Ni linked calcium mobilization sensitive to PMA is important to the regulation of the human neutrophil.

  4. Besnoitia besnoiti infections activate primary bovine endothelial cells and promote PMN adhesion and NET formation under physiological flow condition.

    PubMed

    Maksimov, P; Hermosilla, C; Kleinertz, S; Hirzmann, J; Taubert, A

    2016-05-01

    Besnoitia besnoiti is an obligate intracellular and emerging coccidian parasite of cattle that mainly infects host endothelial cells during acute infection. We here analyzed early innate immune reactions of B. besnoiti-infected primary bovine umbilical vein endothelial cells (BUVEC). B. besnoiti infections significantly activated BUVEC since the gene transcripts of several adhesion molecules (P-selectin, intercellular adhesion molecule 1(ICAM-1)), chemokines (CXCL1, CXCL8, CCL5), and of COX-2 were significantly upregulated during in vitro infection. Overall, the highest upregulation of most transcripts was observed at 24 or 48 h post infection (p.i.). Enhanced adhesion molecule expression in infected host cells was confirmed by PMN adhesion assays being performed under physiological flow conditions revealing a significantly increased PMN adhesion on B. besnoiti-infected BUVEC layers at 24 h p.i. Furthermore, we were able to illustrate neutrophil extracellular traps (NETs) being released by PMN under physiological flow conditions after adhesion to B. besnoiti-infected BUVEC layers. The present study shows that B. besnoiti infections of primary BUVEC induce a cascade of pro-inflammatory reactions and triggers early innate immune responses.

  5. Microscopic evidence of strain-mediated magnetoelectric coupling in Co/Pt multilayers/PMN-PT(011) heterostructures

    NASA Astrophysics Data System (ADS)

    Sun, Ying; Wang, Wenbo; Wu, Weida; Zheng, Xiaoli; Cai, Jianwang; Zhao, Yonggang; Liu, Ming

    A promising way to control magnetization(M) via an electric field(E-field) is using magnetoelectric(ME) effect in FM/FE heterostructures. We use magnetic(electric) force microscopy(M(e)FM) to study the strain-mediated E-field modulation of M in (Co/Pt)n with perpendicular magnetic anisotropy(PMA) or in-plane anisotropy on PMN-PT(011) substrates. MFM were performed on (Co/Pt)n with an DC E-field applied to PMN-PT. In MeFM, we superimpose an AC modulation on a DC one and utilize lock-in technique to detect weak ME effect. For (Co/Pt)n with PMA, MFM images show stripe domains with no obvious changes at varied DC E-fields. However, MeFM shows interesting structures and the image contrast reverses sign at opposite strain slopes of the PMN-PT substrate. For sample with in-plane anisotropy, both MFM and MeFM images show dipole-like domains. Interestingly, the MeFM image contrast reverses sign at opposite strain slopes of the substrate. The sign reversal of MeFM contrast indicates that features revealed by MeFM are intrinsic local ME effect. Our MeFM data are consistent with the ferromagnetic resonance results showing that strain-induced anisotropy change will cause part of M switching to the in-plane direction. Possible scenarios will be discussed.

  6. Linear Thermal Expansion Measurements of Lead Magnesium Niobate (PMN) Electroceramic Material for the Terrestrial Planet Finder Coronagraph

    NASA Technical Reports Server (NTRS)

    Karlmann, Paul B.; Halverson, Peter G.; Peters, Robert D.; Levine, Marie B.; VanBuren, David; Dudik, Matthew J.

    2005-01-01

    Linear thermal expansion measurements of nine samples of Lead Magnesium Niobate (PMN) electroceramic material were recently performed in support of NASA's Terrestrial Planet Finder Coronagraph (TPF-C) mission. The TPF-C mission is a visible light coronagraph designed to look at roughly 50 stars pre- selected as good candidates for possessing earth-like planets. Upon detection of an earth-like planet, TPF-C will analyze the visible-light signature of the planet's atmosphere for specific spectroscopic indicators that life may exist there. With this focus, the project's primary interest in PMN material is for use as a solid-state actuator for deformable mirrors or compensating optics. The nine test samples were machined from three distinct boules of PMN ceramic manufactured by Xinetics Inc. Thermal expansion measurements were performed in 2005 at NASA Jet Propulsion Laboratory (JPL) in their Cryogenic Dilatometer Facility. All measurements were performed in vacuum with sample temperature actively controlled over the range of 270K to 3 10K. Expansion and contraction of the test samples with temperature was measured using a JPL developed interferometric system capable of sub-nanometer accuracy. Presented in this paper is a discussion of the sample configuration, test facilities, test method, data analysis, test results, and future plans.

  7. Linear thermal expansion measurements of lead magnesium niobate (PMN) electroceramic material for the Terrestrial Planet Finder Coronagraph

    NASA Astrophysics Data System (ADS)

    Karlmann, Paul B.; Klein, Kerry J.; Halverson, Peter G.; Peters, Robert D.; Levine, Marie B.; Van Buren, David; Dudik, Matthew J.

    2005-08-01

    Linear thermal expansion measurements of nine samples of Lead Magnesium Niobate (PMN) electroceramic material were recently performed in support of NASA's Terrestrial Planet Finder Coronagraph (TPF-C) mission. The TPF-C mission is a visible light coronagraph designed to look at roughly 50 stars pre-selected as good candidates for possessing earth-like planets. Upon detection of an earth-like planet, TPF-C will analyze the visible-light signature of the planet's atmosphere for specific spectroscopic indicators that life may exist there. With this focus, the project's primary interest in PMN material is for use as a solid-state actuator for deformable mirrors or compensating optics. The nine test samples were machined from three distinct boules of PMN ceramic manufactured by Xinetics Inc. Thermal expansion measurements were performed in 2005 at NASA Jet Propulsion Laboratory (JPL) in their Cryogenic Dilatometer Facility. All measurements were performed in vacuum with sample temperature actively controlled over the range of 270K to 310K. Expansion and contraction of the test samples with temperature was measured using a JPL-developed interferometric system capable of sub-nanometer accuracy. Presented in this paper is a discussion of the sample configuration, test facilities, test method, data analysis, test results, and future plans.

  8. In situ hard x-ray photoemission spectroscopy of barrier-height control at metal/PMN-PT interfaces

    NASA Astrophysics Data System (ADS)

    Kröger, E.; Petraru, A.; Quer, A.; Soni, R.; Kalläne, M.; Pertsev, N. A.; Kohlstedt, H.; Rossnagel, K.

    2016-06-01

    Metal-ferroelectric interfaces form the basis of novel electronic devices. A key effect determining the device functionality is the bias-dependent change of the electronic energy-level alignment at the interface. Here, hard x-ray photoelectron spectroscopy (HAXPES) is used to determine the energy-level alignment at two metal-ferroelectric interfaces—Au versus SrRuO3 on the relaxor ferroelectric Pb (Mg1 /3Nb2 /3 )0.72Ti0.28O3 (PMN-PT)—directly in situ as a function of electrical bias. The bias-dependent average shifts of the PMN-PT core levels are found to have two dominant contributions on the 0.1 -1-eV energy scale: one depending on the metal electrode and the remanent electric polarization and the other correlated with electric-field-induced strain. Element-specific deviations from the average shifts are smaller than 0.1 eV and appear to be related to predicted dynamical charge variations in PMN-PT. In addition, the efficiency of ferroelectric polarization switching is shown to be reduced near the coercive field under x-ray irradiation. The results establish HAXPES as a tool for the in operando investigation of metal-ferroelectric interfaces and suggest electric-field-induced modifications of the polarization distribution as a novel way to control the barrier height at such interfaces.

  9. Stopover ecology of a migratory ungulate

    USGS Publications Warehouse

    Sawyer, Hall; Kauffman, Matthew J.

    2011-01-01

    1. Birds that migrate long distances use stopover sites to optimize fuel loads and complete migration as quickly as possible. Stopover use has been predicted to facilitate a time-minimization strategy in land migrants as well, but empirical tests have been lacking, and alternative migration strategies have not been considered. 2. We used fine-scale movement data to evaluate the ecological role of stopovers in migratory mule deer Odocoileus hemionus— a land migrant whose fitness is strongly influenced by energy intake rather than migration speed. 3. Although deer could easily complete migrations (range 18–144 km) in several days, they took an average of 3 weeks and spent 95% of that time in a series of stopover sites that had higher forage quality than movement corridors. Forage quality of stopovers increased with elevation and distance from winter range. Mule deer use of stopovers corresponded with a narrow phenological range, such that deer occupied stopovers 44 days prior to peak green-up, when forage quality was presumed to be highest. Mule deer used one stopover for every 5∙3 and 6∙7 km travelled during spring and autumn migrations, respectively, and used the same stopovers in consecutive years. 4. Study findings indicate that stopovers play a key role in the migration strategy of mule deer by allowing individuals to migrate in concert with plant phenology and maximize energy intake rather than speed. Our results suggest that stopover use may be more common among non-avian taxa than previously thought and, although the underlying migration strategies of temperate ungulates and birds are quite different, stopover use is important to both. 5. Exploring the role of stopovers in land migrants broadens the scope of stopover ecology and recognizes that the applied and theoretical benefits of stopover ecology need not be limited to avian taxa.

  10. Stopover ecology of a migratory ungulate.

    PubMed

    Sawyer, Hall; Kauffman, Matthew J

    2011-09-01

    1. Birds that migrate long distances use stopover sites to optimize fuel loads and complete migration as quickly as possible. Stopover use has been predicted to facilitate a time-minimization strategy in land migrants as well, but empirical tests have been lacking, and alternative migration strategies have not been considered. 2. We used fine-scale movement data to evaluate the ecological role of stopovers in migratory mule deer Odocoileus hemionus- a land migrant whose fitness is strongly influenced by energy intake rather than migration speed. 3. Although deer could easily complete migrations (range 18-144 km) in several days, they took an average of 3 weeks and spent 95% of that time in a series of stopover sites that had higher forage quality than movement corridors. Forage quality of stopovers increased with elevation and distance from winter range. Mule deer use of stopovers corresponded with a narrow phenological range, such that deer occupied stopovers 44 days prior to peak green-up, when forage quality was presumed to be highest. Mule deer used one stopover for every 5·3 and 6·7 km travelled during spring and autumn migrations, respectively, and used the same stopovers in consecutive years. 4. Study findings indicate that stopovers play a key role in the migration strategy of mule deer by allowing individuals to migrate in concert with plant phenology and maximize energy intake rather than speed. Our results suggest that stopover use may be more common among non-avian taxa than previously thought and, although the underlying migration strategies of temperate ungulates and birds are quite different, stopover use is important to both. 5. Exploring the role of stopovers in land migrants broadens the scope of stopover ecology and recognizes that the applied and theoretical benefits of stopover ecology need not be limited to avian taxa. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

  11. Spreading the load: antigen transfer between migratory and lymph node-resident dendritic cells promotes T cell priming.

    PubMed

    Mueller, Scott N

    2017-08-28

    Dendritic cells (DC) are specialized in the processing and presentation of antigen for the activation of lymphocytes. Multiple subsets of DCs exist with distinct functions and roles in the initiation of immune responses. DCs found within tissues acquire antigens or become infected by pathogens and migrate to local draining lymph nodes (LN) where they can directly stimulate T cells. These migratory DCs can also transfer antigens to LN-resident DCs and may indirectly enhance T cell priming. In this issue of the European Journal of Immunology, Gurevich et al. [Eur. J. Immunol. 2017. 47: XXXX-XXXX] elegantly demonstrate the influence of the transfer of antigen from migratory DCs to resident DCs on the dynamics of CD8 T cell priming in mice. Using both in vitro imaging to visualise antigen dissemination and intravital 2-photon microscopy to track T cell clustering with migratory and resident DCs, antigen-donor DC were found to efficiently distribute antigen to recipient DC. This process, which involved LFA-1, enhanced the recruitment of CD8(+) T cells into the response and rescued priming when DCs were impaired in presentation capacity. Together, these findings shed light on the dynamics of the transfer of antigens between DCs in vivo for the efficient priming of cytotoxic T cell responses. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  12. Piezo-phototronic effect-induced dual-mode light and ultrasound emissions from ZnS:Mn/PMN-PT thin-film structures.

    PubMed

    Zhang, Yang; Gao, Guanyin; Chan, Helen L W; Dai, Jiyan; Wang, Yu; Hao, Jianhua

    2012-04-03

    Electric-field-controllable luminescence of a ZnS:Mn/PMN-PT system is demonstrated. The light-emission of ZnS:Mn is caused by the piezoelectric potential, resulting from the converse piezoelectric effect of the PMN-PT substrate. Simultaneous generation of light and ultrasound waves is observed in this single system, which offers great potential to develop a dual-modal source combing light and ultrasonic waves for various applications.

  13. Modeling seasonal interactions in the population dynamics of migratory birds

    USGS Publications Warehouse

    Runge, M.C.; Marra, P.P.; Greenberg, Russell; Marra, Peter P.

    2005-01-01

    Understanding the population dynamics of migratory birds requires understanding the relevant biological events that occur during breeding, migratory, and overwintering periods. The few available population models for passerine birds focus on breeding-season events, disregard or oversimplify events during nonbreeding periods, and ignore interactions that occur between periods of the annual cycle. Identifying and explicitly incorporating seasonal interactions into population models for migratory birds could provide important insights about when population limitation actually occurs in the annual cycle. We present a population model for the annual cycle of a migratory bird, based on the American Redstart (Setophaga ruticilla) but more generally applicable, that examines the importance of seasonal interactions by incorporating: (1) density dependence during the breeding and winter seasons, (2) a carry-over effect of winter habitat on breeding-season productivity, and (3) the effects of behavioral dominance on seasonal and habitat specific demographic rates. First, we show that habitat availability on both the wintering and breeding grounds can strongly affect equilibrium population size and sex ratio. Second, sex ratio dynamics, as mediated by behavioral dominance, can affect all other aspects of population dynamics. Third, carry-over effects can be strong, especially when winter events are limiting. These results suggest that understanding the population dynamics of migratory birds may require more consideration of the seasonal interactions induced by carry-over effects and density dependence in multiple seasons. This model provides a framework in which to explore more fully these seasonal dynamics and a context for estimation of life history parameters.

  14. Evolutionary Divergence in Brain Size between Migratory and Resident Birds

    PubMed Central

    Sol, Daniel; Garcia, Núria; Iwaniuk, Andrew; Davis, Katie; Meade, Andrew; Boyle, W. Alice; Székely, Tamás

    2010-01-01

    Despite important recent progress in our understanding of brain evolution, controversy remains regarding the evolutionary forces that have driven its enormous diversification in size. Here, we report that in passerine birds, migratory species tend to have brains that are substantially smaller (relative to body size) than those of resident species, confirming and generalizing previous studies. Phylogenetic reconstructions based on Bayesian Markov chain methods suggest an evolutionary scenario in which some large brained tropical passerines that invaded more seasonal regions evolved migratory behavior and migration itself selected for smaller brain size. Selection for smaller brains in migratory birds may arise from the energetic and developmental costs associated with a highly mobile life cycle, a possibility that is supported by a path analysis. Nevertheless, an important fraction (over 68%) of the correlation between brain mass and migratory distance comes from a direct effect of migration on brain size, perhaps reflecting costs associated with cognitive functions that have become less necessary in migratory species. Overall, our results highlight the importance of retrospective analyses in identifying selective pressures that have shaped brain evolution, and indicate that when it comes to the brain, larger is not always better. PMID:20224776

  15. Evolutionary divergence in brain size between migratory and resident birds.

    PubMed

    Sol, Daniel; Garcia, Núria; Iwaniuk, Andrew; Davis, Katie; Meade, Andrew; Boyle, W Alice; Székely, Tamás

    2010-03-10

    Despite important recent progress in our understanding of brain evolution, controversy remains regarding the evolutionary forces that have driven its enormous diversification in size. Here, we report that in passerine birds, migratory species tend to have brains that are substantially smaller (relative to body size) than those of resident species, confirming and generalizing previous studies. Phylogenetic reconstructions based on Bayesian Markov chain methods suggest an evolutionary scenario in which some large brained tropical passerines that invaded more seasonal regions evolved migratory behavior and migration itself selected for smaller brain size. Selection for smaller brains in migratory birds may arise from the energetic and developmental costs associated with a highly mobile life cycle, a possibility that is supported by a path analysis. Nevertheless, an important fraction (over 68%) of the correlation between brain mass and migratory distance comes from a direct effect of migration on brain size, perhaps reflecting costs associated with cognitive functions that have become less necessary in migratory species. Overall, our results highlight the importance of retrospective analyses in identifying selective pressures that have shaped brain evolution, and indicate that when it comes to the brain, larger is not always better.

  16. Is there a "migratory syndrome" common to all migrant birds?

    PubMed

    Piersma, Theunis; Pérez-Tris, Javier; Mouritsen, Henrik; Bauchinger, Ulf; Bairlein, Franz

    2005-06-01

    Bird migration has been assumed, mostly implicitly, to represent a distinct class of animal behavior, with deep and strong homologies in the various phenotypic expressions of migratory behavior between different taxa. Here the evidence for the existence of what could be called a "migratory syndrome," a tightly integrated, old group of adaptive traits that enables birds to commit themselves to highly organized seasonal migrations, is assessed. A list of problems faced by migratory birds is listed first and the traits that migratory birds have evolved to deal with these problems are discussed. The usefulness of comparative approaches to investigate which traits are unique to migrants is then discussed. A provisional conclusion that, perhaps apart from a capacity for night-time compass orientation, there is little evidence for deeply rooted coadapted trait complexes that could make up such a migratory syndrome, is suggested. Detailed analyses of the genetic and physiological architecture of potential adaptations to migration, combined with a comparative approach to further identify the phylogenetic levels at which different adaptive traits for migration have evolved, are recommended.

  17. Do artisanal fishers perceive declining migratory shorebird populations?

    PubMed

    Andrade, Luciano Pires; Silva-Andrade, Horasa Maria Lima; Lyra-Neves, Rachel Maria; Albuquerque, Ulysses Paulino; Telino-Júnior, Wallace Rodrigues

    2016-03-03

    This paper discusses the results of ethno-ornithological research conducted on the local ecological knowledge (LEK) of artisanal fishers in northeast Brazil between August 2013 and October 2014. The present study analyzed the LEK of 240 artisanal fishermen in relation to Nearctic shorebirds and the factors that may be affecting their populations. We examined whether differences occurred according to the gender and age of the local population. The research instruments included semi-structured and check-list interviews. We found that greater knowledge of migratory birds and the areas where they occur was retained by the local men compared with the local women. Half of the male respondents stated that the birds are always in the same locations, and most of the respondents believed that changes in certain populations were caused by factors related to habitat disturbance, particularly to increases in housing construction and visitors to the island. The main practices affecting the presence of migratory birds mentioned by the locals were boat traffic and noise from bars and vessels. According to the artisanal fishermen, the population of migratory birds that use the area for foraging and resting has been reduced over time. Changes in the local landscape related to urbanization and tourism are most likely the primary causes underlying the reduced migratory shorebird populations as reported by local inhabitants. Thus, managing and monitoring urbanization and tourism are fundamental to increasing the success of the migration process and improving the conservation of migratory shorebird species.

  18. Marsh frogs, Pelophylax ridibundus, determine migratory direction by magnetic field.

    PubMed

    Shakhparonov, Vladimir V; Ogurtsov, Sergei V

    2017-01-01

    Orientation by magnetic cues appears to be adaptive during animal migrations. Whereas the magnetic orientation in birds, mammals, and urodele amphibians is being investigated intensively, the data about anurans are still scarce. This study tests whether marsh frogs could determine migratory direction between the breeding pond and the wintering site by magnetic cues in the laboratory. Adult frogs (N = 32) were individually tested in the T-maze 127 cm long inside the three-axis Helmholtz coil system (diameter 3 m). The arms of the maze were positioned parallel to the natural migratory route of this population when measured in accordance with magnetic field. The frogs were tested under two-motivational conditions mediated by temperature/light regime: the breeding migratory state and the wintering state. The frogs' choice in a T-maze was evident only when analyzed in accordance with the direction of the magnetic field: they moved along the migratory route to the breeding pond and followed the reversion of the horizontal component of the magnetic field. This preference has been detected in both sexes only in the breeding migratory state. This suggests that adult ranid frogs can obtain directional information from the Earth's magnetic field as was shown earlier in urodeles and anuran larvae.

  19. Setting conservation priorities for migratory networks under uncertainty.

    PubMed

    Dhanjal-Adams, Kiran L; Klaassen, Marcel; Nicol, Sam; Possingham, Hugh P; Chadès, Iadine; Fuller, Richard A

    2017-06-01

    Conserving migratory species requires protecting connected habitat along the pathways they travel. Despite recent improvements in tracking animal movements, migratory connectivity remains poorly resolved at a population level for the vast majority of species, thus conservation prioritization is hampered. To address this data limitation, we developed a novel approach to spatial prioritization based on a model of potential connectivity derived from empirical data on species abundance and distance traveled between sites during migration. We applied the approach to migratory shorebirds of the East Asian-Australasian Flyway. Conservation strategies that prioritized sites based on connectivity and abundance metrics together maintained larger populations of birds than strategies that prioritized sites based only on abundance metrics. The conservation value of a site therefore depended on both its capacity to support migratory animals and its position within the migratory pathway; the loss of crucial sites led to partial or total population collapse. We suggest that conservation approaches that prioritize sites supporting large populations of migrants should, where possible, also include data on the spatial arrangement of sites. © 2016 Society for Conservation Biology.

  20. Effect of Elevated Pressure on the Heat Transfer and Power Requirements During Bridgman Growth of PMN-PT Crystals

    NASA Technical Reports Server (NTRS)

    Bune, Andris; Ostrogorsky, Aleksandar; Marin, Carlos; Nicoara, Irina; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Performance of the furnace during Bridgman growth of the lead magnesium niobate-lead titanate crystal (PMN-PT) is analyzed. PMN-PT is electrostrictive ceramic that has near ideal strain-voltage function. Furthermore piezoelectric (2000 to 2300 pC/N) and coupling (92 to 95%) constants are exceptionally good. Due to these properties PMN-PT has wide range of applications - from sonars to transducers in a high precision optical systems. In this research first attempt to crystallize PMN-PT in a Mellen type vertical Bridgman furnace was not successful, as melting temperature of precursor materials was not achieved. At this point choice was between building a new more powerful facility or finding ways to enhance performance of the existing furnace. Besides adjusting power supply to the individual heating elements, redesigning ampoule holding cartridge and improving furnace insulation one more radical improvement was proposed. The entire furnace was placed into the high pressure chamber. Further experiments confirmed that temperature inside the furnace was increased sufficiently to melt precursor materials to obtain PMN-PT. Numerical modeling is undertaken to find limitations of this technique and to predict temperature distribution inside the ampoule. It is of interest also to account for main factors contributing to a higher temperatures achieved in the furnace under the higher pressure (up to 10 atm.). Numerical model of the furnace is based on general purpose finite - element code FIDAP and on previous efforts to model Bridgman type furnace with multiply heaters. In order to account for all heat transfer mechanism involved - conduction, convection and radiation - different parts of the furnace are modeled in accordance with expected dominant mode of heat transfer - conduction in the solid parts, conduction and radiation in the ampoule, gas convection and conduction in the furnace openings complemented with wall-to-wall radiation. Because of these complicating factors

  1. The Most Powerful Flaring Activity from the NLSy1 PMN J0948+0022

    NASA Technical Reports Server (NTRS)

    D'Ammando, F.; Orienti, M.; Finke, J.; Raiteri, C. M.; Hovatta, T.; Larsson, J.; Max-Moerbeck, W.; Perkins, J.; Readhead, A. C. S.; Richards, J. L.

    2014-01-01

    We report on multifrequency observations performed during 2012 December-2013 August of the first narrow-line Seyfert 1 galaxy detected in gamma rays, PMN J0948+0022 (z equal to 0.5846). A gamma-ray flare was observed by the Large Area Telescope on board Fermi during 2012 December-2013 January, reaching a daily peak flux in the 0.1-100 GeV energy range of (155 plus or minus 31)×10(exp -8) ph cm (exp -2) s (exp -1) on 2013 January 1, corresponding to an apparent isotropic luminosity of approximately 1.5×10)exp 48) erg s(exp -1). The gamma-ray flaring period triggered Swift and VERITAS observations in addition to radio and optical monitoring by OVRO, MOJAVE, and CRTS. A strong flare was observed in optical, UV, and X- rays on 2012 December 30, quasi-simultaneously to the gamma-ray flare, reaching a record flux for this source from optical to gamma rays. VERITAS observations at very high energy (E greater than 100 GeV) during 2013 January 6-17 resulted in an upper limit of F(sub greater than 0.2 TeV) less than 4.0 × 10(exp -12) ph cm(exp -2) s(exp -1). We compared the spectral energy distribution (SED) of the flaring state in 2013 January with that of an intermediate state observed in 2011. The two SEDs, modelled as synchrotron emission and an external Compton scattering of seed photons from a dust torus, can be modelled by changing both the electron distribution parameters and the magnetic field.

  2. The most powerful flaring activity from the NLSy1 PMN J0948+0022

    DOE PAGES

    D'Ammando, F.; Orienti, M.; Finke, J.; ...

    2014-11-27

    Here, we report on multifrequency observations performed during 2012 December–2013 August of the first narrow-line Seyfert 1 galaxy detected in γ-rays, PMN J0948+0022 (z = 0.5846). A γ-ray flare was observed by the Large Area Telescope on board Fermi during 2012 December–2013 January, reaching a daily peak flux in the 0.1–100 GeV energy range of (155 ± 31) × 10–8 ph cm–2 s–1 on 2013 January 1, corresponding to an apparent isotropic luminosity of ~1.5 × 1048 erg s–1. The γ-ray flaring period triggered Swift and Very Energetic Radiation Imaging Telescope Array System (VERITAS) observations in addition to radio andmore » optical monitoring by Owens Valley Radio Observatory, Monitoring Of Jets in Active galactic nuclei with VLBA Experiments, and Catalina Real-time Transient Survey. A strong flare was observed in optical, UV, and X-rays on 2012 December 30, quasi-simultaneously to the γ-ray flare, reaching a record flux for this source from optical to γ-rays. VERITAS observations at very high energy (E > 100 GeV) during 2013 January 6–17 resulted in an upper limit of F>0.2 TeV < 4.0 × 10–12 ph cm–2 s–1. We compared the spectral energy distribution (SED) of the flaring state in 2013 January with that of an intermediate state observed in 2011. Here, the two SEDs, modelled as synchrotron emission and an external Compton scattering of seed photons from a dust torus, can be modelled by changing both the electron distribution parameters and the magnetic field.« less

  3. Anisotropic Laminar Piezocomposite Actuator Incorporating Machined PMN-PT Single Crystal Fibers

    NASA Technical Reports Server (NTRS)

    Wilkie, W. Keats; Inman, Daniel J.; Lloyd, Justin M.; High, James W.

