Polarization phenomena in few-body systems

International Nuclear Information System (INIS)

Conzett, H.E.

1975-12-01

Recent polarization studies in N--N scattering at and below 50 MeV have provided specific and significant improvements in the phase-shift parameters. High energy investigations with both polarized proton beams and targets have shown unexpectedly large spin effects, and this provides a challenge for theoretical effort to explain these results. Experimental and theoretical work on the three-nucleon problem continues to yield new and interesting results, with the emphasis now shifting to polarization studies in the breakup reaction. On-going work on several-nucleon systems continues to provide polarization data for general analyses, nuclear structure information, or specific resonance effects. Finally, the basic interaction symmetries continue to have unique and important consequences for polarization observables. 17 figures

Animal physiology. Summer declines in activity and body temperature offer polar bears limited energy savings.

Science.gov (United States)

Whiteman, J P; Harlow, H J; Durner, G M; Anderson-Sprecher, R; Albeke, S E; Regehr, E V; Amstrup, S C; Ben-David, M

2015-07-17

Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of "ice" bears in summer is unknown, "shore" bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation. Copyright © 2015, American Association for the Advancement of Science.

Theoretical analysis of polarized structure functions

International Nuclear Information System (INIS)

Altarelli, G.; ); Ball, R.D.; Forte, S.; Ridolfi, G.

1998-01-01

We review the analysis of polarized structure function data using perturbative QCD and NLO We use the most recent experimental data to obtain updated results for polarized parton distributions, first moments and the strong coupling. We also discuss several theoretical issues involving in this analysis and in the interpretation of its results. Finally, we compare our results with other similar analyses in the recent literature. (author)

Determination of the polarization states of an arbitrary polarized terahertz beam: vectorial vortex analysis.

Science.gov (United States)

Wakayama, Toshitaka; Higashiguchi, Takeshi; Oikawa, Hiroki; Sakaue, Kazuyuki; Washio, Masakazu; Yonemura, Motoki; Yoshizawa, Toru; Tyo, J Scott; Otani, Yukitoshi

2015-03-24

Vectorial vortex analysis is used to determine the polarization states of an arbitrarily polarized terahertz (0.1-1.6 THz) beam using THz achromatic axially symmetric wave (TAS) plates, which have a phase retardance of Δ = 163° and are made of polytetrafluorethylene. Polarized THz beams are converted into THz vectorial vortex beams with no spatial or wavelength dispersion, and the unknown polarization states of the incident THz beams are reconstructed. The polarization determination is also demonstrated at frequencies of 0.16 and 0.36 THz. The results obtained by solving the inverse source problem agree with the values used in the experiments. This vectorial vortex analysis enables a determination of the polarization states of the incident THz beam from the THz image. The polarization states of the beams are estimated after they pass through the TAS plates. The results validate this new approach to polarization detection for intense THz sources. It could find application in such cutting edge areas of physics as nonlinear THz photonics and plasmon excitation, because TAS plates not only instantaneously elucidate the polarization of an enclosed THz beam but can also passively control THz vectorial vortex beams.

Theoretical Analysis of Polarized Structure Functions

CERN Document Server

Altarelli, Guido; Forte, Stefano; Ridolfi, G

1998-01-01

We review the analysis of polarized structure function data using perturbative QCD at next-to-leading order. We use the most recent experimental data to obtain updated results for polarized parton distributions, first moments and the strong coupling. We also discuss several theoretical issues involved in this analysis and in the interpretation of its results. Finally, we compare our results with other similar analyses in the recent literature.

QCD Analysis of Polarized Scattering Data and New Polarized Parton Distributions

International Nuclear Information System (INIS)

Bluemlein, J.; Boettcher, H.

2002-01-01

In this talk results from a new QCD analysis in Leading (LO) and Next-to-Leading (NLO) Order are presented. New parametrizations of the polarized quark and gluon densities are derived together with parametrizations of their fully correlated 1σ error bands. Furthermore the value of α s (M 2 Z ) is determined. Finally a number of low moments of the polarized parton densities are compared with results from lattice simulations. All details of the analysis are given in J. Bluemlein, H. Boettcher, Nucl. Phys. B636, 225 (2002). (author)

Recent progress on HYSPEC, and its polarization analysis capabilities

Directory of Open Access Journals (Sweden)

Winn Barry

2015-01-01

Full Text Available HYSPEC is a high-intensity, direct-geometry time-of-flight spectrometer at the Spallation Neutron Source, optimized for measurement of excitations in small single-crystal specimens with optional polarization analysis capabilities. The incident neutron beam is monochromated using a Fermi chopper with short, straight blades, and is then vertically focused by Bragg scattering onto the sample position by either a highly oriented pyrolitic graphite (unpolarized or a Heusler (polarized crystal array. Neutrons are detected by a bank of 3He tubes that can be positioned over a wide range of scattering angles about the sample axis. HYSPEC entered the user program in February 2013 for unpolarized experiments, and is already experiencing a vibrant research program. Polarization analysis will be accomplished by using the Heusler crystal array to polarize the incident beam, and either a 3He spin filter or a supermirror wide-angle polarization analyser to analyse the scattered beam. The 3He spin filter employs the spin-exchange optical pumping technique. A 60∘ wide angle 3He cell that matches the detector coverage will be used for polarization analysis. The polarized gas in the post-sample wide angle cell is designed to be periodically and automatically refreshed with an adjustable pressure of polarized gas, optically pumped in a separate cell and then transferred to the wide angle cell. The supermirror analyser has 960 supermirror polarizers distributed over 60∘, and has been characterized at the Swiss Spallation Neutron Source. The current status of the instrument and the development of its polarization analysis capabilities are presented.

Metamaterial polarization converter analysis: limits of performance

DEFF Research Database (Denmark)

Markovich, Dmitry L.; Andryieuski, Andrei; Zalkovskij, Maksim

2013-01-01

and a single layer with a ground plane can have 100 % polarization conversion efficiency. We tested our conclusions numerically reaching the designated limits of efficiency using a simple metamaterial design. Our general analysis provides useful guidelines for the metamaterial polarization converter design......In this paper, we analyze the theoretical limits of a metamaterial-based converter with orthogonal linear eigenpolarizations that allow linear-to-elliptical polarization transformation with any desired ellipticity and ellipse orientation. We employ the transmission line approach providing a needed...... level of the design generalization. Our analysis reveals that the maximal conversion efficiency for transmission through a single metamaterial layer is 50 %, while the realistic reflection configuration can give the conversion efficiency up to 90 %. We show that a double layer transmission converter...

Polar source analysis : technical memorandum

Science.gov (United States)

2017-09-29

The following technical memorandum describes the development, testing and analysis of various polar source data sets. The memorandum also includes recommendation for potential inclusion in future releases of AEDT. This memorandum is the final deliver...

Time-of-flight and vector polarization analysis for diffuse neutron scattering

International Nuclear Information System (INIS)

Schweika, W.

2003-01-01

The potential of pulsed neutron sources for diffuse scattering including time-of-flight (TOF) and polarization analysis is discussed in comparison to the capabilities of the present instrument diffuse neutron scattering at the research center Juelich. We present first results of a new method for full polarization analysis using precessing neutron polarization. A proposal is made for a new type of instrument at pulsed sources, which allows for vector polarization analysis in TOF instruments with multi-detectors

Evaluation of Extraction Protocols for Simultaneous Polar and Non-Polar Yeast Metabolite Analysis Using Multivariate Projection Methods

Directory of Open Access Journals (Sweden)

Nicolas P. Tambellini

2013-07-01

Full Text Available Metabolomic and lipidomic approaches aim to measure metabolites or lipids in the cell. Metabolite extraction is a key step in obtaining useful and reliable data for successful metabolite studies. Significant efforts have been made to identify the optimal extraction protocol for various platforms and biological systems, for both polar and non-polar metabolites. Here we report an approach utilizing chemoinformatics for systematic comparison of protocols to extract both from a single sample of the model yeast organism Saccharomyces cerevisiae. Three chloroform/methanol/water partitioning based extraction protocols found in literature were evaluated for their effectiveness at reproducibly extracting both polar and non-polar metabolites. Fatty acid methyl esters and methoxyamine/trimethylsilyl derivatized aqueous compounds were analyzed by gas chromatography mass spectrometry to evaluate non-polar or polar metabolite analysis. The comparative breadth and amount of recovered metabolites was evaluated using multivariate projection methods. This approach identified an optimal protocol consisting of 64 identified polar metabolites from 105 ion hits and 12 fatty acids recovered, and will potentially attenuate the error and variation associated with combining metabolite profiles from different samples for untargeted analysis with both polar and non-polar analytes. It also confirmed the value of using multivariate projection methods to compare established extraction protocols.

Wavelet analysis of polarization maps of polycrystalline biological fluids networks

Science.gov (United States)

Ushenko, Y. A.

2011-12-01

The optical model of human joints synovial fluid is proposed. The statistic (statistic moments), correlation (autocorrelation function) and self-similar (Log-Log dependencies of power spectrum) structure of polarization two-dimensional distributions (polarization maps) of synovial fluid has been analyzed. It has been shown that differentiation of polarization maps of joint synovial fluid with different physiological state samples is expected of scale-discriminative analysis. To mark out of small-scale domain structure of synovial fluid polarization maps, the wavelet analysis has been used. The set of parameters, which characterize statistic, correlation and self-similar structure of wavelet coefficients' distributions of different scales of polarization domains for diagnostics and differentiation of polycrystalline network transformation connected with the pathological processes, has been determined.

An analysis of heat conduction in polar bear hairs using one-dimensional fractional model

Directory of Open Access Journals (Sweden)

Zhu Wei-Hong

2016-01-01

Full Text Available Hairs of a polar bear are of superior properties such as the excellent thermal protection. The polar bears can perennially live in an extremely cold environment and can maintain body temperature at around 37 °C. Why do polar bears can resist such cold environment? Its membrane-pore structure plays an important role. In the previous work, we established a 1-D fractional heat conduction equation to reveal the hidden mechanism for the hairs. In this paper, we further discuss solutions and parameters of the equation established and analyze heat conduction in polar bear hairs.

Improved techniques for the analysis of experiments with polarized targets. [1 to 2 GeV/c, polarization

Energy Technology Data Exchange (ETDEWEB)

Barrelet, E.

1975-06-01

An experiment was performed at the Bevatron to measure the polarization in the reaction ..pi../sup -/p ..-->.. ..pi../sup 0/n from a polarized target, at beam momenta between 1 and 2 GeV/c. Concentration is placed on the original aspects of our analysis, in particular: the geometrical reconstruction of the elastic events; the use of the high analyzing power of the reaction studied to probe the polarization of the target in magnitude and distribution; a study of the statistical estimation of the polarization parameter; a detailed study of the quasielastic background. (JFP)

Vesicular transport protein Arf6 modulates cytoskeleton dynamics for polar body extrusion in mouse oocyte meiosis.

Science.gov (United States)

Duan, Xing; Zhang, Hao-Lin; Pan, Meng-Hao; Zhang, Yu; Sun, Shao-Chen

2018-02-01

Arf6 (ADP-ribosylation factor 6) is known to play important roles in membrane dynamics through the regulation of actin filament reorganization for multiple cellular processes such as cytokinesis, phagocytosis, cell migration and tumor cell invasion. However, the functions of Arf6 in mammalian oocyte meiosis have not been clarified. In present study we showed that Arf6 expressed in mouse oocytes and was mainly distributed around the spindle during meiosis. Depletion of Arf6 by morpholino microinjection caused oocytes failing to extrude first polar body. Further analysis indicated that Arf6 knock down caused the aberrant actin distribution, which further induced the failure of meiotic spindle movement. And the loss of oocyte polarity also confirmed this. The regulation of Arf6 on actin filaments in mouse oocytes might be due to its effects on the phosphorylation level of cofilin and the expression of Arp2/3 complex. Moreover, we found that the decrease of Arf6 caused the disruption of spindle formation, indicating the multiple roles of Arf6 on cytoskeleton dynamics in meiosis. In summary, our results indicated that Arf6 was involved in mouse oocyte meiosis through its functional roles in actin-mediated spindle movement and spindle organization. Copyright © 2017 Elsevier B.V. All rights reserved.

Preliminary Analysis of Chinese GF-3 SAR Quad-Polarization Measurements to Extract Winds in Each Polarization

Directory of Open Access Journals (Sweden)

Lin Ren

2017-11-01

Full Text Available This study analyzed the noise equivalent sigma zero (NESZ and ocean wind sensitivity for Chinese C-band Gaofen-3 (GF-3 quad-polarization synthetic aperture radar (SAR measurements to facilitate further operational wind extraction from GF-3 data. Data from the GF-3 quad-polarization SAR and collocated winds from both NOAA/NCEP Global Forecast System (GFS atmospheric model and National Data Buoy Center (NDBC buoys were used in the analysis. For NESZ, the co-polarization was slightly higher compared to the cross-polarization. Regarding co-polarization and cross-polarization, NESZ was close to RadarSAT-2 and Sentinel-1 A. Wind sensitivity was analyzed by evaluating the dependence on winds in terms of normalized radar cross-sections (NRCS and polarization combinations. The closest geophysical model function (GMF and the polarization ratio (PR model to GF-3 data were determined by comparing data and the model results. The dependence of co-polarized NRCS on wind speed and azimuth angle was consistent with the proposed GMF models. The combination of CMOD5 and CMOD5.N was considered to be the closest GMF in co-polarization. The cross-polarized NRCS exhibited a strong linear relationship with moderate wind speeds higher than 4 m·s−1, but a weak correlation with the azimuth angle. The proposed model was considered as the closest GMF in cross-polarization. For polarization combinations, PR and polarization difference (PD were considered. PR increased only with the incidence angle, whereas PD increased with wind speed and varied with azimuth angle. There were three very close PR models and each can be considered as the closest. Preliminary results indicate that GF-3 quad-polarization data are valid and have the ability to extract winds in each polarization.

Techniques of production and analysis of polarized synchrotron radiation

International Nuclear Information System (INIS)

Mills, D.M.

1992-01-01

The use of the unique polarization properties of synchrotron radiation in the hard x-ray spectral region (E>3 KeV) is becoming increasingly important to many synchrotron radiation researchers. The radiation emitted from bending magnets and conventional (planar) insertion devices (IDs) is highly linearly polarized in the plane of the particle's orbit. Elliptically polarized x-rays can also be obtained by going off axis on a bending magnet source, albeit with considerable loss of flux. The polarization properties of synchrotron radiation can be further tailored to the researcher's specific needs through the use of specialized insertion devices such as helical and crossed undulators and asymmetrical wigglers. Even with the possibility of producing a specific polarization, there is still the need to develop x-ray optical components which can manipulate the polarization for both analysis and further modification of the polarization state. A survey of techniques for producing and analyzing both linear and circular polarized x-rays will be presented with emphasis on those techniques which rely on single crystal optical components

DMFC anode polarization: Experimental analysis and model validation

Energy Technology Data Exchange (ETDEWEB)

Casalegno, A.; Marchesi, R. [Dipartimento di Energetica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

2008-01-03

Anode two-phase flow has an important influence on DMFC performance and methanol crossover. In order to elucidate two-phase flow influence on anode performance, in this work, anode polarization is investigated combining experimental and modelling approach. A systematic experimental analysis of operating conditions influence on anode polarization is presented. Hysteresis due to operating condition is observed; experimental results suggest that it arises from methanol accumulation and has to be considered in evaluating DMFC performances and measurements reproducibility. A model of DMFC anode polarization is presented and utilised as tool to investigate anode two-phase flow. The proposed analysis permits one to produce a confident interpretation of the main involved phenomena. In particular, it confirms that methanol electro-oxidation kinetics is weakly dependent on methanol concentration and that methanol transport in gas phase produces an important contribution in anode feeding. Moreover, it emphasises the possibility to optimise anode flow rate in order to improve DMFC performance and reduce methanol crossover. (author)

Role of Securin, Separase and Cohesins in female meiosis and polar body formation in Drosophila.

Science.gov (United States)

Guo, Zhihao; Batiha, Osamah; Bourouh, Mohammed; Fifield, Eric; Swan, Andrew

2016-02-01

Chromosome segregation in meiosis is controlled by a conserved pathway that culminates in Separase-mediated cleavage of the α-kleisin Rec8, leading to dissolution of cohesin rings. Drosophila has no gene encoding Rec8, and the absence of a known Separase target raises the question of whether Separase and its regulator Securin (Pim in Drosophila) are important in Drosophila meiosis. Here, we investigate the role of Securin, Separase and the cohesin complex in female meiosis using fluorescence in situ hybridization against centromeric and arm-specific sequences to monitor cohesion. We show that Securin destruction and Separase activity are required for timely release of arm cohesion in anaphase I and centromere-proximal cohesion in anaphase II. They are also required for release of arm cohesion on polar body chromosomes. Cohesion on polar body chromosomes depends on the cohesin components SMC3 and the mitotic α-kleisin Rad21 (also called Vtd in Drosophila). We provide cytological evidence that SMC3 is required for arm cohesion in female meiosis, whereas Rad21, in agreement with recent findings, is not. We conclude that in Drosophila meiosis, cohesion is regulated by a conserved Securin-Separase pathway that targets a diverged Separase target, possibly within the cohesin complex. © 2016. Published by The Company of Biologists Ltd.

Polarization effects in the 3-body system

International Nuclear Information System (INIS)

Ohlsen, G.G.

1978-01-01

An experimental review is given of polarization effects in the three-nucleon system. Inelastic processes are emphasized and some special topics on elastic scattering are also considered. The recent elastic nucleon--deuteron scattering result are discussed including the determination of the deuteron D state, vector n - d vs vector p - d vector analyzing power, the status of fits to polarization observables via Faddeev-type theory, and medium-energy elastic scattering. The treatment of the breakup experiments covers a general discussion of some of the possible kinematically complete breakup measurements and kinematically incomplete breakup experiments. 71 references

Detailed analysis of evolution of the state of polarization in all-fiber polarization transformers.

Science.gov (United States)

Zhu, Xiushan; Jain, Ravinder K

2006-10-30

We present a detailed analysis of key attributes and performance characteristics of controllably-spun birefringent-fiber-based all-fiber waveplates or "all fiber polarization transformers" (AFPTs), first proposed and demonstrated by Huang [11]; these AFPTs consist essentially of a long carefully-designed "spin-twisted" high-birefringence fiber, fabricated by slowly varying the spin rate of a birefringent fiber preform (either from very fast to very slow or vice versa) while the fiber is being drawn. The evolution of the eigenstate from a linear polarization state to a circular polarization state, induced by slow variation of the intrinsic structure from linear anisotropy at the unspun end to circular anisotropy at the fast-spun end, enables the AFPT to behave like an all-fiber quarter-wave plate independent of the wavelength of operation. Power coupling between local eigenstates causes unique evolution of the polarization state along the fiber, and has been studied to gain insight into - as well as to understand detailed characteristics of -- the polarization transformation behavior. This has been graphically illustrated via plots of the relative power in these local eigenstates as a function of distance along the length of the fiber and plots of the extinction ratio of the output state of polarization (SOP) as a function of distance and the normalized spin rate. Deeper understanding of such polarization transformers has been further elucidated by quantitative calculations related to two crucial requirements for fabricating practical AFPT devices. Our calculations have also indicated that the polarization mode dispersion behaviour of the AFPT is much smaller than that of the original birefringent fiber. Finally, a specific AFPT was experimentally investigated at two widely-separated wavelengths (1310 nm and 1550 nm) of interest in telecommunications systems applications, further demonstrating and elucidating the broadband character of such AFPTs.