    2006-01-01

    The design, fabrication, and testing of a flexible, laminar, anisotropic piezoelectric composite actuator utilizing machined PMN-32%PT single crystal fibers is presented. The device consists of a layer of rectangular single crystal piezoelectric fibers in an epoxy matrix, packaged between interdigitated electrode polyimide films. Quasistatic free-strain measurements of the single crystal device are compared with measurements from geometrically identical specimens incorporating polycrystalline PZT-5A and PZT-5H piezoceramic fibers. Free-strain actuation of the single crystal actuator at low bipolar electric fields (+/- 250 V/mm) is approximately 400% greater than that of the baseline PZT-5A piezoceramic device, and 200% greater than that of the PZT-5H device. Free-strain actuation under high unipolar electric fields (0-4kV/mm) is approximately 200% of the PZT-5A baseline device, and 150% of the PZT-5H alternate piezoceramic device. Performance increases at low field are qualitatively consistent with predicted increases based on scaling the low-field d33 piezoelectric constants of the respective piezoelectric materials. High-field increases are much less than scaled d33 estimates, but appear consistent with high-field freestrain measurements reported for similar bulk single-crystal and piezoceramic compositions. Measurements of single crystal actuator capacitance and coupling coefficient are also provided. These properties were poorly predicted using scaled bulk material dielectric and coupling coefficient data. Rules-of-mixtures calculations of the effective elastic properties of the single crystal device and estimated actuation work energy densities are also presented. Results indicate longitudinal stiffnesses significantly lower (50% less) than either piezoceramic device. This suggests that single-crystal piezocomposite actuators will be best suited to low induced-stress, high strain and deflection applications.

  4. Anisotropic Piezocomposite Actuator Incorporating Machined PMN-PT Single Crystal Fibers

    NASA Technical Reports Server (NTRS)

    Wilkie, W. Keats; Inman, Daniel J.; Lloyd, Justin M.; High, James W.

    2004-01-01

    The design, fabrication, and testing of a flexible, planar, anisotropic piezoelectric composite actuator utilizing machined PMN-32%PT single crystal fibers is presented. The device consists of a layer of rectangular single crystal piezoelectric fibers in an epoxy matrix, packaged between interdigitated electrode polyimide films. Quasistatic free-strain measurements of the single crystal device are compared with measurements from geometrically identical specimens incorporating polycrystalline PZT-5A and PZT-5H piezoceramic fibers. Free-strain actuation of the single crystal actuator at low bipolar electric fields (+/- 250 V/mm) is approximately 400% greater than that of the baseline PZT-5A piezoceramic device, and 200% greater than that of the PZT-5H device. Free-strain actuation under high unipolar electric fields (0-4kV/mm) is approximately 200% of the PZT-5A baseline device, and 150% of the PZT-5H alternate piezoceramic device. Performance increases at low field are qualitatively consistent with predicted increases based on scaling the low-field d(sub 33) piezoelectric constants of the respective piezoelectric materials. High-field increases are much less than scaled d(sub 33) estimates, but appear consistent with high-field freestrain measurements reported for similar bulk single-crystal and piezoceramic compositions. Measurements of single crystal actuator capacitance and coupling coefficient are also provided. These properties were poorly predicted using scaled bulk material dielectric and coupling coefficient data. Rules-of-mixtures calculations of the effective elastic properties of the single crystal device and estimated actuation work energy densities are also presented. Results indicate longitudinal stiffnesses significantly lower (50% less) than either piezoceramic device. This suggests that single-crystal piezocomposite actuators will be best suited to low induced-stress, high strain and deflection applications.

  5. The most powerful flaring activity from the NLSy1 PMN J0948+0022

    NASA Astrophysics Data System (ADS)

    D'Ammando, F.; Orienti, M.; Finke, J.; Raiteri, C. M.; Hovatta, T.; Larsson, J.; Max-Moerbeck, W.; Perkins, J.; Readhead, A. C. S.; Richards, J. L.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Bugaev, V.; Cardenzana, J. V.; Cerruti, M.; Chen, X.; Ciupik, L.; Dickinson, H. J.; Eisch, J. D.; Errando, M.; Falcone, A.; Finley, J. P.; Fleischhack, H.; Fortin, P.; Fortson, L.; Furniss, A.; Gerard, L.; Gillanders, G. H.; Griffiths, S. T.; Grube, J.; Gyuk, G.; Håkansson, N.; Holder, J.; Humensky, T. B.; Kar, P.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krennrich, F.; Kumar, S.; Lang, M. J.; Maier, G.; McCann, A.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Nieto, D.; de Bhróithe, A. O'Faoláin; Ong, R. A.; Otte, A. N.; Pohl, M.; Popkow, A.; Prokoph, H.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Rousselle, J.; Santander, M.; Sembroski, G. H.; Smith, A. W.; Staszak, D.; Telezhinsky, I.; Tucci, J. V.; Tyler, J.; Varlotta, A.; Vassiliev, V. V.; Wakely, S. P.; Weinstein, A.; Welsing, R.; Williams, D. A.; Zitzer, B.

    2015-01-01

    We report on multifrequency observations performed during 2012 December-2013 August of the first narrow-line Seyfert 1 galaxy detected in γ-rays, PMN J0948+0022 (z = 0.5846). A γ-ray flare was observed by the Large Area Telescope on board Fermi during 2012 December-2013 January, reaching a daily peak flux in the 0.1-100 GeV energy range of (155 ± 31) × 10-8 ph cm-2 s-1 on 2013 January 1, corresponding to an apparent isotropic luminosity of ˜1.5 × 1048 erg s-1. The γ-ray flaring period triggered Swift and Very Energetic Radiation Imaging Telescope Array System (VERITAS) observations in addition to radio and optical monitoring by Owens Valley Radio Observatory, Monitoring Of Jets in Active galactic nuclei with VLBA Experiments, and Catalina Real-time Transient Survey. A strong flare was observed in optical, UV, and X-rays on 2012 December 30, quasi-simultaneously to the γ-ray flare, reaching a record flux for this source from optical to γ-rays. VERITAS observations at very high energy (E > 100 GeV) during 2013 January 6-17 resulted in an upper limit of F>0.2 TeV < 4.0 × 10-12 ph cm-2 s-1. We compared the spectral energy distribution (SED) of the flaring state in 2013 January with that of an intermediate state observed in 2011. The two SEDs, modelled as synchrotron emission and an external Compton scattering of seed photons from a dust torus, can be modelled by changing both the electron distribution parameters and the magnetic field.

  6. The most powerful flaring activity from the NLSy1 PMN J0948+0022

    SciTech Connect

    D'Ammando, F.; Orienti, M.; Finke, J.; Raiteri, C. M.; Hovatta, T.; Larsson, J.; Max-Moerbeck, W.; Perkins, J.; Readhead, A. C. S.; Richards, J. L.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Bugaev, V.; Cardenzana, J. V.; Cerruti, M.; Chen, X.; Ciupik, L.; Dickinson, H. J.; Eisch, J. D.; Errando, M.; Falcone, A.; Finley, J. P.; Fleischhack, H.; Fortin, P.; Fortson, L.; Furniss, A.; Gerard, L.; Gillanders, G. H.; Griffiths, S. T.; Grube, J.; Gyuk, G.; Hakansson, N.; Holder, J.; Humensky, T. B.; Kar, P.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krennrich, F.; Kumar, S.; Lang, M. J.; Maier, G.; McCann, A.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Nieto, D.; de Bhroithe, A. O.; Ong, R. A.; Otte, A. N.; Pohl, M.; Popkow, A.; Prokoph, H.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Rousselle, J.; Santander, M.; Sembroski, G. H.; Smith, A. W.; Staszak, D.; Telezhinsky, I.; Tucci, J. V.; Tyler, J.; Varlotta, A.; Vassiliev, V. V.; Wakely, S. P.; Weinstein, A.; Welsing, R.; Williams, D. A.; Zitzer, B.

    2014-11-27

    Here, we report on multifrequency observations performed during 2012 December–2013 August of the first narrow-line Seyfert 1 galaxy detected in γ-rays, PMN J0948+0022 (z = 0.5846). A γ-ray flare was observed by the Large Area Telescope on board Fermi during 2012 December–2013 January, reaching a daily peak flux in the 0.1–100 GeV energy range of (155 ± 31) × 10–8 ph cm–2 s–1 on 2013 January 1, corresponding to an apparent isotropic luminosity of ~1.5 × 1048 erg s–1. The γ-ray flaring period triggered Swift and Very Energetic Radiation Imaging Telescope Array System (VERITAS) observations in addition to radio and optical monitoring by Owens Valley Radio Observatory, Monitoring Of Jets in Active galactic nuclei with VLBA Experiments, and Catalina Real-time Transient Survey. A strong flare was observed in optical, UV, and X-rays on 2012 December 30, quasi-simultaneously to the γ-ray flare, reaching a record flux for this source from optical to γ-rays. VERITAS observations at very high energy (E > 100 GeV) during 2013 January 6–17 resulted in an upper limit of F>0.2 TeV < 4.0 × 10–12 ph cm–2 s–1. We compared the spectral energy distribution (SED) of the flaring state in 2013 January with that of an intermediate state observed in 2011. Here, the two SEDs, modelled as synchrotron emission and an external Compton scattering of seed photons from a dust torus, can be modelled by changing both the electron distribution parameters and the magnetic field.

  7. Hybrid songbirds employ intermediate routes in a migratory divide.

    PubMed

    Delmore, Kira E; Irwin, Darren E

    2014-10-01

    Migratory divides are contact zones between populations that use different routes to navigate around unsuitable areas on seasonal migration. Hybrids in divides have been predicted to employ intermediate and potentially inferior routes. We provide the first direct test of this hypothesis, using light-level geolocators to track birds breeding in a hybrid zone between Swainson's thrushes in western Canada. Compared to parental forms, hybrids exhibited increased variability in their migratory routes, with some using intermediate routes that crossed arid and mountainous regions, and some using the same routes as one parental group on fall migration and the other on spring migration. Hybrids also tended to use geographically intermediate wintering sites. Analysis of genetic variation across the hybrid zone suggests moderately strong selection against hybrids. These results indicate that seasonal migratory behaviour might be a source of selection against hybrids, supporting a possible role for migration in speciation.

  8. Migratory Passerine Birds as Reservoirs of Lyme Borreliosis in Europe

    PubMed Central

    Comstedt, Pär; Bergström, Sven; Olsen, Björn; Garpmo, Ulf; Marjavaara, Lisette; Mejlon, Hans; Barbour, Alan G.

    2006-01-01

    To define the role of birds as reservoirs and disseminators of Borrelia spirochetes, we characterized tick infestation and reservoir competence of migratory passerine birds in Sweden. A total of 1,120 immature Ixodes ricinus ticks were removed from 13,260 birds and assayed by quantitative polymerase chain reaction (PCR) for Borrelia, followed by DNA sequencing for species and genotype identification. Distributions of ticks on birds were aggregated, presumably because of varying encounters with ticks along migratory routes. Lyme borreliosis spirochetes were detected in 160 (14%) ticks. Borrelia garinii was the most common species in PCR-positive samples and included genotypes associated with human infections. Infestation prevalence with infected ticks was 5 times greater among ground-foraging birds than other bird species, but the 2 groups were equally competent in transmitting Borrelia. Migratory passerine birds host epidemiologically important vector ticks and Borrelia species and vary in effectiveness as reservoirs on the basis of their feeding behavior. PMID:16836825

  9. Migration costs drive convergence of threshold traits for migratory tactics.

    PubMed

    Sahashi, Genki; Morita, Kentaro

    2013-12-22

    Partial migration of some, but not all, members of a population is a common form of migration. We evaluated how migration costs influence which members migrate in 10 populations of two salmonid species. The migratory patterns of both species were evaluated based on the size at maturity for resident males, which is the threshold trait that determines the migratory tactics used within a population. In both species, this size was smaller in males located further from the sea, where migration costs are presumably higher. Moreover, the threshold sizes at maturity in males were correlated between both species. Our results suggest that migration costs are a significant convergent selective force on migratory tactics and life-history traits in nature.

  10. Food availability during migratory stopover affects testis growth and reproductive behaviour in a migratory passerine.

    PubMed

    Bauchinger, Ulf; Van't Hof, Thomas; Biebach, Herbert

    2009-03-01

    Long-distance migratory passerines initiate testicular recrudescence during spring migration to meet the demands of timely reproduction upon immediate arrival on the breeding grounds. The degree of testicular development is known to depend on environmental factors like stopover habitat quality; reproductive performance may be strongly impacted by testicular maturation upon arrival on the breeding grounds. We investigated the effect of stopover food availability on subsequent reproductive performance in garden warblers (Sylvia borin). Spring migration was simulated by repeated food deprivation and re-feeding to imitate the alternation of flight and stopover periods. During the two final stopover periods, males were either kept under ad libitum food (ad libitum males) or under limited food conditions (limited males). After simulated arrival in the breeding area, manipulation of previous stopover food availability resulted in significantly slower testicular recrudescence (p<0.001) and decreased plasma testosterone (p<0.01) in limited males compared to ad libitum males. Body mass change was not significantly different between the two groups (p=0.38). Limited males also exhibited reduced performance in reproductive behaviours employed in territorial and sexual contexts. Limited males had a longer 'freezing' interval (p<0.05) and decreased activity (p<0.01) when challenged with a live male decoy. In direct confrontation between limited and ad libitum males in the presence of a female, limited males exhibited significantly fewer behavioural traits in sexual context, i.e. directed to the female (p<0.001). Therefore, we suggest that conditions encountered during previous migratory stopover may affect subsequent annual reproductive success by influencing key reproductive behaviours.

  11. Counterintuitive roles of experience and weather on migratory performance

    USGS Publications Warehouse

    Rus, Adrian I.; Duerr, Adam E.; Miller, Tricia A.; Belthoff, James R; Katzner, Todd E.

    2017-01-01

    Migration allows animals to live in resource-rich but seasonally variable environments. Because of the costs of migration, there is selective pressure to capitalize on variation in weather to optimize migratory performance. To test the degree to which migratory performance (defined as speed of migration) of Golden Eagles (Aquila chrysaetos) was determined by age- and season-specific responses to variation in weather, we analyzed 1,863 daily tracks (n = 83 migrant eagles) and 8,047 hourly tracks (n = 83) based on 15 min GPS telemetry data from Golden Eagles and 277 hourly tracks based on 30 s data (n = 37). Spring migrant eagles traveled 139.75 ± 82.19 km day−1 (mean ± SE; n = 57) and 25.59 ± 11.75 km hr−1 (n = 55). Autumn migrant eagles traveled 99.14 ± 59.98 km day−1 (n = 26) and 22.18 ± 9.18 km hr−1 (n = 28). Weather during migration varied by season and by age class. During spring, best-supported daily and hourly models of 15 min data suggested that migratory performance was influenced most strongly by downward solar radiation and that older birds benefited less from flow assistance (tailwinds). During autumn, best-supported daily and hourly models of 15 min data suggested that migratory performance was influenced most strongly by south–north winds and by flow assistance, again less strongly for older birds. In contrast, models for hourly performance based on data collected at 30 s intervals were not well described by a single model, likely reflecting eagles' rapid responses to the many weather conditions they experienced. Although daily speed of travel was similar for all age classes, younger birds traveled at faster hourly speeds than did adults. Our analyses uncovered strong, sometimes counterintuitive, relationships among weather, experience, and migratory flight, and they illustrate the significance of factors other than age in determining migratory performance.

  12. Acephate affects migratory orientation of the white-throated sparrow (Zonotrichia albicollis)

    USGS Publications Warehouse

    Vyas, N.B.; Kuenzel, W.J.; Hill, E.F.; Sauer, J.R.

    1995-01-01

    Migratory white-throated sparrows (Zonotrichia albicollis) were exposed to acephate (acetylphosphoramidothioic acid O,S-dimethyl ester), an organophosphorus pesticide, to determine its effects on migratory orientation and behavior. Birds were also exposed to polarizer sheets to determine the mechanism by which acephate may affect migratory orientation. Adult birds exposed to 256 ppm acephate a.i. were not able to establish a preferred migratory orientation and exhibited random activity. All juvenile treatment groups displayed a seasonally correct southward migratory orientation. We hypothesize that acephate may have produced aberrant migratory behavior by affecting the memory of the migratory route and wintering ground. This experiment reveals that an environmentally relevant concentration of a common organophosphorus pesticide can alter migratory orientation, but its effect is markedly different between adult and juvenile sparrows. Results suggest that the survival of free-flying adult passerine migrants may be compromised following organophosphorus pesticide exposure.

  13. Migratory pathways of GABAergic interneurons when they enter the neocortex.

    PubMed

    Tanaka, Daisuke H; Nakajima, Kazunori

    2012-06-01

    Inhibitory gamma-aminobutyric-acid-containing interneurons play important roles in the functions of the neocortex. During rodent development, most neocortical interneurons are generated in the subpallium and migrate tangentially toward the neocortex. They migrate through multiple pathways to enter the neocortex. Failure of interneuron migration through these pathways during development leads to an abnormal distribution and abnormal functions of interneurons in the postnatal brain. Because of recent discoveries regarding the novel origins and migratory pathways of neocortical interneurons, in this article we review the literature on the migratory pathways of interneurons when they enter the neocortex.

  14. [Exchanges, transportation, and communication: Turkish circulation and migratory domain].

    PubMed

    De Tapia, S

    1996-01-01

    "In this article, the author first describes and then analyzes how networks of exchange, transportation, and communication function to animate and irrigate the Turkish migratory domain, which currently covers Europe, the Middle East, and the CIS, and which has become transoceanic (North America and Australia).... The author suggests a dynamic vision of the migratory domain, based on the mobility of people and goods, and associated with various means of transportation (air, sea, rail, and road), as a complement to the static vision, which observes the emergence of immigrant communities undergoing a complex process of ethnicization (or assimilation) in highly diversified environments." (SUMMARY IN ENG AND SPA)

  15. 77 FR 34931 - Migratory Bird Hunting; Meeting Regarding Regulations for the 2012-13 Hunting Season

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-12

    ... earlier document to establish annual hunting regulations for certain migratory game birds for the 2012-13... hunting migratory game birds under Sec. Sec. 20.101 through 20.107, 20.109, and 20.110 of subpart K. On... migratory game bird hunting regulations (77 FR 29516). In that document, we announced a meeting of the...

  16. Migratory divides and their consequences for dispersal, population size and parasite-host interactions.

    PubMed

    Møller, A P; Garamszegi, L Z; Peralta-Sánchez, J M; Soler, J J

    2011-08-01

    Populations of migratory birds differ in their direction of migration with neighbouring populations often migrating in divergent directions separated by migratory divides. A total of 26% of 103 passerine bird species in Europe had migratory divides that were located disproportionately often along a longitudinal gradient in Central Europe, consistent with the assumption of a Quaternary glacial origin of such divides in the Iberian and Balkan peninsulas followed by recolonization. Given that studies have shown significant genetic differentiation and reduced gene flow across migratory divides, we hypothesized that an absence of migratory divides would result in elevated rates of gene flow and hence a reduced level of local adaptation. In a comparative study, species with migratory divides had larger population sizes and population densities and longer dispersal distances than species without migratory divides. Species with migratory divides tended to be habitat generalists. Bird species with migratory divides had higher richness of blood parasites and higher growth rates of Staphylococcus on their eggs during the incubation period. There was weaker cell-mediated immunity in adults and stronger cell lysis in species with migratory divides. These findings may suggest that migratory divides constitute barriers to dispersal with consequences for ecology and evolution of distributions, population sizes, habitats and parasite-host interactions. They also suggest that migratory divides may play a role in local adaptation in host-parasite interactions.

  17. 50 CFR 92.6 - Use and possession of migratory birds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Provisions § 92.6 Use and possession of migratory birds. You may not sell, offer for sale, purchase, or offer...

  18. 50 CFR 92.10 - Alaska Migratory Bird Co-management Council.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Alaska Migratory Bird Co-management... THE INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.10 Alaska Migratory Bird Co-management Council. (a) Establishment. The U.S. Fish and Wildlife...

  19. 77 FR 39983 - Migratory Bird Hunting; Application for Approval of Fluoropolymeric Shot Coatings as Nontoxic for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

    ... Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AY66 Migratory Bird Hunting; Application for Approval... INFORMATION CONTACT: George Allen, at 703-358-1825. SUPPLEMENTARY INFORMATION: Background The Migratory Bird Treaty Act of 1918 (Act) (16 U.S.C. 703-712 and 16 U.S.C. 742 a-j) implements migratory bird treaties...

  20. 50 CFR 92.6 - Use and possession of migratory birds.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Provisions § 92.6 Use and possession of migratory birds. You may not sell, offer for sale, purchase, or offer...

  1. 77 FR 66406 - Migratory Bird Permits; Delegating Falconry Permitting Authority to Seven States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-05

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AZ16 Migratory Bird Permits; Delegating Falconry... Reduction Act of 1995. OMB has approved the information collection requirements of the Migratory Bird..., as follows: PART 21--MIGRATORY BIRD PERMITS 0 1. The authority citation for part 21 continues to read...

  2. 75 FR 56555 - Migratory Birds; Take of Migrant Peregrine Falcons for Use in Falconry

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... Fish and Wildlife Service Migratory Birds; Take of Migrant Peregrine Falcons for Use in Falconry AGENCY... FURTHER INFORMATION CONTACT: Dr. George Allen, Division of Migratory Bird Management, U.S. Fish and... derived from the Migratory Bird Treaty Act (16 U.S.C. 703-712), which prohibits any person from taking...

  3. 50 CFR 92.6 - Use and possession of migratory birds.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Provisions § 92.6 Use and possession of migratory birds. You may not sell, offer for sale, purchase, or offer...

  4. 50 CFR 92.10 - Alaska Migratory Bird Co-management Council.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Alaska Migratory Bird Co-management... THE INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.10 Alaska Migratory Bird Co-management Council. (a) Establishment. The U.S. Fish and Wildlife...

  5. 50 CFR 92.10 - Alaska Migratory Bird Co-management Council.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Alaska Migratory Bird Co-management... THE INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.10 Alaska Migratory Bird Co-management Council. (a) Establishment. The U.S. Fish and Wildlife...

  6. 77 FR 65201 - Proposed Information Collection; Alaska Migratory Bird Subsistence Harvest Household Survey

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-25

    ... Fish and Wildlife Service Proposed Information Collection; Alaska Migratory Bird Subsistence Harvest... 703-358- 2482 (telephone). SUPPLEMENTARY INFORMATION: I. Abstract The Migratory Bird Treaty Act of... Department of the Interior as the key agency responsible for managing migratory bird populations that...

  7. 50 CFR 92.10 - Alaska Migratory Bird Co-management Council.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Alaska Migratory Bird Co-management... THE INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.10 Alaska Migratory Bird Co-management Council. (a) Establishment. The U.S. Fish and Wildlife...

  8. 50 CFR 92.6 - Use and possession of migratory birds.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Provisions § 92.6 Use and possession of migratory birds. You may not sell, offer for sale, purchase, or offer...

  9. 78 FR 72830 - Migratory Bird Permits; Delegating Falconry Permitting Authority to 17 States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-04

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-BA01 Migratory Bird Permits; Delegating Falconry... Migratory Bird Permits Program and assigned OMB control number 1018-0022, which expires February 28, 2014..., as follows: PART 21--MIGRATORY BIRD PERMITS 0 1. The authority citation for part 21 continues to read...

  10. 50 CFR 92.10 - Alaska Migratory Bird Co-management Council.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Alaska Migratory Bird Co-management... THE INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.10 Alaska Migratory Bird Co-management Council. (a) Establishment. The U.S. Fish and Wildlife...

  11. 50 CFR 92.6 - Use and possession of migratory birds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Provisions § 92.6 Use and possession of migratory birds. You may not sell, offer for sale, purchase, or offer...

  12. Microwave Magnetoelectric Effects in Single Crystal YIG/PMN-PT Bilayers

    NASA Astrophysics Data System (ADS)

    Shastry, S.; Srinivasan, G.; Mantese, J. V.

    2004-03-01

    Layered magnetostrictive/piezoelectric structures are multifunctional due to mechanical force mediated electromagnetic coupling. This study is concerned with microwave magnetoelectric (ME) interactions in layered ferrite-piezoelectric oxides. Ferromagnetic resonance (FMR) is a powerful tool for such studies. An electric field E applied to the composite produces a mechanical deformation in PZT that in turn is coupled to the ferrite, resulting in a shift in the resonance field. Information on the nature of high frequency ME coupling could therefore be obtained from data on field shift vs E. Since the measurement accuracy depends very much on the FMR line width, bilayers consisting of single crystal or epitaxial low-loss ferrites are ideal for the investigations. Studies were performed at 9.4 GHz on bilayers consisting of (100), (110) or (111) epitaxial yttrium iron garnet (YIG) films (1-130 micron) and (100) lead magnesium niobate-lead titanate (PMN-PT). The samples were positioned outside a hole at the bottom or side of a TE102-reflection type cavity. Resonance absorption vs bias magnetic field H were obtained as a function of E = 0-8 kV/cm for both in-plane and out-of-plane H. Important results are as follows. (i) The ME coupling is stronger for H perpendicular to the bilayer than for in-plane H. (ii) The coupling strength is maximum for E and H along <111> in YIG. (iii) The ME constant varies from a maximum of 6 Oe cm/kV for bilayers with 4 micron YIG to a minimum of 3 Oe cm/kV for 110 micron YIG. (iv) The variation of resonance field shift with the volume ratio for the two phases is in agreement with theory [1,2]. 1. M. I. Bichurin, I. A. Kornev, V. M. Petrov, A. S. Tatarenko, Yu. V. Kiliba, and G. Srinivasan, Phys. Rev. B 64, 094409 (2001). 2. M. I. Bichurin, V. M. Petrov, Yu. V. Kiliba, G. Srinivasan, Phys. Rev. B 66, 134404 (2002). This work was supported by a grant from the National Science Foundation (DMR-0322254)

  13. Distinct migratory and non-migratory ecotypes of an endemic New Zealand eleotrid (Gobiomorphus cotidianus) – implications for incipient speciation in island freshwater fish species

    PubMed Central

    2008-01-01

    Background Many postglacial lakes contain fish species with distinct ecomorphs. Similar evolutionary scenarios might be acting on evolutionarily young fish communities in lakes of remote islands. One process that drives diversification in island freshwater fish species is the colonization of depauperate freshwater environments by diadromous (migratory) taxa, which secondarily lose their migratory behaviour. The loss of migration limits dispersal and gene flow between distant populations, and, therefore, is expected to facilitate local morphological and genetic differentiation. To date, most studies have focused on interspecific relationships among migratory species and their non-migratory sister taxa. We hypothesize that the loss of migration facilitates intraspecific morphological, behavioural, and genetic differentiation between migratory and non-migratory populations of facultatively diadromous taxa, and, hence, incipient speciation of island freshwater fish species. Results Microchemical analyses of otolith isotopes (88Sr, 137Ba and 43Ca) differentiated migratory and non-migratory stocks of the New Zealand endemic Gobiomorphus cotidianus McDowall (Eleotridae). Samples were taken from two rivers, one lake and two geographically-separated outgroup locations. Meristic analyses of oculoscapular lateral line canals documented a gradual reduction of these structures in the non-migratory populations. Amplified fragment length polymorphism (AFLP) fingerprints revealed considerable genetic isolation between migratory and non-migratory populations. Temporal differences in reproductive timing (migratory = winter spawners, non-migratory = summer spawners; as inferred from gonadosomatic indices) provide a prezygotic reproductive isolation mechanism between the two ecotypes. Conclusion This study provides a holistic look at the role of diadromy in incipient speciation of island freshwater fish species. All four analytical approaches (otolith microchemistry, morphology

  14. Fermi-LAT detection of a new gamma-ray flare from the NLSy1 PMN J0948+0022

    NASA Astrophysics Data System (ADS)

    D'Ammando, F.; Orienti, M.