Some Remarks on Methods of QCD Analysis of Polarized DIS Data

CERN Document Server

Leader, Elliot; Stamenov, Dimiter B

2009-01-01

The results on polarized parton densities (PDFs) obtained using different methods of QCD analysis of the present polarized DIS data are discussed. Their dependence on the method used in the analysis, accounting or not for the kinematic and dynamic 1/Q^2 corrections to spin structure function g_1, is demonstrated. It is pointed out that the precise data in the preasymptotic region require a more careful matching of the QCD predictions to the data in this region in order to determine the polarized PDFs correctly.

Few-body physics investigated through polarized neutron experiments in A ≤ 3 systems at TUNL

International Nuclear Information System (INIS)

Tornow, W.; Howell, C.R.; Walter, R.L.

1989-01-01

Accurate polarization data obtained with neutrons below 20 MeV in the A ≤ 3 systems provide important new information on details of the nucleon-nucleon (NN) interaction. The two-nucleon and three-nucleon data favor the Paris potential over the new Bonn (OBEPQ) potential. However, one of the realistic potential models describes the elastic neutron-deuteron analyzing power satisfactorily. Charge independence breaking in the 3 P NN interactions and/or three-body force effects must be considered. (orig.)

Few-body physics investigated through polarized neutron experiments in A /le/ 3 systems at TUNL

Energy Technology Data Exchange (ETDEWEB)

Tornow, W.; Howell, C.R.; Walter, R.L.

1989-04-01

Accurate polarization data obtained with neutrons below 20 MeV in the A /le/ 3 systems provide important new information on details of the nucleon-nucleon (NN) interaction. The two-nucleon and three-nucleon data favor the Paris potential over the new Bonn (OBEPQ) potential. However, one of the realistic potential models describes the elastic neutron-deuteron analyzing power satisfactorily. Charge independence breaking in the /sup 3/P NN interactions and/or three-body force effects must be considered. (orig.).

Polarized neutrons

International Nuclear Information System (INIS)

Williams, W.G.

1988-01-01

The book on 'polarized neutrons' is intended to inform researchers in condensed matter physics and chemistry of the diversity of scientific problems that can be investigated using polarized neutron beams. The contents include chapters on:- neutron polarizers and instrumentation, polarized neutron scattering, neutron polarization analysis experiments and precessing neutron polarization. (U.K.)

Small-Body Extensions for the Satellite Orbit Analysis Program (SOAP)

Science.gov (United States)

Carnright, Robert; Stodden, David; Coggi, John

2008-01-01

An extension to the SOAP software allows users to work with tri-axial ellipsoid-based representations of planetary bodies, primarily for working with small, natural satellites, asteroids, and comets. SOAP is a widely used tool for the visualization and analysis of space missions. The small body extension provides the same visualization and analysis constructs for use with small bodies. These constructs allow the user to characterize satellite path and instrument cover information for small bodies in both 3D display and numerical output formats. Tri-axial ellipsoids are geometric shapes the diameters of which are different in each of three principal x, y, and z dimensions. This construct provides a better approximation than using spheres or oblate spheroids (ellipsoids comprising two common equatorial diameters as a distinct polar diameter). However, the tri-axial ellipsoid is considerably more difficult to work with from a modeling perspective. In addition, the SOAP small-body extensions allow the user to actually employ a plate model for highly irregular surfaces. Both tri-axial ellipsoids and plate models can be assigned to coordinate frames, thus allowing for the modeling of arbitrary changes to body orientation. A variety of features have been extended to support tri-axial ellipsoids, including the computation and display of the spacecraft sub-orbital point, ground trace, instrument footprints, and swathes. Displays of 3D instrument volumes can be shown interacting with the ellipsoids. Longitude/latitude grids, contour plots, and texture maps can be displayed on the ellipsoids using a variety of projections. The distance along an arbitrary line of sight can be computed between the spacecraft and the ellipsoid, and the coordinates of that intersection can be plotted as a function of time. The small-body extension supports the same visual and analytical constructs that are supported for spheres and oblate spheroids in SOAP making the implementation of the more

Microtubules Enable the Planar Cell Polarity of Airway Cilia

Science.gov (United States)

Vladar, Eszter K.; Bayly, Roy D.; Sangoram, Ashvin; Scott, Matthew P.; Axelrod, Jeffrey D.

2012-01-01

Summary Background Airway cilia must be physically oriented along the longitudinal tissue axis for concerted, directional motility that is essential for proper mucociliary clearance. Results We show that Planar Cell Polarity (PCP) signaling specifies directionality and orients respiratory cilia. Within all airway epithelial cells a conserved set of PCP proteins shows interdependent, asymmetric junctional localization; non-autonomous signaling coordinates polarization between cells; and a polarized microtubule (MT) network is likely required for asymmetric PCP protein localization. We find that basal bodies dock after polarity of PCP proteins is established, are polarized nearly simultaneously, and refinement of basal body/cilium orientation continues during airway epithelial development. Unique to mature multiciliated cells, we identify PCP-regulated, planar polarized MTs that originate from basal bodies and interact, via their plus ends, with membrane domains associated with the PCP proteins Frizzled and Dishevelled. Disruption of MTs leads to misoriented cilia. Conclusions A conserved PCP pathway orients airway cilia by communicating polarity information from asymmetric membrane domains at the apical junctions, through MTs, to orient the MT and actin based network of ciliary basal bodies below the apical surface. PMID:23122850

Loss of monocyte chemoattractant protein-1 alters macrophage polarization and reduces NFκB activation in the foreign body response.

Science.gov (United States)

Moore, Laura Beth; Sawyer, Andrew J; Charokopos, Antonios; Skokos, Eleni A; Kyriakides, Themis R

2015-01-01

Implantation of biomaterials elicits a foreign body response characterized by fusion of macrophages to form foreign body giant cells and fibrotic encapsulation. Studies of the macrophage polarization involved in this response have suggested that alternative (M2) activation is associated with more favorable outcomes. Here we investigated this process in vivo by implanting mixed cellulose ester filters or polydimethylsiloxane disks in the peritoneal cavity of wild-type (WT) and monocyte chemoattractant protein-1 (MCP-1) knockout mice. We analyzed classical (M1) and alternative (M2) gene expression via quantitative polymerase chain reaction, immunohistochemistry and enzyme-linked immunosorbent assay in both non-adherent cells isolated by lavage and implant-adherent cells. Our results show that macrophages undergo unique activation that displays features of both M1 and M2 polarization including induction of tumor necrosis factor α (TNF), which induces the expression and nuclear translocation of p50 and RelA determined by immunofluorescence and Western blot. Both processes were compromised in fusion-deficient MCP-1 KO macrophages in vitro and in vivo. Furthermore, inclusion of BAY 11-7028, an inhibitor of NFκB activation, reduced nuclear translocation of RelA and fusion in WT macrophages. Our studies suggest that peritoneal implants elicit a unique macrophage polarization phenotype leading to induction of TNF and activation of the NFκB pathway. Published by Elsevier Ltd.

SANS polarization analysis at V4 SANS instrument of HMI Berlin

International Nuclear Information System (INIS)

Keiderling, U; Wiedenmann, A; Rupp, A; Klenke, J; Heil, W

2008-01-01

The V4 instrument has recently been upgraded with a 3 He spin filter cell, placed directly in the homogeneous field B of the sample magnet, to enhance the SANSPOL option for polarization analysis. The prototype setup was still affected by: (a) a quick relaxation of the 3 He nuclear polarization in the cell with a time constant of only ≈130 min which significantly changes the spin filter transmissions T + and T − for neutrons polarized parallel I + and anti-parallel I − to B, and (b) the absence of a flipping aid behind the sample. The usual polarization analysis procedure, expecting virtually time-independent transmissions and a second flipping device, is therefore not applicable. We present an alternative way of polarization analysis, developed especially for this case of a spin filter cell with insufficient time stability, and not requiring a second flipper. A concentrated Co-ferrofluid sample 'MFT3N' was measured with the spin filter cell for 5.5 h. From the time-dependent change of I + and I − caused by the change of T + and T − , the spin-flip and non-spin-flip components of the scattering were calculated by fitting procedures. The two-dimensional flip patterns obtained represent the purely magnetic scattering contribution, featuring the typical (sin αcos α) 2 angular behavior expected for superparamagnetic systems

Towards an Italian Lexicon for Polarity Classification (polarITA): a Comparative Analysis of Lexical Resources for Sentiment Analysis

OpenAIRE

Hernández Farías, Delia Irazú; Laganà, Irene; Patti, Viviana; Bosco, Cristina

2018-01-01

The paper describes a preliminary study for the development of a novel lexicon for Italian sentiment analysis, i.e. where words are associated with polarity values. Given the influence of sentiment lexica on the performance of sentiment analysis systems, a methodology based on the detection and classification of errors in existing lexical resources is proposed and an extrinsic evaluation of the impact of such errors is applied. The final aim is to build a novel resource from the filtering app...

Geomorphometric analysis of selected Martian craters using polar coordinate transformation

Science.gov (United States)

Magyar, Zoltán; Koma, Zsófia; Székely, Balázs

2016-04-01

Centrally symmetric landform elements are very common features on the surface of the planet Mars. The most conspicuous ones of them are the impact craters of various size. However, a closer look on these features reveals that they show often asymmetric patterns as well. These are partially related to the geometry of the trajectory of the impacting body, but sometimes it is a result of surface processes (e.g., freeze/thaw cycles, mass movements). Geomorphometric studies have already been carried out to reveal these pecularities. Our approach, the application of polar coordinate transformation (PCT) very sensitively enhances the non-radial and non-circular shapes. We used digital terrain models (DTMs) derived from the ESA Mars Express HRSC imagery. The original DTM or its derivatives (e.g. slope angle or aspect) are PCT transformed. We analyzed the craters inter alia with scattergrams in polar coordinates. The resulting point cloud can be used directly for the analysis, but in some cases an interpolation should be applied to enhance certain non-circular features (especially in case of smaller craters). Visual inspection of the crater slopes, coloured by the aspect, reveals smaller features. Some of them are processing artefacts, but many of them are related to local undulations in the topography or indications of mass movements. In many cases the undulations of the crater rim are due to erosional processes. The drawbacks of the technology are related to the uneven resolution of the projected image: features in the crater centre should be left out from the analysis because PCT has a low resolution around the projection center. Furthermore, the success of the PCT depends on the correct definition of the projection centre: erroneously centered images are not suitable for analysis. The PCT transformed images are also suitable for radial averaging and calculation of standard deviations, resulting in typical, comparable craters shapes. These studies may lead to a deeper

Suomi National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite Polarization Sensitivity Analysis

Science.gov (United States)

Sun, Junqiang; Xiong, Xiaoxiong; Waluschka, Eugene; Wang, Menghua

2016-01-01

The Visible Infrared Imaging Radiometer Suite (VIIRS) is one of five instruments onboard the Suomi National Polar-Orbiting Partnership (SNPP) satellite that launched from Vandenberg Air Force Base, California, on October 28, 2011. It is a whiskbroom radiometer that provides +/-56.28deg scans of the Earth view. It has 22 bands, among which 14 are reflective solar bands (RSBs). The RSBs cover a wavelength range from 410 to 2250 nm. The RSBs of a remote sensor are usually sensitive to the polarization of incident light. For VIIRS, it is specified that the polarization factor should be smaller than 3% for 410 and 862 nm bands and 2.5% for other RSBs for the scan angle within +/-45deg. Several polarization sensitivity tests were performed prelaunch for SNPP VIIRS. The first few tests either had large uncertainty or were less reliable, while the last one was believed to provide the more accurate information about the polarization property of the instrument. In this paper, the measured data in the last polarization sensitivity test are analyzed, and the polarization factors and phase angles are derived from the measurements for all the RSBs. The derived polarization factors and phase angles are band, detector, and scan angle dependent. For near-infrared bands, they also depend on the half-angle mirror side. Nevertheless, the derived polarization factors are all within the specification, although the strong detector dependence of the polarization parameters was not expected. Compared to the Moderate Resolution Imaging Spectroradiometer on both Aqua and Terra satellites, the polarization effect on VIIRS RSB is much smaller.

Mitogenomes of polar bodies and corresponding oocytes.

Directory of Open Access Journals (Sweden)

Luca Gianaroli

Full Text Available The objective of the present study was to develop an approach that could assess the chromosomal status and the mitochondrial DNA (mtDNA content of oocytes and their corresponding polar bodies (PBs with the goal of obtaining a comparative picture of the segregation process both for nuclear and mtDNA. After Whole Genome Amplification (WGA, sequencing of the whole mitochondrial genome was attempted to analyze the segregation of mutant and wild-type mtDNA during human meiosis. Three triads, composed of oocyte and corresponding PBs, were analyzed and their chromosome status was successfully assessed. The complete mitochondrial genome (mitogenome was almost entirely sequenced in the oocytes (95.99% compared to 98.43% in blood, while the percentage of sequences obtained in the corresponding PB1 and PB2 was lower (69.70% and 69.04% respectively. The comparison with the mtDNA sequence in blood revealed no changes in the D-loop region for any of the cells of each triad. In the coding region of blood mtDNA and oocyte mtDNA sequences showed full correspondence, whereas all PBs had at least one change with respect to the blood-oocyte pairs. In all, 9 changes were found, either in PB1 or PB2: 4 in MT-ND5, 2 in MT-RNR2, and 1 each in MT-ATP8, MT-ND4, MT-CYTB. The full concordance between oocyte and blood in the 3 triads, and the relegation of changes to PBs, revealed the unexpected coexistence of different variants, giving a refined estimation of mitochondrial heteroplasmy. Should these findings be confirmed by additional data, an active mechanism could be postulated in the oocyte to preserve a condition of 'normality'.

Scattering with polarized neutrons

International Nuclear Information System (INIS)

Schweizer, J.

2007-01-01

In the history of neutron scattering, it was shown very soon that the use of polarized neutron beams brings much more information than usual scattering with unpolarized neutrons. We shall develop here the different scattering methods that imply polarized neutrons: 1) polarized beams without polarization analysis, the flipping ratio method; 2) polarized beams with a uniaxial polarization analysis; 3) polarized beams with a spherical polarization analysis. For all these scattering methods, we shall give examples of the physical problems which can been solved by these methods, particularly in the field of magnetism: investigation of complex magnetic structures, investigation of spin or magnetization densities in metals, insulators and molecular compounds, separation of magnetic and nuclear scattering, investigation of magnetic properties of liquids and amorphous materials and even, for non magnetic material, separation between coherent and incoherent scattering. (author)

The response of macrophages to titanium particles is determined by macrophage polarization.

Science.gov (United States)

Pajarinen, Jukka; Kouri, Vesa-Petteri; Jämsen, Eemeli; Li, Tian-Fang; Mandelin, Jami; Konttinen, Yrjö T

2013-11-01

Aseptic loosening of total joint replacements is driven by the reaction of macrophages to foreign body particles released from the implant. It was hypothesized that the macrophages' response to these particles is dependent, in addition to particle characteristics and contaminating biomolecules, on the state of macrophage polarization as determined by the local cytokine microenvironment. To test this hypothesis we differentiated M1 and M2 macrophages from human peripheral blood monocytes and compared their responses to titanium particles using genome-wide microarray analysis and a multiplex cytokine assay. In comparison to non-activated M0 macrophages, the overall chemotactic and inflammatory responses to titanium particles were greatly enhanced in M1 macrophages and effectively suppressed in M2 macrophages. In addition, the genome-wide approach revealed several novel, potentially osteolytic, particle-induced mediators, and signaling pathway analysis suggested the involvement of toll-like and nod-like receptor signaling in particle recognition. It is concluded that the magnitude of foreign body reaction caused by titanium particles is dependent on the state of macrophage polarization. Thus, by limiting the action of M1 polarizing factors, e.g. bacterial biofilm formation, in peri-implant tissues and promoting M2 macrophage polarization by biomaterial solutions or pharmacologically, it might be possible to restrict wear-particle-induced inflammation and osteolysis. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Oocyte Polarization Is Coupled to the Chromosomal Bouquet, a Conserved Polarized Nuclear Configuration in Meiosis.

Directory of Open Access Journals (Sweden)

Yaniv M Elkouby

2016-01-01

Full Text Available The source of symmetry breaking in vertebrate oocytes is unknown. Animal-vegetal oocyte polarity is established by the Balbiani body (Bb, a conserved structure found in all animals examined that contains an aggregate of specific mRNAs, proteins, and organelles. The Bb specifies the oocyte vegetal pole, which is key to forming the embryonic body axes as well as the germline in most vertebrates. How Bb formation is regulated and how its asymmetric position is established are unknown. Using quantitative image analysis, we trace oocyte symmetry breaking in zebrafish to a nuclear asymmetry at the onset of meiosis called the chromosomal bouquet. The bouquet is a universal feature of meiosis where all telomeres cluster to one pole on the nuclear envelope, facilitating chromosomal pairing and meiotic recombination. We show that Bb precursor components first localize with the centrosome to the cytoplasm adjacent to the telomere cluster of the bouquet. They then aggregate around the centrosome in a specialized nuclear cleft that we identified, assembling the early Bb. We show that the bouquet nuclear events and the cytoplasmic Bb precursor localization are mechanistically coordinated by microtubules. Thus the animal-vegetal axis of the oocyte is aligned to the nuclear axis of the bouquet. We further show that the symmetry breaking events lay upstream to the only known regulator of Bb formation, the Bucky ball protein. Our findings link two universal features of oogenesis, the Bb and the chromosomal bouquet, to oocyte polarization. We propose that a meiotic-vegetal center couples meiosis and oocyte patterning. Our findings reveal a novel mode of cellular polarization in meiotic cells whereby cellular and nuclear polarity are aligned. We further reveal that in zygotene nests, intercellular cytoplasmic bridges remain between oocytes and that the position of the cytoplasmic bridge coincides with the location of the centrosome meiotic-vegetal organizing center

Elite Polarization and Public Opinion

DEFF Research Database (Denmark)

Robison, Joshua; Mullinix, Kevin

2016-01-01

Elite polarization has reshaped American politics and is an increasingly salient aspect of news coverage within the United States. As a consequence, a burgeoning body of research attempts to unravel the effects of elite polarization on the mass public. However, we know very little about how...... polarization is communicated to the public by news media. We report the results of one of the first content analyses to delve into the nature of news coverage of elite polarization. We show that such coverage is predominantly critical of polarization. Moreover, we show that unlike coverage of politics focused...... on individual politicians, coverage of elite polarization principally frames partisan divisions as rooted in the values of the parties rather than strategic concerns. We build on these novel findings with two survey experiments exploring the influence of these features of polarization news coverage on public...

Fractal analysis of polar bear hairs

Directory of Open Access Journals (Sweden)

Wang Qing-Li

2015-01-01

Full Text Available Hairs of a polar bear (Ursus maritimus are of superior properties such as the excellent thermal protection. Why do polar bears can resist such cold environment? The paper concludes that its fractal porosity plays an important role, and its fractal dimensions are very close to the golden mean, 1.618, revealing the possible optimal structure of polar bear hair.

Increasing nest predation will be insufficient to maintain polar bear body condition in the face of sea ice loss.