    2013-01-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed an increasing gamma-ray flux from a source positionally consistent with PMN J0948+0022 (also known as 2FGL J0948.8+0020, Nolan et al. 2012, ApJS, 199, 31; R.A.= 09h48m57.3201s, Dec.= +00d22'25.558", J2000, Beasley et al. 2002, ApJS, 141, 13), a radio-loud narrow-line Seyfert 1 at z=0.5846 (Sloan Digital Sky Survey, 2004, SDSS2.C).

  15. Management and conservation of migratory landbirds overwintering in the neotropics

    Treesearch

    Daniel R. Petit; James F. Lynch; Richard L. Hutto; John G. Blake; Robert B. Waide

    1993-01-01

    Loss of tropical broadleaved forests and concurrent population declines of long-distance migratory birds in temperate breeding areas have been closely linked in both scientific and popular literature; however, little evidence of a causal association currently exists. We review the current land use situation in the neotropics, the projected outcome of deforestation...

  16. Migratory Waterfowl Habitat Selection in Relation to Aquatic Vegetation

    DTIC Science & Technology

    2004-09-01

    composition. Aquatic vegetation is a critical food source for many migratory waterfowl, and numerous studies have shown that water bodies with abundant...also provide better habitat for invertebrate recruitment, an important supplemental food source for many waterfowl species (Keast 1984). Conversely

  17. 75 FR 9314 - Migratory Bird Permits; Control of Purple Swamphens

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-01

    ... gallinules without a permit on rice-producing property in Louisiana according to the terms of a separate... Migratory Bird Treaty Act, or the Bald and Golden Eagle Protection Act, that person must immediately report... threatened or endangered species or any bird species protected by the Bald and Golden Eagle Protection Act or...

  18. Shared wilderness, shared responsibility, shared vision: Protecting migratory wildlife

    Treesearch

    Will Meeks; Jimmy Fox; Nancy Roeper

    2011-01-01

    Wilderness plays a vital role in global and landscape-level conservation of wildlife. Millions of migratory birds and mammals rely on wilderness lands and waters during critical parts of their life. As large, ecologically intact landscapes, wilderness areas also play a vital role in addressing global climate change by increasing carbon sequestration, reducing...

  19. A neotropical migratory bird prioritization for National Forests and Grasslands

    Treesearch

    Dick Roth; Richard Peterson

    1997-01-01

    The Rocky Mountain Region of the USDA Forest Service provides nesting habitat for 146 species of neotropical migratory birds. Interactive, prioritization databases were developed for each National Forest and National Grassland in the Region to assist land managers in making informed decisions about resource allocations. The data was processed using Paradox software....

  20. 75 FR 64994 - Atlantic Highly Migratory Species; Advisory Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-21

    ... the Atlantic Highly Migratory Species (HMS) Advisory Panel (AP). NMFS consults with and considers the comments and views of the HMS AP when preparing and implementing Fishery Management Plans (FMPs) or FMP...-third (11) of the seats on the HMS AP for a 3-year appointment. Individuals with definable interests...

  1. 77 FR 64318 - Atlantic Highly Migratory Species; Advisory Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-19

    ... the Atlantic Highly Migratory Species (HMS) Advisory Panel (AP). NMFS consults with and considers the comments and views of the HMS AP when preparing and implementing Fishery Management Plans (FMPs) or FMP... approximately one-third (10) of the seats on the HMS AP for a 3-year appointment. Individuals with...

  2. Desired Mobility or Satisfied Immobility? Migratory Aspirations among Knowledge Workers

    ERIC Educational Resources Information Center

    Ferro, Anna

    2006-01-01

    Among the aspects discussed within the globalisation process, the international mobility of professional workers assumes considerable relevance. This paper focuses on migratory aspirations among knowledge workers within the context of economic globalisation and market restructuring in Romania. Due to a lack of literature dealing with these issues,…

  3. Otolith microchemistry of tropical diadromous fishes: spatial and migratory dynamics

    USGS Publications Warehouse

    Smith, William E.; Kwak, Thomas J.

    2014-01-01

    Otolith microchemistry was applied to quantify migratory variation and the proportion of native Caribbean stream fishes that undergo full or partial marine migration. Strontium and barium water chemistry in four Puerto Rico, U.S.A., rivers was clearly related to a salinity gradient; however, variation in water barium, and thus fish otoliths, was also dependent on river basin. Strontium was the most accurate index of longitudinal migration in tropical diadromous fish otoliths. Among the four species examined, bigmouth sleeper Gobiomorus dormitor, mountain mullet Agonostomus monticola, sirajo goby Sicydium spp. and river goby Awaous banana, most individuals were fully amphidromous, but 9-12% were semi-amphidromous as recruits, having never experienced marine or estuarine conditions in early life stages and showing no evidence of marine elemental signatures in their otolith core. Populations of one species, G. dormitor, may have contained a small contingent of semi-amphidromous adults, migratory individuals that periodically occupied marine or estuarine habitats (4%); however, adult migratory elemental signatures may have been confounded with those related to diet and physiology. These findings indicate the plasticity of migratory strategies of tropical diadromous fishes, which may be more variable than simple categorization might suggest.

  4. Population ecology, habitat requirements, and conservation of neotropical migratory birds

    Treesearch

    Deborah M. Finch

    1991-01-01

    This report was prepared in support of the National Fish and Wildlife Foundation's Neotropical Migratory Bird Conservation Program and the USDA Forest Service's role in the program. Recent analyses of data on forest-dwelling species, many of which are neotropical migrants, show population declines in many North American areas. The literature review summarizes...

  5. 78 FR 66684 - Atlantic Highly Migratory Species; Advisory Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-06

    ... are no Academic terms expiring, so no nominations for that sector will be considered at this time... comments and views of the HMS AP when preparing and implementing Fishery Management Plans (FMPs) or FMP...: ``HMS AP Nominations.'' Mail: Jenni Wallace, Highly Migratory Species Management Division, NMFS,...

  6. Do monarch butterflies use polarized skylight for migratory orientation?

    PubMed

    Stalleicken, Julia; Mukhida, Maya; Labhart, Thomas; Wehner, Rüdiger; Frost, Barrie; Mouritsen, Henrik

    2005-06-01

    To test if migratory monarch butterflies use polarized light patterns as part of their time-compensated sun compass, we recorded their virtual flight paths in a flight simulator while the butterflies were exposed to patches of naturally polarized blue sky, artificial polarizers or a sunny sky. In addition, we tested butterflies with and without the polarized light detectors of their compound eye being occluded. The monarchs' orientation responses suggested that the butterflies did not use the polarized light patterns as a compass cue, nor did they exhibit a specific alignment response towards the axis of polarized light. When given direct view of the sun, migratory monarchs with their polarized light detectors painted out were still able to use their time-compensated compass: non-clockshifted butterflies, with their dorsal rim area occluded, oriented in their typical south-southwesterly migratory direction. Furthermore, they shifted their flight course clockwise by the predicted approximately 90 degrees after being advance clockshifted 6 h. We conclude that in migratory monarch butterflies, polarized light cues are not necessary for a time-compensated celestial compass to work and that the azimuthal position of the sun disc and/or the associated light-intensity and spectral gradients seem to be the migrants' major compass cue.

  7. Status and management of neotropical migratory birds: Introduction

    Treesearch

    Deborah M.; Peter W. Stangel

    1993-01-01

    The future for neotropical migratory birds rests with our commitment and ability to provide them adequate habitat during all periods of their life cycle. Our commitment to this cause is apparent in the groundswell of interest in neotropical migrants and the many proactive and coopemtive partnerships resulting from the Partners in Flight - Aves de las Americas...

  8. Desired Mobility or Satisfied Immobility? Migratory Aspirations among Knowledge Workers

    ERIC Educational Resources Information Center

    Ferro, Anna

    2006-01-01

    Among the aspects discussed within the globalisation process, the international mobility of professional workers assumes considerable relevance. This paper focuses on migratory aspirations among knowledge workers within the context of economic globalisation and market restructuring in Romania. Due to a lack of literature dealing with these issues,…

  9. Partial migration: growth varies between resident and migratory fish.

    PubMed

    Gillanders, Bronwyn M; Izzo, Christopher; Doubleday, Zoë A; Ye, Qifeng

    2015-03-01

    Partial migration occurs in many taxa and ecosystems and may confer survival benefits. Here, we use otolith chemistry data to determine whether fish from a large estuarine system were resident or migratory, and then examine whether contingents display differences in modelled growth based on changes in width of otolith growth increments. Sixty-three per cent of fish were resident based on Ba : Ca of otoliths, with the remainder categorized as migratory, with both contingents distributed across most age/size classes and both sexes, suggesting population-level bet hedging. Migrant fish were in slightly better condition than resident fish based on Fulton's K condition index. Migration type (resident versus migratory) was 56 times more likely to explain variation in growth than a model just incorporating year- and age-related growth trends. While average growth only varied slightly between resident and migratory fish, year-to-year variation was significant. Such dynamism in growth rates likely drives persistence of both life-history types. The complex relationships in growth between contingents suggest that management of species exhibiting partial migration is challenging, especially in a world subject to a changing climate. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  10. Leadership, collective motion and the evolution of migratory strategies.

    PubMed

    Guttal, Vishwesha; Couzin, Iain D

    2011-05-01

    Migration is a hallmark life history strategy of a diverse range of organisms, and also ubiquitous in ontogenic processes including normal embryonic development as well as tumor progression. In such scenarios, individual organisms/cells typically respond to long range (and often noisy) environmental cues. In addition, individuals may interact socially with one another leading to emergent group-level navigational abilities. Although much progress has been made in understanding the mechanisms of taxis, there is a lack of theoretical and quantitative understanding of how individuals trade-off information obtained through their own migratory ability and that via social interactions. Here, we discuss results and insights from a recent computational model developed to investigate the evolution of leadership and collective motion in migratory populations. It is shown that, for a broad range of parameter values, only a small proportion of the population gather directional information while the majority employ social cues alone. More generally, ecological conditions for the evolution of resident, solitary and collective migratory strategies are obtained. We discuss how consideration of both proximate and ultimate factors within the same framework may provide insights into preserving migratory patterns that are in grave danger due to anthropogenic pressures.

  11. Links between scale and neotropical migratory bird populations

    Treesearch

    Deborah M. Finch

    1994-01-01

    Recent concerns about the future for migratory birds, particularly those that migrate to the Tropics, have led to the development of a variety of new research and education initiatives addressing avian population ecology and conservation. Research that focuses on the relationships between migrant population trends, geographical patterns, and spatial and temporal scales...

  12. Genetics of migratory and invasive pests in Florida

    USDA-ARS?s Scientific Manuscript database

    Overview of genetic research on migratory and invasive pests being performed at CMAVE. Emphasis will be on efforts to monitor the movements of fall armyworm, Spodoptera frugiperda (J.E. Smith)(Lepidoptera: Noctuidae) during its annual migration, model the behavior in order to predict the effect of r...

  13. Understanding the stopover of migratory birds: a scale dependent approach

    Treesearch

    Frank R. Moore; Mark S. Woodrey; Jeffrey J. Buler; Stefan Woltmann; Ted R. Simons

    2005-01-01

    The development of comprehensive conservation strategies and management plans for migratory birds depends on understanding migrant-habitat relations throughout the annual cycle, including the time when migrants stopover en route. Yet, the complexity of migration makes the assessment of habitat requirements and development of a comprehensive...

  14. Meeting migratory bird management needs by integrated disease control

    USGS Publications Warehouse

    Friend, M.

    1984-01-01

    The need to combat diseases of migratory birds more effectively will intensify because of need to counteract effects of continual habitat losses. Degradation of habitat will increase potential for disease transmission and the emergence of new disease problems. Migratory bird mobility provides a ready mechanism for spread of disease to locations greatly removed from the site of initial outbreaks. Disease control and management on a flyway basis is needed to combat disease problems of migratory birds more effectively. Modifications in the flyway council system are suggested for implementation of an integrated approach to disease control. Flyway management of disease problems is not a new concept and has been used for addressing lead poisoning in waterfowl (Greenwalt 1976). However, integration of disease concepts in the management of migratory birds on a flyway basis has not been attempted to the extent identified in this paper. Information and communication needs to achieve the goal of minimizing losses of migratory birds to disease are also identified. The limited resources available for disease investigations dictate that sound planning efforts serve as the foundation for program development, priority assessment, and coordination of efforts. Effective disease control in migratory birds is achievable. However, disease control will not happen without adjustments in current perspectives and approaches to disease problems. 'A prime requisite of long range planning for animal disease control or eradication is an attitude of mind that sustains an unflagging optimism toward the ultimate accomplishment of desired results, coupled with an equally persistent skepticism toward dogmatic formulae promising either certain success or certain failure. A long range plan cannot remain inviolate. It must undergo constant critical review and modification as necessary to: accommodate newly acquired scientific or practical information; meet changing economic conditions; account for

  15. Silver Doped 0.9PMN-PT-0.1PZT Composite Films for very High Frequency Ultrasonic Transducer Applications.

    PubMed

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Wei, Qiang; Huang, Yuhong; Zhou, Qifa; Shung, K Kirk

    2013-05-01

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+ 2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 µC/cm(2) at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a -6 dB bandwidth of 29% (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications.

  16. 76 FR 59271 - Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ...This rule prescribes the hunting seasons, hours, areas, and daily bag and possession limits for general waterfowl seasons and those early seasons for which States previously deferred selection. Taking of migratory birds is prohibited unless specifically provided for by annual regulations. This rule permits the taking of designated species during the 2011-12...

  17. Taste - impaired

    MedlinePlus

    ... longer. Causes of impaired taste include: Bell's palsy Common cold Flu and other viral infections Nasal infection, nasal ... your diet. For taste problems due to the common cold or flu, normal taste should return when the ...

  18. Impaired Driving

    MedlinePlus

    Impaired driving is dangerous. It's the cause of more than half of all car crashes. It means operating a ... texting Having a medical condition which affects your driving For your safety and the safety of others, ...

  19. Impaired Driving

    MedlinePlus

    ... people were killed in alcohol-impaired driving crashes, accounting for nearly one-third (31%) of all traffic- ... promotion efforts into practice that influence economic, organizational, policy, and school/community action. 13,14 Using community- ...

  20. Multiwavelength Monitoring of the Enigmatic Narrow-Line Seyfert 1 PMN J0948 0022 in March-July 2009

    SciTech Connect

    Abdo, A.A.; Ackermann, M.; Ajello, M.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B.M.; Bechtol, K.; Bellazzini, R. Berenji, B.; Bloom, E.D.; Bonamente, E. Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T.H.; Caliandro, G.A.; /more authors..

    2012-03-29

    Following the recent discovery of {gamma} rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to {gamma} rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to {gamma}-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the {gamma}-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

  1. Multiwavelength observations of the γ-ray-emitting narrow-line Seyfert 1 PMN J0948+0022 in 2011

    DOE PAGES

    D'Ammando, F.; Larsson, J.; Orienti, M.; ...

    2014-01-28

    Here, we report on radio-to-γ-ray observations during 2011 May–September of PMN J0948+0022, the first narrow-line Seyfert 1 (NLSy1) galaxy detected in γ-rays by Fermi-Large Area Telescope. Strong variability was observed in γ-rays, with two flaring periods peaking on 2011 June 20 and July 28. The variability observed in optical and near-infrared seems to have no counterpart in γ-rays. The difference in behaviour could be related to a bending and inhomogeneous jet or a turbulent extreme multicell scenario. The radio spectra showed a variability pattern typical of relativistic jets. The XMM spectrum shows that the emission from the jet dominates abovemore » ~2 keV, while a soft X-ray excess is evident in the low-energy part of the X-ray spectrum. Models where the soft emission is partly produced by blurred reflection or Comptonization of the thermal disc emission provide good fits to the data. The X-ray spectral slope is similar to that found in radio-quiet NLSy1, suggesting that a standard accretion disc is present, as expected from the high accretion rate. Except for the soft X-ray excess, unusual in jet-dominated active galactic nuclei, PMN J0948+0022, shows all characteristics of the blazar class.« less

  2. Multiwavelength observations of the γ-ray-emitting narrow-line Seyfert 1 PMN J0948+0022 in 2011

    SciTech Connect

    D'Ammando, F.; Larsson, J.; Orienti, M.; Raiteri, C. M.; Angelakis, E.; Carraminana, A.; Carrasco, L.; Drake, A. J.; Fuhrmann, L.; Giroletti, M.; Hovatta, T.; Max-Moerbeck, W.; Porras, A.; Readhead, A. C. S.; Recillas, E.; Richards, J. L.

    2014-01-28

    Here, we report on radio-to-γ-ray observations during 2011 May–September of PMN J0948+0022, the first narrow-line Seyfert 1 (NLSy1) galaxy detected in γ-rays by Fermi-Large Area Telescope. Strong variability was observed in γ-rays, with two flaring periods peaking on 2011 June 20 and July 28. The variability observed in optical and near-infrared seems to have no counterpart in γ-rays. The difference in behaviour could be related to a bending and inhomogeneous jet or a turbulent extreme multicell scenario. The radio spectra showed a variability pattern typical of relativistic jets. The XMM spectrum shows that the emission from the jet dominates above ~2 keV, while a soft X-ray excess is evident in the low-energy part of the X-ray spectrum. Models where the soft emission is partly produced by blurred reflection or Comptonization of the thermal disc emission provide good fits to the data. The X-ray spectral slope is similar to that found in radio-quiet NLSy1, suggesting that a standard accretion disc is present, as expected from the high accretion rate. Except for the soft X-ray excess, unusual in jet-dominated active galactic nuclei, PMN J0948+0022, shows all characteristics of the blazar class.

  3. NuSTAR, SWIFT, and GROND Observations of the Flairing MeV Blazar PMN J0641-0320

    NASA Technical Reports Server (NTRS)

    Ajello, M.; Ghisellini, G.; Paliya, V. S.; Kocevski, D.; Tagliaferri, G; Madejski, G.; Rau, A.; Schady, P.; Greiner, J.; Massaro, F.; hide

    2016-01-01

    MeV blazars are a sub-population of the blazar family, exhibiting larger-than-average jet powers, accretion luminosities, and black hole masses. Because of their extremely hard X-ray continua, these objects are best studied in the X-ray domain. Here, we report on the discovery by the Fermi Large Area Telescope and subsequent follow-up observations with NuSTAR, Swift, and GROND of a new member of the MeV blazar family: PMN J0641-0320. Our optical spectroscopy provides confirmation that this is a flat-spectrum radio quasar located at a redshift of z = 1.196. Its very hard NuSTAR spectrum (power-law photon index of approx.1 up to approx. 80 keV) indicates that the emission is produced via inverse Compton scattering off of photons coming from outside the jet. The overall spectral energy distribution of PMN J0641-0320 is typical of powerful blazars and, using a simple one-zone leptonic emission model, we infer that the emission region is located either inside the broad line region or within the dusty torus.

  4. Performance of PIN-PMN-PT Single Crystal Piezoelectric versus PZT8 Piezoceramic Materials in Ultrasonic Transducers

    NASA Astrophysics Data System (ADS)

    DeAngelis, D. A.; Schulze, G. W.

    The recent advancements in the manufacturing of single crystal PIN-PMN-PT piezoelectric materials now make them a cost-competitive alternative to PZT4 and PZT8 (Navy Types I and III) piezoceramic materials, which have been the workhorse of power ultrasonic applications (e.g., welding, cutting, sonar, etc.) for over 50 years. Although there are great benefits to the use of single crystal materials with respect to high output, as well as added actuating and sensing abilities, many transducer designers are still reluctant to explore these materials due to inadequate design guidelines for substituting the familiar PZT materials; for example, what are the implications of the higher capacitance, sensitivity to chipping/cracks, aging effects, frequency shifts, or how much preload can be used are all common questions. This research is a case study on the performance of identical ultrasonic transducer bodies, used for semiconductor wire bonding, assembled with either PZT8 or PIN-PMN-PT piezo material. The main purpose of the study is to establish rule-of-thumb design guidelines for direct substitution of single crystal materials in existing PZT8 transducer designs, along with a side-by-side performance comparison to highlight benefits. Several metrics are investigated such as impedance, frequency, displacement gain, quality factor and electromechanical coupling factor.

  5. Surface acoustic load sensing using a face-shear PIN-PMN-PT single-crystal resonator.

    PubMed

    Kim, Kyungrim; Zhang, Shujun; Jiang, Xiaoning

    2012-11-01

    Pb(In(0.5)Nb(0.5))O(3)-Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PIN-PMN-PT) resonators for surface acoustic load sensing are presented in this paper. Different acoustic loads are applied to thickness mode, thickness-shear mode, and face-shear mode resonators, and the electrical impedances at resonance and anti-resonance frequencies are recorded. More than one order of magnitude higher sensitivity (ratio of electrical impedance change to surface acoustic impedance change) at the resonance is achieved for the face-shear-mode resonator compared with other resonators with the same dimensions. The Krimholtz, Leedom, and Matthaei (KLM) model is used to verify the surface acoustic loading effect on the electrical impedance spectrum of face-shear PIN-PMN-PT single-crystal resonators. The demonstrated high sensitivity of face-shear mode resonators to surface loads is promising for a broad range of applications, including artificial skin, biological and chemical sensors, touch screens, and other touch-based sensors.

  6. X-ray Observations of the Radio-loud Narrow-Line Seyfert 1 Galaxy PMN J0948+0022

    NASA Astrophysics Data System (ADS)

    Brenneman, Laura; Reynolds, Christopher S.; Markoff, Sera; Parker, Michael; Miller, Jon M.

    2017-08-01

    We report on the 200-ks NuSTAR observation of the narrow-line Seyfert 1 (NLS1) AGN, PMN J0948+0022, executed simultaneously with an 80-ks XMM-Newton observation in 2016. PMN J0948+0022 was chosen because it is one of seven known, powerfully-jetted radio-loud (RL) NLS1s that have been observed with Fermi. We will detail our progress toward meeting the following campaign objectives with the analysis of these datasets: (1) Confirming the presence of the soft excess and look for any evidence of reflection, either in Fe K emission or the Compton hump above 10 keV; (2) Determining the correct spectral model across the entire X-ray bandpass (e.g., Comptonization vs. blurred reflection for the soft excess); (3) Measuring the coronal parameters (temperature, optical depth, compactness) by constraining the high-energy cutoff of the power-law and the low-energy UV/optical data simultaneously; (4) Looking for any correlations between the corona, jet and accretion properties by examining radio and Fermi monitoring of the source contemporaneous with the X-ray and UV/optical data and comparing fits to pure disk/corona models vs. jet models; (5) Furthering our understanding of the jet emission mechanism(s) in RLNLS1s by adding new information to the SED modeling of this source.

  7. PMN-PT single crystal, high-frequency ultrasonic needle transducers for pulsed-wave Doppler application.

    PubMed

    Zhou, Qifa; Xu, Xiaochen; Gottlieb, Emanuel J; Sun, Lei; Cannata, Jonathan M; Ameri, Hossein; Humayun, Mark S; Han, Pengdi; Shung, K Kirk

    2007-03-01

    High-frequency needle ultrasound transducers with an aperture size of 0.4 mm were fabricated using lead magnesium niobate-lead titanate (PMN-33% PT) as the active piezoelectric material. The active element was bonded to a conductive silver particle matching layer and a conductive epoxy backing through direct contact curing. An outer matching layer of parylene was formed by vapor deposition. The active element was housed within a polyimide tube and a 20-gauge needle housing. The magnitude and phase of the electrical impedance of the transducer were 47 omega and -38 degrees, respectively. The measured center frequency and -6 dB fractional bandwidth of the PMN-PT needle transducer were 44 MHz and 45%, respectively. The two-way insertion loss was approximately 15 dB. In vivo high-frequency, pulsed-wave Doppler patterns of blood flow in the posterior portion and in vitro ultrasonic backscatter microscope (UBM) images of the rabbit eye were obtained with the 44-MHz needle transducer.

  8. Shear piezoelectric coefficients of PZT, LiNbO3 and PMN-PT at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Bukhari, Syed; Islam, Md; Haziot, Ariel; Beamish, John

    2014-12-01

    Piezoelectric transducers are used to detect stress and to generate nanometer scale displacements but their piezoelectric coefficients decrease with temperature, limiting their performance in cryogenic applications. We have developed a capacitive technique and directly measured the temperature dependence of the shear coefficient d15 for ceramic lead zirconium titanate (PZT), 41° X-cut lithium niobate (LiNbO3) and single crystal lead magnesium niobium-lead titanate (PMN-PT). In PZT, d15 decreases nearly linearly with temperature, dropping by factor of about 4 by 1.3 K. LiNbO3 has the smallest room temperature d15, but its value decreased by only 6% at the lowest temperatures. PMN-PT had the largest value of d15 at room temperature (2.9 × 10-9 m/V, about 45 times larger than for LiNbO3) but it decreased rapidly below 75 K; at 1.3 K, d15 was only about 8% of its room temperature value.

  9. Multipeak self-biased magnetoelectric coupling characteristics in four-phase Metglas/Terfenol-D/Be-bronze/PMN-PT structure

    NASA Astrophysics Data System (ADS)

    Huang, Dongyan; Lu, Caijiang; Bing, Han

    2015-04-01

    This letter develops a self-biased magnetoelectric (ME) structure Metglas/Terfenol-D/Be-bronze/PMN-PT (MTBP) consisting of a magnetization-graded Metglas/Terfenol-D layer, a elastic Be-bronze plate, and a piezoelectric 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 (PMN-PT) plate. By using the magnetization-graded Metglas/Terfenol-D layer and the elastic Be-bronze plate, multi-peak self-biased ME responses are obtained in MTBP structure. The experimental results show that the MTBP structure with two layers of Metglas foil has maximum zero-biased ME voltage coefficient (MEVC). As frequency increases from 0.5 to 90 kHz, eleven large peaks of MEVC with magnitudes of 0.75-33 V/(cm Oe) are observed at zero-biased magnetic field. The results demonstrate that the proposed multi-peak self-biased ME structure may be useful for multifunctional devices such as multi-frequency energy harvesters or low-frequency ac magnetic field sensors.

  10. Ferroic superglasses: Polar nanoregions in relaxor ferroelectric PMN versus CoFe superspins in a discontinuous multilayer

    NASA Astrophysics Data System (ADS)

    Kleemann, Wolfgang; Dec, Jan

    2016-11-01

    Superdipolar glass properties of polar nanoregions (PNRs) in relaxor ferroelectric PbM g1 /3N b2 /3O3 (PMN) are compared to those of ferromagnetic nanoparticles (FNPs) in the superspin glass [Co80Fe20(0.9 nm ) /A l2O3(3 nm ) ] 10. Both the dynamic critical properties at T >Tg and nonergodicity phenomena at T PMN is subject to a crossover from Lacroix-Béné to Cole-Davidson statistics on cooling toward Tg. Surprisingly, it becomes replaced by relaxation and creeplike domain-wall dynamics below Tg as a consequence of volume percolation of the PNR at Tg and formation of a ferroelectric microdomain state under the simultaneous control by quenched random electric fields and the softening ferroelectric F1 u lattice mode.