Science.gov (United States)

Dey, Cody J; Richardson, Evan; McGeachy, David; Iverson, Samuel A; Gilchrist, Hugh G; Semeniuk, Christina A D

2017-05-01

Climate change can influence interspecific interactions by differentially affecting species-specific phenology. In seasonal ice environments, there is evidence that polar bear predation of Arctic bird eggs is increasing because of earlier sea ice breakup, which forces polar bears into nearshore terrestrial environments where Arctic birds are nesting. Because polar bears can consume a large number of nests before becoming satiated, and because they can swim between island colonies, they could have dramatic influences on seabird and sea duck reproductive success. However, it is unclear whether nest foraging can provide an energetic benefit to polar bear populations, especially given the capacity of bird populations to redistribute in response to increasing predation pressure. In this study, we develop a spatially explicit agent-based model of the predator-prey relationship between polar bears and common eiders, a common and culturally important bird species for northern peoples. Our model is composed of two types of agents (polar bear agents and common eider hen agents) whose movements and decision heuristics are based on species-specific bioenergetic and behavioral ecological principles, and are influenced by historical and extrapolated sea ice conditions. Our model reproduces empirical findings that polar bear predation of bird nests is increasing and predicts an accelerating relationship between advancing ice breakup dates and the number of nests depredated. Despite increases in nest predation, our model predicts that polar bear body condition during the ice-free period will continue to decline. Finally, our model predicts that common eider nests will become more dispersed and will move closer to the mainland in response to increasing predation, possibly increasing their exposure to land-based predators and influencing the livelihood of local people that collect eider eggs and down. These results show that predator-prey interactions can have nonlinear responses to

Thermal analysis of a prototype cryogenic polarization modulator for use in a space-borne CMB polarization experiment

Science.gov (United States)

Iida, T.; Sakurai, Y.; Matsumura, T.; Sugai, H.; Imada, H.; Kataza, H.; Ohsaki, H.; Hazumi, M.; Katayama, N.; Yamamoto, R.; Utsunomiya, S.; Terao, Y.

2017-12-01

We report a thermal analysis of a polarization modulator unit (PMU) for use in a space-borne cosmic microwave background (CMB) project. A measurement of the CMB polarization allows us to probe the physics of early universe, and that is the best method to test the cosmic inflation experimentally. One of the key instruments for this science is to use a halfwave plate (HWP) based polarization modulator. The HWP is required to rotate continuously at about 1 Hz below 10 K to minimize its own thermal emission to a detector system. The rotating HWP system at the cryogenic environment can be realized by using a superconducting magnetic bearing (SMB) without significant heat dissipation by mechanical friction. While the SMB achieves the smooth rotation due to the contactless bearing, an estimation of a levitating HWP temperature becomes a challenge. We manufactured a one-eighth scale prototype model of PMU and built a thermal model. We verified our thermal model with the experimental data. We forecasted the projected thermal performance of PMU for a full-scale model based on the thermal model. From this analysis, we discuss the design requirement toward constructing the full-scale model for use in a space environment such as a future CMB satellite mission, LiteBIRD.

Linearly Polarized IR Spectroscopy Theory and Applications for Structural Analysis

CERN Document Server

Kolev, Tsonko

2011-01-01

A technique that is useful in the study of pharmaceutical products and biological molecules, polarization IR spectroscopy has undergone continuous development since it first emerged almost 100 years ago. Capturing the state of the science as it exists today, "Linearly Polarized IR Spectroscopy: Theory and Applications for Structural Analysis" demonstrates how the technique can be properly utilized to obtain important information about the structure and spectral properties of oriented compounds. The book starts with the theoretical basis of linear-dichroic infrared (IR-LD) spectroscop

Goal scoring in soccer: A polar coordinate analysis of motor skills used by Lionel Messi

Directory of Open Access Journals (Sweden)

Marta eCastañer

2016-05-01

Full Text Available Soccer research has traditionally focused on technical and tactical aspects of team play, but few studies have analyzed motor skills in individual actions, such as goal scoring. The objective of this study was to investigate how Lionel Messi, one of the world’s top soccer players, uses his motor skills and laterality in individual attacking actions resulting in a goal. We analyzed 103 goals scored by Messi between over a decade in three competitions: La Liga (n = 74, Copa del Rey (n = 8, and the UEFA Champions League (n = 21. We used an ad hoc observation instrument (OSMOS-soccer player comprising 10 criteria and 50 categories; polar coordinate analysis, a powerful data reduction technique, revealed significant associations for body part and orientation, foot contact zone, turn direction, and locomotion. No significant associations were observed for pitch area or interaction with opponents. Our analysis confirms significant associations between different aspects of motor skill use by Messi immediately before scoring, namely use of lower limbs, foot contact zones, turn direction, use of wings, and orientation of body to move towards the goal. Studies of motor skills in soccer could shed light on the qualities that make certain players unique.

Recent advancements of wide-angle polarization analysis with 3He neutron spin filters

International Nuclear Information System (INIS)

Chen, W.C.; Gentile, T.R.; Ye, Q.; Kirchhoff, A.; Watson, S.M.; Rodriguez-Rivera, J.A.; Qiu, Y.; Broholm, C.

2016-01-01

Wide-angle polarization analysis with polarized 3 He based neutron spin filters (NSFs) has recently been employed on the Multi-Axis Crystal Spectrometer (MACS) at the National Institute of Standards and Technology Center for Neutron Research (NCNR). Over the past several years, the apparatus has undergone many upgrades to address the fundamental requirements for wide angle polarization analysis using spin exchange optical pumping based 3 He NSFs. In this paper, we report substantial improvements in the on-beam-line performance of the apparatus and progress toward routine user capability. We discuss new standard samples used for 3 He NSF characterization and the flipping ratio measurement on MACS. We further discuss the management of stray magnetic fields produced by operation of superconducting magnets on the MACS instrument, which can significantly reduce the 3 He polarization relaxation time. Finally, we present the results of recent development of horseshoe-shaped wide angle cells. (paper)

Analysis of the international distribution of per capita CO2 emissions using the polarization concept

International Nuclear Information System (INIS)

Duro, Juan Antonio; Padilla, Emilio

2008-01-01

The concept of polarization is linked to the extent that a given distribution leads to the formation of homogeneous groups with opposing interests. This concept, which is basically different from the traditional one of inequality, is related to the level of inherent potential conflict in a distribution. The polarization approach has been widely applied in the analysis of income distribution. The extension of this approach to the analysis of international distribution of CO 2 emissions is quite useful as it gives a potent informative instrument for characterizing the state and evolution of the international distribution of emissions and its possible political consequences in terms of tensions and the probability of achieving agreements. In this paper we analyze the international distribution of per capita CO 2 emissions between 1971 and 2001 through the adaptation of the polarization concept and measures. We find that the most interesting grouped description deriving from the analysis is a two groups' one, which broadly coincide with Annex B and non-Annex B countries of the Kyoto Protocol, which shows the power of polarization analysis for explaining the generation of groups in the real world. The analysis also shows a significant reduction in international polarization in per capita CO 2 emissions between 1971 and 1995, but not much change since 1995, which might indicate that polarized distribution of emission is still one of the important factors leading to difficulties in achieving agreements for reducing global emissions. (author)

Semileptonic weak and electromagnetic interactions in nuclei: recoil polarization in muon capture

International Nuclear Information System (INIS)

Rosenfelder, R.

1979-01-01

An analysis of the polarization of the recoiling nucleus following the capture of polarized muons by nuclei is performed. New general expressions for arbitrary nuclear spin are obtained in terms of the same reduced matrix elements which govern inelastic electron scattering and β-decay. As an application the A = 12 system is considered and uncertainties in the nuclear structure are studied by using different sets of one-body density matrices. With the canonical values of the weak form factors (i.e. absence of second-class currents) a fairly good agreement with the experimental data is achieved including the inelastic form factor at high momentum transfers and the recently measured average 12 B polarization. Implications of the new corrected value of the average polarization on weak form factors and nuclear structure are discussed. (Auth.)

Polarized neutron spectrometer

International Nuclear Information System (INIS)

Abov, Yu.G.; Novitskij, V.V.; Alfimenkov, V.P.; Galinskij, E.M.; Mareev, Yu.D.; Pikel'ner, L.B.; Chernikov, A.N.; Lason', L.; Tsulaya, V.M.; Tsulaya, M.I.

2000-01-01

The polarized neutron spectrometer, intended for studying the interaction of polarized neutrons with nuclei and condensed media in the area of energies from thermal up to several electron-volt, is developed at the IBR-2 reactor (JINR, Dubna). Diffraction on the Co(92%)-Fe(8%) magnetized monocrystals is used for the neutron polarization and polarization analysis. The neutron polarization within the whole energy range equals ∼ 95% [ru

Dual-Polarized Planar Phased Array Analysis for Meteorological Applications

Directory of Open Access Journals (Sweden)

Chen Pang

2015-01-01

Full Text Available This paper presents a theoretical analysis for the accuracy requirements of the planar polarimetric phased array radar (PPPAR in meteorological applications. Among many factors that contribute to the polarimetric biases, four factors are considered and analyzed in this study, namely, the polarization distortion due to the intrinsic limitation of a dual-polarized antenna element, the antenna pattern measurement error, the entire array patterns, and the imperfect horizontal and vertical channels. Two operation modes, the alternately transmitting and simultaneously receiving (ATSR mode and the simultaneously transmitting and simultaneously receiving (STSR mode, are discussed. For each mode, the polarimetric biases are formulated. As the STSR mode with orthogonal waveforms is similar to the ATSR mode, the analysis is mainly focused on the ATSR mode and the impacts of the bias sources on the measurement of polarimetric variables are investigated through Monte Carlo simulations. Some insights of the accuracy requirements are obtained and summarized.

Analysis on Coupled Vibration of a Radially Polarized Piezoelectric Cylindrical Transducer

Directory of Open Access Journals (Sweden)

Jie Xu

2017-12-01

Full Text Available Coupled vibration of a radially polarized piezoelectric cylindrical transducer is analyzed with the mechanical coupling coefficient method. The method has been utilized to analyze the metal cylindrical transducer and the axially polarized piezoelectric cylindrical transducer. In this method, the mechanical coupling coefficient is introduced and defined as the stress ratio in different directions. Coupled vibration of the cylindrical transducer is regarded as the interaction of the plane radial vibration of a ring and the longitudinal vibration of a tube. For the radially polarized piezoelectric cylindrical transducer, the radial and longitudinal electric admittances as functions of mechanical coupling coefficients and angular frequencies are derived, respectively. The resonance frequency equations are obtained. The dependence of resonance frequency and mechanical coupling coefficient on aspect ratio is studied. Vibrational distributions on the surfaces of the cylindrical transducer are presented with experimental measurement. On the support of experiments, this work is verified and provides a theoretical foundation for the analysis and design of the radially polarized piezoelectric cylindrical transducer.

A High-Resolution Continuous Flow Analysis System for Polar Ice Cores

DEFF Research Database (Denmark)

Dallmayr, Remi; Goto-Azuma, Kumiko; Kjær, Helle Astrid

2016-01-01

of Polar Research (NIPR) in Tokyo. The system allows the continuous analysis of stable water isotopes and electrical conductivity, as well as the collection of discrete samples from both inner and outer parts of the core. This CFA system was designed to have sufficiently high temporal resolution to detect...... signals of abrupt climate change in deep polar ice cores. To test its performance, we used the system to analyze different climate intervals in ice drilled at the NEEM (North Greenland Eemian Ice Drilling) site, Greenland. The quality of our continuous measurement of stable water isotopes has been......In recent decades, the development of continuous flow analysis (CFA) technology for ice core analysis has enabled greater sample throughput and greater depth resolution compared with the classic discrete sampling technique. We developed the first Japanese CFA system at the National Institute...

Preliminary observations on polar body extrusion and pronuclear formation in human oocytes using time-lapse video cinematography.

Science.gov (United States)

Payne, D; Flaherty, S P; Barry, M F; Matthews, C D

1997-03-01

In this study, we have used time-lapse video cinematography to study fertilization in 50 human oocytes that had undergone intracytoplasmic sperm injection (ICSI). Time-lapse recording commenced shortly after ICSI and proceeded for 17-20 h. Oocytes were cultured in an environmental chamber which was maintained under standard culture conditions. Overall, 38 oocytes (76%) were fertilized normally, and the fertilization rate and embryo quality were not significantly different from 487 sibling oocytes cultured in a conventional incubator. Normal fertilization followed a defined course of events, although the timing of these events varied markedly between oocytes. In 35 of the 38 fertilized oocytes (92%), there were circular waves of granulation within the ooplasm which had a periodicity of 20-53 min. The sperm head decondensed during this granulation phase. The second polar body was then extruded, and this was followed by the central formation of the male pronucleus. The female pronucleus formed in the cytoplasm adjacent to the second polar body at the same time as, or slightly after, the male pronucleus, and was subsequently drawn towards the male pronucleus until the two abutted. Both pronuclei then increased in size, the nucleoli moved around within the pronuclei and some nucleoli coalesced. During pronuclear growth, the organelles contracted from the cortex towards the centre of the oocyte, leaving a clear cortical zone. The oocyte decreased in diameter from 112 to 106 microm (P cinematography is an excellent tool for studying fertilization and early embryo development, and have demonstrated that human fertilization comprises numerous complex dynamic events.

QCD analysis of polarized deep inelastic scattering data

International Nuclear Information System (INIS)

Bluemlein, Johannes; Boettcher, Helmut

2010-05-01

A QCD analysis of the world data on polarized deep inelastic scattering is presented in next-to-leading order, including the heavy flavor Wilson coefficient in leading order in the fixed flavor number scheme. New parameterizations are derived for the quark and gluon distributions and the value of α s (M z 2 ) is determined. The impact of the variation of both the renormalization and factorization scales on the distributions and the value of α s is studied. We obtain α s NLO (M Z 2 )=0.1132 -0.0095 +0.0056 . The first moments of the polarized twist-2 parton distribution functions are calculated with correlated errors to allow for comparisons with results from lattice QCD simulations. Potential higher twist contributions to the structure function g 1 (x,Q 2 ) are determined and found to be compatible with zero both for proton and deuteron targets. (orig.)

A large area silicon UCN detector with the analysis of UCN polarization

International Nuclear Information System (INIS)

Lasakov, M.S.; Serebrov, A.P.; Khusainov, A.Kh.; Pustovoit, A.; Borisov, Yu.V.; Fomin, A.K.; Geltenbort, P.; Kon'kov, O.I.; Kotina, I.M.; Shablii, A.I.; Solovei, V.A.; Vasiliev, A.V.

2005-01-01

A silicon UCN detector with an area of 45cm 2 and with a 6 LiF converter was developed at PNPI. The spectral efficiency of the silicon UCN detector was measured by means of a gravitational spectrometer at ILL. The sandwich-type detector from two silicon plates with a 6 LiF converter placed between them was also studied. Using this type of technology the UCN detector with analysis of polarization was developed and tested. The analyzing power of this detector assembly reaches up to 75% for the main part of UCN spectrum. This UCN detector with analysis of UCN polarization can be used in the new EDM spectrometer

Membrane Transport across Polarized Epithelia.

Science.gov (United States)

Garcia-Castillo, Maria Daniela; Chinnapen, Daniel J-F; Lencer, Wayne I

2017-09-01

Polarized epithelial cells line diverse surfaces throughout the body forming selective barriers between the external environment and the internal milieu. To cross these epithelial barriers, large solutes and other cargoes must undergo transcytosis, an endocytic pathway unique to polarized cell types, and significant for the development of cell polarity, uptake of viral and bacterial pathogens, transepithelial signaling, and immunoglobulin transport. Here, we review recent advances in our knowledge of the transcytotic pathway for proteins and lipids. We also discuss briefly the promise of harnessing the molecules that undergo transcytosis as vehicles for clinical applications in drug delivery. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

Status of the analysis for the search of polarization in the antiproton production process

International Nuclear Information System (INIS)

Alfs, D.; Asaturyan, A.; Carmignotto, M.; Diermaier, M.; Eyrich, W.; Głowacz, B.; Grzonka, D.; Hauenstein, F.; Horn, T.; Kilian, K.; Malbrunot-Ettenauer, S.; Mkrtchyan, A.; Mkrtchyan, H.; Moskal, P.; Nadel-Turonski, P.; Oelert, W.; Ritman, J.; Sefzick, T.; Tadevosyan, V.; Widmann, E.; Wolke, M.; Zhamkochyan, S.; Zieliński, M.; Zink, A.; Zmeskal, J.

2016-01-01

The P-349 experiment aims to test whether for antiprotons the production process itself can be a source of polarization in view of the preparation of a polarized antiproton beam. In this article we present the details of performed measurements and report on the status of the ongoing analysis.

General analysis for experimental studies of time-reversal-violating effects in slow neutron propagation through polarized matter

International Nuclear Information System (INIS)

Lamoreaux, S.K.; Golub, R.

1994-01-01

A general technique is developed for the analysis of proposed experimental studies of possible P,T-violating effects in the neutron-nucleus interaction based on low-energy neutron transmission through polarized matter. The analysis is applied to proposed experimental schemes and we determine the levels at which the absolute neutron polarization, magnetic fields, and target polarization must be controlled in order for these experiments to obtain a given sensitivity to P,T-violating effects

Analysis of polarization characteristics of plant canopies using ground-based remote sensing measurements

International Nuclear Information System (INIS)

Sid’ko, A.F.; Botvich, I.Yu.; Pisman, T.I.; Shevyrnogov, A.P.

2014-01-01

The paper presents results and analysis of a study on polarized characteristics of the reflectance factor of different plant canopies under field conditions, using optical remote sensing techniques. Polarization characteristics were recorded from the elevated work platform at heights of 10–18 m in June and July. Measurements were performed using a double-beam spectrophotometer with a polarized light filter attachment, within the spectral range from 400 to 820 nm. The viewing zenith angle was below 20 degree. Birch (Betila pubescens), pine (Pinus sylvestris L.), wheat (Triticum acstivum) [L.] crops, corn (Zea mays L. ssp. mays) crops, and various grass canopies were used in this study. The following polarization characteristics were studied: the reflectance factor of the canopy with the polarizer adjusted to transmit the maximum and minimum amounts of light (R max and R min ), polarized component of the reflectance factor (R q ), and the degree of polarization (P). Wheat, corn, and grass canopies have higher R max and R min values than forest plants. The R q and P values are higher for the birch than for the pine within the wavelength range between 430 and 740 nm. The study shows that polarization characteristics of plant canopies may be used as an effective means of decoding remote sensing data. - Highlights: • The reflection and polarization properties of plant were studied. • The compiled electronic database of the spectrophotometric information of plant. • Polarization characteristics are a source of useful data on the state of plants

Why might they be giants? Towards an understanding of polar gigantism.

Science.gov (United States)

Moran, Amy L; Woods, H Arthur

2012-06-15

Beginning with the earliest expeditions to the poles, over 100 years ago, scientists have compiled an impressive list of polar taxa whose body sizes are unusually large. This phenomenon has become known as 'polar gigantism'. In the intervening years, biologists have proposed a multitude of hypotheses to explain polar gigantism. These hypotheses run the gamut from invoking release from physical and physiological constraints, to systematic changes in developmental trajectories, to community-level outcomes of broader ecological and evolutionary processes. Here we review polar gigantism and emphasize two main problems. The first is to determine the true strength and generality of this pattern: how prevalent is polar gigantism across taxonomic units? Despite many published descriptions of polar giants, we still have a poor grasp of whether these species are unusual outliers or represent more systematic shifts in distributions of body size. Indeed, current data indicate that some groups show gigantism at the poles whereas others show nanism. The second problem is to identify underlying mechanisms or processes that could drive taxa, or even just allow them, to evolve especially large body size. The contenders are diverse and no clear winner has yet emerged. Distinguishing among the contenders will require better sampling of taxa in both temperate and polar waters and sustained efforts by comparative physiologists and evolutionary ecologists in a strongly comparative framework.

Analysis of JPSS J1 VIIRS Polarization Sensitivity Using the NIST T-SIRCUS

Science.gov (United States)

McIntire, Jeffrey W.; Young, James B.; Moyer, David; Waluschka, Eugene; Oudrari, Hassan; Xiong, Xiaoxiong

2015-01-01

The polarization sensitivity of the Joint Polar Satellite System (JPSS) J1 Visible Infrared Imaging Radiometer Suite (VIIRS) measured pre-launch using a broadband source was observed to be larger than expected for many reflective bands. Ray trace modeling predicted that the observed polarization sensitivity was the result of larger diattenuation at the edges of the focal plane filter spectral bandpass. Additional ground measurements were performed using a monochromatic source (the NIST T-SIRCUS) to input linearly polarized light at a number of wavelengths across the bandpass of two VIIRS spectral bands and two scan angles. This work describes the data processing, analysis, and results derived from the T-SIRCUS measurements, comparing them with broadband measurements. Results have shown that the observed degree of linear polarization, when weighted by the sensor's spectral response function, is generally larger on the edges and smaller in the center of the spectral bandpass, as predicted. However, phase angle changes in the center of the bandpass differ between model and measurement. Integration of the monochromatic polarization sensitivity over wavelength produced results consistent with the broadband source measurements, for all cases considered.

ULF Narrowband Emissions Analysis in the Terrestrial Polar Cusps

Science.gov (United States)

Grison, B.; Pisa, D.

2013-05-01

Polar cusps are known to be a key region for transfer of mass and momentum between the adjacent magnetosheath and the magnetosphere. The 4 spacecraft of the Cluster ESA mission crossed the polar cusps in their most distant part to the Earth in the early years of the mission (2000-2004) because of their highly eccentric orbit. The ULF wave activity in the cusp region has been linked with the magnetosheath plasma penetration since HEOS observations (D'Angelo et al., 1974). Wave and particle interaction play an important role in this colisionless plasma. The observed wave activity certainly results from both distant and local generation mechanisms. From Cluster case studies we propose to focus on one aspect for each of this place of generation. Concerning the distant generation, the possibility of a wave generation at the magnetopause itself is investigated. For this purpose we compare the propagation of the emissions on each side of the magnetopasue, i.e. in the cusp and in the magnetosheath. Concerning the local generation, the presence of locally generated waves above the local proton gyrofrequency that display a left hand polarization has been reported in Polar and Cluster studies (Le et al., 2001; Nykyri et al., 2003 ). The Doppler shift was not large enough to explain the observed frequency. We propose here to combine various techniques (k-filtering analysis, WHAMP simulations) to achieve a precise wave vector estimation and to explain these observations. References: D'Angelo, N., A. Bahnsen, and H. Rosenbauer (1974), Wave and particle measurements at the polar cusp, J. Geophys. Res., 79( 22), 3129-3134, doi:10.1029/JA079i022p03129. Le, G., X. Blanco-Cano, C. T. Russell, X.-W. Zhou, F. Mozer, K. J. Trattner, S. A. Fuselier, and B. J. Anderson (2001), Electromagnetic ion cyclotron waves in the high-altitude cusp: Polar observations, J. Geophys. Res., 106(A9), 19067-19079, doi:10.1029/2000JA900163. Nykyri, K., P. J. Cargill, E. A. Lucek, T. S. Horbury, A. Balogh

Can polar bear hairs absorb environmental energy?

Directory of Open Access Journals (Sweden)

He Ji-Huan

2011-01-01

Full Text Available A polar bear (Ursus maritimus has superior ability to survive in harsh Arctic regions, why does the animal have such an excellent thermal protection? The present paper finds that the unique labyrinth cavity structure of the polar bear hair plays an important role. The hair can not only prevent body temperature loss but can also absorb energy from the environment.

Analysis of human knee osteoarthritic cartilage using polarization sensitive second harmonic generation microscopy

Science.gov (United States)

Kumar, Rajesh; Grønhaug, Kirsten M.; Romijn, Elisabeth I.; Drogset, Jon O.; Lilledahl, Magnus B.

2014-05-01

Osteoarthritis is one of the most prevalent joint diseases in the world. Although the cause of osteoarthritis is not exactly clear, the disease results in a degradation of the quality of the articular cartilage including collagen and other extracellular matrix components. We have investigated alterations in the structure of collagen fibers in the cartilage tissue of the human knee using mulitphoton microscopy. Due to inherent high nonlinear susceptibility, ordered collagen fibers present in the cartilage tissue matrix produces strong second harmonic generation (SHG) signals. Significant morphological differences are found in different Osteoarthritic grades of cartilage by SHG microscopy. Based on the polarization analysis of the SHG signal, we find that a few locations of hyaline cartilage (mainly type II collagen) is being replaced by fibrocartilage (mainly type I cartilage), in agreement with earlier literature. To locate the different types and quantify the alteration in the structure of collagen fiber, we employ polarization-SHG microscopic analysis, also referred to as _-tensor imaging. The image analysis of p-SHG image obtained by excitation polarization measurements would represent different tissue constituents with different numerical values at pixel level resolution.

Numerical analysis of fundamental characteristics of superconducting magnetic bearings for a polarization modulator

International Nuclear Information System (INIS)

Terachi, Yusuke; Terao, Yutaka; Ohsaki, Hiroyuki; Sakurai, Yuki; Matsumura, Tomotake; Sugai, Hajime; Utsunomiya, Shin; Kataza, Hirokazu; Yamamoto, Ryo

2017-01-01

We have carried out numerical analysis of mechanical properties of a superconducting magnetic bearing (SMB). A contactless bearing operating at below 10 K with low rotational energy loss is an attractive feature to be used as a rotational mechanism of a polarization modulator for a cosmic microwave background experiment. In such application, a rotor diameter of about 400 mm forces us to employ a segmented magnet. As a result, there is inevitable spatial gap between the segments. In order to understand the path towards the design optimizations, 2D and 3D FEM analyses were carried out to examine fundamental characteristics of the SMBs for a polarization modulator. Two axial flux type SMBs were dealt with in the analysis: (a) the SMB with axially magnetized permanent magnets (PMs), and (b) the SMB with radially magnetized PMs and steel components for magnetic flux paths. Magnetic flux lines and density distributions, electromagnetic force characteristics, spring constants, etc. were compared among some variations of the SMBs. From the numerical analysis results, it is discussed what type, configuration and design of SMBs are more suitable for a polarization modulator. (paper)

Validation of adipose lipid content as a body condition index for polar bears

Science.gov (United States)

McKinney, Melissa A.; Atwood, Todd C.; Dietz, Rune; Sonne, Christian; Iverson, Sara J.; Peacock, Elizabeth

2014-01-01

Body condition is a key indicator of individual and population health. Yet, there is little consensus as to the most appropriate condition index (CI), and most of the currently used CIs have not been thoroughly validated and are logistically challenging. Adipose samples from large datasets of capture biopsied, remote biopsied, and harvested polar bears were used to validate adipose lipid content as a CI via tests of accuracy, precision, sensitivity, biopsy depth, and storage conditions and comparisons to established CIs, to measures of health and to demographic and ecological parameters. The lipid content analyses of even very small biopsy samples were highly accurate and precise, but results were influenced by tissue depth at which the sample was taken. Lipid content of capture biopsies and samples from harvested adult females was correlated with established CIs and/or conformed to expected biological variation and ecological changes. However, lipid content of remote biopsies was lower than capture biopsies and harvested samples, possibly due to lipid loss during dart retrieval. Lipid content CI is a biologically relevant, relatively inexpensive and rapidly assessed CI and can be determined routinely for individuals and populations in order to infer large-scale spatial and long-term temporal trends. As it is possible to collect samples during routine harvesting or remotely using biopsy darts, monitoring and assessment of body condition can be accomplished without capture and handling procedures or noninvasively, which are methods that are preferred by local communities. However, further work is needed to apply the method to remote biopsies.

Gene transcription in polar bears (Ursus maritimus) from disparate populations

Science.gov (United States)

Bowen, Lizabeth; Miles, A. Keith; Waters, Shannon C.; Meyerson, Randi; Rode, Karyn D.; Atwood, Todd C.

2015-01-01

Polar bears in the Beaufort (SB) and Chukchi (CS) Seas experience different environments due primarily to a longer history of sea ice loss in the Beaufort Sea. Ecological differences have been identified as a possible reason for the generally poorer body condition and reproduction of Beaufort polar bears compared to those from the Chukchi, but the influence of exposure to other stressors remains unknown. We use molecular technology, quantitative PCR, to identify gene transcription differences among polar bears from the Beaufort and Chukchi Seas as well as captive healthy polar bears. We identified significant transcriptional differences among a priori groups (i.e., captive bears, SB 2012, SB 2013, CS 2013) for ten of the 14 genes of interest (i.e., CaM, HSP70, CCR3, TGFβ, COX2, THRα, T-bet, Gata3, CD69, and IL17); transcription levels of DRβ, IL1β, AHR, and Mx1 did not differ among groups. Multivariate analysis also demonstrated separation among the groups of polar bears. Specifically, we detected transcript profiles consistent with immune function impairment in polar bears from the Beaufort Sea, when compared with Chukchi and captive polar bears. Although there is no strong indication of differential exposure to contaminants or pathogens between CS and SB bears, there are clearly differences in important transcriptional responses between populations. Further investigation is warranted to refine interpretation of potential effects of described stress-related conditions for the SB population.

Analysis of elliptically polarized maximally entangled states for bell inequality tests

Science.gov (United States)

Martin, A.; Smirr, J.-L.; Kaiser, F.; Diamanti, E.; Issautier, A.; Alibart, O.; Frey, R.; Zaquine, I.; Tanzilli, S.

2012-06-01

When elliptically polarized maximally entangled states are considered, i.e., states having a non random phase factor between the two bipartite polarization components, the standard settings used for optimal violation of Bell inequalities are no longer adapted. One way to retrieve the maximal amount of violation is to compensate for this phase while keeping the standard Bell inequality analysis settings. We propose in this paper a general theoretical approach that allows determining and adjusting the phase of elliptically polarized maximally entangled states in order to optimize the violation of Bell inequalities. The formalism is also applied to several suggested experimental phase compensation schemes. In order to emphasize the simplicity and relevance of our approach, we also describe an experimental implementation using a standard Soleil-Babinet phase compensator. This device is employed to correct the phase that appears in the maximally entangled state generated from a type-II nonlinear photon-pair source after the photons are created and distributed over fiber channels.

Application of neural network in τ→ρυτ polarization analysis

International Nuclear Information System (INIS)

Zhang Ziping; Wang Yifang; Innocente, V.

1994-01-01

An artificial neutral network was built to select events in the τ→ρυ τ polarization analysis at LEP/L3, much better selection efficiency has been achieved. Detailed studies show that no systematic errors or bias have been introduced by the application of neural network. A polarization of P τ = -0.129 +- 0.050 +- 0.050 for this channel was obtained by using a sample of 8977 τ + τ - pairs collected near the peak of Z 0 resonance. The neural network training method and some details are described

Small angle scattering polarization biopsy: a comparative analysis of various skin diseases

Science.gov (United States)

Zimnyakov, D. A.; Alonova, M. V.; Yermolenko, S. B.; Ivashko, P. V.; Reshetnikova, E. M.; Galkina, E. M.; Utz, S. R.

2013-12-01

An approach to differentiation of the morphological features of normal and pathological human epidermis on the base of statistical analysis of the local polarization states of laser light forward scattered by in-vitro tissue samples is discussed. The eccentricity and the azimuth angle of local polarization ellipses retrieved for various positions of the focused laser beam on the tissue surface, and the coefficient of collimated transmittance are considered as the diagnostic parameters for differentiation. The experimental data obtained with the psoriasis, discoid lupus erythematosus, alopecia, lichen planus, scabies, demodex, and normal skin samples are presented.

The polarization of fast neutrons

International Nuclear Information System (INIS)

Talov, V.V.

2000-01-01

The present work is the review of polarization of fast neutrons and methods of polarization analysis. This also includes information about polarization of fast neutrons from first papers, which described polarization in the D(d,n) 3 He, 7 Li(p,n) 7 Be, and T(p,n) 3 He reactions. (authors)

Coronal Polarization of Pseudostreamers and the Solar Polar Field Reversal

Science.gov (United States)

Rachmeler, L. A.; Guennou, C.; Seaton, D. B.; Gibson, S. E.; Auchere, F.

2016-01-01

The reversal of the solar polar magnetic field is notoriously hard to pin down due to the extreme viewing angle of the pole. In Cycle 24, the southern polar field reversal can be pinpointed with high accuracy due to a large-scale pseudostreamer that formed over the pole and persisted for approximately a year. We tracked the size and shape of this structure with multiple observations and analysis techniques including PROBA2/SWAP EUV images, AIA EUV images, CoMP polarization data, and 3D tomographic reconstructions. We find that the heliospheric field reversed polarity in February 2014, whereas in the photosphere, the last vestiges of the previous polar field polarity remained until March 2015. We present here the evolution of the structure and describe its identification in the Fe XII 1074nm coronal emission line, sensitive to the Hanle effect in the corona.

Climate change threatens polar bear populations: a stochastic demographic analysis.

Science.gov (United States)

Hunter, Christine M; Caswell, Hal; Runge, Michael C; Regehr, Eric V; Amstrup, Steve C; Stirling, Ian

2010-10-01

The polar bear (Ursus maritimus) depends on sea ice for feeding, breeding, and movement. Significant reductions in Arctic sea ice are forecast to continue because of climate warming. We evaluated the impacts of climate change on polar bears in the southern Beaufort Sea by means of a demographic analysis, combining deterministic, stochastic, environment-dependent matrix population models with forecasts of future sea ice conditions from IPCC general circulation models (GCMs). The matrix population models classified individuals by age and breeding status; mothers and dependent cubs were treated as units. Parameter estimates were obtained from a capture-recapture study conducted from 2001 to 2006. Candidate statistical models allowed vital rates to vary with time and as functions of a sea ice covariate. Model averaging was used to produce the vital rate estimates, and a parametric bootstrap procedure was used to quantify model selection and parameter estimation uncertainty. Deterministic models projected population growth in years with more extensive ice coverage (2001-2003) and population decline in years with less ice coverage (2004-2005). LTRE (life table response experiment) analysis showed that the reduction in lambda in years with low sea ice was due primarily to reduced adult female survival, and secondarily to reduced breeding. A stochastic model with two environmental states, good and poor sea ice conditions, projected a declining stochastic growth rate, log lambdas, as the frequency of poor ice years increased. The observed frequency of poor ice years since 1979 would imply log lambdas approximately - 0.01, which agrees with available (albeit crude) observations of population size. The stochastic model was linked to a set of 10 GCMs compiled by the IPCC; the models were chosen for their ability to reproduce historical observations of sea ice and were forced with "business as usual" (A1B) greenhouse gas emissions. The resulting stochastic population

Broad-Band Analysis of Polar Motion Excitations

Science.gov (United States)

Chen, J.

2016-12-01

Earth rotational changes, i.e. polar motion and length-of-day (LOD), are driven by two types of geophysical excitations: 1) mass redistribution within the Earth system, and 2) angular momentum exchange between the solid Earth (more precisely the crust) and other components of the Earth system. Accurate quantification of Earth rotational excitations has been difficult, due to the lack of global-scale observations of mass redistribution and angular momentum exchange. The over 14-years time-variable gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) have provided a unique means for quantifying Earth rotational excitations from mass redistribution in different components of the climate system. Comparisons between observed Earth rotational changes and geophysical excitations estimated from GRACE, satellite laser ranging (SLR) and climate models show that GRACE-derived excitations agree remarkably well with polar motion observations over a broad-band of frequencies. GRACE estimates also suggest that accelerated polar region ice melting in recent years and corresponding sea level rise have played an important role in driving long-term polar motion as well. With several estimates of polar motion excitations, it is possible to estimate broad-band noise variance and noise power spectra in each, given reasonable assumptions about noise independence. Results based on GRACE CSR RL05 solutions clearly outperform other estimates with the lowest noise levels over a broad band of frequencies.

Spatio-temporal dynamics of an active, polar, viscoelastic ring.

Science.gov (United States)

Marcq, Philippe

2014-04-01

Constitutive equations for a one-dimensional, active, polar, viscoelastic liquid are derived by treating the strain field as a slow hydrodynamic variable. Taking into account the couplings between strain and polarity allowed by symmetry, the hydrodynamics of an active, polar, viscoelastic body include an evolution equation for the polarity field that generalizes the damped Kuramoto-Sivashinsky equation. Beyond thresholds of the active coupling coefficients between the polarity and the stress or the strain rate, bifurcations of the homogeneous state lead first to stationary waves, then to propagating waves of the strain, stress and polarity fields. I argue that these results are relevant to living matter, and may explain rotating actomyosin rings in cells and mechanical waves in epithelial cell monolayers.

Relationships between POPs, biometrics and circulating steroids in male polar bears (Ursus maritimus) from Svalbard.

Science.gov (United States)

Ciesielski, Tomasz M; Hansen, Ingunn Tjelta; Bytingsvik, Jenny; Hansen, Martin; Lie, Elisabeth; Aars, Jon; Jenssen, Bjørn M; Styrishave, Bjarne

2017-11-01

The aim of this study was to determine the effects of persistent organic pollutants (POPs) and biometric variables on circulating levels of steroid hormones (androgens, estrogens and progestagens) in male polar bears (Ursus maritimus) from Svalbard, Norway (n = 23). Levels of pregnenolone (PRE), progesterone (PRO), androstenedione (AN), dehydroepiandrosterone (DHEA), testosterone (TS), dihydrotestosterone (DHT), estrone (E1), 17α-estradiol (αE2) and 17β-estradiol (βE2) were quantified in polar bear serum by gas chromatography tandem mass spectrometry (GC-MS/MS), while POPs were measured in plasma. Subsequently, associations between hormone concentrations (9 steroids), POPs (21 polychlorinated biphenyls (PCBs), 8 OH-PCBs, 8 organochlorine pesticides (OCPs) and OCP metabolites, and 2 polybrominated diphenyl ethers (PBDEs)) and biological variables (age, head length, body mass, girth, body condition index), capture date, location (latitude and longitude), lipid content and cholesterol levels were examined using principal component analysis (PCA) and orthogonal projections to latent structures (OPLS) modelling. Average concentrations of androgens, estrogens and progestagens were in the range of 0.57-83.7 (0.57-12.4 for subadults, 1.02-83.7 for adults), 0.09-2.69 and 0.57-2.44 nmol/L, respectively. The steroid profiles suggest that sex steroids were mainly synthesized through the Δ-4 pathway in male polar bears. The ratio between androgens and estrogens significantly depended on sexual maturity with androgen/estrogen ratios being approximately 60 times higher in adult males than in subadult males. PCA plots and OPLS models indicated that TS was positively related to biometrics, such as body condition index in male polar bears. A negative relationship was also observed between POPs and DHT. Consequently, POPs and body condition may potentially affect the endocrinological function of steroids, including development of reproductive tissues and sex organs and the

Body checking and body avoidance in eating disorders: Systematic review and meta-analysis.

Science.gov (United States)

Nikodijevic, Alexandra; Buck, Kimberly; Fuller-Tyszkiewicz, Matthew; de Paoli, Tara; Krug, Isabel

2018-05-01

This review sought to systematically review and quantify the evidence related to body checking and body avoidance in eating disorders (EDs) to gauge the size of effects, as well as examine potential differences between clinical and nonclinical populations, and between different ED subtypes. PsycINFO, PsycARTICLES, PsycEXTRA, Cochrane Library, and MEDLINE databases were searched for academic literature published until October 2017. A grey literature search was also conducted. Fifty-two studies were identified for the systematic review, of which 34 were eligible for meta-analysis. Only female samples were included in the meta-analysis. ED cases experienced significantly higher body checking (d = 1.26, p < .001) and body avoidance (d = 1.88, p < .001) overall relative to healthy controls, but neither behaviour varied by ED subtype. In nonclinical samples, body checking (r = .60) and body avoidance (r = .56) were significantly correlated with ED pathology (p < .001). These findings support transdiagnostic theoretical models and approaches to ED treatment and early intervention programmes. Copyright © 2018 John Wiley & Sons, Ltd and Eating Disorders Association.