  11. A comparative study of ultrasonic micro-motors based on single crystal PMN-PT and polycrystalline PZT ceramics

    NASA Astrophysics Data System (ADS)

    Wilson, Stephen A.; Rayner, Philip J.; Gore, Jonathan; Bowles, Adrian R.; McBride, Richard C.

    2008-03-01

    A comparative study has been made to explore the potential benefits of newly available single-crystal ferroelectric materials when used in a practical device, in this case an ultrasonic micro-motor. This type of micro-motor exhibits exceptional power-to-weight characteristics, which could be exploited beneficially, for example, in unmanned air-vehicle (UAV) systems. The operating principles of a range of commercial and experimental motor designs were evaluated objectively in order to identify areas of performance that can potentially be enhanced using PMN-PT single-crystal piezoelectric ceramics. Based on this analysis a practical motor design was selected for construction and experimentation. Detailed numerical analysis indicated that a motor constructed from single crystal PMN-PT could be expected to provide an improvement in motor stall-torque by up to a factor of 2.8 and a no-load speed improvement by a factor of 1.5 when compared with motors based on standard polycrystalline lead-zirconate-titanate (PZT) ceramics. In practice single-crystal versions of the motor were found to produce double the power output of their polycrystalline counterparts. Overall efficiency was found to be improved two-fold. There were significant discrepancies between the numerical predictions for the single-crystal devices and their measured performance, whereas the polycrystalline devices were found to perform closely in line with predictions.

  12. Probing the Nanodomain Origin and Phase Transition Mechanisms in (Un)Poled PMN-PT Single Crystals and Textured Ceramics

    PubMed Central

    Slodczyk, Aneta; Colomban, Philippe

    2010-01-01

    Outstanding electrical properties of solids are often due to the composition heterogeneity and/or the competition between two or more sublattices. This is true for superionic and superprotonic conductors and supraconductors, as well as for many ferroelectric materials. As in PLZT ferroelectric materials, the exceptional ferro- and piezoelectric properties of the PMN-PT ((1−x)PbMg1/3Nb2/3O3−xPbTiO3) solid solutions arise from the coexistence of different symmetries with long and short scales in the morphotropic phase boundary (MPB) region. This complex physical behavior requires the use of experimental techniques able to probe the local structure at the nanoregion scale. Since both Raman signature and thermal expansion behavior depend on the chemical bond anharmonicity, these techniques are very efficient to detect and then to analyze the subtitle structural modifications with an efficiency comparable to neutron scattering. Using the example of poled (field cooling or room temperature) and unpoled PMN-PT single crystal and textured ceramic, we show how the competition between the different sublattices with competing degrees of freedom, namely the Pb-Pb dominated by the Coulombian interactions and those built of covalent bonded entities (NbO6 and TiO6), determine the short range arrangement and the outstanding ferro- and piezoelectric properties. PMID:28883367

  13. Multiwavelength Monitoring of the Enigmatic Narrow-Line Seyfert 1 PMN J0948+0022 in 2009 March-July

    DOE PAGES

    Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

    2009-11-25

    For this research, following the recent discovery of γ rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to γ rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to γ-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the γ-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band.more » The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. In conclusion, these results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.« less

  14. Multiwavelength Monitoring of the Enigmatic Narrow-Line Seyfert 1 PMN J0948+0022 in 2009 March-July

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T. H.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö.; Celotti, A.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Collmar, W.; Conrad, J.; Costamante, L.; Cutini, S.; de Angelis, A.; de Palma, F.; Do Couto e Silva, E.; Drell, P. S.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Fortin, P.; Foschini, L.; Frailis, M.; Fuhrmann, L.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gehrels, N.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hanabata, Y.; Hays, E.; Hughes, R. E.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kadler, M.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Kerr, M.; Knödlseder, J.; Kocian, M. L.; Kuss, M.; Lande, J.; Latronico, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Max-Moerbeck, W.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; McGlynn, S.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Nestoras, I.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Parent, D.; Pavlidou, V.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Readhead, A.; Reimer, O.; Reposeur, T.; Richards, J. L.; Rodriguez, A. Y.; Roth, M.; Ryde, F.; Sadrozinski, H. F. -W.; Sanchez, D.; Sander, A.; Saz Parkinson, P. M.; Scargle, J. D.; Sgrò, C.; Shaw, M. S.; Smith, P. D.; Spandre, G.; Spinelli, P.; Strickman, M. S.; Suson, D. J.; Tagliaferri, G.; Tajima, H.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Wehrle, A. E.; Winer, B. L.; Wood, K. S.; Ylinen, T.; Zensus, J. A.; Ziegler, M.; Angelakis, E.; Bailyn, C.; Bignall, H.; Blanchard, J.; Bonning, E. W.; Buxton, M.; Canterna, R.; Carramiñana, A.; Carrasco, L.; Colomer, F.; Doi, A.; Ghisellini, G.; Hauser, M.; Hong, X.; Isler, J.; Kino, M.; Kovalev, Y. Y.; Kovalev, Yu. A.; Krichbaum, T. P.; Kutyrev, A.; Lahteenmaki, A.; van Langevelde, H. J.; Lister, M. L.; Macomb, D.; Maraschi, L.; Marchili, N.; Nagai, H.; Paragi, Z.; Phillips, C.; Pushkarev, A. B.; Recillas, E.; Roming, P.; Sekido, M.; Stark, M. A.; Szomoru, A.; Tammi, J.; Tavecchio, F.; Tornikoski, M.; Tzioumis, A. K.; Urry, C. M.; Wagner, S.

    2009-11-25

    For this research, following the recent discovery of γ rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to γ rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to γ-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the γ-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. In conclusion, these results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

  15. Suppression of polymorphonuclear (PMN) and monocyte-mediated inhibition of Candida albicans growth by delta-9-tetrahydrocannabinol

    SciTech Connect

    Djeu, J.Y.; Parapanios, A.; Halkias, D.; Friedman, H.

    1986-03-05

    This study was an in vitro attempt to identify the effector cells responsible for growth inhibition of the opportunistic fungus, candida albicans, and to determine if THC or another marijuana derivatives, 11-hydroxyTHC, would adversely affect their function. Using a 24h radiolabel assay, the authors found that growth inhibition of C. albicans was primarily mediated by PMN and monocytes that could be isolated normal human peripheral blood. Both effector cell types caused almost complete inhibition of Candida growth at effector/target ratio of 300/1 and inhibition was often still seen at 30/1-. Incubation of PMN, PBL, or monocytes for 1 hr at 37C with THC or 11-hydroxyTHC caused a marked suppression of function in all 3 cell populations. Maximal suppression was obtained with 7.5-10..mu..g/ml of the drugs in medium containing 10% fetal bovine serum (FBS) or with 2-4..mu..g/ml in 1% FBS. These drug concentrations did not affect lymphoid cell viability or candida growth in the absence of lymphoid effector cells. Marijuana derivatives, therefore, are doubly dangerous in that opportunistic fungi such as C. albicans can grow in their presence while the effector cells that control fungal growth are readily inactivated.

  16. Catecholamine stress alters neutrophil trafficking and impairs wound healing by β2-adrenergic receptor-mediated upregulation of IL-6.

    PubMed

    Kim, Min-Ho; Gorouhi, Farzam; Ramirez, Sandra; Granick, Jennifer L; Byrne, Barbara A; Soulika, Athena M; Simon, Scott I; Rivkah Isseroff, R

    2014-03-01

    Stress-induced hormones can alter the inflammatory response to tissue injury; however, the precise mechanism by which epinephrine influences inflammatory response and wound healing is not well defined. Here we demonstrate that epinephrine alters the neutrophil (polymorphonuclear leukocyte (PMN))-dependent inflammatory response to a cutaneous wound. Using noninvasive real-time imaging of genetically tagged PMNs in a murine skin wound, chronic, epinephrine-mediated stress was modeled by sustained delivery of epinephrine. Prolonged systemic exposure of epinephrine resulted in persistent PMN trafficking to the wound site via an IL-6-mediated mechanism, and this in turn impaired wound repair. Further, we demonstrate that β2-adrenergic receptor-dependent activation of proinflammatory macrophages is critical for epinephrine-mediated IL-6 production. This study expands our current understanding of stress hormone-mediated impairment of wound healing and provides an important mechanistic link to explain how epinephrine stress exacerbates inflammation via increased number and lifetime of PMNs.

  17. The suppressor of cytokine signaling (SOCS)-3 determines keratinocyte proliferative and migratory potential during skin repair.

    PubMed

    Linke, Andreas; Goren, Itamar; Bösl, Michael R; Pfeilschifter, Josef; Frank, Stefan

    2010-03-01

    Recently, the suppressor of cytokine signaling (SOCS)-3 has been shown to be expressed in disturbed wound margin epithelia during diabetes-impaired wound healing in mice. To functionally connect a potential contribution of SOCS-3 expression to the control of wound keratinocyte behavior in skin repair, we created a transgenic mouse (tsgn-K5/SOCS3) overexpressing SOCS-3 in keratinocytes using the bovine keratin 5 promoter. Tsgn-K5/SOCS3 mice showed a constitutive expression of SOCS-3 in the basal layer of skin epidermis. Keratinocytes of tsgn-K5/SOCS3 mice showed full inhibition of signal transducer and activator of transcription (STAT)-3 phosphorylation. Tsgn-K5/SOCS3 keratinocytes also showed a strong inhibition of migratory and proliferative potential in vitro. In addition, tsgn-K5/SOCS3 keratinocytes co-expressed the differentiation marker loricrin in the basal layer of nonwounded skin in vivo. Upon wounding, wound tissues of tsgn-K5/SOCS3 mice showed an impairment of wound closure characterized by strongly atrophied wound margin epithelia. Atrophied epithelia of tsgn-K5/SOCS3 mice exhibited a marked reduction in proliferating cells and reduced total keratinocyte numbers. In summary, this study suggests that the presence of SOCS-3 in keratinocytes strongly disturbs epithelial repair of cutaneous wounds by interfering with keratinocyte proliferation and migration.

  18. Four-state memory based on a giant and non-volatile converse magnetoelectric effect in FeAl/PIN-PMN-PT structure

    NASA Astrophysics Data System (ADS)

    Wei, Yanping; Gao, Cunxu; Chen, Zhendong; Xi, Shibo; Shao, Weixia; Zhang, Peng; Chen, Guilin; Li, Jiangong

    2016-07-01

    We report a stable, tunable and non-volatile converse magnetoelectric effect (ME) in a new type of FeAl/PIN-PMN-PT heterostructure at room temperature, with a giant electrical modulation of magnetization for which the maximum relative magnetization change (ΔM/M) is up to 66%. The 109° ferroelastic domain switching in the PIN-PMN-PT and coupling with the ferromagnetic (FM) film via uniaxial anisotropy originating from the PIN-PMN-PT (011) surface are the key roles in converse ME effect. We also propose here a new, four-state memory through which it is possible to modify the remanent magnetism state by adjusting the electric field. This work represents a helpful approach to securing electric-writing magnetic-reading with low energy consumption for future high-density information storage applications.

  19. Four-state memory based on a giant and non-volatile converse magnetoelectric effect in FeAl/PIN-PMN-PT structure

    PubMed Central

    Wei, Yanping; Gao, Cunxu; Chen, Zhendong; Xi, Shibo; Shao, Weixia; Zhang, Peng; Chen, Guilin; Li, Jiangong

    2016-01-01

    We report a stable, tunable and non-volatile converse magnetoelectric effect (ME) in a new type of FeAl/PIN-PMN-PT heterostructure at room temperature, with a giant electrical modulation of magnetization for which the maximum relative magnetization change (ΔM/M) is up to 66%. The 109° ferroelastic domain switching in the PIN-PMN-PT and coupling with the ferromagnetic (FM) film via uniaxial anisotropy originating from the PIN-PMN-PT (011) surface are the key roles in converse ME effect. We also propose here a new, four-state memory through which it is possible to modify the remanent magnetism state by adjusting the electric field. This work represents a helpful approach to securing electric-writing magnetic-reading with low energy consumption for future high-density information storage applications. PMID:27417902

  20. Four-state memory based on a giant and non-volatile converse magnetoelectric effect in FeAl/PIN-PMN-PT structure.

    PubMed

    Wei, Yanping; Gao, Cunxu; Chen, Zhendong; Xi, Shibo; Shao, Weixia; Zhang, Peng; Chen, Guilin; Li, Jiangong

    2016-07-15

    We report a stable, tunable and non-volatile converse magnetoelectric effect (ME) in a new type of FeAl/PIN-PMN-PT heterostructure at room temperature, with a giant electrical modulation of magnetization for which the maximum relative magnetization change (ΔM/M) is up to 66%. The 109° ferroelastic domain switching in the PIN-PMN-PT and coupling with the ferromagnetic (FM) film via uniaxial anisotropy originating from the PIN-PMN-PT (011) surface are the key roles in converse ME effect. We also propose here a new, four-state memory through which it is possible to modify the remanent magnetism state by adjusting the electric field. This work represents a helpful approach to securing electric-writing magnetic-reading with low energy consumption for future high-density information storage applications.

  1. Giant electric field control of magnetism and narrow ferromagnetic resonance linewidth in FeCoSiB/Si/SiO2/PMN-PT multiferroic heterostructures

    NASA Astrophysics Data System (ADS)

    Gao, Y.; Wang, X.; Xie, L.; Hu, Z.; Lin, H.; Zhou, Z.; Nan, T.; Yang, X.; Howe, B. M.; Jones, J. G.; Brown, G. J.; Sun, N. X.

    2016-06-01

    It has been challenging to achieve combined strong magnetoelectric coupling and narrow ferromagnetic resonance (FMR) linewidth in multiferroic heterostructures. Electric field induced large effective field of 175 Oe and narrow FMR linewidth of 40 Oe were observed in FeCoSiB/Si/SiO2/PMN-PT heterostructures with substrate clamping effect minimized through removing the Si substrate. As a comparison, FeCoSiB/PMN-PT heterostructures with FeCoSiB film directly deposited on PMN-PT showed a comparable voltage induced effective magnetic field but a significantly larger FMR linewidth of 283 Oe. These multiferroic heterostructures exhibiting combined giant magnetoelectric coupling and narrow ferromagnetic resonance linewidth offer great opportunities for integrated voltage tunable RF magnetic devices.

  2. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Numerical Calculation of SAW Propagation Properties at the x-Cut of Ferroelectric PMN-33%PT Single Crystals

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Li, Xiu-Ming; Zhang, Rui; Huang, Nai-Xing; Cao, Wen-Wu

    2009-06-01

    Surface acoustic wave (SAW) properties at the x-cut of relaxor-based 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 (PMN-33%PT) ferroelectric single crystals are analyzed theoretically when poled along the [001]c cubic direction. It can be found that PMN-33%PT single crystal is a kind of material with a low phase velocity and high electromechanical coupling coefficient, and the single crystal possesses some cuts with zero power flow angle. The results are based on the material parameters at room temperature. The conclusions provide device designers with a few ideal cuts of PMN-33%PT single crystals. Moreover, choosing an optimal cut will dramatically improve the performance of SAW devices, and corresponding results for crystal systems working at other temperatures could also be figured out by employing the method.

  3. Full annual cycle climate change vulnerability assessment for migratory birds

    USGS Publications Warehouse

    Culp, Leah A.; Cohen, Emily B.; Scarpignato, Amy L.; Thogmartin, Wayne E.; Marra, Peter P.

    2017-01-01

    Climate change is a serious challenge faced by all plant and animal species. Climate change vulnerability assessments (CCVAs) are one method to assess risk and are increasingly used as a tool to inform management plans. Migratory animals move across regions and continents during their annual cycles where they are exposed to diverse climatic conditions. Climate change during any period and in any region of the annual cycle could influence survival, reproduction, or the cues used to optimize timing of migration. Therefore, CCVAs for migratory animals best estimate risk when they include climate exposure during the entire annual cycle. We developed a CCVA incorporating the full annual cycle and applied this method to 46 species of migratory birds breeding in the Upper Midwest and Great Lakes (UMGL) region of the United States. Our methodology included background risk, climate change exposure × climate sensitivity, adaptive capacity to climate change, and indirect effects of climate change. We compiled information about migratory connectivity between breeding and stationary non-breeding areas using literature searches and U.S. Geological Survey banding and re-encounter data. Climate change exposure (temperature and moisture) was assessed using UMGL breeding season climate and winter climate from non-breeding regions for each species. Where possible, we focused on non-breeding regions known to be linked through migratory connectivity. We ranked 10 species as highly vulnerable to climate change and two as having low vulnerability. The remaining 34 species were ranked as moderately vulnerable. In general, including non-breeding data provided more robust results that were highly individualistic by species. Two species were found to be highly vulnerable throughout their annual cycle. Projected drying will have the greatest effect during the non-breeding season for species overwintering in Mexico and the Caribbean. Projected temperature increases will have the greatest

  4. In situ detection of Bacillus anthracis spores using fully submersible, self-exciting, self-sensing PMN-PT/Sn piezoelectric microcantilevers.

    PubMed

    McGovern, John-Paul; Shih, Wan Y; Shih, Wei-Heng

    2007-08-01

    In this study, we have demonstrated in situ, all-electrical detection of Bacillus anthracis (BA) spores using lead magnesium niobate-lead titanate/tin (PMN-PT/Sn) piezoelectric microcantilever sensors (PEMS) fabricated from PMN-PT freestanding films and electrically insulated with methyltrimethoxysilane (MTMS) coatings on the tin surface. Antibody specific to BA spore surface antigen was immobilized on the platinum electrode of the PMN-PT layer. In phosphate-buffered saline (PBS) solution, the PMN-PT/Sn PEMS exhibited quality (Q) values ranging from 50 to 75. The detection was carried out in a closed-loop flow cell with a liquid volume of 0.8 ml and a flow rate of 1 ml min(-1). It was shown that one sensor, "PEMS-A" (500 microm long, 800 microm wide, with a 22 microm thick PMN-PT layer, a 20 microm thick tin layer and a 1 +/- 0.5 x 10(-12) g Hz(-1) mass detection sensitivity) exhibited resonance frequency shifts of 2100 +/- 200, 1100 +/- 100 and 700 +/- 100 Hz at concentrations of 20,000, 2000, and 200 spores ml(-1) or 16,000, 1600, and 160 total spores, respectively. Additionally, "PEMS-B" (350 microm long, 800 microm wide, with an 8 microm thick PMN-PT layer, a 6 microm thick tin layer and a 2 +/- 1 x 10(-13) g Hz(-1) mass detection sensitivity) exhibited resonance frequency shifts of 2400 +/- 200, 1500 +/- 200, 500 +/- 150 and 200 +/- 100 Hz at concentrations of 20,000, 2000, 100, and 45 spores ml(-1) or 16,000, 1600, 80, and 36 total spores, respectively.

  5. Physical Impairment

    NASA Astrophysics Data System (ADS)

    Trewin, Shari

    Many health conditions can lead to physical impairments that impact computer and Web access. Musculoskeletal conditions such as arthritis and cumulative trauma disorders can make movement stiff and painful. Movement disorders such as tremor, Parkinsonism and dystonia affect the ability to control movement, or to prevent unwanted movements. Often, the same underlying health condition also has sensory or cognitive effects. People with dexterity impairments may use a standard keyboard and mouse, or any of a wide range of alternative input mechanisms. Examples are given of the diverse ways that specific dexterity impairments and input mechanisms affect the fundamental actions of Web browsing. As the Web becomes increasingly sophisticated, and physically demanding, new access features at the Web browser and page level will be necessary.

  6. New Mexico Title I, ESEA Migrant Program: Projects for Migratory Children of Migratory Agricultural Workers. State Annual Evaluation Report for Fiscal Year 1967.

    ERIC Educational Resources Information Center

    Caperton, Bill; And Others

    Prepared by the Title I, Elementary and Secondary Education Act, (ESEA) Migrant Program director, this State annual evaluation report for fiscal year 1967 includes projects for migratory children of migratory agricultural workers in New Mexico. The material in this report represents a comprehensive analysis of Title I Migrant Program activity…

  7. New Mexico Title I, ESEA Migrant Program: Projects for Migratory Children of Migratory Agricultural Workers. State Annual Evaluation Report for Fiscal Year 1967.

    ERIC Educational Resources Information Center

    Caperton, Bill; And Others

    Prepared by the Title I, Elementary and Secondary Education Act, (ESEA) Migrant Program director, this State annual evaluation report for fiscal year 1967 includes projects for migratory children of migratory agricultural workers in New Mexico. The material in this report represents a comprehensive analysis of Title I Migrant Program activity…

  8. Winter temperatures limit population growth rate of a migratory songbird

    PubMed Central

    Woodworth, Bradley K.; Wheelwright, Nathaniel T.; Newman, Amy E.; Schaub, Michael; Norris, D. Ryan

    2017-01-01

    Understanding the factors that limit and regulate wildlife populations requires insight into demographic and environmental processes acting throughout the annual cycle. Here, we combine multi-year tracking data of individual birds with a 26-year demographic study of a migratory songbird to evaluate the relative effects of density and weather at the breeding and wintering grounds on population growth rate. Our results reveal clear support for opposing forces of winter temperature and breeding density driving population dynamics. Above-average temperatures at the wintering grounds lead to higher population growth, primarily through their strong positive effects on survival. However, population growth is regulated over the long term by strong negative effects of breeding density on both fecundity and adult male survival. Such knowledge of how year-round factors influence population growth, and the demographic mechanisms through which they act, will vastly improve our ability to predict species responses to environmental change and develop effective conservation strategies for migratory animals. PMID:28317843

  9. Possibly drug-induced palpable migratory arciform erythema*

    PubMed Central

    Dantas, Fernando Luiz Teixeira; Valente, Neusa Yuriko Sakai; Veronez, Isis Suga; Kakizaki, Priscila; Leitão, Juliana Ribeiro; Fraga, Rafael Cavanellas

    2015-01-01

    Palpable migratory arciform erythema is an entity of unknown etiology, with few published cases in the literature. The clinical and histopathological features of this disease are difficult to be distinguished from those of Jessner’s lymphocytic infiltration of the skin, lupus erythematous tumidus and the deep erythema annulare centrifugum. We describe here the first two Brazilian cases of palpable migratory arciform erythema. The patients presented with infiltrated annular plaques and erythematous arcs without scales. These showed centrifugal growth before disappearing without scarring or residual lesions after a few days. They had a chronic course with repeated episodes for years. In addition, these cases provide evidence of a drug-induced etiology. PMID:26312680

  10. On fuel choice and water balance during migratory bird flights.

    PubMed

    Giulivi, Cecilia; Ramsey, Jon

    2015-01-01

    It has been proposed that water loss during flight in migratory birds under high evaporative conditions can be offset by the production of water through increased protein catabolism. Indeed, oxidation of protein may supply 7-times more water/kJ than fat. However, the lack of a relative increase in protein catabolism over that of fat during long flights indicates that processes other than water balance may be the primary drivers of protein catabolism during long and strenuous flights. These processes include the release of stress hormones (which increase both protein and fat catabolism) and protein catabolism triggered by increased oxidative damage to muscle proteins from reactive oxygen species produced by mitochondria. Protein catabolism is an important source of water for birds during migratory flight, but it remains to be determined if this process is directly regulated by hydration status.

  11. Perflubron emulsion prevents PMN activation and improves myocardial functional recovery after cold ischemia and reperfusion.

    PubMed

    Gale, Stephen C; Gorman, Grace D; Copeland, Jack G; McDonagh, Paul F

    2007-03-01

    In cardiopulmonary bypass, extracorporeal circulation activates neutrophils, which contribute to ischemia reperfusion injury and postoperative myocardial dysfunction. Perfluorocarbons (PFCs) are compounds that dissolve oxygen and have anti-inflammatory and neutrophil-stabilizing properties. We hypothesized that perflubron emulsion (PFE), a PFC, would attenuate neutrophil activation during simulated extracorporeal circulation (SECC) and would preserve myocardial functional recovery during reperfusion after cold ischemia. In a SECC, diluted blood was circulated for 120 min and subsequently used to reperfuse isolated rat hearts after 2 h of cold (12 degrees C) ischemia. Three groups were studied: noncirculated control; SECC/no additive; and SECC/PFE added. In control and SECC/no additive groups, whole blood was diluted 1:1 with plasmalyte. SECC/PFE blood was diluted 1:1 with plasmalyte and PFE (0.075 mL/mL diluted whole blood). Blood counts and neutrophil activation experiments were performed before and after 120 min of SECC. Reperfusion was accomplished using a modified Langendorff preparation. Left ventricular developed pressure, dP/dt, and coronary flow were measured at 10, 15, and 20 min of reperfusion. After 120 min SECC, neutrophil activation was significantly reduced in the SECC/PFE group compared to the SECC/no additive group (38.1 +/- 2.3% versus 51.7 +/- 1.0%, P < 0.05). Compared to cold ischemic hearts reperfused with fresh, non-recirculated blood, left ventricular developed pressure and dP/dt were significantly impaired in the cold ischemic hearts reperfused with SECC/no additive blood (P < 0.05). In contrast, myocardial functional recovery was not impaired in the hearts reperfused with SECC/PFE blood. SECC-induced neutrophil activation was attenuated with Perflubron treatment. In addition, the progressive impairment in myocardial functional recovery after cold ischemia was significantly improved with treatment. PFE has clinical potential to limit

  12. Migratory bats respond to artificial green light with positive phototaxis.

    PubMed

    Voigt, Christian C; Roeleke, Manuel; Marggraf, Lara; Pētersons, Gunārs; Voigt-Heucke, Silke L

    2017-01-01

    Artificial light at night is spreading worldwide at unprecedented rates, exposing strictly nocturnal animals such as bats to a novel anthropogenic stressor. Previous studies about the effect of artificial light on bats focused almost exclusively on non-migratory species, yet migratory animals such as birds are known to be largely affected by light pollution. Thus, we conducted a field experiment to evaluate if bat migration is affected by artificial light at night. In late summer, we presented artificial green light of 520 nm wavelength to bats that were migrating south along the shoreline of the Baltic Sea. Using a light on-off treatment, we observed that the activity of Pipistrellus nathusii and P. pygmaeus, the two most abundant migratory species at our site, increased by more than 50% in the light-on compared to the light-off treatment. We observed an increased number of feeding buzzes during the light-on compared to the light-off treatment for P. nathusii. However, feeding activity was low in general and did not increase disproportionately during the light-on treatment in relation to the overall echolocation call activity of bats. Further, P. nathusii were attracted towards the green light at a distance of about 23 m, which is way beyond the echolocation detection range for insects of Nathusius' bats. We therefore infer that migratory bats were not attracted to artificial green light because of high insect densities, but instead by positive phototaxis. We conclude that artificial light at night may potentially impact bat migration in a yet unrecognized way.