Earth orientation from lunar laser ranging and an error analysis of polar motion services

Science.gov (United States)

Dickey, J. O.; Newhall, X. X.; Williams, J. G.

1985-01-01

Lunar laser ranging (LLR) data are obtained on the basis of the timing of laser pulses travelling from observatories on earth to retroreflectors placed on the moon's surface during the Apollo program. The modeling and analysis of the LLR data can provide valuable insights into earth's dynamics. The feasibility to model accurately the lunar orbit over the full 13-year observation span makes it possible to conduct relatively long-term studies of variations in the earth's rotation. A description is provided of general analysis techniques, and the calculation of universal time (UT1) from LLR is discussed. Attention is also given to a summary of intercomparisons with different techniques, polar motion results and intercomparisons, and a polar motion error analysis.

Development and application of an analysis of axisymmetric body effects on helicopter rotor aerodynamics using modified slender body theory

Science.gov (United States)

Yamauchi, G.; Johnson, W.

1984-01-01

A computationally efficient body analysis designed to couple with a comprehensive helicopter analysis is developed in order to calculate the body-induced aerodynamic effects on rotor performance and loads. A modified slender body theory is used as the body model. With the objective of demonstrating the accuracy, efficiency, and application of the method, the analysis at this stage is restricted to axisymmetric bodies at zero angle of attack. By comparing with results from an exact analysis for simple body shapes, it is found that the modified slender body theory provides an accurate potential flow solution for moderately thick bodies, with only a 10%-20% increase in computational effort over that of an isolated rotor analysis. The computational ease of this method provides a means for routine assessment of body-induced effects on a rotor. Results are given for several configurations that typify those being used in the Ames 40- by 80-Foot Wind Tunnel and in the rotor-body aerodynamic interference tests being conducted at Ames. A rotor-hybrid airship configuration is also analyzed.

Performance Analysis of Dual-Polarized Massive MIMO System with Human-Care IoT Devices for Cellular Networks

Directory of Open Access Journals (Sweden)

Jun-Ki Hong

2018-01-01

Full Text Available The performance analysis of the dual-polarized massive multiple-input multiple-output (MIMO system with Internet of things (IoT devices is studied when outdoor human-care IoT devices are connected to a cellular network via a dual-polarized massive MIMO system. The research background of the performance analysis of dual-polarized massive MIMO system with IoT devices is that recently the data usage of outdoor human-care IoT devices has increased. Therefore, the outdoor human-care IoT devices are necessary to connect with 5G cellular networks which can expect 1000 times higher performance compared with 4G cellular networks. Moreover, in order to guarantee the safety of the patient for emergency cases, a human-care Iot device must be connected to cellular networks which offer more stable communication for outdoors compared to short-range communication technologies such as Wi-Fi, Zigbee, and Bluetooth. To analyze the performance of the dual-polarized massive MIMO system for human-care IoT devices, a dual-polarized MIMO spatial channel model (SCM is proposed which considers depolarization effect between the dual-polarized transmit-antennas and the receive-antennas. The simulation results show that the performance of the dual-polarized massive MIMO system is improved about 16% to 92% for 20 to 150 IoT devices compared to conventional single-polarized massive MIMO system for identical size of the transmit array.

Analysis of CMOS Compatible Cu-Based TM-Pass Optical Polarizer

KAUST Repository

Ng, Tien Khee; Khan, Mohammed Zahed Mustafa; Al-Jabr, Ahmad Ali; Ooi, Boon S.

2012-01-01

for the polarizer, it was found that the metal-insulator-metal (MIM) polarizer structure is superior compared to the insulator-metal-insulator polarizer structure due to its higher polarization extinction ratio (PER) and low insertion loss. An optimized MIM TM

The ablated volume and the thermal field distribution in swine vertebral body created by multi-polar radiofrequency ablation: an experiment in vitro

International Nuclear Information System (INIS)

Peng Zhaohong; Zhao Wei; Shen Jin; Hu Jihong; Li Zhaopeng; Wang Tao

2009-01-01

Objective: To observe the extent of bone coagulation and the thermal field distribution created in ablating the swine vertebral bodies in vitro with multi-polar radiofrequency and to discuss the correlation between the electrode position in the vertebral body and the safety of the spinal cord as well as the soft tissue injury around the vertebral body. Methods: Thirty fresh adult porcine vertebrae were randomly and equally divided into two groups. The depth of the electrode needle was 10 mm or 20 mm.When the ablation process reached to a stable state, the temperature at the scheduled spots was estimated. Twenty minutes after ablation, the vertebral body was cut along the electrode needle plane and also along the plane perpendicular to the electrode needle to observe the extent of bone coagulation. Results: The temperature at the scheduled spots reached to a stable state in 3.5 minutes. The more close to the electrode the spot was, the more quickly the temperature rose. No soft tissue injury around the vertebral body was observed in both groups and no spinal cord injury occurred when the electrode needle was 10 mm or 20 mm deep in the vertebral body. Conclusion: In treating vertebral metastases, the radiofrequency ablation is safe and reliable if the posterior wall of the vertebral body remains intact. (authors)

Nonlinear optical polarization analysis in chemistry and biology

CERN Document Server

Simpson, Garth J

2017-01-01

This rigorous yet accessible guide presents a molecular-based description of nonlinear optical polarization analysis of chemical and biological assemblies. It includes discussion of the most common nonlinear optical microscopy and interfacial measurements used for quantitative analysis, specifically second harmonic generation (SHG), two-photon excited fluorescence (2PEF), vibrational sum frequency generation (SFG), and coherent anti-Stokes Raman spectroscopy/stimulated Raman spectroscopy (CARS/SRS). A linear algebra mathematical framework is developed, allowing step-wise systematic connections to be made between the observable measurements and the molecular response. Effects considered include local field corrections, the molecular orientation distribution, rotations between the molecular frame, the local frame and the laboratory frame, and simplifications from molecular and macromolecular symmetry. Specific examples are provided throughout the book, working from the common and relatively simple case studies ...

Precision polarization measurements of atoms in a far-off-resonance optical dipole trap

International Nuclear Information System (INIS)

Fang, F.; Vieira, D. J.; Zhao, X.

2011-01-01

Precision measurement of atomic and nuclear polarization is an essential step for beta-asymmetry measurement of radioactive atoms. In this paper, we report the polarization measurement of Rb atoms in an yttrium-aluminum-garnet (YAG) far-off-resonance optical dipole trap. We have prepared a cold cloud of polarized Rb atoms in the YAG dipole trap by optical pumping and achieved an initial nuclear polarization of up to 97.2(5)%. The initial atom distribution in different Zeeman levels is measured by using a combination of microwave excitation, laser pushing, and atomic retrap techniques. The nuclear-spin polarization is further purified to 99.2(2)% in 10 s and maintained above 99% because the two-body collision loss rate between atoms in mixed spin states is greater than the one-body trap loss rate. Systematic effects on the nuclear polarization, including the off-resonance Raman scattering, magnetic field gradient, and background gas collisions, are discussed.

Relativistic analysis of four-body final states

International Nuclear Information System (INIS)

Adhikari, S.K.

1977-01-01

The constraints of unitarity and analyticity on four-body final states are studied. It is shown that unitarity alone forces the amplitudes to be coherent and have singular behaviour. The implementation of unitarity with total energy analyticity yields a set of relativistic linear integral equations for the four-body amplitude. This is the minimal set consistent with quantum mechanics and also is the full dynamical set of equations with two-body separable interactions. These equations will provide important ingredients for the phenomenological analysis of four-body final states using the isobar model. (Auth.)

RHIC FY15 pp Run RHIC and AGS polarization analysis

Energy Technology Data Exchange (ETDEWEB)

Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Adams, P. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2016-02-20

The polarization information is important for the spin physics program in Relativistic Heavy Ion Collider (RHIC). There are discrepancies between AGS and RHIC polarization measurements. First, the face value of AGS polarization is higher than RHIC ones in general. Second, the measured polarization profile (described by the profile ratio R) is stronger in AGS than in RHIC. This note analyzes the polarization data from FY15 pp run period. The results show that the differences between AGS and RHIC polarization measurements are reasonable, but the R value difference is puzzling. The difference between blue and yellow ring is worth of spin simulation to explain.

Novel type of neutron polarization analysis using the multianalyzer-equipment of the three-axes spectrometer PUMA

Science.gov (United States)

Schwesig, Steffen; Maity, Avishek; Sobolev, Oleg; Ziegler, Fabian; Eckold, Götz

2018-01-01

The combination of polarization analysis and multianalyzer system available at the three axes spectrometer PUMA@FRM II allows the simultaneous determination of both spin states of the scattered neutrons and the absolute value of the polarization. The present paper describes the technical details along with the basic formalism used for the precise calibration. Moreover, the performance of this method is illustrated by several test experiments including first polarized inelastic studies of the magnetic excitations of CuO in the multiferroic and the uniaxial antiferromagnetic phases.

THE EFFECT OF GRAVITATION ON THE POLARIZATION STATE OF A LIGHT RAY

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Tanay; Sen, A. K. [Department of Physics Assam University, Silchar-788011, Assam (India)

2016-12-10

In the present work, detailed calculations have been carried out on the rotation of the polarization vector of an electromagnetic wave due to the presence of a gravitational field of a rotating body. This has been done using the general expression of Maxwell’s equation in curved spacetime. Considering the far-field approximation (i.e., the impact parameter is greater than the Schwarzschild radius and rotation parameter), the amount of rotation of the polarization vector as a function of impact parameter has been obtained for a rotating body (considering Kerr geometry). The present work shows that the rotation of the polarization vector cannot be observed in the case of Schwarzschild geometry. This work also calculates the rotational effect when considering prograde and retrograde orbits for the light ray. Although the present work demonstrates the effect of rotation of the polarization vector, it confirms that there would be no net polarization of an electromagnetic wave due to the curved spacetime geometry in a Kerr field.

Optimization of a polarized source for in vivo x-ray fluorescence analysis of platinum and other heavy metals

International Nuclear Information System (INIS)

Lewis, D.G.

1994-01-01

The Monte Carlo method was used to optimize a polarized photon source for the x-ray fluorescence analysis of platinum and other heavy metals in vivo. The source consisted of a 140 kVp, 25 mA x-ray tube with the photons plane-polarized by 90 o scattering. The use of plane-polarized photons results in a significant reduction in background when the fluorescent radiation is measured along the direction of polarization. A Monte Carlo computer programme was written to simulate the production and interaction of polarized photons in order to determine the optimal polarizing material and dimensions, together with beam width and geometrical arrangement of source, polarizer and beam collimators. Calculated photon energy distributions are compared with experimental data to test the validity of the model. (author)

Climate change threatens polar bear populations: A stochastic demographic analysis

Science.gov (United States)

Hunter, C.M.; Caswell, H.; Runge, M.C.; Regehr, E.V.; Amstrup, Steven C.; Stirling, I.

2010-01-01

The polar bear (Ursus maritimus) depends on sea ice for feeding, breeding, and movement. Significant reductions in Arctic sea ice are forecast to continue because of climate warming. We evaluated the impacts of climate change on polar bears in the southern Beaufort Sea by means of a demographic analysis, combining deterministic, stochastic, environment-dependent matrix population models with forecasts of future sea ice conditions from IPCC general circulation models (GCMs). The matrix population models classified individuals by age and breeding status; mothers and dependent cubs were treated as units. Parameter estimates were obtained from a capture-recapture study conducted from 2001 to 2006. Candidate statistical models allowed vital rates to vary with time and as functions of a sea ice covariate. Model averaging was used to produce the vital rate estimates, and a parametric bootstrap procedure was used to quantify model selection and parameter estimation uncertainty. Deterministic models projected population growth in years with more extensive ice coverage (2001-2003) and population decline in years with less ice coverage (2004-2005). LTRE (life table response experiment) analysis showed that the reduction in ?? in years with low sea ice was due primarily to reduced adult female survival, and secondarily to reduced breeding. A stochastic model with two environmental states, good and poor sea ice conditions, projected a declining stochastic growth rate, log ??s, as the frequency of poor ice years increased. The observed frequency of poor ice years since 1979 would imply log ??s ' - 0.01, which agrees with available (albeit crude) observations of population size. The stochastic model was linked to a set of 10 GCMs compiled by the IPCC; the models were chosen for their ability to reproduce historical observations of sea ice and were forced with "business as usual" (A1B) greenhouse gas emissions. The resulting stochastic population projections showed drastic

VCS-SSA Mainz Experiment. Measurement of the beam spin asymmetry in (e polarized p {yields} ep{gamma}) and (e polarized p {yields} ep{pi}{sup 0}). Final analysis - MEMO I

Energy Technology Data Exchange (ETDEWEB)

Fonvieille, H.; Bensafa, I. [LPC-Clermont-Fd, Universite Blaise Pascal, F-63170 Aubiere Cedex (France)

2006-02-15

This note gives details on the final analysis of the VCS-SSA experiment in terms of Beam Spin Asymmetry. It summarizes the changes between the first and second pass analysis. Then the measured asymmetry is presented for both channels e polarized p {yields} ep{gamma} and e polarized p {yields} ep{pi}{sup 0} including systematic studies. The final experimental result is briefly compared to some model predictions. (authors)

Analysis of CMOS Compatible Cu-Based TM-Pass Optical Polarizer

KAUST Repository

Ng, Tien Khee

2012-02-10

A transverse-magnetic-pass (TM-pass) optical polarizer based on Cu complementary metal-oxide-semiconductor technology platform is proposed and analyzed using the 2-D method-of-lines numerical model. In designing the optimum configuration for the polarizer, it was found that the metal-insulator-metal (MIM) polarizer structure is superior compared to the insulator-metal-insulator polarizer structure due to its higher polarization extinction ratio (PER) and low insertion loss. An optimized MIM TM-pass polarizer exhibits simulated long wavelength pass filter characteristics of > ?1.2 ?m, with fundamental TM 0 and TE 0 mode transmissivity of >70% and <5%, respectively, and with PER ?11.5 dB in the wavelength range of 1.2-1.6 ?m. The subwavelength and submicrometer features of this TM-polarizer are potentially suitable for compact and low power photonics integrated circuit implementation on silicon-based substrates. © 1989-2012 IEEE.

Polarized Light Microscopy

Science.gov (United States)

Frandsen, Athela F.

2016-01-01

Polarized light microscopy (PLM) is a technique which employs the use of polarizing filters to obtain substantial optical property information about the material which is being observed. This information can be combined with other microscopy techniques to confirm or elucidate the identity of an unknown material, determine whether a particular contaminant is present (as with asbestos analysis), or to provide important information that can be used to refine a manufacturing or chemical process. PLM was the major microscopy technique in use for identification of materials for nearly a century since its introduction in 1834 by William Fox Talbot, as other techniques such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy), XPD (X-ray Powder Diffraction), and TEM (Transmission Electron Microscopy) had not yet been developed. Today, it is still the only technique approved by the Environmental Protection Agency (EPA) for asbestos analysis, and is often the technique first applied for identification of unknown materials. PLM uses different configurations in order to determine different material properties. With each configuration additional clues can be gathered, leading to a conclusion of material identity. With no polarizing filter, the microscope can be used just as a stereo optical microscope, and view qualities such as morphology, size, and number of phases. With a single polarizing filter (single polars), additional properties can be established, such as pleochroism, individual refractive indices, and dispersion staining. With two polarizing filters (crossed polars), even more can be deduced: isotropy vs. anisotropy, extinction angle, birefringence/degree of birefringence, sign of elongation, and anomalous polarization colors, among others. With the use of PLM many of these properties can be determined in a matter of seconds, even for those who are not highly trained. McCrone, a leader in the field of polarized light microscopy, often

Degree of polarization and source counts of faint radio sources from Stacking Polarized intensity

International Nuclear Information System (INIS)

Stil, J. M.; George, S. J.; Keller, B. W.; Taylor, A. R.

2014-01-01

We present stacking polarized intensity as a means to study the polarization of sources that are too faint to be detected individually in surveys of polarized radio sources. Stacking offers not only high sensitivity to the median signal of a class of radio sources, but also avoids a detection threshold in polarized intensity, and therefore an arbitrary exclusion of sources with a low percentage of polarization. Correction for polarization bias is done through a Monte Carlo analysis and tested on a simulated survey. We show that the nonlinear relation between the real polarized signal and the detected signal requires knowledge of the shape of the distribution of fractional polarization, which we constrain using the ratio of the upper quartile to the lower quartile of the distribution of stacked polarized intensities. Stacking polarized intensity for NRAO VLA Sky Survey (NVSS) sources down to the detection limit in Stokes I, we find a gradual increase in median fractional polarization that is consistent with a trend that was noticed before for bright NVSS sources, but is much more gradual than found by previous deep surveys of radio polarization. Consequently, the polarized radio source counts derived from our stacking experiment predict fewer polarized radio sources for future surveys with the Square Kilometre Array and its pathfinders.

MEASUREMENT OF POLARIZATION OBSERVABLES IN VECTOR MESON PHOTOPRODUCTION USING A TRANSVERSELY-POLARIZED FROZEN-SPIN TARGET AND POLARIZED PHOTONS AT CLAS, JEFFERSON LAB

Energy Technology Data Exchange (ETDEWEB)

Roy, Priyashree [Florida State Univ., Tallahassee, FL (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

2016-11-30

The study of baryon resonances provides a deeper understanding of the strong interaction because the dynamics and relevant degrees of freedom hidden within them are re ected by the properties of the excited states of baryons. Higher-lying excited states at and above 1.7 GeV/c2 are generally predicted to have strong couplings to final states involving a heavier meson, e. g. one of the vector mesons, ρ, ω φ, as compared to a lighter pseudoscalar meson, e. g. π and η. Decays to the ππΝ final states via πΔ also become more important through the population of intermediate resonances. We observe that nature invests in mass rather than momentum. The excited states of the nucleon are usually found as broadly overlapping resonances which may decay into a multitude of final states involving mesons and baryons. Polarization observables make it possible to isolate single resonance contributions from other interference terms. The CLAS g9 (FROST) experiment, as part of the N* spectroscopy program at Je?erson Laboratory, accumulated photoproduction data using circularly- & linearly-polarized photons incident on a transversely-polarized butanol target (g9b experiment) in the photon energy range 0:3-2:4 GeV & 0:7-2:1 GeV, respectively. In this work, the analysis of reactions and polarization observables which involve two charged pions, either in the fully exclusive reaction γρ -> ρπ+π- or in the semi-exclusive reaction with a missing neutral pion, γρ -> ρπ+π-(π0) will be presented. For the reaction ρπ+π-, eight polarization observables (Is, Ic, Px, Py, Psx; y, Pcx; y) have been extracted. The high statistics data rendered it possible to extract these observables in three dimensions. All of them are first-time measurements. The fairly good agreement of Is, Ic obtained from this analysis with the experimental results from a previous CLAS experiment provides support for the first-time measurements. For the reaction γρ -> ρω -> ρπ+π(π0, five polarization

The thermospheric auroral red line polarization: confirmation of detection and first quantitative analysis

Directory of Open Access Journals (Sweden)

Moen Joran

2013-01-01

Full Text Available The thermospheric atomic oxygen red line is among the brightest in the auroral spectrum. Previous observations in Longyearbyen, Svalbard, indicated that it may be intrinsically polarized, but a possible contamination by light pollution could not be ruled out. During the winter 2010/2011, the polarization of the red line was measured for the first time at the Polish Hornsund polar base without contamination. Two methods of data analysis are presented to compute the degree of linear polarization (DoLP and angle of linear polarization (AoLP: one is based on averaging and the other one on filtering. Results are compared and are in qualitative agreement. For solar zenith angles (SZA larger than 108° (with no contribution from Rayleigh scattering, the DoLP ranges between 2 and 7%. The AoLP is more or less aligned with the direction of the magnetic field line, in agreement with the theoretical predictions of Bommier et al. (2010. However, the AoLP values range between ±20° around this direction, depending on the auroral conditions. Correlations between the polarization parameters and the red line intensity I were considered. The DoLP decreases when I increases, confirming a trend observed during the observations in Longyearbyen. However, for small values of I, DoLP varies within a large range of values, while for large values of I, DoLP is always small. The AoLP also varies with the red line intensity, slightly rotating around the magnetic field line.

Numerical modeling of polar mesocyclones generation mechanisms

Science.gov (United States)

Sergeev, Dennis; Stepanenko, Victor

2013-04-01

parameters, lateral boundary conditions are varied in the typically observed range. The approach is fully nonlinear: we use a three-dimensional non-hydrostatic mesoscale model NH3D_MPI [1] coupled with one-dimensional water body model LAKE. A key method used in the present study is the analysis of eddy kinetic and available potential energy budgets. References 1. Mikushin, D.N., and Stepanenko, V.M., The implementation of regional atmospheric model numerical algorithms for CBEA-based clusters. Lecture Notes in Computer Science, Parallel Processing and Applied Mathematics, 2010, vol. 6067, p. 525-534. 2. Rasmussen, E., and Turner, J. (eds), Polar Lows: Mesoscale Weather Systems in the Polar Regions. Cambridge: Cambridge University Press, 2003, 612 pp. 3. Yanase, W., and Niino, H., Dependence of Polar Low Development on Baroclinicity and Physical Processes: An Idealized High-Resolution Experiment, J. Atmos. Sci., 2006, vol. 64, p. 3044-3067.

Lunar true polar wander inferred from polar hydrogen.

Science.gov (United States)

Siegler, M A; Miller, R S; Keane, J T; Laneuville, M; Paige, D A; Matsuyama, I; Lawrence, D J; Crotts, A; Poston, M J

2016-03-24

The earliest dynamic and thermal history of the Moon is not well understood. The hydrogen content of deposits near the lunar poles may yield insight into this history, because these deposits (which are probably composed of water ice) survive only if they remain in permanent shadow. If the orientation of the Moon has changed, then the locations of the shadowed regions will also have changed. The polar hydrogen deposits have been mapped by orbiting neutron spectrometers, and their observed spatial distribution does not match the expected distribution of water ice inferred from present-day lunar temperatures. This finding is in contrast to the distribution of volatiles observed in similar thermal environments at Mercury's poles. Here we show that polar hydrogen preserves evidence that the spin axis of the Moon has shifted: the hydrogen deposits are antipodal and displaced equally from each pole along opposite longitudes. From the direction and magnitude of the inferred reorientation, and from analysis of the moments of inertia of the Moon, we hypothesize that this change in the spin axis, known as true polar wander, was caused by a low-density thermal anomaly beneath the Procellarum region. Radiogenic heating within this region resulted in the bulk of lunar mare volcanism and altered the density structure of the Moon, changing its moments of inertia. This resulted in true polar wander consistent with the observed remnant polar hydrogen. This thermal anomaly still exists and, in part, controls the current orientation of the Moon. The Procellarum region was most geologically active early in lunar history, which implies that polar wander initiated billions of years ago and that a large portion of the measured polar hydrogen is ancient, recording early delivery of water to the inner Solar System. Our hypothesis provides an explanation for the antipodal distribution of lunar polar hydrogen, and connects polar volatiles to the geologic and geophysical evolution of the Moon

Instrumentation with polarized neutrons

International Nuclear Information System (INIS)

Boeni, P.; Muenzer, W.; Ostermann, A.

2009-01-01

Neutron scattering with polarization analysis is an indispensable tool for the investigation of novel materials exhibiting electronic, magnetic, and orbital degrees of freedom. In addition, polarized neutrons are necessary for neutron spin precession techniques that path the way to obtain extremely high resolution in space and time. Last but not least, polarized neutrons are being used for fundamental studies as well as very recently for neutron imaging. Many years ago, neutron beam lines were simply adapted for polarized beam applications by adding polarizing elements leading usually to unacceptable losses in neutron intensity. Recently, an increasing number of beam lines are designed such that an optimum use of polarized neutrons is facilitated. In addition, marked progress has been obtained in the technology of 3 He polarizers and the reflectivity of large-m supermirrors. Therefore, if properly designed, only factors of approximately 2-3 in neutron intensity are lost. It is shown that S-benders provide neutron beams with an almost wavelength independent polarization. Using twin cavities, polarized beams with a homogeneous phase space and P>0.99 can be produced without significantly sacrificing intensity. It is argued that elliptic guides, which are coated with large m polarizing supermirrors, provide the highest flux.

An analysis of the electromagnetic field in multi-polar linear induction system

International Nuclear Information System (INIS)

Chervenkova, Todorka; Chervenkov, Atanas

2002-01-01

In this paper a new method for determination of the electromagnetic field vectors in a multi-polar linear induction system (LIS) is described. The analysis of the electromagnetic field has been done by four dimensional electromagnetic potentials in conjunction with theory of the magnetic loops . The electromagnetic field vectors are determined in the Minkovski's space as elements of the Maxwell's tensor. The results obtained are compared with those got from the analysis made by the finite elements method (FEM).With the method represented in this paper one can determine the electromagnetic field vectors in the multi-polar linear induction system using four-dimensional potential. A priority of this method is the obtaining of analytical results for the electromagnetic field vectors. These results are also valid for linear media. The dependencies are valid also at high speeds of movement. The results of the investigated linear induction system are comparable to those got by the finite elements method. The investigations may be continued in the determination of other characteristics such as drag force, levitation force, etc. The method proposed in this paper for an analysis of linear induction system can be used for optimization calculations. (Author)

System for measuring of proton polarization in polarized target

International Nuclear Information System (INIS)

Derkach, A.Ya.; Lukhanin, A.A.; Karnaukhov, I.M.; Kuz'menko, V.S.; Telegin, Yu.N.; Trotsenko, V.I.; Chechetenko, V.F.

1981-01-01

Measurement system of proton polarization in the target, which uses the method of nuclear magnetic resonance is described. To record the signal of NMR-absorption a parallel Q-meter of voltage with analogous subtraction of resonance characteristics of measurement circuit is used. To obtain gradual sensitivity of the system to polarization state in the whole volume of the target the measurement coils is made of tape conductor. The analysis and mathematical modelling of Q-meter are carried out. Corrections for nonlinearity and dispersion are calculated. Key diagrams of the main electron blocks of Q-meter are presented. The system described operates on line with the M6000 computer. Total error of measurement of polarization value of free protons in the target does not exceed 6% [ru

Nanopatterned bulk metallic glass-based biomaterials modulate macrophage polarization.

Science.gov (United States)

Shayan, Mahdis; Padmanabhan, Jagannath; Morris, Aaron H; Cheung, Bettina; Smith, Ryan; Schroers, Jan; Kyriakides, Themis R

2018-06-01

Polarization of macrophages by chemical, topographical and mechanical cues presents a robust strategy for designing immunomodulatory biomaterials. Here, we studied the ability of nanopatterned bulk metallic glasses (BMGs), a new class of metallic biomaterials, to modulate murine macrophage polarization. Cytokine/chemokine analysis of IL-4 or IFNγ/LPS-stimulated macrophages showed that the secretion of TNF-α, IL-1α, IL-12, CCL-2 and CXCL1 was significantly reduced after 24-hour culture on BMGs with 55 nm nanorod arrays (BMG-55). Additionally, under these conditions, macrophages increased phagocytic potential and exhibited decreased cell area with multiple actin protrusions. These in vitro findings suggest that nanopatterning can modulate biochemical cues such as IFNγ/LPS. In vivo evaluation of the subcutaneous host response at 2 weeks demonstrated that the ratio of Arg-1 to iNOS increased in macrophages adjacent to BMG-55 implants, suggesting modulation of polarization. In addition, macrophage fusion and fibrous capsule thickness decreased and the number and size of blood vessels increased, which is consistent with changes in macrophage responses. Our study demonstrates that nanopatterning of BMG implants is a promising technique to selectively polarize macrophages to modulate the immune response, and also presents an effective tool to study mechanisms of macrophage polarization and function. Implanted biomaterials elicit a complex series of tissue and cellular responses, termed the foreign body response (FBR), that can be influenced by the polarization state of macrophages. Surface topography can influence polarization, which is broadly characterized as either inflammatory or repair-like. The latter has been linked to improved outcomes of the FBR. However, the impact of topography on macrophage polarization is not fully understood, in part, due to a lack of high moduli biomaterials that can be reproducibly processed at the nanoscale. Here, we studied

Spin-polarized ballistic conduction through correlated Au-NiMnSb-Au heterostructures

KAUST Repository

Morari, C.

2017-11-20

We examine the ballistic conduction through Au-NiMnSb-Au heterostructures consisting of up to four units of the half-metallic NiMnSb in the scattering region, using density functional theory (DFT) methods. For a single NiMnSb unit the transmission function displays a spin polarization of around 50% in a window of 1eV centered around the Fermi level. By increasing the number of layers, an almost complete spin polarization of the transmission is obtained in this energy range. Supplementing the DFT calculations with local electronic interactions, of Hubbard-type on the Mn sites, leads to a hybridization between the interface and many-body states. The significant reduction of the spin polarization seen in the density of states is not apparent in the spin polarization of the conduction electron transmission, which suggests that the hybridized interface and many-body induced states are localized.

Vertically Polarized Omnidirectional Printed Slot Loop Antenna

DEFF Research Database (Denmark)

Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren H.; Thaysen, Jesper

2015-01-01

A novel vertically polarized omnidirectional printed slot loop antenna has been designed, simulated, fabricated and measured. The slot loop works as a magnetic loop. The loop is loaded with inductors to insure uniform and in-phase fields in the slot in order to obtain an omnidirectional radiation...... pattern. The antenna is designed for the 2.45 GHz Industrial, Scientific and Medical band. Applications of the antenna are many. One is for on-body applications since it is ideal for launching a creeping waves due to the polarization....

Sentiment Polarity Analysis based multi-dictionary

Science.gov (United States)

Jiao, Jian; Zhou, Yanquan

This paper presents a novel algorithm for Chinese online reviews, which identifies sentiment polarity. To determine the sentence is negative or positive, we extracted opinion words and identified their opinion targets by CRFs and establish the absolute emotional dictionary (AbED), the relative emotional dictionary (ReED), the field of emotional dictionary (FiED) and the field of targets and opinion words dictionary (TfED). With those emotional dictionary, negative dictionary and modified dictionary, we achieved an effective algorithm to discriminate sentiment polarity by multi-string pattern matching algorithm. For evaluation, we used car online reviews, hotel online reviews and computer online reviews which annotated positive or negative. Experimental results show that our proposed method has made a higher precision and recall rate.

New Applications of m-Polar Fuzzy Matroids

Directory of Open Access Journals (Sweden)

Musavarah Sarwar

2017-12-01

Full Text Available Mathematical modelling is an important aspect in apprehending discrete and continuous physical systems. Multipolar uncertainty in data and information incorporates a significant role in various abstract and applied mathematical modelling and decision analysis. Graphical and algebraic models can be studied more precisely when multiple linguistic properties are dealt with, emphasizing the need for a multi-index, multi-object, multi-agent, multi-attribute and multi-polar mathematical approach. An m-polar fuzzy set is introduced to overcome the limitations entailed in single-valued and two-valued uncertainty. Our aim in this research study is to apply the powerful methodology of m-polar fuzzy sets to generalize the theory of matroids. We introduce the notion of m-polar fuzzy matroids and investigate certain properties of various types of m-polar fuzzy matroids. Moreover, we apply the notion of the m-polar fuzzy matroid to graph theory and linear algebra. We present m-polar fuzzy circuits, closures of m-polar fuzzy matroids and put special emphasis on m-polar fuzzy rank functions. Finally, we also describe certain applications of m-polar fuzzy matroids in decision support systems, ordering of machines and network analysis.

Polarized Light from the Sun: Unification of the Corona and Analysis of the Second Solar Spectrum — Further Implications of a Liquid Metallic Hydrogen Solar Model

Directory of Open Access Journals (Sweden)

Robitaille P.-M.

2015-07-01

Full Text Available In order to account for the slight polarization of the continuum towards the limb, propo- nents of the Standard Solar Model (SSM must have recourse to electron or hydrogen- based scattering of light, as no other mechanism is possible in a gaseous Sun. Con- versely, acceptance that the solar body is comprised of condensed matter opens up new avenues in the analysis of this problem, even if the photospheric surface itself is viewed as incapable of emitting polarized light. Thus, the increased disk polarization, from the center to the limb, can be explained by invoking the scattering of light by the at- mosphere above the photosphere. The former is reminiscent of mechanisms which are known to account for the polarization of sunlight in the atmosphere of the Earth. Within the context of the Liquid Metallic Hydrogen Solar Model (LMHSM, molecules and small particles, not electrons or hydrogen atoms as required by the SSM, would primarily act as scattering agents in regions also partially comprised of condensed hy- drogen structures (CHS. In addition, the well-known polarization which characterizes the K-corona would become a sign of emission polarization from an anisotropic source, without the need for scattering. In the LMHSM, the K, F, and T- coronas can be viewed as emissive and reflective manifestations of a single corona l entity adopting a radially anisotropic structure, while slowly cooling with altitude above the photosphere. The presence of “dust particles”, advanced by proponents of the SSM, would no longer be required to explain the F and T-corona, as a single cooling structure would account for the properties of the K, F, and T coronas. At the same time, the polarized “Second Solar Spectrum”, characterized by the dominance of certain elemental or ionic spectral lines and an abundance of molecular lines, could be explained in the LMHSM, by first invoking interface polarization and coordination of these species with condensed matter

Polarization division multiple access with polarization modulation for LOS wireless communications

Directory of Open Access Journals (Sweden)

Cao Bin

2011-01-01

Full Text Available Abstract In this paper, we discuss a potential multiple access and modulation scheme based on polarized states (PS of electromagnetic (EM waves for line-of-sight (LOS communications. The proposed scheme is theoretic different from the existing polar modulation for EDGE and WCDMA systems. We propose the detailed bit representation (modulation and multiple access scheme using PS. Because of the inflexibility of polarization information in the time and frequency domains, as well as independence of frequency and space, the polarization information can be used independently for wireless communications, i.e., another independent resource domain that can be utilized. Due to the independence between the PS and the specific features of signals (such as waveform, bandwidth and data rate, the discussed polarization division multiple access (PDMA and polarization modulation (PM are expected to improve the spectrum utilization effectively. It is proved that the polarization filtering technique can be adopted in the PDMA-PM wireless communications to separate the multiuser signals and demodulate the bit information representing by PS for desired user. Some theoretical analysis is done to demonstrate the feasibility of the proposed scheme, and the simulation results are made to evaluate the performance of the suggested system.

Validation of Heart Rate Monitor Polar RS800 for Heart Rate Variability Analysis During Exercise.

Science.gov (United States)

Hernando, David; Garatachea, Nuria; Almeida, Rute; Casajús, Jose A; Bailón, Raquel

2018-03-01

Hernando, D, Garatachea, N, Almeida, R, Casajús, JA, and Bailón, R. Validation of heart rate monitor Polar RS800 for heart rate variability analysis during exercise. J Strength Cond Res 32(3): 716-725, 2018-Heart rate variability (HRV) analysis during exercise is an interesting noninvasive tool to measure the cardiovascular response to the stress of exercise. Wearable heart rate monitors are a comfortable option to measure interbeat (RR) intervals while doing physical activities. It is necessary to evaluate the agreement between HRV parameters derived from the RR series recorded by wearable devices and those derived from an electrocardiogram (ECG) during dynamic exercise of low to high intensity. Twenty-three male volunteers performed an exercise stress test on a cycle ergometer. Subjects wore a Polar RS800 device, whereas ECG was also recorded simultaneously to extract the reference RR intervals. A time-frequency spectral analysis was performed to extract the instantaneous mean heart rate (HRM), and the power of low-frequency (PLF) and high-frequency (PHF) components, the latter centered on the respiratory frequency. Analysis was done in intervals of different exercise intensity based on oxygen consumption. Linear correlation, reliability, and agreement were computed in each interval. The agreement between the RR series obtained from the Polar device and from the ECG is high throughout the whole test although the shorter the RR is, the more differences there are. Both methods are interchangeable when analyzing HRV at rest. At high exercise intensity, HRM and PLF still presented a high correlation (ρ > 0.8) and excellent reliability and agreement indices (above 0.9). However, the PHF measurements from the Polar showed reliability and agreement coefficients around 0.5 or lower when the level of the exercise increases (for levels of O2 above 60%).

Measurement of polarization observables in the reaction γp→ pπ0π0 using linearly polarized photons with the CBELSA/TAPS experiment

International Nuclear Information System (INIS)

Sokhoyan, Vahe

2012-01-01

The spectrum and the properties of baryon resonances can be studied using photons with energies appropriate to excite baryonic states. Double meson photoproduction allows access to cascading resonance decays via other excited states. Also, at higher energies the importance of the double meson photoproduction increases due to higher cross-sections in comparison to single meson photoproduction. To study baryon resonances, the measurement of polarization observables as well as the measurement of differential cross-sections plays a very important role. In this work the three-body polarization observables I s , I c and the respective twobody asymmetry Σ were measured for the reaction γp → pπ 0 π 0 in an incoming photon energy range of E γ = 970 - 1650 MeV. The data were acquired with the CBELSA/TAPS experiment located at the ELSA accelerator in Bonn, using a linearly polarized photon beam impinging on a liquid hydrogen target. The observables I s and I c which occur in two-meson final states are measured for the first time in the reaction γp → pπ 0 π 0 . The corresponding two-body asymmetry Σ is measured in an extended energy range in comparison to already existing data. A comparison with theoretical models shows that the polarization observables provide valuable input to study resonance contributions and their decay modes. The D 33 (1700) → Δπ decay is studied based on the comparison of the Bonn-Gatchina Partial Wave Analysis (PWA) predictions with the data. Furthermore, a comparison of the data with the Bonn-Gatchina PWA and the Fix isobar model predictions allows to distinguish between these two models. Additionally, band-like structures and peaks are observed in the mass ranges of Δ(1232), D 13 (1520), F 15 (1680), f 0 (980) and f 2 (1270) in the according Dalitz plots and invariant mass distributions. The contributions of these states are confirmed by the Bonn-Gatchina PWA. An excellent compatibility with the existing data from the previous CBELSA

Regulating Readers' Bodies: A Discourse Analysis of Teachers' Body Talk

Science.gov (United States)

Lester, Jessica Nina; Gabriel, Rachael

2017-01-01

In this paper, we report findings from a discourse analysis study of reading instruction in eight primary/elementary school classrooms in the United States. Drawing upon discursive psychology, we specifically examined 96 hours of reading comprehension instruction, with a focus on how teachers talked about the body during the instruction and noted…

Effect-Directed Analysis to Explore the Polar Bear Exposome: the Identification of Thyroid Hormone Disrupting Compounds in Plasma

NARCIS (Netherlands)

Simon, E.; van Velzen, M.J.M.; Brandsma, S.H.; Lie, E.; Loken, K.; de Boer, J.; Bytingsvik, J.; Jenssen, B.M.; Aars, J.; Hamers, T.; Lamoree, M.H.

2013-01-01

Compounds with transthyretin (TTR)-binding potency in the blood plasma of polar bear cubs were identified with effect-directed analysis (EDA). This approach contributes to the understanding of the thyroid disrupting exposome of polar bears. The selection of these samples for in-depth EDA was based

Optimum measurement and analysis of small polarization asymmetry in high-energy inelastic scattering using a polarized target

International Nuclear Information System (INIS)

Niinikoski, T.O.