  13. Norepinephrine inhibits the migratory activity of pancreatic cancer cells.

    PubMed

    Stock, Anna-Maria; Powe, Desmond G; Hahn, Stephan A; Troost, Gabriele; Niggemann, Bernd; Zänker, Kurt S; Entschladen, Frank

    2013-07-15

    We have shown previously that norepinephrine induces migratory activity of tumour cells from breast, colon and prostate tissue via activation of beta-2 adrenergic receptors. Consequently, this effect can be inhibited pharmacologically by clinically established beta-blockers. Tumour cell migration is a prerequisite for metastasis formation, and accordingly we and others have shown that breast cancer patients, which take beta-blockers due to hypertension, have reduced metastasis formation and increased survival probability as compared to patients without hypertension or using other anti-hypertensive medication. Unlike the aforementioned tumour cells, pancreatic cancer cells show a reduced migratory activity upon norepinephrine treatment. By means of our three-dimensional, collagen-based cell migration assay, we have investigated the signal transduction pathways involved in this phenomenon. We have found that this conflicting effect of norepinephrine on pancreatic cancer cells is due to an imbalanced activation of the two pathways that usually mediate a pro-migratory effect of norepinephrine in other tumour cell types. Firstly, the inhibitory effect results from activation of a pathway which causes a strong increase of the secondary cell signalling molecule, cAMP. In addition, activation of phospholipase C gamma and the downstream protein kinase C alpha were shown to be already activated in pancreatic cancer cells and cannot be further activated by norepinephrine. We hypothesize that this constitutive activation of the phospholipase C gamma pathway is due to a cross-talk with receptor tyrosine kinase signalling, and this might also deliver an explanation for the unusual high spontaneous migratory activity of pancreatic cancer cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Biocomplexity in a highly migratory pelagic marine fish, Atlantic herring

    PubMed Central

    Ruzzante, Daniel E; Mariani, Stefano; Bekkevold, Dorte; André, Carl; Mosegaard, Henrik; Clausen, Lotte A.W; Dahlgren, Thomas G; Hutchinson, William F; Hatfield, Emma M.C; Torstensen, Else; Brigham, Jennifer; Simmonds, E. John; Laikre, Linda; Larsson, Lena C; Stet, René J.M; Ryman, Nils; Carvalho, Gary R

    2006-01-01

    The existence of biologically differentiated populations has been credited with a major role in conferring sustainability and in buffering overall productivity of anadromous fish population complexes where evidence for spatial structure is uncontroversial. Here, we describe evidence of correlated genetic and life history (spawning season linked to spawning location) differentiation in an abundant and highly migratory pelagic fish, Atlantic herring, Clupea harengus, in the North Sea (NS) and adjacent areas. The existence of genetically and phenotypically diverse stocks in this region despite intense seasonal mixing strongly implicates natal homing in this species. Based on information from genetic markers and otolith morphology, we estimate the proportional contribution by NS, Skagerrak (SKG) and Kattegat and western Baltic (WBS) fish to mixed aggregations targeted by the NS fishery. We use these estimates to identify spatial and temporal differences in life history (migratory behaviour) and habitat use among genetically differentiated migratory populations that mix seasonally. Our study suggests the existence of more complex patterns of intraspecific diversity than was previously recognized. Sustainability may be compromised if such complex patterns are reduced through generalized management (e.g. area closures) that overlooks population differences in spatial use throughout the life cycle. PMID:16777738

  15. Night-vision brain area in migratory songbirds

    PubMed Central

    Mouritsen, Henrik; Feenders, Gesa; Liedvogel, Miriam; Wada, Kazuhiro; Jarvis, Erich D.

    2005-01-01

    Twice each year, millions of night-migratory songbirds migrate thousands of kilometers. To find their way, they must process and integrate spatiotemporal information from a variety of cues including the Earth's magnetic field and the night-time starry sky. By using sensory-driven gene expression, we discovered that night-migratory songbirds possess a tight cluster of brain regions highly active only during night vision. This cluster, here named “cluster N,” is located at the dorsal surface of the brain and is adjacent to a known visual pathway. In contrast, neuronal activation of cluster N was not increased in nonmigratory birds during the night, and it disappeared in migrants when both eyes were covered. We suggest that in night-migratory songbirds cluster N is involved in enhanced night vision, and that it could be integrating vision-mediated magnetic and/or star compass information for night-time navigation. Our findings thus represent an anatomical and functional demonstration of a specific night-vision brain area. PMID:15928090

  16. Feeding impairs chill coma recovery in the migratory locust (Locusta migratoria).

    PubMed

    Andersen, Jonas Lembcke; Findsen, Anders; Overgaard, Johannes

    2013-10-01

    Low temperature causes loss of neuromuscular function in a wide range of insects, such that the animals enter a state known as chill coma. The ability to recover from chill coma (chill coma recovery time) is often a popular phenotype to characterise chill tolerance in insects. Chill coma in insects has been shown to be associated with a decrease in haemolymph volume and a marked increase in [K(+)], causing dissipation of K(+) equilibrium potential and resting membrane potential. High potassium diet (wheat) has also previously been shown to increase haemolymph [K(+)] in Locusta migratoria leading to sluggish behaviour. The present study combined these two independent stressors of ion and water homeostasis, in order to investigate the role of K(+)- and water-balance during recovery from chill coma, in the chill sensitive insect L. migratoria. We confirmed that cold shock elicits a fast increase in haemolymph [K(+)] which is likely caused by a water shift from the haemolymph to the muscles and other tissues. Recovery of haemolymph [K(+)] is however not only reliant on recovery of haemolymph volume, as the recovery of water and K(+) is decoupled. Chill coma recovery time, after 2h at -4 °C, differed significantly between fasted animals and those fed on high K(+) diet. This difference was not associated with an increased disturbance of haemolymph [K(+)] in the fed animals, instead it was associated with a slowed recovery of muscle [K(+)], muslce water, haemolymph [Na(+)] and K(+)equilibrium potential in the fed animals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Dysfunctions in the migratory phenotype and properties of circulating immature transitional B cells during HIV-1 infection.

    PubMed

    Amu, Sylvie; Fievez, Virginie; Nozza, Silvia; Lopalco, Lucia; Chiodi, Francesca

    2016-09-10

    The frequency of immature transitional B cells is increased in blood of HIV-1-infected individuals. We investigated whether HIV-1 infection affects expression and function of chemokine receptors important for egress of immature transitional B cells from bone marrow and migration to lymphoid organs. This is a cross-sectional study analysing the migratory phenotype and function of immature transitional B cells in HIV-1-infected individuals, in relation to antiretroviral treatment and age. Frequency of blood immature transitional B cells and their phenotypic characteristics, including chemokine receptors and a maturation marker, were determined by immunostainings. Migratory capacities were studied in a migration assay. The increased frequency of immature transitional B cells in untreated HIV-1 infection was normalized in patients receiving antiretroviral treatment; in our cohorts, age did not have an impact on the frequency of circulating immature transitional B cells. Immature transitional B cells from nontreated patients expressed low levels of CD21 molecule. We found an elevated frequency of CXCR3 and CXCR4 expressing immature transitional B cells in treated and nontreated patients. CXCR4 receptor was unresponsive to CXCL12 ligand in in-vitro migration and internalization assays. In addition, CXCR5 expression was downregulated on immature transitional B cells from infected patients, and these cells migrated poorly in response to CXCR5 ligand. Circulating immature transitional B cells from HIV-1-infected patients are not fully mature, probably due to premature egress from bone marrow; these cells showed a phenotype which could impair entry into secondary lymphoid organs. Changes in migratory capacity of immature transitional B cells may affect B-cell maturation during HIV-1 infection.

  18. Hearing Impairment

    MedlinePlus

    ... may include inserting an object such as a cotton swab too far into the ear, a sudden explosion or other loud noise, a sudden change in air pressure, a head injury, or repeated ear infections. Sensorineural hearing impairment results from problems with or damage ...

  19. The memory effect of magnetoelectric coupling in FeGaB/NiTi/PMN-PT multiferroic heterostructure

    NASA Astrophysics Data System (ADS)

    Zhou, Ziyao; Zhao, Shishun; Gao, Yuan; Wang, Xinjun; Nan, Tianxiang; Sun, Nian X.; Yang, Xi; Liu, Ming

    2016-02-01

    Magnetoelectric coupling effect has provided a power efficient approach in controlling the magnetic properties of ferromagnetic materials. However, one remaining issue of ferromagnetic/ferroelectric magnetoelectric bilayer composite is that the induced effective anisotropy disappears with the removal of the electric field. The introducing of the shape memory alloys may prevent such problem by taking the advantage of its shape memory effect. Additionally, the shape memory alloy can also “store” the magnetoelectric coupling before heat release, which introduces more functionality to the system. In this paper, we study a FeGaB/NiTi/PMN-PT multiferroic heterostructure, which can be operating in different states with electric field and temperature manipulation. Such phenomenon is promising for tunable multiferroic devices with multi-functionalities.

  20. The memory effect of magnetoelectric coupling in FeGaB/NiTi/PMN-PT multiferroic heterostructure.

    PubMed

    Zhou, Ziyao; Zhao, Shishun; Gao, Yuan; Wang, Xinjun; Nan, Tianxiang; Sun, Nian X; Yang, Xi; Liu, Ming

    2016-02-05

    Magnetoelectric coupling effect has provided a power efficient approach in controlling the magnetic properties of ferromagnetic materials. However, one remaining issue of ferromagnetic/ferroelectric magnetoelectric bilayer composite is that the induced effective anisotropy disappears with the removal of the electric field. The introducing of the shape memory alloys may prevent such problem by taking the advantage of its shape memory effect. Additionally, the shape memory alloy can also "store" the magnetoelectric coupling before heat release, which introduces more functionality to the system. In this paper, we study a FeGaB/NiTi/PMN-PT multiferroic heterostructure, which can be operating in different states with electric field and temperature manipulation. Such phenomenon is promising for tunable multiferroic devices with multi-functionalities.

  1. Magnetic microscopy and simulation of strain-mediated control of magnetization in Ni/PMN-PT nanostructures.

    PubMed

    Gilbert, Ian; Chavez, Andres C; Pierce, Daniel T; Unguris, John; Sun, Wei-Yang; Liang, Cheng-Yen; Carman, Gregory P

    2016-10-01

    Strain-mediated thin film multiferroics comprising piezoelectric/ferromagnetic heterostructures enable the electrical manipulation of magnetization with much greater efficiency than other methods; however, the investigation of nanostructures fabricated from these materials is limited. Here we characterize ferromagnetic Ni nanostructures grown on a ferroelectric PMN-PT substrate using scanning electron microscopy with polarization analysis (SEMPA) and micromagnetic simulations. The magnetization of the Ni nanostructures can be controlled with a combination of sample geometry and applied electric field, which strains the ferroelectric substrate and changes the magnetization via magnetoelastic coupling. We evaluate two types of simulations of ferromagnetic nanostructures on strained ferroelectric substrates: conventional micromagnetic simulations including a simple uniaxial strain, and coupled micromagnetic-elastodynamic simulations. Both simulations qualitatively capture the response of the magnetization changes produced by the applied strain, with the coupled solution providing more accurate representation.

  2. Tunable fringe magnetic fields induced by converse magnetoelectric coupling in a FeGa/PMN-PT multiferroic heterostructure

    NASA Astrophysics Data System (ADS)

    Fitchorov, Trifon; Chen, Yajie; Hu, Bolin; Gillette, Scott M.; Geiler, Anton; Vittoria, Carmine; Harris, Vincent G.

    2011-12-01

    The fringe magnetic field, induced by magnetoelectric coupling in a bilayer Fe-Ga/Pb(Mg1/3Nb2/3)O3_PbTiO3 (PMN-PT) multifunctional composite, was investigated. The induced external field is characterized as having a butterfly hysteresis loop when tuned by an applied electric field. A tuning coefficient of the electrically induced fringe magnetic field is derived from the piezoelectric and magnetostrictive properties of the composite. A measured maximum tuning coefficient, 4.5 Oe/(kV cm-1), is found to agree well with theoretical prediction. This work establishes a foundation in the design of transducers based on the magnetoelectric effect.

  3. The memory effect of magnetoelectric coupling in FeGaB/NiTi/PMN-PT multiferroic heterostructure

    PubMed Central

    Zhou, Ziyao; Zhao, Shishun; Gao, Yuan; Wang, Xinjun; Nan, Tianxiang; Sun, Nian X.; Yang, Xi; Liu, Ming

    2016-01-01

    Magnetoelectric coupling effect has provided a power efficient approach in controlling the magnetic properties of ferromagnetic materials. However, one remaining issue of ferromagnetic/ferroelectric magnetoelectric bilayer composite is that the induced effective anisotropy disappears with the removal of the electric field. The introducing of the shape memory alloys may prevent such problem by taking the advantage of its shape memory effect. Additionally, the shape memory alloy can also “store” the magnetoelectric coupling before heat release, which introduces more functionality to the system. In this paper, we study a FeGaB/NiTi/PMN-PT multiferroic heterostructure, which can be operating in different states with electric field and temperature manipulation. Such phenomenon is promising for tunable multiferroic devices with multi-functionalities. PMID:26847469

  4. Angioplastic necrolytic migratory erythema. Unique association of necrolytic migratory erythema, extensive angioplasia, and high molecular weight glucagon-like polypeptide

    SciTech Connect

    Franchimont, C.; Pierard, G.E.; Luyckx, A.S.; Gerard, J.; Lapiere, C.M.

    1982-12-01

    A diabetic patient developed necrolytic migratory erythema with extensive angioplasia and high molecular weight glucagon-like polypeptide. There was no associated neoplasm such as glucagonoma. Lesions in the skin were studied by standard optical microscopy and by radioautography after incorporation of tritiated thymidine. Alterations in the skin begin as focal necrosis in the epidermis and in epithelial structures of adnexa, followed by marked angioplasia and a superficial and deep perivascular dermatitis.

  5. Effects of Fe2O3 Additive on the Structure and Piezoelectric Properties of PZT-PFW-PMN Ceramics

    NASA Astrophysics Data System (ADS)

    Zong, Ximei; Yang, Zupei

    2015-01-01

    Quaternary piezoelectric ceramics 0.90Pb0.95Sr0.05(Zr0.52Ti0.48)O3-0.03Pb(Fe2/3W1/3)O3-0.07Pb(Mn1/3Nb2/3)O3 (PZT-PFW-PMN) + 0.2 wt.% CeO2 + x wt.% Fe2O3 ( x = 0.0 to 0.20) were prepared by the conventional solid-state method. The effects of Fe2O3 addition on the structure and electrical properties of the system were systematically investigated. The results revealed that the phase structure of all samples was tetragonal phase and the piezoelectric and dielectric properties were significantly promoted with increasing Fe2O3 addition. The coercive field E C and internal bias field E i were found to increase with increasing Fe2O3 content. As a result, addition of 0.05 wt.% Fe2O3 for this system resulted in excellent electrical properties, with the following parameter values: Q m = 1839, K p = 0.61, d 33 = 382 pC/N, ɛ r = 1823, tan δ = 0.0054, P r = 19.26 μC/cm2, E C = 13.28 kV/cm, and E i = 0.76 kV/cm. The results indicate that the Fe2O3-modified PZT-PFW-PMN ceramics exhibited favorable properties and could be good candidates for use in high-power piezoelectric transformer applications.

  6. Endogenous PMN sialidase activity exposes activation epitope on CD11b/CD18 which enhances its binding interaction with ICAM-1.

    PubMed

    Feng, Chiguang; Zhang, Lei; Almulki, Lama; Faez, Sepideh; Whitford, Melissa; Hafezi-Moghadam, Ali; Cross, Alan S

    2011-08-01

    Diapedesis is a dynamic, highly regulated process by which leukocytes are recruited to inflammatory sites. We reported previously that removal of sialyl residues from PMNs enables these cells to become more adherent to EC monolayers and that sialidase activity within intracellular compartments of resting PMNs translocates to the plasma membrane following activation. We did not identify which surface adhesion molecules were targeted by endogenous sialidase. Upon activation, β2 integrin (CD11b/CD18) on the PMN surface undergoes conformational change, which allows it to bind more tightly to the ICAM-1 and ICAM-2 on the EC surface. Removal of sialyl residues from CD18 and CD11b, by exogenous neuraminidase or mobilization of PMN sialidase, unmasked activation epitopes, as detected by flow cytometry and enhanced binding to ICAM-1. One sialidase isoform, Neu1, colocalized with CD18 on confocal microscopy. Using an autoperfused microflow chamber, desialylation of immobilized ICAM-1 enhanced leukocyte arrest in vivo. Further, treatment with a sialidase inhibitor in vivo reversed endotoxin-induced binding of leukocytes to ICAM-1, thereby suggesting a role for leukocyte sialidase in the cellular arrest. These data suggest that PMN sialidase could be a physiologic source of the enzymatic activity that removes sialyl residues on β2 integrin and ICAM-1, resulting in their enhanced interaction. Thus, PMN sialidase may be an important regulator of the recruitment of these cells to inflamed sites.

  7. Bordetella parapertussis Survives the Innate Interaction with Human Neutrophils by Impairing Bactericidal Trafficking inside the Cell through a Lipid Raft-Dependent Mechanism Mediated by the Lipopolysaccharide O Antigen

    PubMed Central

    Gorgojo, Juan; Lamberti, Yanina; Valdez, Hugo; Harvill, Eric T.

    2012-01-01

    Whooping cough is a reemerging disease caused by two closely related pathogens, Bordetella pertussis and Bordetella parapertussis. The incidence of B. parapertussis in whooping cough cases has been increasing since the introduction of acellular pertussis vaccines containing purified antigens that are common to both strains. Recently published results demonstrated that these vaccines do not protect against B. parapertussis due to the presence of the O antigen on the bacterial surface that impairs antibody access to shared antigens. We have investigated the effect of the lack of opsonization of B. parapertussis on the outcome of its interaction with human neutrophils (polymorphonuclear leukocytes [PMNs]). In the absence of opsonic antibodies, PMN interaction with B. parapertussis resulted in nonbactericidal trafficking upon phagocytosis. A high percentage of nonopsonized B. parapertussis was found in nonacidic lysosome marker (lysosome-associated membrane protein [LAMP])-negative phagosomes with access to the host cell-recycling pathway of external nutrients, allowing bacterial survival as determined by intracellular CFU counts. The lipopolysaccharide (LPS) O antigen was found to be involved in directing B. parapertussis to PMN lipid rafts, eventually determining the nonbactericidal fate inside the PMN. IgG opsonization of B. parapertussis drastically changed this interaction by not only inducing efficient PMN phagocytosis but also promoting PMN bacterial killing. These data provide new insights into the immune mechanisms of hosts against B. parapertussis and document the crucial importance of opsonic antibodies in immunity to this pathogen. PMID:23027528

  8. Modeling vector-borne disease risk in migratory animals under climate change.

    PubMed

    Hall, Richard J; Brown, Leone M; Altizer, Sonia

    2016-08-01

    Recent theory suggests that animals that migrate to breed at higher latitudes may benefit from reduced pressure from natural enemies, including pathogens ("migratory escape"), and that migration itself weeds out infected individuals and lowers infection prevalence ("migratory culling"). The distribution and activity period of arthropod disease vectors in temperate regions is expected to respond rapidly to climate change, which could reduce the potential for migratory escape. However, climate change could have the opposite effect of reducing transmission if differential responses in the phenology and distribution of migrants and disease vectors reduce their overlap in space and time. Here we outline a simple modeling framework for exploring the influence of climate change on vector-borne disease dynamics in a migratory host. We investigate two scenarios under which pathogen transmission dynamics might be mediated by climate change: (1) vectors respond more rapidly than migrants to advancing phenology at temperate breeding sites, causing peak susceptible host density and vector emergence to diverge ("migratory mismatch") and (2) reduced migratory propensity allows increased nonbreeding survival of infected hosts and larger breeding-site epidemics (loss of migratory culling, here referred to as "sedentary amplification"). Our results highlight the need for continued surveillance of climate-induced changes to migratory behavior and vector activity to predict pathogen prevalence and its impacts on migratory animals. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  9. Annual life-history dependent seasonal differences in neural activity of the olfactory system between non-migratory and migratory songbirds.

    PubMed

    Rastogi, Ashutosh; Surbhi; Malik, Shalie; Rani, Sangeeta; Kumar, Vinod

    2016-01-01

    Present study investigated seasonal plasticity in neural activity of the olfactory system, and assessed whether this was influenced by differences in seasonal life-history states (LHSs) between the non-migratory and migratory birds. Brains of non-migratory Indian weaver birds and migratory redheaded buntings were processed for ZENK immunohistochemistry, a marker of neuronal activation, at the times of equinoxes (March, September) and solstices (June, December), which correspond with the periods of different seasonal LHSs during the year. Immunoreactivity was quantified in brain regions comprising the olfactory system viz. olfactory bulb (OB), anterior olfactory nucleus (AON), prepiriform cortex (CPP), lateral olfactory tract (LOT) and olfactory cortex (piriform cortex, CPI; lateral olfactory cortex, LOC). In weaver birds, ZENK-like immunoreactive (ZENK-lir) cells were significantly higher in all the brain areas during post-breeding season (September) than during the other seasons; OBs had higher neuronal activity in the breeding season (June), however. A similar neural activity pattern but at enhanced levels was found in migratory buntings almost all the year. These results for the first time show LHS-associated differences in the seasonal plasticity of a sensory system between the non-migratory and migratory songbirds.

  10. Inactivation of CD11b in a mouse transgenic model protects against sepsis-induced lung PMN infiltration and vascular injury.

    PubMed

    Gao, Xiao-Pei; Liu, Qinghui; Broman, Michael; Predescu, Dan; Frey, Randall S; Malik, Asrar B

    2005-04-14

    To inactivate chronically the beta2-integrin CD11b (Mac-1), we made a transgenic model in mice in which we expressed the CD11b antagonist polypeptide neutrophil inhibitory factor (NIF). Using these mice, we determined the in vivo effects of CD11b inactivation on polymorphonuclear leukocyte (PMN) function and acute lung injury (ALI) induced by Escherichia coli septicemia. In wild-type PMNs, CD11b expression was induced within 1 h after E. coli challenge, whereas this response was significantly reduced in NIF(+/+) PMNs. Coimmunoprecipitation studies showed that NIF associated with CD11b in NIF(+/+) PMNs. To validate the effectiveness of CD11b blockade, we compared PMN function in NIF(+/+) and Mac-1-deficient (Mac-1(-/-)) mice. Adhesion of both Mac-1(-/-) and NIF(+/+) PMNs to endothelial cells in response to LPS was reduced in both types of PMNs and fully blocked only by the addition of anti-CD11a monoclonal antibody. This finding is indicative of intact CD11a function in the NIF(+/+) PMNs but the blockade of CD11b function. CD11b inactivation in NIF(+/+) mice interfered with lung PMN infiltration induced by E. coli and prevented the increase in lung microvessel permeability and edema formation, with most of the protection seen in the 1-h period after the E. coli. Thus our results demonstrate that CD11b plays a crucial role in mediating lung PMN sequestration and vascular injury in the early phase of gram-negative septicemia. The NIF(+/+) mouse model, in which CD11b is inactivated by binding to NIF, is a potentially useful model for in vivo assessment of the role of PMN CD11b in the mechanism of vascular inflammation.

  11. Wetland Suitability and Connectivity for Trans-Saharan Migratory Waterbirds

    PubMed Central

    Teunen, Joachim; Saura, Santiago; Koedam, Nico

    2015-01-01

    To complete their life cycle waterbirds rely on patchily distributed and often ephemeral wetlands along their migration route in a vast unsuitable matrix. However, further loss and degradation of remaining wetland habitats might lead to a configuration and size of stopovers that is no longer sufficient to ensure long-term survival of waterbird populations. By identifying optimal conservation targets to maintain overall habitat availability en route, we can accommodate an as yet absent functional connectivity component in larger management frameworks for migratory waterbirds, such as the Ramsar Convention and the EU Natura 2000 Network. Using a graph-based habitat availability metric (Equivalent Connected Area) we determine the functional connectivity of wetland networks for seven migratory waterbirds with divergent habitat requirements. Analyses are performed at two spatial extents both spanning the Mediterranean Sea and centered around Greece (Balkan-Cyrenaica and Greece-Cyrenaica). We create species-specific suitable habitat maps and account for human disturbance by species-specific disturbance buffers, based on expert estimates of Flight Initiation Distances. At both spatial extents we quantitatively determine the habitat networks’ overall functional connectivity and identify wetland sites that are crucial for maintaining a well-connected network. We show that the wetland networks for both spatial extents are relatively well connected and identify several wetland sites in Greece and Libya as important for maintaining connectivity. The application of disturbance buffers results in wetland site-specific reduction of suitable habitat area (0.90–7.36%) and an overall decrease of the network’s connectivity (0.65–6.82%). In addition, we show that the habitat networks of a limited set of species can be combined into a single network which accounts for their autoecological requirements. We conclude that targeted management in few but specific wetland complexes

  12. Key Features of Intertidal Food Webs That Support Migratory Shorebirds

    PubMed Central

    Saint-Béat, Blanche; Dupuy, Christine; Bocher, Pierrick; Chalumeau, Julien; De Crignis, Margot; Fontaine, Camille; Guizien, Katell; Lavaud, Johann; Lefebvre, Sébastien; Montanié, Hélène; Mouget, Jean-Luc; Orvain, Francis; Pascal, Pierre-Yves; Quaintenne, Gwenaël; Radenac, Gilles; Richard, Pierre; Robin, Frédéric; Vézina, Alain F.; Niquil, Nathalie

    2013-01-01

    The migratory shorebirds of the East Atlantic flyway land in huge numbers during a migratory stopover or wintering on the French Atlantic coast. The Brouage bare mudflat (Marennes-Oléron Bay, NE Atlantic) is one of the major stopover sites in France. The particular structure and function of a food web affects the efficiency of carbon transfer. The structure and functioning of the Brouage food web is crucial for the conservation of species landing within this area because it provides sufficient food, which allows shorebirds to reach the north of Europe where they nest. The aim of this study was to describe and understand which food web characteristics support nutritional needs of birds. Two food-web models were constructed, based on in situ measurements that were made in February 2008 (the presence of birds) and July 2008 (absence of birds). To complete the models, allometric relationships and additional data from the literature were used. The missing flow values of the food web models were estimated by Monte Carlo Markov Chain – Linear Inverse Modelling. The flow solutions obtained were used to calculate the ecological network analysis indices, which estimate the emergent properties of the functioning of a food-web. The total activities of the Brouage ecosystem in February and July are significantly different. The specialisation of the trophic links within the ecosystem does not appear to differ between the two models. In spite of a large export of carbon from the primary producer and detritus in winter, the higher recycling leads to a similar retention of carbon for the two seasons. It can be concluded that in February, the higher activity of the ecosystem coupled with a higher cycling and a mean internal organization, ensure the sufficient feeding of the migratory shorebirds. PMID:24204666

  13. Key features of intertidal food webs that support migratory shorebirds.

    PubMed

    Saint-Béat, Blanche; Dupuy, Christine; Bocher, Pierrick; Chalumeau, Julien; De Crignis, Margot; Fontaine, Camille; Guizien, Katell; Lavaud, Johann; Lefebvre, Sébastien; Montanié, Hélène; Mouget, Jean-Luc; Orvain, Francis; Pascal, Pierre-Yves; Quaintenne, Gwenaël; Radenac, Gilles; Richard, Pierre; Robin, Frédéric; Vézina, Alain F; Niquil, Nathalie

    2013-01-01

    The migratory shorebirds of the East Atlantic flyway land in huge numbers during a migratory stopover or wintering on the French Atlantic coast. The Brouage bare mudflat (Marennes-Oléron Bay, NE Atlantic) is one of the major stopover sites in France. The particular structure and function of a food web affects the efficiency of carbon transfer. The structure and functioning of the Brouage food web is crucial for the conservation of species landing within this area because it provides sufficient food, which allows shorebirds to reach the north of Europe where they nest. The aim of this study was to describe and understand which food web characteristics support nutritional needs of birds. Two food-web models were constructed, based on in situ measurements that were made in February 2008 (the presence of birds) and July 2008 (absence of birds). To complete the models, allometric relationships and additional data from the literature were used. The missing flow values of the food web models were estimated by Monte Carlo Markov Chain--Linear Inverse Modelling. The flow solutions obtained were used to calculate the ecological network analysis indices, which estimate the emergent properties of the functioning of a food-web. The total activities of the Brouage ecosystem in February and July are significantly different. The specialisation of the trophic links within the ecosystem does not appear to differ between the two models. In spite of a large export of carbon from the primary producer and detritus in winter, the higher recycling leads to a similar retention of carbon for the two seasons. It can be concluded that in February, the higher activity of the ecosystem coupled with a higher cycling and a mean internal organization, ensure the sufficient feeding of the migratory shorebirds.

  14. Wetland suitability and connectivity for trans-Saharan migratory waterbirds.

    PubMed

    Merken, Ronny; Deboelpaep, Evelien; Teunen, Joachim; Saura, Santiago; Koedam, Nico

    2015-01-01

    To complete their life cycle waterbirds rely on patchily distributed and often ephemeral wetlands along their migration route in a vast unsuitable matrix. However, further loss and degradation of remaining wetland habitats might lead to a configuration and size of stopovers that is no longer sufficient to ensure long-term survival of waterbird populations. By identifying optimal conservation targets to maintain overall habitat availability en route, we can accommodate an as yet absent functional connectivity component in larger management frameworks for migratory waterbirds, such as the Ramsar Convention and the EU Natura 2000 Network. Using a graph-based habitat availability metric (Equivalent Connected Area) we determine the functional connectivity of wetland networks for seven migratory waterbirds with divergent habitat requirements. Analyses are performed at two spatial extents both spanning the Mediterranean Sea and centered around Greece (Balkan-Cyrenaica and Greece-Cyrenaica). We create species-specific suitable habitat maps and account for human disturbance by species-specific disturbance buffers, based on expert estimates of Flight Initiation Distances. At both spatial extents we quantitatively determine the habitat networks' overall functional connectivity and identify wetland sites that are crucial for maintaining a well-connected network. We show that the wetland networks for both spatial extents are relatively well connected and identify several wetland sites in Greece and Libya as important for maintaining connectivity. The application of disturbance buffers results in wetland site-specific reduction of suitable habitat area (0.90-7.36%) and an overall decrease of the network's connectivity (0.65-6.82%). In addition, we show that the habitat networks of a limited set of species can be combined into a single network which accounts for their autoecological requirements. We conclude that targeted management in few but specific wetland complexes could

  15. Atlantic Leatherback Migratory Paths and Temporary Residence Areas

    PubMed Central

    López-Mendilaharsu, Milagros; Miller, Philip; Domingo, Andrés; Evans, Daniel; Kelle, Laurent; Plot, Virginie; Prosdocimi, Laura; Verhage, Sebastian; Gaspar, Philippe; Georges, Jean-Yves

    2010-01-01

    Background Sea turtles are long-distance migrants with considerable behavioural plasticity in terms of migratory patterns, habitat use and foraging sites within and among populations. However, for the most widely migrating turtle, the leatherback turtle Dermochelys coriacea, studies combining data from individuals of different populations are uncommon. Such studies are however critical to better understand intra- and inter-population variability and take it into account in the implementation of conservation strategies of this critically endangered species. Here, we investigated the movements and diving behaviour of 16 Atlantic leatherback turtles from three different nesting sites and one foraging site during their post-breeding migration to assess the potential determinants of intra- and inter-population variability in migratory patterns. Methodology/Principal Findings Using satellite-derived behavioural and oceanographic data, we show that turtles used Temporary Residence Areas (TRAs) distributed all around the Atlantic Ocean: 9 in the neritic domain and 13 in the oceanic domain. These TRAs did not share a common oceanographic determinant but on the contrary were associated with mesoscale surface oceanographic features of different types (i.e., altimetric features and/or surface chlorophyll a concentration). Conversely, turtles exhibited relatively similar horizontal and vertical behaviours when in TRAs (i.e., slow swimming velocity/sinuous path/shallow dives) suggesting foraging activity in these productive regions. Migratory paths and TRAs distribution showed interesting similarities with the trajectories of passive satellite-tracked drifters, suggesting that the general dispersion pattern of adults from the nesting sites may reflect the extent of passive dispersion initially experienced by hatchlings. Conclusions/Significance Intra- and inter-population behavioural variability may therefore be linked with initial hatchling drift scenarios and be highly

  16. Atlantic leatherback migratory paths and temporary residence areas.

    PubMed

    Fossette, Sabrina; Girard, Charlotte; López-Mendilaharsu, Milagros; Miller, Philip; Domingo, Andrés; Evans, Daniel; Kelle, Laurent; Plot, Virginie; Prosdocimi, Laura; Verhage, Sebastian; Gaspar, Philippe; Georges, Jean-Yves

    2010-11-09

    Sea turtles are long-distance migrants with considerable behavioural plasticity in terms of migratory patterns, habitat use and foraging sites within and among populations. However, for the most widely migrating turtle, the leatherback turtle Dermochelys coriacea, studies combining data from individuals of different populations are uncommon. Such studies are however critical to better understand intra- and inter-population variability and take it into account in the implementation of conservation strategies of this critically endangered species. Here, we investigated the movements and diving behaviour of 16 Atlantic leatherback turtles from three different nesting sites and one foraging site during their post-breeding migration to assess the potential determinants of intra- and inter-population variability in migratory patterns. Using satellite-derived behavioural and oceanographic data, we show that turtles used Temporary Residence Areas (TRAs) distributed all around the Atlantic Ocean: 9 in the neritic domain and 13 in the oceanic domain. These TRAs did not share a common oceanographic determinant but on the contrary were associated with mesoscale surface oceanographic features of different types (i.e., altimetric features and/or surface chlorophyll a concentration). Conversely, turtles exhibited relatively similar horizontal and vertical behaviours when in TRAs (i.e., slow swimming velocity/sinuous path/shallow dives) suggesting foraging activity in these productive regions. Migratory paths and TRAs distribution showed interesting similarities with the trajectories of passive satellite-tracked drifters, suggesting that the general dispersion pattern of adults from the nesting sites may reflect the extent of passive dispersion initially experienced by hatchlings. Intra- and inter-population behavioural variability may therefore be linked with initial hatchling drift scenarios and be highly influenced by environmental conditions. This high degree of behavioural

  17. HIF-1α-PDK1 axis-induced active glycolysis plays an essential role in macrophage migratory capacity

    PubMed Central

    Semba, Hiroaki; Takeda, Norihiko; Isagawa, Takayuki; Sugiura, Yuki; Honda, Kurara; Wake, Masaki; Miyazawa, Hidenobu; Yamaguchi, Yoshifumi; Miura, Masayuki; Jenkins, Dana M. R.; Choi, Hyunsung; Kim, Jung-whan; Asagiri, Masataka; Cowburn, Andrew S.; Abe, Hajime; Soma, Katsura; Koyama, Katsuhiro; Katoh, Manami; Sayama, Keimon; Goda, Nobuhito; Johnson, Randall S.; Manabe, Ichiro; Nagai, Ryozo; Komuro, Issei

    2016-01-01

    In severely hypoxic condition, HIF-1α-mediated induction of Pdk1 was found to regulate glucose oxidation by preventing the entry of pyruvate into the tricarboxylic cycle. Monocyte-derived macrophages, however, encounter a gradual decrease in oxygen availability during its migration process in inflammatory areas. Here we show that HIF-1α-PDK1-mediated metabolic changes occur in mild hypoxia, where mitochondrial cytochrome c oxidase activity is unimpaired, suggesting a mode of glycolytic reprogramming. In primary macrophages, PKM2, a glycolytic enzyme responsible for glycolytic ATP synthesis localizes in filopodia and lammelipodia, where ATP is rapidly consumed during actin remodelling processes. Remarkably, inhibition of glycolytic reprogramming with dichloroacetate significantly impairs macrophage migration in vitro and in vivo. Furthermore, inhibition of the macrophage HIF-1α-PDK1 axis suppresses systemic inflammation, suggesting a potential therapeutic approach for regulating inflammatory processes. Our findings thus demonstrate that adaptive responses in glucose metabolism contribute to macrophage migratory activity. PMID:27189088

  18. On the evolution of brain size in relation to migratory behaviour in birds

    PubMed Central

    PRAVOSUDOV, VLADIMIR V.; SANFORD, KIRSTEN; HAHN, THOMAS P.

    2007-01-01

    Migratory birds appear to have relatively smaller brain size compared to sedentary species. It has been hypothesized that initial differences in brain size underlying behavioural flexibility drove the evolution of migratory behaviour; birds with relatively large brains evolved sedentary habits and those with relatively small brains evolved migratory behaviour (migratory precursor hypothesis). Alternative hypotheses suggest that changes in brain size might follow different behavioural strategies and that sedentary species might have evolved larger brains because of differences in selection pressures on brain size in migratory and nonmigratory species. Here we present the first evidence arguing against the migratory precursor hypothesis. We compared relative brain volume of three subspecies of the white-crowned sparrow: sedentary Zonotrichia leucophrys nuttalli and migratory Z. l. gambelii and Z. l. oriantha. Within the five subspecies of the white-crowned sparrow, only Z. l. nuttalli is strictly sedentary. The sedentary behaviour of Z. l. nuttalli is probably a derived trait, because Z. l. nuttalli appears to be the most recent subspecies and because all species ancestral to Zonotrichia as well as all older subspecies of Z. leucophrys are migratory. Compared to migratory Z. l. gambelii and Z. l. oriantha, we found that sedentary Z. l. nuttalli had a significantly larger relative brain volume, suggesting that the larger brain of Z. l. nuttalli evolved after a switch to sedentary behaviour. Thus, in this group, brain size does not appear to be a precursor to the evolution of migratory or sedentary behaviour but rather an evolutionary consequence of a change in migratory strategy. PMID:18311316

  19. Argonaute 1 is indispensable for juvenile hormone mediated oogenesis in the migratory locust, Locusta migratoria.

    PubMed

    Song, Jiasheng; Guo, Wei; Jiang, Feng; Kang, Le; Zhou, Shutang

    2013-09-01

    Juvenile hormone (JH) is the primary hormone controlling vitellogenesis and oocyte maturation in the migratory locust Locusta migratoria, an evolutionarily primitive insect species with panoistic ovaries. However, molecular mechanisms of locust oogenesis remain unclear and the role of microRNA (miRNA) in JH mediated locust vitellogenesis and oocyte maturation has not been explored. Using miRNA sequencing and quantification with small RNA libraries derived from fat bodies of JH-deprived versus JH analog-exposed female adult locusts, we have identified 83 JH up-regulated and 60 JH down-regulated miRNAs. QRT-PCR validation has confirmed that transcription of selected miRNAs responded to JH administration and correlated with changes in endogenous hemolymph JH titers. Depletion of Argonaute 1 (Ago1), a key regulator of miRNA biogenesis and function by RNAi in female adult locusts dramatically decreased the expression of vitellogenin (Vg) and severely impaired follicular epithelium development, terminal oocyte maturation and ovarian growth. Our data indicate that Ago1 and Ago1-dependent miRNAs play a crucial role in locust vitellogenesis and egg production.

  20. Tumor-Activated Mesenchymal Stromal Cells Promote Osteosarcoma Stemness and Migratory Potential via IL-6 Secretion

    PubMed Central

    Cortini, Margherita; Massa, Annamaria; Avnet, Sofia; Bonuccelli, Gloria; Baldini, Nicola

    2016-01-01

    Osteosarcoma (OS) is an aggressive bone malignancy with a high relapse rate despite combined treatment with surgery and multiagent chemotherapy. As for other cancers, OS-associated microenvironment may contribute to tumor initiation, growth, and metastasis. We consider mesenchymal stromal cells (MSC) as a relevant cellular component of OS microenvironment, and have previously found that the interaction between MSC and tumor cells is bidirectional: tumor cells can modulate their peripheral environment that in turn becomes more favorable to tumor growth through metabolic reprogramming. Here, we determined the effects of MSC on OS stemness and migration, two major features associated with recurrence and chemoresistance. The presence of stromal cells enhanced the number of floating spheres enriched in cancer stem cells (CSC) of the OS cell population. Furthermore, the co-culturing with MSC stimulated the migratory capacity of OS via TGFβ1 and IL-6 secretion, and the neutralizing antibody anti-IL-6 impaired this effect. Thus, stromal cells in combination with OS spheres exploit a vicious cycle where the presence of CSC stimulates mesenchymal cytokine secretion, which in turn increases stemness, proliferation, migration, and metastatic potential of CSC, also through the increase of expression of adhesion molecules like ICAM-1. Altogether, our data corroborate the concept that a comprehensive knowledge of the interplay between tumor and stroma that also includes the stem-like fraction of tumor cells is needed to develop novel and effective anti-cancer therapies. PMID:27851822

  1. All Vision Impairment

    MedlinePlus

    ... USAJobs Home > Statistics and Data > All Vision Impairment All Vision Impairment Vision Impairment Defined Vision impairment is ... being blind by the U.S. definition.) The category “All Vision Impairment” includes both low vision and blindness. ...

  2. Role of Migratory Birds in Spreading Crimean-Congo Hemorrhagic Fever, Turkey

    PubMed Central

    Eroglu, Cafer; Erciyas-Yavuz, Kiraz; Hokelek, Murat; Acici, Mustafa; Yilmaz, Hava

    2014-01-01

    We investigated migratory birds’ role in spreading Crimean-Congo hemorrhagic fever virus (CCHFV) through attached ticks. We detected CCHFV RNA in ticks on migratory birds in Turkey. Two isolates showed similarity with CCHFV genotype 4, suggesting a role for ticks in CCHFV epidemics in Turkey and spread of CCHFV by birds. PMID:25062428

  3. Important Bird Areas and international Migratory Bird Day - a beneficial convergence in 2002

    Treesearch

    Jennifer Wheeler; Susan Bonfield

    2005-01-01

    International Migratory Bird Day (IMBD) was created in 1993 to increase public awareness, education, and concern for migratory birds and their habitats. As a day of recognition, it serves as both a celebration and a call to conservation action.4 Programmatically, IMBD offers resources to celebrants in the form of a suite of promotional and educational products as well...

  4. Opportunities and goals of the Neotropical Migratory Bird Conservation Program - Partners in Flight

    Treesearch

    Deborah M. Finch

    1992-01-01

    In the fall of 1990, a major program for the conservation of migratory landbirds that breed in North America and winter in Latin America and the Caribbean Basin was initiated. Numerous federal, state. and private organizations in the United States endorsed the initiative by signing an official agreement to cooperatively conserve populations of neotropical migratory...

  5. Migratory Recovery from Infection as a Selective Pressure for the Evolution of Migration.

    PubMed

    Shaw, Allison K; Binning, Sandra A

    2016-04-01

    Migration, a widespread animal behavior, can influence how individuals acquire and transmit pathogens. Past work has demonstrated that migration can reduce the costs of pathogen or parasite infection through two processes: migratory escape from infected areas or individuals and migratory culling of infected individuals. Here, we propose a third process: migratory recovery, where infected individuals lose their parasites and recover from infection during migration. Recovery can occur when parasites and/or their intermediate hosts cannot support changes in the migratory host's internal or external environment during migration. Thus, parasite mortality increases with migration. Although migratory recovery is likely widespread across species, it remains challenging to empirically test it as a selective force promoting migration. We develop a model and determine the conditions under which migratory recovery theoretically favors the evolution of migration. We show that incorporating migratory recovery into a model of migratory escape increases the range of biologically realistic conditions favoring migration and leads to scenarios where partial migration can evolve. Motivated by empirical estimates of infection costs, our model shows how recovery from infection could drive the evolution of migration. We suggest a number of future directions for both theoretical and empirical research in this area.

  6. Seasonal survival estimation for a long-distance migratory bird and the influence of winter precipitation

    Treesearch

    Sarah M. Rockwell; Joseph M. Wunderle; T. Scott Sillett; Carol I. Bocetti; David N. Ewert; Dave Currie; Jennifer D. White; Peter P. Marra

    2017-01-01

    Conservation of migratory animals requires information about seasonal survival rates. Identifying factors that limit populations, and the portions of the annual cycle in which they occur, are critical for recognizing and reducing potential threats. However, such data are lacking for virtually all migratory taxa. We investigated patterns and environmental correlates of...

  7. Role of migratory birds in spreading Crimean-Congo hemorrhagic fever, Turkey.

    PubMed

    Leblebicioglu, Hakan; Eroglu, Cafer; Erciyas-Yavuz, Kiraz; Hokelek, Murat; Acici, Mustafa; Yilmaz, Hava

    2014-08-01

    We investigated migratory birds' role in spreading Crimean-Congo hemorrhagic fever virus (CCHFV) through attached ticks. We detected CCHFV RNA in ticks on migratory birds in Turkey. Two isolates showed similarity with CCHFV genotype 4, suggesting a role for ticks in CCHFV epidemics in Turkey and spread of CCHFV by birds.

  8. 77 FR 4272 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-27

    ... reduces the commercial trip limit of Atlantic migratory group Spanish mackerel in or from the exclusive... mackerel, Spanish mackerel, cero, cobia, little tunny, dolphin, and, in the Gulf of Mexico only, bluefish... 3.87 million lb (1.76 million kg) for the Atlantic migratory group of Spanish mackerel (65 FR 41015...

  9. 76 FR 9692 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-22

    ... reduces the commercial trip limit of Atlantic migratory group Spanish mackerel in or from the exclusive... mackerel, Spanish mackerel, cero, cobia, little tunny, dolphin, and, in the Gulf of Mexico only, bluefish... Spanish mackerel. Atlantic migratory group Spanish mackerel are divided into a northern and southern zone...

  10. 76 FR 60444 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... accountability measures (AMs) for king mackerel, Spanish mackerel, and cobia. In addition, Amendment 18 proposes... allowable biological catch (ABC). Currently two migratory groups of king mackerel and Spanish mackerel are... for cobia; and establish ACLs, ACTs, and AMs for each migratory group of king mackerel, Spanish...

  11. 50 CFR 20.25 - Wanton waste of migratory game birds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Wanton waste of migratory game birds. 20.25 Section 20.25 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE... game birds. No person shall kill or cripple any migratory game bird pursuant to this part without...

  12. Noninvasive In Toto Imaging of the Thymus Reveals Heterogeneous Migratory Behavior of Developing T Cells.

    PubMed

    Bajoghli, Baubak; Kuri, Paola; Inoue, Daigo; Aghaallaei, Narges; Hanelt, Marleen; Thumberger, Thomas; Rauzi, Matteo; Wittbrodt, Joachim; Leptin, Maria

    2015-09-01

    The migration of developing T cells (thymocytes) between distinct thymic microenvironments is crucial for their development. Ex vivo studies of thymus tissue explants suggest two distinct migratory behaviors of thymocytes in the thymus. In the cortex, thymocytes exhibit a stochastic migration, whereas medullary thymocytes show confined migratory behavior. Thus far, it has been difficult to follow all thymocytes in an entire thymus and relate their differentiation steps to their migratory dynamics. To understand the spatial organization of the migratory behavior and development of thymocytes in a fully functional thymus, we developed transgenic reporter lines for the chemokine receptors ccr9a and ccr9b, as well as for rag2, and used them for noninvasive live imaging of the entire thymus in medaka (Oryzias latipes). We found that the expression of these two chemokine receptors in the medaka juvenile thymus defined two spatially distinct subpopulations of thymocytes. Landmark events of T cell development including proliferation, somatic recombination, and thymic selection can be mapped to subregions of the thymus. The migratory behavior of thymocytes within each of the subpopulations is equally heterogeneous, and specific migratory behaviors are not associated with particular domains in the thymus. During the period when thymocytes express rag2 their migratory behavior was more homogeneous. Therefore, the migratory behavior of thymocytes is partly correlated with their developmental stage rather than being defined by their spatial localization. Copyright © 2015 by The American Association of Immunologists, Inc.

  13. Decline of the migratory form in bull charr, Salvelinus confluentus, and implications for conservation

    Treesearch

    M. Lee Nelson; Thomas E. McMahon; Russell F. Thurow

    2002-01-01

    Large-bodied, migratory life history forms of bull charr, Salvelinus confluentus, were historically abundant in northwestern North America, but many remaining populations of this now-threatened species presently persist as small-bodied residents isolated in headwater streams.We examined whether the migratory form has been lost from headwater...

  14. Fatalities at wind turbines may threaten population viability of a migratory bat

    Treesearch

    W.F. Frick; E.F. Baerwald; J.F. Pollock; R.M.R. Barclay; J.A. Szymanski; Ted Weller; A.L. Russell; Susan Loeb; R.A. Medellin; L.P. McGuire

    2017-01-01

    Large numbers of migratory bats are killed every year at wind energy facilities. However, population-level impacts are unknown as we lack basic demographic information about these species. We investigated whether fatalities at wind turbines could impact population viability of migratory bats, focusing on the hoary bat (Lasiurus cinereus),...

  15. 78 FR 65953 - Migratory Bird Permits; Removal of Regulations Concerning Certain Depredation Orders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX92 Migratory Bird Permits; Removal of Regulations.... SUMMARY: We propose to remove regulations that set forth certain depredation orders for migratory birds... these regulations apparently are unused, we propose to remove them. Control of depredating birds could...

  16. 77 FR 15284 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-15

    ... the coastal migratory pelagic fishery for king mackerel in the Florida east coast subzone. This closure is necessary to protect the Gulf king mackerel resource. DATES: This rule is effective 12:01 a.m...: The fishery for coastal migratory pelagic fish (king mackerel, Spanish mackerel, and cobia) is...

  17. 77 FR 11411 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-27

    ... component of the commercial sector of the coastal migratory pelagic fishery for king mackerel in the southern Florida west coast subzone. This closure is necessary to protect the Gulf king mackerel resource... . SUPPLEMENTARY INFORMATION: The fishery for coastal migratory pelagic fish ] (king mackerel, Spanish...

  18. USDA Forest Service goals and programs for monitoring neotropical migratory birds

    Treesearch

    Patricia Manley

    1993-01-01

    The USDA Forest Service (USFS) developed goals, objectives, and guidelines for monitoring neotropical migratory birds (NTMB) on National Forest System lands in response to the Neotropical Migratory Bird Conservation Program Partners in Flight. A USFS task group developed a hierarchical monitoring framework designed to define priorities for type of monitoring data....

  19. 34 CFR 300.213 - Records regarding migratory children with disabilities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false Records regarding migratory children with disabilities... THE EDUCATION OF CHILDREN WITH DISABILITIES Local Educational Agency Eligibility § 300.213 Records regarding migratory children with disabilities. The LEA must cooperate in the Secretary's efforts...

  20. Management of midwestern landscapes for the conservation of neotropical migratory birds; 1995 December 5; Detroit, MI.

    Treesearch

    Frank R. III Thompson

    1996-01-01

    Reviews status of Neotropical migratory landbirds, and effects of land-use practices in the Midwestern United States, from a landscape perspective, through a series of papers authored by regional experts. Includes recommendations for the conservation of Midwestern Neotropical migratory landbirds.

  1. Navigation and seasonal migratory orientation in juvenile sea turtles.

    PubMed

    Avens, Larisa; Lohmann, Kenneth J

    2004-05-01

    Juvenile loggerhead and green turtles that inhabit inshore waters of North Carolina, USA undertake long seasonal migrations, after which they often return to specific feeding areas. In addition, juvenile turtles are capable of homing to specific sites after being displaced. As a first step towards investigating the navigational mechanisms that underlie these movements, juvenile turtles were captured in coastal waters of North Carolina and displaced 30-167 km along circuitous routes while deprived of visual cues. At the testing location, turtles were tethered in a circular arena and permitted to swim while their orientation was monitored. Between May and September, when juvenile loggerhead and green turtles inhabit feeding areas along the North Carolina coast, turtles oriented in directions that corresponded closely with the most direct route back to their capture locations. During October and November, however, both loggerhead and green turtles oriented southward, a direction consistent with the migratory paths of turtles beginning their autumn migration. The results demonstrate for the first time that both homing and migratory orientation can be elicited in juvenile turtles under laboratory conditions in which orientation cues can be readily manipulated. In addition, the results provide evidence that juvenile loggerheads can assess their position relative to a goal using local cues available at the test site and are therefore capable of map-based navigation.

  2. Endocrine regulation of fueling by hyperphagia in migratory birds.

    PubMed

    Eikenaar, Cas

    2017-02-17

    To support migratory endurance flight, birds accumulate large amounts of fat by hyperphagia (fueling). Whereas the factors influencing migrants' motivation to fuel are well described, the physiological mechanism regulating fueling is largely unknown. Hormones are likely involved and arguably the best studied with respect to food intake and fueling is corticosterone. Corticosterone has a permissive effect, as blocking the hormone's actions prohibits efficient fueling. There are no indications, though that corticosterone stimulates fueling, and some studies even observed negative correlations between corticosterone level and food intake and speed of fueling. The latter is unexpected as slow fueling could reduce the overall speed of migration. To test the causality of these negative correlations, I non-invasively increased circulating corticosterone levels in captive migrants and determined its effect on food intake and fuel accumulation. Neither food intake nor fuel accumulation differed between corticosterone-treated and control-treated individuals. This indicates that corticosterone does not hamper food intake and fueling during stopovers, nor does it stimulate these processes. Promising alternative candidates for the regulation of migratory hyperphagia are 'appetite regulating' hormones secreted by the adipose tissue, gut, or gastro-intestinal tract. The advance of next-generation sequencing will facilitate a bottom-up approach when investigating these.