1976-01-01

Optimum linear filter theory is employed for maximizing the signal-to-noise ratio in measurements of small polarization asymmetry in the presence of severe counting efficiency fluctuation, most likely to occur in high-energy inclusive and inelastic scattering experiments, using a polarized target. The r.m.s. error of the polarization asymmetry is obtained in closed form, allowing numeric optimization of the operation of the target. Guidelines are given for processing the record of data. (Auth.)

A Simplified, Low-Cost Method for Polarized Light Microscopy

Science.gov (United States)

Maude, Richard J.; Buapetch, Wanchana; Silamut, Kamolrat

2009-01-01

Malaria pigment is an intracellular inclusion body that appears in blood and tissue specimens on microscopic examination and can help in establishing the diagnosis of malaria. In simple light microscopy, it can be difficult to discern from cellular background and artifacts. It has long been known that if polarized light microscopy is used, malaria pigment can be much easier to distinguish. However, this technique is rarely used because of the need for a relatively costly polarization microscope. We describe a simple and economical technique to convert any standard light microscope suitable for examination of malaria films into a polarization microscope. PMID:19861611

Gradient effects in a new class of electro-elastic bodies

Science.gov (United States)

Arvanitakis, Antonios

2018-06-01

Continuum theories for electro-elastic solids suggest the development of electric field or polarization-based models. Advanced versions of these models are the so-called gradient models, i.e., polarization gradient and electric field gradient models, which prove to be more than capable of explaining the behavior of a continuum in a wider range of length scales. In this work, implicit constitutive relations for electro-elastic bodies are considered with the introduction of polarization and electric field gradient effects. In this sense, the new class of electro-elastic bodies extends even further to account for nonlocality in constitutive equations, besides strain-limiting behavior and polarization saturation for large values of stresses and electric field, respectively. Nonlocality in constitutive equations is essential in modeling various phenomena.

Circular polarization analyzer with polarization tunable focusing of surface plasmon polaritons

Energy Technology Data Exchange (ETDEWEB)

Wang, Sen; Zhang, Yan, E-mail: yzhang@mail.cnu.edu.cn [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Beijing Key Laboratory for Metamaterials and Devices, and Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Wang, Xinke [Beijing Key Laboratory for Metamaterials and Devices, and Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Kan, Qiang [State Key Laboratory for Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Qu, Shiliang [Optoelectronics Department, Harbin Institute of Technology at Weihai, Weihai 264209 (China)

2015-12-14

A practical circular polarization analyzer (CPA) that can selectively focus surface plasmon polaritons (SPPs) at two separate locations, according to the helicity of the circularly polarized light, is designed and experimentally verified in the terahertz frequency range. The CPA consists of fishbone-slit units and is designed using the simulated annealing algorithm. By differentially detecting the intensities of the two SPPs focuses, the helicity of the incident circularly polarized light can be obtained and the CPA is less vulnerable to the noise of incident light. The proposed device may also have wide potential applications in chiral SPPs photonics and the analysis of chiral molecules in biology.

Volume sums of polar Blaschke–Minkowski homomorphisms

Indian Academy of Sciences (India)

In this article, we establish Minkowski and Aleksandrov–Fenchel type inequalities for the volume sum of polars of Blaschke–Minkowski homomorphisms. Keywords. Blaschke–Minkowski homomorphism; volume differences; volume sum; projection body operator. 2010 Mathematics Subject Classification. 52A40, 52A30. 1.

Neutron xyz - polarization analysis at a time-of-flight instrument

Energy Technology Data Exchange (ETDEWEB)

Ehlers, Georg [ORNL; Stewart, John Ross [ISIS Facility, Rutherford Appleton Laboratory; Andersen, Ken [ESS

2015-01-01

When implementing a dedicated polarization analysis setup at a neutron time-of-flight instrument with a large area detector, one faces enormous challenges. Nevertheless, significant progress has been made towards this goal over the last few years. This paper addresses systematic limitations of the traditional method that is used to make these measurements, and a possible strategy to overcome these limitations. This will be important, for diffraction as well as inelastic experiments, where the scattering occurs mostly out-of-plane.

Neutron multimonochromator-bipolarizer based on magnetic multilayer Fe/Co and new scheme for the total neutron polarization analysis

International Nuclear Information System (INIS)

Syromyatnikov, V.G.; Zaw Lin, Kyaw

2017-01-01

In this paper, we present a new neutron-optical element, Neutron Multimonochromator-Bipolarizer (NMB). It consists of a multimultilayer structure made of 12 periodic multilayer Fe/Co magnetic nanostructures whose period increases with distance from the substrate. Results are presented of calculations of the reflection coefficients from the NMB. We propose a new scheme of the total neutron polarization analysis for the time-of-flight method in the reflectometry. In this scheme, double NMB is used as a polarizer and there is no spin-flipper before the sample. NMB can be used in polarized neutron reflectometry, in SESANS, and for research of low-angle and inelastic scattering of polarized neutrons. (paper)

Body image disturbance in adults treated for cancer - a concept analysis.

Science.gov (United States)

Rhoten, Bethany A

2016-05-01

To report an analysis of the concept of body image disturbance in adults who have been treated for cancer as a phenomenon of interest to nurses. Although the concept of body image disturbance has been clearly defined in adolescents and adults with eating disorders, adults who have been treated for cancer may also experience body image disturbance. In this context, the concept of body image disturbance has not been clearly defined. Concept analysis. PubMed, Psychological Information Database and Cumulative Index of Nursing and Allied Health Literature were searched for publications from 1937 - 2015. Search terms included body image, cancer, body image disturbance, adult and concept analysis. Walker and Avant's 8-step method of concept analysis was used. The defining attributes of body image disturbance in adults who have been treated for cancer are: (1) self-perception of a change in appearance and displeasure with the change or perceived change in appearance; (2) decline in an area of function; and (3) psychological distress regarding changes in appearance and/or function. This concept analysis provides a foundation for the development of multidimensional assessment tools and interventions to alleviate body image disturbance in this population. A better understanding of body image disturbance in adults treated for cancer will assist nurses and other clinicians in identifying this phenomenon and nurse scientists in developing instruments that accurately measure this condition, along with interventions that will promote a better quality of life for survivors. © 2016 John Wiley & Sons Ltd.

Measuring fluorescence polarization with a dichrometer.

Science.gov (United States)

Sutherland, John C

2017-09-01

A method for obtaining fluorescence polarization data from an instrument designed to measure circular and linear dichroism is compared with a previously reported approach. The new method places a polarizer between the sample and a detector mounted perpendicular to the direction of the incident beam and results in determination of the fluorescence polarization ratio, whereas the previous method does not use a polarizer and yields the fluorescence anisotropy. A similar analysis with the detector located axially with the excitation beam demonstrates that there is no frequency modulated signal due to fluorescence polarization in the absence of a polarizer. Copyright © 2017. Published by Elsevier Inc.

A bromine-based dichroic X-ray polarization analyser

CERN Document Server

Collins, S P; Brown, S D; Thompson, P

2001-01-01

We have demonstrated the advantages offered by dichroic X-ray polarization filters for linear polarization analysis, and describe such a device, based on a dibromoalkane/urea inclusion compound. The polarizer has been successfully tested by analysing the polarization of magnetic diffraction from holmium.

Analysis of polarization introduced due to the telescope optics of the Thirty Meter Telescope

Science.gov (United States)

Anche, Ramya Manjunath; Sen, Asoke Kumar; Anupama, Gadiyara Chakrapani; Sankarasubramanian, Kasiviswanathan; Skidmore, Warren

2018-01-01

An analytical model has been developed to estimate the polarization effects, such as instrumental polarization (IP), crosstalk (CT), and depolarization, due to the optics of the Thirty Meter Telescope. These are estimated for the unvignetted field-of-view and the wavelengths of interest. The model estimates an IP of 1.26% and a CT of 44% at the Nasmyth focus of the telescope at the wavelength of 0.6 μm at field angle zero with the telescope pointing to zenith. Mueller matrices have been estimated for the primary, secondary, and Nasmyth mirrors. It is found that some of the Mueller matrix elements of the primary and secondary mirrors show a fourfold azimuthal antisymmetry, which indicates that the polarization at the Cassegrain focus is negligible. At the inclined Nasmyth mirror, there is no azimuthal antisymmetry in the matrix elements, and this results in nonzero values for IP and CT, which would negatively impact the polarization measurements at the telescope focus. The averaged Mueller matrix is estimated at the Nasmyth focus at different instrument ports and various zenith angles of the telescope. The variation in the Mueller matrix elements for different coatings is also estimated. The impact of this polarization effect on the science case requirements has been discussed. This analysis will help in achieving precise requirements for future instruments with polarimetric capability.

Sources of linear polarized x-rays

International Nuclear Information System (INIS)

Aiginger, H.; Wobrauschek, P.

1989-01-01

Linear polarized X-rays are used in X-ray fluorescence analysis to decrease the background caused by scattered photons. Various experiments, calculations and constructions have demonstrated the possibility to produce polarized radiation in an analytical laboratory with an X-ray tube and polarizer-analyzer facilities as auxiliary equipment. The results obtained with Bragg-polarizers of flat and curved focussing geometry and of Barkla-polarizers are presented. The advantages and disadvantages of the method are discussed and compared with the respective quality of synchrotron radiation. Polarization by scattering reduces the intensity of the primary radiation. Recently much effort is devoted to the construction of integrated high power X-ray tube polarizer-analyzer arrangements. The detailed design, geometry and performance of such a facility is described. (author)

The scattering of polarized neutrons from statically polarized solid {sup 3}He

Energy Technology Data Exchange (ETDEWEB)

Haase, D.G.; Keith, C.D.; Gould, C.R.; Seely, M.L. [North Carolina State Univ., Raleigh, NC (United States)]|[Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Huffman, P.R.; Roberson, N.R.; Tornow, W.; Wilburn, W.S. [Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)]|[Duke University, Durham, NC 27708-0308 (United States)

1998-01-11

We have constructed a 0.4 mole solid {sup 3}He target, cryogenically polarized at 12 mK in a field of 7 T. The 0.04 atoms/b target reached a polarization of 38% in 35 h. Such a target may be applied to any experiment which is tolerant of the large ambient magnetic field and which produces target heating of less than a microwatt. High energy neutron and photon scattering experiments meet these requirements. The target`s figure of merit for neutron transmission measurement exceeds that of polarized gas targets by greater than 35. At the Triangle Universities Nuclear Laboratory we have used the target to measure the total cross section differences {Delta}{sigma}{sub T} and {Delta}{sigma}{sub L} for incident polarized neutrons of energies 2-8 MeV. The cross section difference is sensitive to the excited state structure of the n-{sup 3}He system. The results have been compared to a recent R-matrix analysis of A=4 scattering and reaction data, and provide support for the {sup 4}He level scheme derived from that analysis. (orig.). 11 refs.

Principal Component Analysis of Body Measurements In Three ...

African Journals Online (AJOL)

This study was conducted to explore the relationship among body measurements in 3 strains of broilers chicken (Arbor Acre, Marshal and Ross) using principal component analysis with the view of identifying those components that define body conformation in broilers. A total of 180 birds were used, 60 per strain.

Asymptotic theory of circular polarization memory.

Science.gov (United States)

Dark, Julia P; Kim, Arnold D

2017-09-01

We establish a quantitative theory of circular polarization memory, which is the unexpected persistence of the incident circular polarization state in a strongly scattering medium. Using an asymptotic analysis of the three-dimensional vector radiative transfer equation (VRTE) in the limit of strong scattering, we find that circular polarization memory must occur in a boundary layer near the portion of the boundary on which polarized light is incident. The boundary layer solution satisfies a one-dimensional conservative scattering VRTE. Through a spectral analysis of this boundary layer problem, we introduce the dominant mode, which is the slowest-decaying mode in the boundary layer. To observe circular polarization memory for a particular set of optical parameters, we find that this dominant mode must pass three tests: (1) this dominant mode is given by the largest, discrete eigenvalue of a reduced problem that corresponds to Fourier mode k=0 in the azimuthal angle, and depends only on Stokes parameters U and V; (2) the polarization state of this dominant mode is largely circular polarized so that |V|≫|U|; and (3) the circular polarization of this dominant mode is maintained for all directions so that V is sign-definite. By applying these three tests to numerical calculations for monodisperse distributions of Mie scatterers, we determine the values of the size and relative refractive index when circular polarization memory occurs. In addition, we identify a reduced, scalar-like problem that provides an accurate approximation for the dominant mode when circular polarization memory occurs.

Polarization measurement for internal polarized gaseous targets

International Nuclear Information System (INIS)

Ye Zhenyu; Ye Yunxiu; Lv Haijiang; Mao Yajun

2004-01-01

The authors present an introduction to internal polarized gaseous targets, polarization method, polarization measurement method and procedure. To get the total nuclear polarization of hydrogen atoms (including the polarization of the recombined hydrogen molecules) in the target cell, authors have measured the parameters relating to atomic polarization and polarized hydrogen atoms and molecules. The total polarization of the target during our measurement is P T =0.853 ± 0.036. (authors)

The polarization of fast neutrons

International Nuclear Information System (INIS)

Talov, V.V.

2001-01-01

It is insufficient to know coordinates and momentum to describe a state of a neutron. It is necessary to define a spin orientation. As far as it is known from quantum mechanics, a half spin has a projection in the positive direction or in the negative direction. The probability of both projections in an unpolarized beam is equal. If a direction exists, in which the projection is more probably then beam is called polarized in this direction. It is essential to know polarization of neutrons for characteristics of a neutron source, which is emitting it. The question of polarization of fast neutrons came up in 50's. The present work is the review of polarization of fast neutrons and methods of polarization analysis. This also includes information about polarization of fast neutrons from first papers, which described polarization in the D(d,n) 3 He, 7 Li (p,n) 7 Be, T(p,n) 3 He reactions. (authors)

Full genome analysis of a novel adenovirus from the South Polar skua (Catharacta maccormicki) in Antarctica.

Science.gov (United States)

Park, Yon Mi; Kim, Jeong-Hoon; Gu, Se Hun; Lee, Sook Young; Lee, Min-Goo; Kang, Yoon Kyoo; Kang, Sung-Ho; Kim, Hak Jun; Song, Jin-Won

2012-01-05

Adenoviruses have been identified in humans and a wide range of vertebrate animals, but not previously from the polar region. Here, we report the entire 26,340-bp genome of a novel adenovirus, detected by PCR, in tissues of six of nine South Polar skuas (Catharacta maccormicki), collected in Lake King Sejong, King George Island, Antarctica, from 2007 to 2009. The DNA polymerase, penton base, hexon and fiber genes of the South Polar skua adenovirus (SPSAdV) exhibited 68.3%, 75.4%, 74.9% and 48.0% nucleotide sequence similarity with their counterparts in turkey hemorrhagic enteritis virus. Phylogenetic analysis based on the entire genome revealed that SPSAdV belonged to the genus Siadenovirus, family Adenoviridae. This is the first evidence of a novel adenovirus, SPSAdV, from a large polar seabird (family Stercorariidae) in Antarctica. Copyright © 2011 Elsevier Inc. All rights reserved.

Nuclear spin polarization of targets

International Nuclear Information System (INIS)

Happer, W.

1990-01-01

Lasers can be used to produce milligrams to grams of noble gas nuclei with spin polarizations in excess of 50%. These quantities are sufficient to be very useful targets in nuclear physics experiments. Alkali-metal atoms are used to capture the angular momentum of circularly polarized laser photons, and the alkali-metal atoms transfer their angular momentum to noble gas atoms in binary or three-body collisions. Non-radiative collisions between the excited alkali atoms and molecular quenching gases are essential to avoid radiation trapping. The spin exchange can involve gas-phase van der Waals molecules, consisting of a noble gas atom and an alkali metal atom. Surface chemistry is also of great importance in determining the wall-induced relaxation rates of the noble gases

Coherent active polarization control without loss

Science.gov (United States)

Ye, Yuqian; Hay, Darrick; Shi, Zhimin

2017-11-01

We propose a lossless active polarization control mechanism utilizing an anisotropic dielectric medium with two coherent inputs. Using scattering matrix analysis, we derive analytically the required optical properties of the anisotropic medium that can behave as a switchable polarizing beam splitter. We also show that such a designed anisotropic medium can produce linearly polarized light at any azimuthal direction through coherent control of two inputs with a specific polarization state. Furthermore, we present a straightforward design-on-demand procedure of a subwavelength-thick metastructure that can possess the desired optical anisotropy at a flexible working wavelength. Our lossless coherent polarization control technique may lead to fast, broadband and integrated polarization control elements for applications in imaging, spectroscopy, and telecommunication.

Design and Polarization Characteristics Analysis of Dihedral Based on Salisbury Screen

Directory of Open Access Journals (Sweden)

Zhang Ran

2016-12-01

Full Text Available Salisbury screens have a number of unique electromagnetic scattering characteristics. When appropriately designed, the Salisbury screen can reach the radar target signature transform. Based on the electromagnetic scattering characteristics of the Salisbury screen, we designed a novel dihedral corner, and theoretically analyzed and simulated its electromagnetic scattering characteristics in this study. The results reveal the monostatic radar cross section curves of the 90°and 60° Salisbury screen dihedral and metal dihedral, respectively. Taking an orthogonal dihedral corner as an example, we obtained the polarization scattering matrixes for different incident degrees. In addition, we investigated the influence of illumination frequency, target gestures, and other key factors on the polarization characteristics of the Salisbury screen dihedral corner. The theoretical and simulation analysis results show that compared with the conventional metal dihedral corner, the Salisbury screen dihedral corner significantly influences the scattering characteristics and will have potential application in electronic warfare.

Comparison of fabric analysis of snow samples by Computer-Integrated Polarization Microscopy and Automatic Ice Texture Analyzer

Science.gov (United States)

Leisinger, Sabine; Montagnat, Maurine; Heilbronner, Renée; Schneebeli, Martin

2014-05-01

Accurate knowledge of fabric anisotropy is crucial to understand the mechanical behavior of snow and firn, but is also important for understanding metamorphism. Computer-Integrated Polarization Microscopy (CIP) method used for the fabric analysis was developed by Heilbronner and Pauli in the early 1990ies and uses a slightly modified traditional polarization microscope for the fabric analysis. First developed for quartz, it can be applied to other uniaxial minerals. Up to now this method was mainly used in structural geology. However, it is also well suited for the fabric analysis of snow, firn and ice. The method is based on the analysis of first- order interference colors images by a slightly modified optical polarization microscope, a grayscale camera and a computer. The optical polarization microscope is featured with high quality objectives, a rotating table and two polarizers that can be introduced above and below the thin section, as well as a full wave plate. Additionally, two quarter-wave plates for circular polarization are needed. Otherwise it is also possible to create circular polarization from a set of crossed polarized images through image processing. A narrow band interference filter transmitting a wavelength between 660 and 700 nm is also required. Finally a monochrome digital camera is used to capture the input images. The idea is to record the change of interference colors while the thin section is being rotated once through 180°. The azimuth and inclination of the c-axis are defined by the color change. Recording the color change through a red filter produces a signal with a well-defined amplitude and phase angle. An advantage of this method lies in the simple conversion of an ordinary optical microscope to a fabric analyzer. The Automatic Ice Texture Analyzer (AITA) as the first fully functional instrument to measure c-axis orientation was developed by Wilson and other (2003). Most recent fabric analysis of snow and firn samples was carried

Partial Polarization in Interfered Plasmon Fields

Directory of Open Access Journals (Sweden)

P. Martínez Vara

2014-01-01

Full Text Available We describe the polarization features for plasmon fields generated by the interference between two elemental surface plasmon modes, obtaining a set of Stokes parameters which allows establishing a parallelism with the traditional polarization model. With the analysis presented, we find the corresponding coherence matrix for plasmon fields incorporating to the plasmon optics the study of partial polarization effects.