  3. Climate change and the optimal arrival of migratory birds

    PubMed Central

    Jonzén, Niclas; Hedenström, Anders; Lundberg, Per

    2006-01-01

    Recent climate change has sparked an interest in the timing of biological events, which is a general problem in life-history evolution. Reproduction in many organisms breeding in seasonal environments, e.g. migratory birds, is dependent on the exploitation of a short but rich food supply. If the seasonal timing of the food peak advances owing to climate change, then one would expect the bird to track those changes, hence, initiate migration and breeding earlier. However, when there is competition for territories and a risk of pre-breeding mortality, the optimal response to a shifting food distribution is no longer obvious. We develop a theoretical model to study how the optimal arrival time depends on the mean and variance of the food distribution, the degree of competition for territories and the risk of mortality. In general, the optimal shift in arrival date should never be as extreme as the shift in food peak date. Our results also show that we should expect the high variation of trends in arrival date observed among migratory birds, even if migration and information about climate change were unconstrained. PMID:17148256

  4. Surveillance of Influenza A Virus and Its Subtypes in Migratory Wild Birds of Nepal.

    PubMed

    Karmacharya, Dibesh; Manandhar, Sulochana; Sharma, Ajay; Bhatta, Tarka; Adhikari, Pratikshya; Sherchan, Adarsh Man; Shrestha, Bishwo; Bista, Manisha; Rajbhandari, Rajesh; Oberoi, Mohinder; Bisht, Khadak; Hero, Jean-Marc; Dissanayake, Ravi; Dhakal, Maheshwar; Hughes, Jane; Debnath, Nitish

    2015-01-01

    Nepal boarders India and China and all three countries lie within the Central Asian Flyway for migratory birds. Novel influenza A H7N9 caused human fatalities in China in 2013. Subclinical infections of influenza A H7N9 in birds and the potential for virus dispersal by migratory birds prompted this study to assess avian H7N9 viral intrusion into Nepal. Surveillance of influenza A virus in migratory birds was implemented in early 2014 with assistance from the Food and Agricultural Organization (FAO). Of 1811 environmental fecal samples collected from seven wetland migratory bird roosting areas, influenza A H9N2 was found in one sample from a ruddy shelduck in Koshi Tappu Wildlife Reserve located in southern Nepal. Avian H7N9 and other highly pathogenic avian influenza viruses were not detected. This study provides baseline data on the status of avian influenza virus in migratory bird populations in Nepal.

  5. Surveillance of Influenza A Virus and Its Subtypes in Migratory Wild Birds of Nepal

    PubMed Central

    Sharma, Ajay; Bhatta, Tarka; Adhikari, Pratikshya; Sherchan, Adarsh Man; Shrestha, Bishwo; Bista, Manisha; Rajbhandari, Rajesh; Oberoi, Mohinder; Bisht, Khadak; Hero, Jean-Marc; Dissanayake, Ravi; Dhakal, Maheshwar; Hughes, Jane; Debnath, Nitish

    2015-01-01

    Nepal boarders India and China and all three countries lie within the Central Asian Flyway for migratory birds. Novel influenza A H7N9 caused human fatalities in China in 2013. Subclinical infections of influenza A H7N9 in birds and the potential for virus dispersal by migratory birds prompted this study to assess avian H7N9 viral intrusion into Nepal. Surveillance of influenza A virus in migratory birds was implemented in early 2014 with assistance from the Food and Agricultural Organization (FAO). Of 1811 environmental fecal samples collected from seven wetland migratory bird roosting areas, influenza A H9N2 was found in one sample from a ruddy shelduck in Koshi Tappu Wildlife Reserve located in southern Nepal. Avian H7N9 and other highly pathogenic avian influenza viruses were not detected. This study provides baseline data on the status of avian influenza virus in migratory bird populations in Nepal. PMID:26176773

  6. Fixed and Flexible: Coexistence of Obligate and Facultative Migratory Strategies in a Freshwater Fish

    PubMed Central

    Brodersen, Jakob; Chapman, Ben B.; Nilsson, P. Anders; Skov, Christian; Hansson, Lars-Anders; Brönmark, Christer

    2014-01-01

    Migration is an important event in many animal life histories, but the degree to which individual animals participate in seasonal migrations often varies within populations. The powerful ecological and evolutionary consequences of such partial migration are now well documented, but the underlying mechanisms are still heavily debated. One potential mechanism of partial migration is between-individual variation in body condition, where animals in poor condition cannot pay the costs of migration and hence adopt a resident strategy. However, underlying intrinsic traits may overrule such environmental influence, dictating individual consistency in migratory patterns. Unfortunately, field tests of individual consistency compared to the importance of individual condition on migratory propensity are rare. Here we analyse 6 years of field data on roach migration, gathered by tagging almost 3000 individual fish and monitoring their seasonal migrations over extended periods of time. Our aims were to provide a field test of the role of condition in wild fish for migratory decisions, and also to assess individual consistency in migratory tendency. Our analyses reveal that (1) migratory strategy, in terms of migration/residency, is highly consistent within individuals over time and (2) there is a positive relationship between condition and the probability of migration, but only in individuals that adopt a migratory strategy at some point during their lives. However, life-long residents do not differ in condition to migrants, hence body condition is only a good predictor of migratory tendency in fish with migratory phenotypes and not a more general determinant of migratory tendency for the population. As resident individuals can achieve very high body condition and still remain resident, we suggest that our data provides some of the first field evidence to show that both facultative and obligate strategies can co-exist within populations of migratory animals. PMID:24594698

  7. 50 CFR 20.109 - Extended seasons, limits, and hours for taking migratory game birds by falconry.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... taking migratory game birds by falconry. 20.109 Section 20.109 Wildlife and Fisheries UNITED STATES FISH... taking migratory game birds by falconry. This section provides annual regulations by which falconers may take permitted migratory game birds. Editorial Note: For Federal Register citations affecting annual...

  8. 50 CFR 92.12 - Relationship to the process for developing national hunting regulations for migratory game birds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... national hunting regulations for migratory game birds. 92.12 Section 92.12 Wildlife and Fisheries UNITED... developing national hunting regulations for migratory game birds. (a) Flyway councils. (1) Proposed annual... published in the Federal Register for public review and comment, similar to the annual migratory game bird...

  9. 50 CFR 20.109 - Extended seasons, limits, and hours for taking migratory game birds by falconry.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... taking migratory game birds by falconry. 20.109 Section 20.109 Wildlife and Fisheries UNITED STATES FISH..., PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING... taking migratory game birds by falconry. This section provides annual regulations by which falconers may...

  10. 50 CFR 92.12 - Relationship to the process for developing national hunting regulations for migratory game birds.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... national hunting regulations for migratory game birds. 92.12 Section 92.12 Wildlife and Fisheries UNITED... MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.12 Relationship to the process for developing national hunting regulations for migratory game birds. (a) Flyway councils. (1) Proposed annual...

  11. 50 CFR 20.109 - Extended seasons, limits, and hours for taking migratory game birds by falconry.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... taking migratory game birds by falconry. 20.109 Section 20.109 Wildlife and Fisheries UNITED STATES FISH..., PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING... taking migratory game birds by falconry. This section provides annual regulations by which falconers may...

  12. 50 CFR 20.109 - Extended seasons, limits, and hours for taking migratory game birds by falconry.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... taking migratory game birds by falconry. 20.109 Section 20.109 Wildlife and Fisheries UNITED STATES FISH..., PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING... taking migratory game birds by falconry. This section provides annual regulations by which falconers may...

  13. 50 CFR 92.12 - Relationship to the process for developing national hunting regulations for migratory game birds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... national hunting regulations for migratory game birds. 92.12 Section 92.12 Wildlife and Fisheries UNITED... MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.12 Relationship to the process for developing national hunting regulations for migratory game birds. (a) Flyway councils. (1) Proposed annual...

  14. 50 CFR 20.109 - Extended seasons, limits, and hours for taking migratory game birds by falconry.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... taking migratory game birds by falconry. 20.109 Section 20.109 Wildlife and Fisheries UNITED STATES FISH..., PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING... taking migratory game birds by falconry. This section provides annual regulations by which falconers may...

  15. 50 CFR 92.12 - Relationship to the process for developing national hunting regulations for migratory game birds.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... national hunting regulations for migratory game birds. 92.12 Section 92.12 Wildlife and Fisheries UNITED... MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.12 Relationship to the process for developing national hunting regulations for migratory game birds. (a) Flyway councils. (1) Proposed annual...

  16. 50 CFR 92.12 - Relationship to the process for developing national hunting regulations for migratory game birds.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... national hunting regulations for migratory game birds. 92.12 Section 92.12 Wildlife and Fisheries UNITED... MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.12 Relationship to the process for developing national hunting regulations for migratory game birds. (a) Flyway councils. (1) Proposed annual...

  17. The Neotropical Migratory Bird Conservation Act: A Workshop to Discuss Improvements and a Brief Summary of First Year Results

    Treesearch

    David Mehlman; Heather Johnson; Bob Ford

    2005-01-01

    The Neotropical Migratory Bird Conservation Act (NMBCA; Public Law 106-247), passed by the U.S. Congress in 2000, establishes a matching grants program to fund projects that promote the conservation of migratory birds in the United States, Latin America, and the Caribbean. During its deliberations, the U.S. Congress recognized that migratory birds provide significant...

  18. 50 CFR 622.373 - Limited access system for charter vessel/headboat permits for Gulf coastal migratory pelagic fish.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .../headboat permits for Gulf coastal migratory pelagic fish. 622.373 Section 622.373 Wildlife and Fisheries... for Gulf coastal migratory pelagic fish. (a) No applications for additional charter vessel/headboat permits for Gulf coastal migratory pelagic fish will be accepted. Existing permits may be renewed, are...

  19. 50 CFR 622.373 - Limited access system for charter vessel/headboat permits for Gulf coastal migratory pelagic fish.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .../headboat permits for Gulf coastal migratory pelagic fish. 622.373 Section 622.373 Wildlife and Fisheries... for Gulf coastal migratory pelagic fish. (a) No applications for additional charter vessel/headboat permits for Gulf coastal migratory pelagic fish will be accepted. Existing permits may be renewed, are...

  20. Management of New England northern hardwoods, spruce-fir, and eastern white pine for neotropical migratory birds

    Treesearch

    Richard M. DeGraaf; Mariko Yamasaki; William B. Leak

    1993-01-01

    Habitat management for neotropical migratory birds must be based upon land capability, vegetation, successional patterns, response to treatments, landscape diversity, and speciedhabitat relationships. Neotropical migratory birds use diverse arrays of aquatic, early successional, and forest habitats. Management of neotropical migratory birds involves enhancement of...

  1. Study of microstructural and dielectric properties of the 2.1PMN-0.3PT non-stoichiometric ceramic.

    NASA Astrophysics Data System (ADS)

    Fundora, A.; Portelles, J.; Siqueiros, J. M.; Hirata, G.; Machorro, R.

    1998-03-01

    Some of the more relevant properties of the ferroelectric ceramics can be fine-tuned by properly doping a well characterized compound. A non stoichiometric solid solution based in Pb(Mg_1/3Nb_2/3)_2.1 Ti_0.3O3 was prepared by the traditional ceramic method with a 5mole MgO excess to obtain a dense material with good dielectric properties in the perovskite phase after sintering. The dielectric and microstructural properties of the non stoichiometric ceramic of the type: 2.1PMN-0.3PT are studied in this work. A dielectric relaxation is observed for this compounds in the 500 Hz-100 kHz frequency range. A morphological study was performed by SEM and the identification of large chemical heterogeneities on a nanometric scale by EELS. The resulting properties of the non-stoichiometric ceramic are matched against its stochiometric counterpart. Supported by CoNaCyT Proj. No. 4143E and 3025P-E9607 and DGAPA Proj. No. IN108995. We thank, I.Gradilla, F. Ruiz and E. Aparicio for their technical help. A. Fundora thanks the Foreign Ministry of Mexico.

  2. Development of a 20-MHz wide-bandwidth PMN-PT single crystal phased-array ultrasound transducer.

    PubMed

    Wong, Chi-Man; Chen, Yan; Luo, Haosu; Dai, Jiyan; Lam, Kwok-Ho; Chan, Helen Lai-Wa

    2017-01-01

    In this study, a 20-MHz 64-element phased-array ultrasound transducer with a one-wavelength pitch is developed using a PMN-30%PT single crystal and double-matching layer scheme. High piezoelectric (d33>1000pC/N) and electromechanical coupling (k33>0.8) properties of the single crystal with an optimized fabrication process involving the photolithography technique have been demonstrated to be suitable for wide-bandwidth (⩾70%) and high-sensitivity (insertion loss ⩽30dB) phased-array transducer application. A -6dBbandwidth of 91% and an insertion loss of 29dBfor the 20-MHz 64-element phased-array transducer were achieved. This result shows that the bandwidth is improved comparing with the investigated high-frequency (⩾20MHz) ultrasound transducers using piezoelectric ceramic and single crystal materials. It shows that this phased-array transducer has potential to improve the resolution of biomedical imaging, theoretically. Based on the hypothesis of resolution improvement, this phased-array transducer is capable for small animal (i.e. mouse and zebrafish) studies.

  3. Study of the Electrocaloric Effect in the Relaxor Ferroelectric Ceramic 0.75PMN-0.25PT

    NASA Astrophysics Data System (ADS)

    Kriaa, I.; Abdelmoula, N.; Maalej, A.; Khemakhem, H.

    2015-12-01

    Electrocaloric (EC) cooling based on the ability of materials to change temperature by applying an electric field under adiabatic conditions is a relatively new and challenging direction in ferroelectrics research. Analytical and simulation data for the electrocaloric effect (ECE) in 0.75Pb(Mg1/3Nb2/3)O3-0.25PbTiO3 (0.75PMN-0.25PT) bulk ceramic samples are reported. The adiabatic temperature change (Δ T) due to a change of the external electric field has been calculated indirectly from the entropy change. The temperature change increases with an increase in the applied electric field and reaches a maximum of 2.1 K in 25 kV/cm electric field shift near the Curie temperature of 398 K; that is, the cooling Δ T per unit field (MV/m) is 0.896 × 10-6 m K/V. This value is significantly large for bulk ceramics and makes the compound promising for room-temperature electric cooling applications.

  4. Electric field controlled strain induced reversible switching of magnetization in Galfenol nanomagnets delineated on PMN-PT substrate

    NASA Astrophysics Data System (ADS)

    Ahmad, Hasnain; Atulasimha, Jayasimha; Bandyopadhyay, Supriyo

    We report a non-volatile converse magneto-electric effect in elliptical Galfenol (FeGa) nanomagnets of ~300 nm lateral dimensions and ~10nm thickness delineated on a PMN-PT substrate. This effect can be harnessed for energy-efficient non-volatile memory. The nanomagnets are fabricated with e-beam lithography and sputtering. Their major axes are aligned parallel to the direction in which the substrate is poled and they are magnetized in this direction with a magnetic field. An electric field in the opposite direction generates compressive strain in the piezoelectric substrate which is partially transferred to the nanomagnets and rotates their magnetization away from the major axes to metastable orientations. There they remain after the field is removed, resulting in non-volatility. Reversing the electric field generates tensile strain which returns the magnetization to the original state. The two states can encode two binary bits which can be written using the correct voltage polarity, resulting in non-toggle behavior. Scaled memory fashioned on this effect can exhibit write energy dissipation of only ~2 aJ. Work is supported by NSF under ECCS-1124714 and CCF-1216614. Sputtering was carried out at NIST Gaithersburg.

  5. Investigations on ferroelectric PMN-PT and PZN-PT single crystals ability for power or resonant actuators.

    PubMed

    Lebrun, L; Sebald, G; Guiffard, B; Richard, C; Guyomar, D; Pleska, E

    2004-04-01

    Ferroelectric single crystals of PZN-PT and PMN-PT exhibit outstanding properties: high charge coefficient (dij), high coupling factor (kij) and high strain levels under DC fields. Besides, their mechanical quality factor is believed to be low. Their usefulness for non-resonant or large bandwidth transducers has therefore been previously investigated. However, few studies have been devoted to the dielectric and mechanical losses of single crystals and to their stability under high levels of excitations (electric fields, temperature and mechanical stress). A knowledge and understanding of such performances is needed to determine whether single crystals are suitable materials for power or resonant transducers. In this work, losses and non-linearity versus external excitations are investigated. Dielectric losses and mechanical losses are measured versus electric field for different compositions, orientations. The evolution of d33 and epsilonT33 are obtained versus electric field and temperature for the longitudinal mode. Strain and hysteresis versus sweep mode (up and down) are measured near the resonance frequency using a laser Doppler vibrometer.

  6. Scintillation kinks, bumps and wiggles in the radio spectrum of the quasar PMN J1106-3647

    NASA Astrophysics Data System (ADS)

    Tuntsov, Artem V.; Stevens, Jamie; Bannister, Keith W.; Bignall, Hayley; Johnston, Simon; Reynolds, Cormac; Walker, Mark A.

    2017-08-01

    We report radio observations of the quasar PMN J1106-3647. Our data, taken with the Australia Telescope Compact Array, show large variations in the amplitude and shape of its spectrum, on a short time-scale. A great variety of spectral features is evident, including sharp kinks, broad spectral peaks and wiggles. No two spectra are alike. We interpret the variations as interstellar scintillation of a radio source that is compact, but not point-like. Under this interpretation, complex spectral structure can arise purely refractively, under high magnification conditions, or from interference between waves that have been scattered by small-scale density fluctuations (diffractive scintillation). Both effects may be playing a role in J1106-3647, and we tentatively identify kinks with the former, and wiggles with the latter. Diffractive scintillation of active galactic nuclei is uncommon, as the fringe visibility is low for all but the most compact radio sources. Refractive interpretation of the kink implies that the source has a sharp, concave boundary. Our data are consistent with a mildly boosted synchrotron source, provided the scattering material is at a distance ˜50 pc from us.

  7. Fabrication and comparison of PMN-PT single crystal, PZT and PZT-based 1-3 composite ultrasonic transducers for NDE applications.

    PubMed

    Kim, Ki-Bok; Hsu, David K; Ahn, Bongyoung; Kim, Young-Gil; Barnard, Daniel J

    2010-08-01

    This paper describes fabrication and comparison of PMN-PT single crystal, PZT, and PZT-based 1-3 composite ultrasonic transducers for NDE applications. As a front matching layer between test material (Austenite stainless steel, SUS316) and piezoelectric materials, alumina ceramics was selected. The appropriate acoustic impedance of the backing materials for each transducer was determined based on the results of KLM model simulation. Prototype ultrasonic transducers with the center frequencies of approximately 2.25 and 5MHz for contact measurement were fabricated and compared to each other. The PMN-PT single crystal ultrasonic transducer shows considerably improved performance in sensitivity over the PZT and PZT-based 1-3 composite ultrasonic transducers. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  8. Effect of biaxial strain induced by piezoelectric PMN-PT on the upconversion photoluminescence of BaTiO₃:Yb/Er thin films.

    PubMed

    Wu, Zhenping; Zhang, Yang; Bai, Gongxun; Tang, Weihua; Gao, Ju; Hao, Jianhua

    2014-11-17

    Thin films of Yb3+/Er3+ co-doped BaTiO3 (BTO:Yb/Er) have been epitaxially grown on piezoelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) substrates. Biaxial strain can be effectively controlled by applying electric field on PMN-PT substrate. A reversible, in situ and dynamic modification of upconversion photoluminescence in BTO:Yb/Er film was observed via converse piezoelectric effect. Detailed analysis and in situ X-ray diffraction indicate that such modulations are possibly due to the change in the lattice deformation of the thin films. This result suggests an alternative method to rationally tune the upconversion emissions via strain engineering.

  9. Tuning of near-infrared luminescence of SrTiO3:Ni2+ thin films grown on piezoelectric PMN-PT via strain engineering.

    PubMed

    Bai, Gongxun; Zhang, Yang; Hao, Jianhua

    2014-07-17

    We report the tunable near-infrared luminescence of Ni(2+) doped SrTiO3 (STO:Ni) thin film grown on piezoelectric Pb(Mg(1/3)Nb(2/3))(0.7)Ti(0.3)O3 (PMN-PT) substrate via strain engineering differing from conventional chemical approach. Through controlling the thickness of STO:Ni film, the luminescent properties of the films including emission wavelength and bandwidth, as well as lifetime can be effectively tuned. The observed phenomena can be explained by the variation in the crystal field around Ni(2+) ions caused by strain due to the lattice mismatch. Moreover, the modulation of strain can be controlled under an external electric field via converse piezoelectric effect of PMN-PT used in this work. Consequently, controllable emission of the STO:Ni thin film is demonstrated in a reversible and real-time way, arising from the biaxial strain produced by piezoelectric PMN-PT. Physical mechanism behind the observation is discussed. This work will open a door for not only investigating the luminescent properties of the phosphors via piezoelectric platform, but also potentially developing novel planar light sources.

  10. Tuning of near-infrared luminescence of SrTiO3:Ni2+ thin films grown on piezoelectric PMN-PT via strain engineering

    PubMed Central

    Bai, Gongxun; Zhang, Yang; Hao, Jianhua

    2014-01-01

    We report the tunable near-infrared luminescence of Ni2+ doped SrTiO3 (STO:Ni) thin film grown on piezoelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) substrate via strain engineering differing from conventional chemical approach. Through controlling the thickness of STO:Ni film, the luminescent properties of the films including emission wavelength and bandwidth, as well as lifetime can be effectively tuned. The observed phenomena can be explained by the variation in the crystal field around Ni2+ ions caused by strain due to the lattice mismatch. Moreover, the modulation of strain can be controlled under an external electric field via converse piezoelectric effect of PMN-PT used in this work. Consequently, controllable emission of the STO:Ni thin film is demonstrated in a reversible and real-time way, arising from the biaxial strain produced by piezoelectric PMN-PT. Physical mechanism behind the observation is discussed. This work will open a door for not only investigating the luminescent properties of the phosphors via piezoelectric platform, but also potentially developing novel planar light sources. PMID:25030046

  11. Room-temperature magneto-dielectric response in multiferroic ZnFe2O4/PMN-PT bilayer thin films

    NASA Astrophysics Data System (ADS)

    Garg, T.; Kulkarni, A. R.; Venkataramani, N.

    2016-08-01

    The magneto-dielectric response in multiferroic ZnFe2O4/PMN-PT bilayer thin films prepared on a glass substrate using RF magnetron sputtering has been investigated in this work. PMN-PT thin films (i.e. PMN-PT/LCMO/Pt/Ti/glass) deposited on glass were used as a substrate for deposition of ZnFe2O4 thin films. ZnFe2O4 thin films were annealed ex situ at different temperatures. Structural, magnetic, ferroelectric, dielectric and magneto-dielectric studies were carried out on these multiferroic bilayer thin films. Structural studies revealed the presence of each layer in its respective single phase. Magnetic and ferroelectric studies revealed the ferromagnetic and ferroelectric behaviors of these bilayers. To quantify the magnetoelectric coupling, the dielectric constant of the bilayer was measured at room temperature as a function of frequency with and without the applied magnetic field. The magneto-dielectric response MD(%) was calculated by finding the relative change in dielectric constant at 1 kHz as a percentage. The observed MD response was correlated with magnetization of the ferrite layer. An MD response of 2.60% was found for a bilayer film annealed at 350 °C. At this particular annealing temperature, the ZnFe2O4 layer also has the highest saturation magnetization of 1900 G.

  12. [New international migrations and migratory models in South European countries].

    PubMed

    De Filippo, E; Pugliese, E

    1996-01-01

    Trends in international migration in the Mediterranean European countries over the course of the 1980s are reviewed. "Particular attention is paid to the different factors that explain the arrival of these migratory fluxes during a period of economic recession and in areas where there is a co-presence of immigration, emigration and unemployment. The involvement of southern European countries as target countries for immigration is not seen as a simple consequence of the [restrictive policies] practiced in the Seventies by European countries with traditional immigration; the push towards these countries as well as the pull to the same are also considered, particularly the acceleration of the internationalization process of the labor markets, the characteristics of the labor markets, and processes of segmentation and tertiarization." (EXCERPT)

  13. Lateralization of magnetic compass orientation in a migratory bird.

    PubMed

    Wiltschko, Wolfgang; Traudt, Joachim; Güntürkün, Onur; Prior, Helmut; Wiltschko, Roswitha

    2002-10-03

    Lateralization of brain functions, once believed to be a human characteristic, has now been found to be widespread among vertebrates. In birds, asymmetries of visual functions are well studied, with each hemisphere being specialized for different tasks. Here we report lateralized functions of the birds' visual system associated with magnetoperception, resulting in an extreme asymmetry of sensing the direction of the magnetic field. We found that captive migrants tested in cages with the magnetic field as the only available orientation cue were well oriented in their appropriate migratory direction when using their right eye only, but failed to show a significant directional preference when using their left eye. This implies that magnetoreception for compass orientation, assumed to take place in the eyes alongside the visual processes, is strongly lateralized, with a marked dominance of the right eye/left brain hemisphere.

  14. Migratory gold resistive shorts - Chemical aspects of a failure mechanism

    NASA Technical Reports Server (NTRS)

    Grunthaner, F. J.; Griswold, T. W.; Clendening, P. J.

    1975-01-01

    Integrated-circuit devices using the Ti/W/Au metal system are subject to failure mechanisms based on electrolytic corrosion. The migratory gold resistive short (MGRS) failure mode is one example of this mechanism and results in the formation of filamentary or dendritic deposits of gold between adjacent stripes on the IC chip. This reaction requires the presence of a sufficient amount of water, a bias voltage between adjacent stripes, and the activation of the cathodic (-) stripe. Gold ions are transported from anode to cathode through a film of moisture adsorbed on the surface of the chip; halide ions are probably involved in the transfer. Their presence is verified experimentally by X-ray photoelectron spectroscopy. Some of the chemical and electrostatic factors involved in the MGRS mechanism are discussed in this paper, including the questions of a threshold level of moisture and contamination.

  15. A migratory mantle plume on Venus: Implications for Earth?

    USGS Publications Warehouse

    Chapman, M.G.; Kirk, R.L.

    1996-01-01

    A spatially fixed or at least internally rigid hotspot reference frame has been assumed for determining relative plate motions on Earth. Recent 1:5,000,000 scale mapping of Venus, a planet without terrestrial-style plate tectonics and ocean cover, reveals a systematic age and dimensional progression of corona-like arachnoids occurring in an uncinate chain. The nonrandom associations between arachnoids indicate they likely formed from a deep-seated mantle plume in a manner similar to terrestrial hotspot features. However, absence of expected convergent "plate" margin deformation suggests that the arachnoids are the surface expression of a migratory mantle plume beneath a stationary surface. If mantle plumes are not stationary on Venus, what if any are the implications for Earth?

  16. [Health risks linked to recent migratory patterns: myth or reality?].

    PubMed

    Durieux-Paillard, Sophie

    2016-05-04

    The migratory crisis currently faced by Europe is of exceptional magnitude since the Second World War. It is mainly related to the conflict in Syria, as well as recurring violations of human rights in other regions of the world. Widely relayed by the media, the unusual number of refugee applicants and the precariousness of their migration routes raise the question of the health risk. From the old concept of quarantine to the new paradigm of migrants' health, it is important to contextualize the screening measures, taking into account the epidemiology of communicable diseases in the countries of origin and of the regions crossed, the ruptures of access to treatments for chronic diseases, but also the impact of multiple trauma (war, violence) on the mental health of refugees.

  17. Passive internal dispersal of insect larvae by migratory birds

    PubMed Central

    Green, Andy J; Sánchez, Marta I

    2005-01-01

    It has long been assumed that the resistant eggs of many zooplankton are able to survive passage through the gut of migratory waterbirds, thus facilitating their dispersal between isolated aquatic habitats. We present the first evidence that such passive internal transport within birds may be relevant for insect populations. In three out of six faecal samples from black-tailed Godwits on autumn migration in southwest Spain, we found larvae of the chironomid Chironomus salinarius which had survived gut passage. Although adult chironomids can fly, they are likely to disperse greater distances when transported as larvae via birds. In insects with discrete generations, such passive transport also enables colonization of new habitats at times when flight by adults is not an option. PMID:17148325

  18. Animal tracking meets migration genomics: transcriptomic analysis of a partially migratory bird species.

    PubMed

    Franchini, Paolo; Irisarri, Iker; Fudickar, Adam; Schmidt, Andreas; Meyer, Axel; Wikelski, Martin; Partecke, Jesko

    2017-03-17

    Seasonal migration is a widespread phenomenon, which is found in many different lineages of animals. This spectacular behaviour allows animals to avoid seasonally adverse environmental conditions to exploit more favourable habitats. Migration has been intensively studied in birds, which display astonishing variation in migration strategies, thus providing a powerful system for studying the ecological and evolutionary processes that shape migratory behaviour. Despite intensive research, the genetic basis of migration remains largely unknown. Here we used state-of-the-art radio-tracking technology to characterize the migratory behaviour of a partially migratory population of European blackbirds (Turdus merula) in southern Germany. We compared gene expression of resident and migrant individuals using high-throughput transcriptomics in blood samples. Analyses of sequence variation revealed a non-significant genetic structure between blackbirds differing by their migratory phenotype. We detected only four differentially expressed genes between migrants and residents, which might be associated with hyperphagia, moulting, and enhanced DNA replication and transcription. The most pronounced changes in gene expression occurred between migratory birds depending on when, in relation to their date of departure, blood was collected. Overall, the differentially expressed genes detected in this analysis may play crucial roles in determining the decision to migrate, or in controlling the physiological processes required for the onset of migration. These results provide new insights into, and testable hypotheses for, the molecular mechanisms controlling the migratory phenotype and its underlying physiological mechanisms in blackbirds and other migratory bird species. This article is protected by copyright. All rights reserved.

  19. Loss of migratory behaviour increases infection risk for a butterfly host

    PubMed Central

    Satterfield, Dara A.; Maerz, John C.; Altizer, Sonia

    2015-01-01

    Long-distance animal migrations have important consequences for infectious disease dynamics. In some cases, migration lowers pathogen transmission by removing infected individuals during strenuous journeys and allowing animals to periodically escape contaminated habitats. Human activities are now causing some migratory animals to travel shorter distances or form sedentary (non-migratory) populations. We focused on North American monarch butterflies and a specialist protozoan parasite to investigate how the loss of migratory behaviours affects pathogen spread and evolution. Each autumn, monarchs migrate from breeding grounds in the eastern US and Canada to wintering sites in central Mexico. However, some monarchs have become non-migratory and breed year-round on exotic milkweed in the southern US. We used field sampling, citizen science data and experimental inoculations to quantify infection prevalence and parasite virulence among migratory and sedentary populations. Infection prevalence was markedly higher among sedentary monarchs compared with migratory monarchs, indicating that diminished migration increases infection risk. Virulence differed among parasite strains but was similar between migratory and sedentary populations, potentially owing to high gene flow or insufficient time for evolutionary divergence. More broadly, our findings suggest that human activities that alter animal migrations can influence pathogen dynamics, with implications for wildlife conservation and future disease risks. PMID:25589600

  20. Loss of migratory behaviour increases infection risk for a butterfly host.

    PubMed

    Satterfield, Dara A; Maerz, John C; Altizer, Sonia

    2015-02-22

    Long-distance animal migrations have important consequences for infectious disease dynamics. In some cases, migration lowers pathogen transmission by removing infected individuals during strenuous journeys and allowing animals to periodically escape contaminated habitats. Human activities are now causing some migratory animals to travel shorter distances or form sedentary (non-migratory) populations. We focused on North American monarch butterflies and a specialist protozoan parasite to investigate how the loss of migratory behaviours affects pathogen spread and evolution. Each autumn, monarchs migrate from breeding grounds in the eastern US and Canada to wintering sites in central Mexico. However, some monarchs have become non-migratory and breed year-round on exotic milkweed in the southern US. We used field sampling, citizen science data and experimental inoculations to quantify infection prevalence and parasite virulence among migratory and sedentary populations. Infection prevalence was markedly higher among sedentary monarchs compared with migratory monarchs, indicating that diminished migration increases infection risk. Virulence differed among parasite strains but was similar between migratory and sedentary populations, potentially owing to high gene flow or insufficient time for evolutionary divergence. More broadly, our findings suggest that human activities that alter animal migrations can influence pathogen dynamics, with implications for wildlife conservation and future disease risks. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  1. Changing migratory patterns in the Jackson elk herd

    USGS Publications Warehouse

    Cole, Eric K.; Foley, Aaron M.; Warren, Jeffrey M.; Smith, Bruce L.; Dewey, Sarah R.; Brimeyer, Douglas G.; Fairbanks, W. Sue; Sawyer, Hall; Cross, Paul C.

    2015-01-01

    Migratory behavior in ungulates has declined globally and understanding the causative factors (environmental change vs. human mediated) is needed to formulate effective management strategies. In the Jackson elk herd of northwest Wyoming, demographic differences between summer elk (Cervus elaphus) population segments have led to changes in migratory patterns over a 35-year time period. The proportion of short-distance migrants (SDM) has increased and the proportion of long-distance migrants (LDM) has concurrently declined. The probability of winter-captured elk on the National Elk Refuge being LDM decreased from 0.99 (95% CI = 0.97–1.00) to 0.59 (95% CI = 0.47–0.70) from 1978 to 2012. We tested 4 hypotheses that could contribute toward the decline in the LDM segment: behavioral switching from LDM to SDM, differential survival, harvest availability, and calf recruitment. Switching rates from LDM to SDM were very low (0.2% each elk-year). Survival rates were similar between LDM and SDM, although harvest availability was relatively low for SDM that tended to use areas close to human development during the hunting season. Average summer calf/cow ratios of LDM declined from 42 to 23 calves per 100 cows from 1978–1984 to 2006–2012. Further, during 2006–2012, LDM summer calf/cow ratios were less than half of SDM (23 vs. 47 calves per 100 cows). Our data suggest recruitment is the driving factor behind the declining proportion of LDM in this region. Effectiveness of altering harvest management strategies to conserve the LDM portion of the Jackson elk herd may be limited.

  2. Tracking climate impacts on the migratory monarch butterfly

    USGS Publications Warehouse

    Zipkin, Elise F.; Ries, Leslie; Reeves, Rick; Regetz, James; Oberhauser, Karen S.

    2012-01-01

    Understanding the impacts of climate on migratory species is complicated by the fact that these species travel through several climates that may be changing in diverse ways throughout their complete migratory cycle. Most studies are not designed to tease out the direct and indirect effects of climate at various stages along the migration route. We assess the impacts of spring and summer climate conditions on breeding monarch butterflies, a species that completes its annual migration cycle over several generations. No single, broad-scale climate metric can explain summer breeding phenology or the substantial year-to-year fluctuations observed in population abundances. As such, we built a Poisson regression model to help explain annual arrival times and abundances in the Midwestern United States. We incorporated the climate conditions experienced both during a spring migration/breeding phase in Texas as well as during subsequent arrival and breeding during the main recruitment period in Ohio. Using data from a state-wide butterfly monitoring network in Ohio, our results suggest that climate acts in conflicting ways during the spring and summer seasons. High spring precipitation in Texas is associated with the largest annual population growth in Ohio and the earliest arrival to the summer breeding ground, as are intermediate spring temperatures in Texas. On the other hand, the timing of monarch arrivals to the summer breeding grounds is not affected by climate conditions within Ohio. Once in Ohio for summer breeding, precipitation has minimal impacts on overall abundances, whereas warmer summer temperatures are generally associated with the highest expected abundances, yet this effect is mitigated by the average seasonal temperature of each location in that the warmest sites receive no benefit of above average summer temperatures. Our results highlight the complex relationship between climate and performance for a migrating species and suggest that attempts to

  3. Contrasting patterns of genetic differentiation among Blackcaps (Sylvia atricapilla) with divergent migratory orientations in Europe.

    PubMed

    Mettler, Raeann; Schaefer, H Martin; Chernetsov, Nikita; Fiedler, Wolfgang; Hobson, Keith A; Ilieva, Mihaela; Imhof, Elisabeth; Johnsen, Arild; Renner, Swen C; Rolshausen, Gregor; Serrano, David; Wesołowski, Tomasz; Segelbacher, Gernot

    2013-01-01

    Migratory divides are thought to facilitate behavioral, ecological, and genetic divergence among populations with different migratory routes. However, it is currently contentious how much genetic divergence is needed to maintain distinct migratory behavior across migratory divides. Here we investigate patterns of neutral genetic differentiation among Blackcap (Sylvia atricapilla) populations with different migratory strategies across Europe. We compare the level of genetic divergence of populations migrating to southwestern (SW) or southeastern (SE) wintering areas with birds wintering in the British Isles following a recently established northwesterly (NW) migration route. The migratory divide between SW and SE wintering areas can be interpreted as a result of a re-colonization process after the last glaciation. Thus we predicted greater levels of genetic differentiation among the SW/SE populations. However, a lack of genetic differentiation was found between SW and SE populations, suggesting that interbreeding likely occurs among Blackcaps with different migratory orientations across a large area; therefore the SW/SE migratory divide can be seen as diffuse, broad band and is, at best, a weak isolating barrier. Conversely, weak, albeit significant genetic differentiation was evident between NW and SW migrants breeding sympatrically in southern Germany, suggesting a stronger isolating mechanism may be acting in this population. Populations located within/near the SW/SE contact zone were the least genetically divergent from NW migrants, confirming NW migrants likely originated from within the contact zone. Significant isolation-by-distance was found among eastern Blackcap populations (i.e. SE migrants), but not among western populations (i.e. NW and SW migrants), revealing different patterns of genetic divergence among Blackcap populations in Europe. We discuss possible explanations for the genetic structure of European Blackcaps and how gene flow influences the

  4. Migratory corridors of adult female Kemp’s ridley turtles in the Gulf of Mexico

    USGS Publications Warehouse

    Shaver, Donna J.; Hart, Kristen M.; Fujisaki, Ikuko; Rubio, Cynthia; Sartain-Iverson, Autumn R.; Pena, Jaime; Gamez, Daniel Gomez; Gonzales Diaz Miron, Raul de Jesus; Burchfield, Patrick M.; Martinez, Hector J.; Ortiz, Jaime

    2016-01-01

    For many marine species, locations of migratory pathways are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to define the migratory corridor used by Kemp's ridley turtles (Lepidochelys kempii) in the Gulf of Mexico. The turtles were tagged after nesting at Padre Island National Seashore, Texas, USA from 1997 to 2014 (PAIS; n = 80); Rancho Nuevo, Tamaulipas, Mexico from 2010 to 2011 (RN; n = 14); Tecolutla, Veracruz, Mexico from 2012 to 2013 (VC; n = 13); and Gulf Shores, Alabama, USA during 2012 (GS; n = 1). The migratory corridor lies in nearshore Gulf of Mexico waters in the USA and Mexico with mean water depth of 26 m and a mean distance of 20 km from the nearest mainland coast. Migration from the nesting beach is a short phenomenon that occurs from late-May through August, with a peak in June. There was spatial similarity of post-nesting migratory pathways for different turtles over a 16 year period. Thus, our results indicate that these nearshore Gulf waters represent a critical migratory habitat for this species. However, there is a gap in our understanding of the migratory pathways used by this and other species to return from foraging grounds to nesting beaches. Therefore, our results highlight the need for tracking reproductive individuals from foraging grounds to nesting beaches. Continued tracking of adult females from PAIS, RN, and VC nesting beaches will allow further study of environmental and bathymetric components of migratory habitat and threats occurring within our defined corridor. Furthermore, the existence of this migratory corridor in nearshore waters of both the USA and Mexico demonstrates that international cooperation is necessary to protect essential migratory habitat for this imperiled species.

  5. Contrasting Patterns of Genetic Differentiation among Blackcaps (Sylvia atricapilla) with Divergent Migratory Orientations in Europe

    PubMed Central

    Mettler, Raeann; Schaefer, H. Martin; Chernetsov, Nikita; Fiedler, Wolfgang; Hobson, Keith A.; Ilieva, Mihaela; Imhof, Elisabeth; Johnsen, Arild; Renner, Swen C.; Rolshausen, Gregor; Serrano, David; Wesołowski, Tomasz; Segelbacher, Gernot

    2013-01-01

    Migratory divides are thought to facilitate behavioral, ecological, and genetic divergence among populations with different migratory routes. However, it is currently contentious how much genetic divergence is needed to maintain distinct migratory behavior across migratory divides. Here we investigate patterns of neutral genetic differentiation among Blackcap (Sylvia atricapilla) populations with different migratory strategies across Europe. We compare the level of genetic divergence of populations migrating to southwestern (SW) or southeastern (SE) wintering areas with birds wintering in the British Isles following a recently established northwesterly (NW) migration route. The migratory divide between SW and SE wintering areas can be interpreted as a result of a re-colonization process after the last glaciation. Thus we predicted greater levels of genetic differentiation among the SW/SE populations. However, a lack of genetic differentiation was found between SW and SE populations, suggesting that interbreeding likely occurs among Blackcaps with different migratory orientations across a large area; therefore the SW/SE migratory divide can be seen as diffuse, broad band and is, at best, a weak isolating barrier. Conversely, weak, albeit significant genetic differentiation was evident between NW and SW migrants breeding sympatrically in southern Germany, suggesting a stronger isolating mechanism may be acting in this population. Populations located within/near the SW/SE contact zone were the least genetically divergent from NW migrants, confirming NW migrants likely originated from within the contact zone. Significant isolation-by-distance was found among eastern Blackcap populations (i.e. SE migrants), but not among western populations (i.e. NW and SW migrants), revealing different patterns of genetic divergence among Blackcap populations in Europe. We discuss possible explanations for the genetic structure of European Blackcaps and how gene flow influences the

  6. [The evolution of the migratory flows in South Catalonia, 1950-1975].

    PubMed

    Miret, N

    1997-01-01

    "This paper retraces the history and the geography of the substitution in the migratory flows to Catalonia...during the last 30 years. After the huge movement of internal migration during the first half of the twentieth century, the first flow of foreign migrants appeared in the [1970s]. This substitution of migratory origin is related to a reconfiguration of the immigrants' geographic polarity of settlements and in their economic role. Based on various statistical indicators and bibliographic references, this paper provides some essential elements for the understanding of the migratory complexity of this space." (EXCERPT)

  7. Magnetic direction finding: evidence for its use in migratory indigo buntings.

    PubMed

    Emlen, S T; Wiltschko, W; Demong, N J; Wiltschko, R; Bergman, S

    1976-08-06

    The orientational capabilities of caged migratory indigo buntings were studied under differing magnetic field conditions. When tested in a situation allowing minimal exposure to visual cues but in the presence of the normal geomagnetic field, the birds demonstrated a significant orientation in the appropriate migratory direction (to the north). When the horizontal component of the magnetic field was deflected clockwise 120 degrees by activation of Helmholtz coils surrounding the cage, the orientation of the buntings shifted accordingly (clockwise to geographic east-southeast). These results suggest that indigo buntings are not only able to detect the geomagnetic field, but also can use this information in the finalization of their migratory direction.

  8. Experimental dental bio-adhesives for direct restorations: the influence of PMnEDM homologs structure on bond strength.

    PubMed

    Kupka, Tomasz W; Gibas, Mirosław; Dabrowska, Agnieszka; Tanasiewicz, Marta; Malec, Witold

    2007-10-01

    The purpose of this study was to evaluate the effect of PMnEDM dental monomer homologs chemical structure on shear bond strength between polymer-based composite and alloy. Four light-cured experimental universal dental bio-adhesives (group codes: A (PMDM), B (PM2EDM), C (PM3EDM), D (PM4EDM)) were preliminarily evaluated with respect to sensitivity to ambient light, curing time, depth of cure, and uncured film thickness according to standardized procedures. Appropriate tests were performed to measure shear bond strength (SBS) of polymer-based composite to cobalt-based alloy with the use of the adhesives investigated. Variability of results was evaluated by use of the coefficient of variation (CV). Results were estimated with the aid of one-way analysis of variance (ANOVA), performed on the logarithmic values, with alpha=0.05 significance level. All materials passed the requirements according to physicochemical properties. Except for formulation D, all results estimating SBS were positive with respect to standardized requirements. The uppermost mean SBS was achieved for the A adhesive (11.45 MPa) and appeared to be significantly different compared to D one (5.07 MPa) (p=0.0495). Also the B adhesive, having slightly lower mean SBS value (10.50 MPa) exhibited a significant difference in respect to D one (p=0.0455). The means for other trial pairs did not differ statistically. The materials here studied might be considered to have a practical use in dental clinics, especially the formulations B and C.

  9. Equivalent properties of 1-3 piezocomposites made of PMN-PT single crystals for underwater sonar transducers

    NASA Astrophysics Data System (ADS)

    Kim, Jinwook; Roh, Yongrae

    2011-04-01

    The design of a piezocomposite transducer is accomplished by such advanced modeling technique as finite element method (FEM). However, accurate analysis of a 1-3 piezocomposite transducer enforces three dimensional (3D) modeling that requires very finemeshing of the transducer structure, which is frequently over affordable calculation resource capacity. In order to simplify the FEM model for complicated underwater transducers, the 1-3 piezocomposite needs to be simulated with a single phase material of equivalent properties. The 1-3 piezocomposite material in this study is made of the PMN-PT single crystal as the active material and urethane as the matrix material. Theoretical models for the calculation of new material parameters of 1-3 composites having fine lateral periodicity have been derived. For the validation of the equivalent properties, TE (thickness extensional), LE (length extensional), LTE (length thickness extensional), and TS (thickness shear) FEM models have been built to compare the impedance-frequency spectra of the 1-3 composite material and an equivalent material. Through the simulation with the models, all the equivalent elastic, dielectric and piezoelectric constants of the single phase material are determined. Further, 3D and axis-symmetric 2D FEM models of a multi-mode Tonpilz transducer have been constructed with the equivalent material properties. The equivalent material provides a very good correlation between the 2D and 3D transducer models, which is not easily attainable with the full 1-3 piezocomposite model. This result confirms the efficacy of the equivalent material properties of the 1-3 piezocomposites.

  10. Cortical Visual Impairment

    MedlinePlus

    ... Frequently Asked Questions Español Condiciones Chinese Conditions Cortical Visual Impairment En Español Read in Chinese What is cortical visual impairment? Cortical visual impairment (CVI) is a decreased ...

  11. Correlates of prolonged swimming performance in F2 hybrids of migratory and non-migratory threespine stickleback.

    PubMed

    Dalziel, Anne C; Schulte, Patricia M

    2012-10-15

    Determining which underlying traits contribute to differences in whole-animal performance can be difficult when many traits differ between individuals with high and low capacities. We have previously found that migratory (anadromous marine) and non-migratory (stream-resident) threespine stickleback (Gasterosteus aculeatus) populations have genetically based differences in prolonged swimming performance (U(crit)) that are associated with divergence of a number of candidate morphological and physiological traits (pectoral fin size and shape, body shape, pectoral muscle and heart size, and pectoral muscle metabolic enzyme activities). Here, we use F2 hybrid crosses to determine which traits are correlated with U(crit) when expressed in a largely randomized genetic background and a range of trait values for other divergent traits. We found that four of our 12 candidate traits were positively correlated with U(crit) in F2 hybrids and that the combined effects of ventricle mass, pectoral adductor mass and adductor citrate synthase activity accounted for 17.9% of the variation in U(crit). These data provide additional support for a causal role of muscle and heart size in mediating intraspecific differences in U(crit), but indicate that many candidate morphological and biochemical traits do not have a strong effect on U(crit) when disassociated from other divergent traits. However, the limited variation in U(crit) in our F2 hybrid families may have decreased our ability to detect correlations among these candidate traits and U(crit). These data suggest that many traits, interactions among traits and traits not measured in this study affect prolonged swimming performance in threespine stickleback.

  12. A survey of North American migratory waterfowl for duck plague (duck virus enteritis) virus

    USGS Publications Warehouse

    Brand, Christopher J.; Docherty, Douglas E.

    1984-01-01

    A survey of migratory waterfowl for duck plague (DP) virus was conducted in the Mississippi and Central flyways during 1982 and in the Atlantic and Pacific flyways during 1983. Cloacal and pharyngeal swabs were collected from 3,169 migratory waterfowl in these four flyways, principally mallards (Anas platyrhynchos L.), black ducks (Anas rubripes Brewster), and pintails (Anas acuta L). In addition 1,033 birds were sampled from areas of recurrent DP outbreaks among nonmigratory and captive waterfowl, and 590 from Lake Andes National Wildlife Refuge, the site of the only known major DP outbreak in migratory waterfowl. Duck plague virus was not found in any of the samples. Results support the hypothesis that DP is not established in North American migratory waterfowl as an enzootic disease.

  13. 76 FR 65500 - Proposed Information Collection; Comment Request; Highly Migratory Species Permit Family of Forms

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Proposed Information Collection; Comment Request; Highly Migratory Species Permit Family of Forms AGENCY: National Oceanic and Atmospheric Administration...

  14. Migratory beekeeping practices contribute insignificantly to transgenic pollen flow among fields of alfalfa produced for seed

    USDA-ARS?s Scientific Manuscript database

    Increased use of genetically engineered crops in agriculture has raised concerns over pollinator-mediated gene flow between transgenic and conventional agricultural varieties. This study evaluated whether contracted migratory beekeeping practices influence transgenic pollen flow among spatially iso...

  15. A visual pathway links brain structures active during magnetic compass orientation in migratory birds.

    PubMed

    Heyers, Dominik; Manns, Martina; Luksch, Harald; Güntürkün, Onur; Mouritsen, Henrik

    2007-09-26

    The magnetic compass of migratory birds has been suggested to be light-dependent. Retinal cryptochrome-expressing neurons and a forebrain region, "Cluster N", show high neuronal activity when night-migratory songbirds perform magnetic compass orientation. By combining neuronal tracing with behavioral experiments leading to sensory-driven gene expression of the neuronal activity marker ZENK during magnetic compass orientation, we demonstrate a functional neuronal connection between the retinal neurons and Cluster N via the visual thalamus. Thus, the two areas of the central nervous system being most active during magnetic compass orientation are part of an ascending visual processing stream, the thalamofugal pathway. Furthermore, Cluster N seems to be a specialized part of the visual wulst. These findings strongly support the hypothesis that migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds "see" the reference compass direction provided by the geomagnetic field.

  16. A Visual Pathway Links Brain Structures Active during Magnetic Compass Orientation in Migratory Birds

    PubMed Central

    Heyers, Dominik; Manns, Martina; Luksch, Harald; Güntürkün, Onur; Mouritsen, Henrik

    2007-01-01

    The magnetic compass of migratory birds has been suggested to be light-dependent. Retinal cryptochrome-expressing neurons and a forebrain region, “Cluster N”, show high neuronal activity when night-migratory songbirds perform magnetic compass orientation. By combining neuronal tracing with behavioral experiments leading to sensory-driven gene expression of the neuronal activity marker ZENK during magnetic compass orientation, we demonstrate a functional neuronal connection between the retinal neurons and Cluster N via the visual thalamus. Thus, the two areas of the central nervous system being most active during magnetic compass orientation are part of an ascending visual processing stream, the thalamofugal pathway. Furthermore, Cluster N seems to be a specialized part of the visual wulst. These findings strongly support the hypothesis that migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds “see” the reference compass direction provided by the geomagnetic field. PMID:17895978

  17. 78 FR 33857 - Meeting Announcements: North American Wetlands Conservation Council; Neotropical Migratory Bird...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ...; 91100-3740-GRNT 7C] Meeting Announcements: North American Wetlands Conservation Council; Neotropical... meetings. SUMMARY: The North American Wetlands Conservation Council (Council) will meet to select North American Wetlands Conservation Act (NAWCA) grant proposals for recommendation to the Migratory...

  18. Prevalence of West Nile virus in migratory birds during spring and fall migration.

    PubMed

    Dusek, Robert J; McLean, Robert G; Kramer, Laura D; Ubico, Sonya R; Dupuis, Alan P; Ebel, Gregory D; Guptill, Stephen C

    2009-12-01

    To investigate the role of migratory birds in the dissemination of West Nile virus (WNV), we measured the prevalence of infectious WNV and specific WNV neutralizing antibodies in birds, principally Passeriformes, during spring and fall migrations in the Atlantic and Mississippi flyways from 2001-2003. Blood samples were obtained from 13,403 birds, representing 133 species. Specific WNV neutralizing antibody was detected in 254 resident and migratory birds, representing 39 species, and was most commonly detected in northern cardinals (Cardinalis cardinalis) (9.8%, N = 762) and gray catbirds (Dumetella carolinensis) (3.2%, N = 3188). West Nile virus viremias were detected in 19 birds, including 8 gray catbirds, and only during the fall migratory period. These results provide additional evidence that migratory birds may have been a principal agent for the spread of WNV in North America and provide data on the occurrence of WNV in a variety of bird species.

  19. 76 FR 23962 - Fisheries Off West Coast States; Highly Migratory Species Fisheries; Annual Catch Limits and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-29

    ... States; Highly Migratory Species Fisheries; Annual Catch Limits and Accountability Measures AGENCY... annual catch limits (ACLs) and accountability measures (AMs). This proposed rule to implement Amendment 2... have any direct or indirect socioeconomic impacts, because harvest limits and management measures...

  20. Estimating migratory connectivity of birds when re-encounter probabilities are heterogeneous.

    PubMed

    Cohen, Emily B; Hostetler, Jeffrey A; Royle, J Andrew; Marra, Peter P

    2014-05-01

    Understanding the biology and conducting effective conservation of migratory species requires an understanding of migratory connectivity - the geographic linkages of populations between stages of the annual cycle. Unfortunately, for most species, we are lacking such information. The North American Bird Banding Laboratory (BBL) houses an extensive database of marking, recaptures and recoveries, and such data could provide migratory connectivity information for many species. To date, however, few species have been analyzed for migratory connectivity largely because heterogeneous re-encounter probabilities make interpretation problematic. We accounted for regional variation in re-encounter probabilities by borrowing information across species and by using effort covariates on recapture and recovery probabilities in a multistate capture-recapture and recovery model. The effort covariates were derived from recaptures and recoveries of species within the same regions. We estimated the migratory connectivity for three tern species breeding in North America and over-wintering in the tropics, common (Sterna hirundo), roseate (Sterna dougallii), and Caspian terns (Hydroprogne caspia). For western breeding terns, model-derived estimates of migratory connectivity differed considerably from those derived directly from the proportions of re-encounters. Conversely, for eastern breeding terns, estimates were merely refined by the inclusion of re-encounter probabilities. In general, eastern breeding terns were strongly connected to eastern South America, and western breeding terns were strongly linked to the more western parts of the nonbreeding range under both models. Through simulation, we found this approach is likely useful for many species in the BBL database, although precision improved with higher re-encounter probabilities and stronger migratory connectivity. We describe an approach to deal with the inherent biases in BBL banding and re-encounter data to demonstrate that