Errors and corrections in the separation of spin-flip and non-spin-flip thermal neutron scattering using the polarization analysis technique

International Nuclear Information System (INIS)

Williams, W.G.

1975-01-01

The use of the polarization analysis technique to separate spin-flip from non-spin-flip thermal neutron scattering is especially important in determining magnetic scattering cross-sections. In order to identify a spin-flip ratio in the scattering with a particular scattering process, it is necessary to correct the experimentally observed 'flipping-ratio' to allow for the efficiencies of the vital instrument components (polarizers and spin-flippers), as well as multiple scattering effects in the sample. Analytical expressions for these corections are presented and their magnitudes in typical cases estimated. The errors in measurement depend strongly on the uncertainties in the calibration of the efficiencies of the polarizers and the spin-flipper. The final section is devoted to a discussion of polarization analysis instruments

Analysis of the local worst-case SAR exposure caused by an MRI multi-transmit body coil in anatomical models of the human body

International Nuclear Information System (INIS)

Neufeld, Esra; Gosselin, Marie-Christine; Murbach, Manuel; Christ, Andreas; Cabot, Eugenia; Kuster, Niels

2011-01-01

Multi-transmit coils are increasingly being employed in high-field magnetic resonance imaging, along with a growing interest in multi-transmit body coils. However, they can lead to an increase in whole-body and local specific absorption rate (SAR) compared to conventional body coils excited in circular polarization for the same total incident input power. In this study, the maximum increase of SAR for three significantly different human anatomies is investigated for a large 3 T (128 MHz) multi-transmit body coil using numerical simulations and a (generalized) eigenvalue-based approach. The results demonstrate that the increase of SAR strongly depends on the anatomy. For the three models and normalization to the sum of the rung currents squared, the whole-body averaged SAR increases by up to a factor of 1.6 compared to conventional excitation and the peak spatial SAR (averaged over any 10 cm 3 of tissue) by up to 13.4. For some locations the local averaged SAR goes up as much as 800 times (130 when looking only at regions where it is above 1% of the peak spatial SAR). The ratio of the peak spatial SAR to the whole-body SAR increases by a factor of up to 47 and can reach values above 800. Due to the potentially much larger power deposition, additional, preferably patient-specific, considerations are necessary to avoid injuries by such systems.

MAGNETIC FIELD COMPONENTS ANALYSIS OF THE SCUPOL 850 μm POLARIZATION DATA CATALOG

Energy Technology Data Exchange (ETDEWEB)

Poidevin, Frédérick [Department of Physics and Astronomy, University College London, Kathleen Lonsdale Building, Gower Place, London WC1E 6BT (United Kingdom); Falceta-Gonçalves, Diego [SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS (United Kingdom); Kowal, Grzegorz [Universidade de São Paulo, Escola de Artes, Ciências e Humanidades Rua Arlindo Béttio, No. 1000, Ermelino Matarazzo, São Paulo, SP 03828-000 (Brazil); De Gouveia Dal Pino, Elisabete; Magalhães, Antonio Mário, E-mail: poidevin@star.ucl.ac.uk, E-mail: dfalceta@usp.br, E-mail: kowal@astro.iag.usp.br, E-mail: dalpino@astro.iag.usp.br, E-mail: mario@astro.iag.usp.br [Universidade de São Paulo, Instituto de Astronomia, Geofísica e Cîenças Atmosféricas, Rua do Matão 1226, Butantã, São Paulo, SP 05508-900 (Brazil)

2013-11-10

We present an extensive analysis of the 850 μm polarization maps of the SCUBA Polarimeter Legacy (SCUPOL) Catalogue produced by Matthews et al., focusing exclusively on the molecular clouds and star-forming regions. For the sufficiently sampled regions, we characterize the depolarization properties and the turbulent-to-mean magnetic field ratio of each region. Similar sets of parameters are calculated from two-dimensional synthetic maps of dust-emission polarization produced with three-dimensional magnetohydrodynamics (MHD) numerical simulations scaled to the S106, OMC-2/3, W49, and DR21 molecular cloud polarization maps. For these specific regions, the turbulent MHD regimes retrieved from the simulations, as described by the turbulent Alfvén and Sonic Mach numbers, are consistent within a factor one to two with the values of the same turbulent regimes estimated from the analysis of Zeeman measurements data provided by Crutcher. Constraints on the values of the inclination angle α of the mean magnetic field with respect to the line of sight are also given. The values obtained from the comparison of the simulations with the SCUPOL data are consistent with the estimates made by using two observational methods provided by other authors. Our main conclusion is that simple, ideal, isothermal, and non-self-gravitating MHD simulations are sufficient in order to describe the large-scale observed physical properties of the envelopes of this set of regions.

[Particle Size and Number Density Online Analysis for Particle Suspension with Polarization-Differentiation Elastic Light Scattering Spectroscopy].

Science.gov (United States)

Chen, Wei-kang; Fang, Hui

2016-03-01

The basic principle of polarization-differentiation elastic light scattering spectroscopy based techniques is that under the linear polarized light incidence, the singlely scattered light from the superficial biological tissue and diffusively scattered light from the deep tissue can be separated according to the difference of polarization characteristics. The novel point of the paper is to apply this method to the detection of particle suspension and, to realize the simultaneous measurement of its particle size and number density in its natural status. We design and build a coaxial cage optical system, and measure the backscatter signal at a specified angle from a polystyrene microsphere suspension. By controlling the polarization direction of incident light with a linear polarizer and adjusting the polarization direction of collected light with another linear polarizer, we obtain the parallel polarized elastic light scattering spectrum and cross polarized elastic light scattering spectrum. The difference between the two is the differential polarized elastic light scattering spectrum which include only the single scattering information of the particles. We thus compare this spectrum to the Mie scattering calculation and extract the particle size. We then also analyze the cross polarized elastic light scattering spectrum by applying the particle size already extracted. The analysis is based on the approximate expressions taking account of light diffusing, from which we are able to obtain the number density of the particle suspension. We compare our experimental outcomes with the manufacturer-provided values and further analyze the influence of the particle diameter standard deviation on the number density extraction, by which we finally verify the experimental method. The potential applications of the method include the on-line particle quality monitoring for particle manufacture as well as the fat and protein density detection of milk products.

Synchronous wearable wireless body sensor network composed of autonomous textile nodes.

Science.gov (United States)

Vanveerdeghem, Peter; Van Torre, Patrick; Stevens, Christiaan; Knockaert, Jos; Rogier, Hendrik

2014-10-09

A novel, fully-autonomous, wearable, wireless sensor network is presented, where each flexible textile node performs cooperative synchronous acquisition and distributed event detection. Computationally efficient situational-awareness algorithms are implemented on the low-power microcontroller present on each flexible node. The detected events are wirelessly transmitted to a base station, directly, as well as forwarded by other on-body nodes. For each node, a dual-polarized textile patch antenna serves as a platform for the flexible electronic circuitry. Therefore, the system is particularly suitable for comfortable and unobtrusive integration into garments. In the meantime, polarization diversity can be exploited to improve the reliability and energy-efficiency of the wireless transmission. Extensive experiments in realistic conditions have demonstrated that this new autonomous, body-centric, textile-antenna, wireless sensor network is able to correctly detect different operating conditions of a firefighter during an intervention. By relying on four network nodes integrated into the protective garment, this functionality is implemented locally, on the body, and in real time. In addition, the received sensor data are reliably transferred to a central access point at the command post, for more detailed and more comprehensive real-time visualization. This information provides coordinators and commanders with situational awareness of the entire rescue operation. A statistical analysis of measured on-body node-to-node, as well as off-body person-to-person channels is included, confirming the reliability of the communication system.

Polarized neutrons for Australian scientific research

International Nuclear Information System (INIS)

Kennedy, Shane J.

2005-01-01

Polarized neutron scattering has been a feature at ANSTO's HIFAR research reactor since the first polarization analysis (PA) spectrometer Longpol began operation over 30 years ago. Since that time, we have improved performance of Longpol and added new capabilities in several reincarnations of the instrument. Most of the polarized neutron experiments have been in the fields of magnetism and superconductivity, and most of that research has involved PA. Now as we plan our next generation neutron beam facility, at the Replacement Research Reactor (RRR), we intend to continue the tradition of PA but with a far broader scope in mind. Our new capabilities will combine PA and energy analysis with both cold and thermal neutron source spectra. We will also provide capabilities for research with polarized neutrons in small-angle neutron scattering and in neutron reflectometry. The discussion includes a brief historical account of the technical developments with a summary of past and present applications of polarized neutrons at HIFAR, and an outline of the polarized neutron capabilities that will be included in the first suite of instruments, which will begin operation at the new reactor in 2006

Cross-sex hormone therapy in transgender persons affects total body weight, body fat and lean body mass: a meta-analysis.

Science.gov (United States)

Klaver, M; Dekker, M J H J; de Mutsert, R; Twisk, J W R; den Heijer, M

2017-06-01

Weight gain and body fat increase the risk of cardiometabolic disease. Cross-sex hormone therapy in transgender persons leads to changes in body weight and body composition, but it is unclear to what extent. We performed a meta-analysis to investigate the changes in body weight, body fat and lean body mass during cross-sex hormone therapy in transgender persons. We searched the PubMed database for eligible studies until November 2015. Ten studies reporting changes in body weight, body fat or lean mass in hormone naive transgender persons were included, examining 171 male-to-female and 354 female-to-male transgender people. Pooled effect estimates in the male-to-female group were +1.8 kg (95% CI: 0.2;3.4) for body weight, +3.0 kg (2.0;3.9) for body fat and -2.4 kg (-2.8; -2.1) for lean body mass. In the female-to-male group, body weight changed with +1.7 kg (0.7;2.7), body fat with -2.6 kg (-3.9; -1.4) and lean body mass with +3.9 kg (3.2;4.5). Cross-sex hormone therapy increases body weight in both sexes. In the male-to-female group, a gain in body fat and a decline in lean body mass are observed, while the opposite effects are seen in the female-to-male group. Possibly, these changes increase the risk of cardiometabolic disease in the male-to-female group. © 2016 Blackwell Verlag GmbH.

NMR-Based Identification of Metabolites in Polar and Non-Polar Extracts of Avian Liver.

Science.gov (United States)

Fathi, Fariba; Brun, Antonio; Rott, Katherine H; Falco Cobra, Paulo; Tonelli, Marco; Eghbalnia, Hamid R; Caviedes-Vidal, Enrique; Karasov, William H; Markley, John L

2017-11-16

Metabolites present in liver provide important clues regarding the physiological state of an organism. The aim of this work was to evaluate a protocol for high-throughput NMR-based analysis of polar and non-polar metabolites from a small quantity of liver tissue. We extracted the tissue with a methanol/chloroform/water mixture and isolated the polar metabolites from the methanol/water layer and the non-polar metabolites from the chloroform layer. Following drying, we re-solubilized the fractions for analysis with a 600 MHz NMR spectrometer equipped with a 1.7 mm cryogenic probe. In order to evaluate the feasibility of this protocol for metabolomics studies, we analyzed the metabolic profile of livers from house sparrow ( Passer domesticus ) nestlings raised on two different diets: livers from 10 nestlings raised on a high protein diet (HP) for 4 d and livers from 12 nestlings raised on the HP diet for 3 d and then switched to a high carbohydrate diet (HC) for 1 d. The protocol enabled the detection of 52 polar and nine non-polar metabolites in ¹H NMR spectra of the extracts. We analyzed the lipophilic metabolites by one-way ANOVA to assess statistically significant concentration differences between the two groups. The results of our studies demonstrate that the protocol described here can be exploited for high-throughput screening of small quantities of liver tissue (approx. 100 mg wet mass) obtainable from small animals.

Coherent active polarization control without loss

Directory of Open Access Journals (Sweden)

Yuqian Ye

2017-11-01

Full Text Available We propose a lossless active polarization control mechanism utilizing an anisotropic dielectric medium with two coherent inputs. Using scattering matrix analysis, we derive analytically the required optical properties of the anisotropic medium that can behave as a switchable polarizing beam splitter. We also show that such a designed anisotropic medium can produce linearly polarized light at any azimuthal direction through coherent control of two inputs with a specific polarization state. Furthermore, we present a straightforward design-on-demand procedure of a subwavelength-thick metastructure that can possess the desired optical anisotropy at a flexible working wavelength. Our lossless coherent polarization control technique may lead to fast, broadband and integrated polarization control elements for applications in imaging, spectroscopy, and telecommunication.

Model of the negative polarization of light of cosmic bodies deprived by atmospheres

International Nuclear Information System (INIS)

Shkuratov, Yu.G.

1982-01-01

The formulae are obtained describing the polarization of light scattered by planets deprived of atmospheres, for small phase angles (up to 30 deg). It is suggested that the negative polarization is due to a combination of the shadow effect with single and double noncoplanar Fresnel reflections from microfacets of particles. Theoretical calculations are compared with the experimental data obtained by Lio and Dollfus during Moon observation as well as Zellner and others during 324 Bamberga asteroid observation. In the case with the Moon the best agreement with the experiment is obtained when the actual part of the refractive index n=1.60 and for asteroid n=1.78

Combined thin layer chromatography and gas chromatography with mass spectrometric analysis of lipid classes and fatty acids in malnourished polar bears (Ursus maritimus) which swam to Iceland.

Science.gov (United States)

Eibler, Dorothee; Krüger, Sabine; Skírnisson, Karl; Vetter, Walter

2017-03-01

Between 2008 and 2011, four polar bears (Ursus maritimus) from the Greenland population swam and/or drifted on ice to Iceland where they arrived in very poor body condition. Body fat resources in these animals were only between 0% and 10% of the body weight (usually 25%). Here we studied the lipid composition in different tissues (adipose tissue if available, liver, kidney and muscle). Lipid classes were determined by thin layer chromatography (TLC) and on-column gas chromatography with mass spectrometry (GC/MS). The fatty acid pattern of total lipids and free fatty acids was analyzed by GC/MS in selected ion monitoring (SIM) mode. Additionally, cholesteryl esters and native fatty acid methyl esters, initially detected as zones in thin layer chromatograms, were enriched by solid phase extraction and quantified by GC/MS. The ratio of free fatty acids to native fatty acid methyl esters could be correlated with the remained body lipids in the polar bears and thus may also serve as a marker for other starving animals or even for humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Climate Drives Polar Bear Origins

Science.gov (United States)

In their provocative analysis of northern bears (“Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage,” Reports, 20 April, p. 344), F. Hailer et al. use independent nuclear loci to show that polar bears originated during the middle Pleistocene, rather than during t...

Full-Stokes polarimetry with circularly polarized feeds. Sources with stable linear and circular polarization in the GHz regime

Science.gov (United States)

Myserlis, I.; Angelakis, E.; Kraus, A.; Liontas, C. A.; Marchili, N.; Aller, M. F.; Aller, H. D.; Karamanavis, V.; Fuhrmann, L.; Krichbaum, T. P.; Zensus, J. A.

2018-01-01

We present an analysis pipeline that enables the recovery of reliable information for all four Stokes parameters with high accuracy. Its novelty relies on the effective treatment of the instrumental effects even before the computation of the Stokes parameters, contrary to conventionally used methods such as that based on the Müller matrix. For instance, instrumental linear polarization is corrected across the whole telescope beam and significant Stokes Q and U can be recovered even when the recorded signals are severely corrupted by instrumental effects. The accuracy we reach in terms of polarization degree is of the order of 0.1-0.2%. The polarization angles are determined with an accuracy of almost 1°. The presented methodology was applied to recover the linear and circular polarization of around 150 active galactic nuclei, which were monitored between July 2010 and April 2016 with the Effelsberg 100-m telescope at 4.85 GHz and 8.35 GHz with a median cadence of 1.2 months. The polarized emission of the Moon was used to calibrate the polarization angle measurements. Our analysis showed a small system-induced rotation of about 1° at both observing frequencies. Over the examined period, five sources have significant and stable linear polarization; three sources remain constantly linearly unpolarized; and a total of 11 sources have stable circular polarization degree mc, four of them with non-zero mc. We also identify eight sources that maintain a stable polarization angle. All this is provided to the community for future polarization observations reference. We finally show that our analysis method is conceptually different from those traditionally used and performs better than the Müller matrix method. Although it has been developed for a system equipped with circularly polarized feeds, it can easily be generalized to systems with linearly polarized feeds as well. The data used to create Fig. C.1 are only available at the CDS via anonymous ftp to http

Computer simulations analysis for determining the polarity of charge generated by high energy electron irradiation of a thin film

DEFF Research Database (Denmark)

Malac, Marek; Hettler, Simon; Hayashida, Misa

2017-01-01

Detailed simulations are necessary to correctly interpret the charge polarity of electron beam irradiated thin film patch. Relying on systematic simulations we provide guidelines and movies to interpret experimentally the polarity of the charged area, to be understood as the sign of the electrost......Detailed simulations are necessary to correctly interpret the charge polarity of electron beam irradiated thin film patch. Relying on systematic simulations we provide guidelines and movies to interpret experimentally the polarity of the charged area, to be understood as the sign...... of the electrostatic potential developed under the beam with reference to a ground electrode. We discuss the two methods most frequently used to assess charge polarity: Fresnel imaging of the irradiated area and Thon rings analysis. We also briefly discuss parameter optimization for hole free phase plate (HFPP...

Hair Mercury Concentrations in Western Hudson Bay Polar Bear Family Groups.

Science.gov (United States)

Bechshoft, Thea; Derocher, Andrew E; Richardson, Evan; Lunn, Nicholas J; St Louis, Vincent L

2016-05-17

Methylmercury is one of the more toxic forms of mercury (Hg), the biomagnification of which is prevalent in the Arctic where apex predators such as polar bears (Ursus maritimus) can carry high loads. The maternal transfer of contaminants to offspring is a concern, as offspring may be particularly sensitive to the effects of environmental pollutants during early development. However, few studies of polar bears report on Hg in dependent young. We examined hair total Hg (THg) concentrations in 24 polar bear family groups in western Hudson Bay: mother, cub-of-the-year (COY), yearling, and 2 year old. THg concentrations increased with bear age, with COYs having lower concentrations than other offspring groups (p ≤ 0.008). Using AICc-based regression models, we found maternal THg to be positively related to body condition and litter size, while overall offspring THg was positively related to maternal body condition in addition to being dependent on the sex and age of the offspring. COY THg concentrations were positively related to maternal THg while also depending on the sex of the offspring. Considering our results, future studies in polar bear ecotoxicology are encouraged to include offspring of different ages and sexes.

[Analysis of influencing factors of snow hyperspectral polarized reflections].

Science.gov (United States)

Sun, Zhong-Qiu; Zhao, Yun-Sheng; Yan, Guo-Qian; Ning, Yan-Ling; Zhong, Gui-Xin

2010-02-01

Due to the need of snow monitoring and the impact of the global change on the snow, on the basis of the traditional research on snow, starting from the perspective of multi-angle polarized reflectance, we analyzed the influencing factors of snow from the incidence zenith angles, the detection zenith angles, the detection azimuth angles, polarized angles, the density of snow, the degree of pollution, and the background of the undersurface. It was found that these factors affected the spectral reflectance values of the snow, and the effect of some factors on the polarization hyperspectral reflectance observation is more evident than in the vertical observation. Among these influencing factors, the pollution of snow leads to an obvious change in the snow reflectance spectrum curve, while other factors have little effect on the shape of the snow reflectance spectrum curve and mainly impact the reflection ratio of the snow. Snow reflectance polarization information has not only important theoretical significance, but also wide application prospect, and provides new ideas and methods for the quantitative research on snow using the remote sensing technology.

Detection of polar vapours

International Nuclear Information System (INIS)

Blyth, D.A.

1980-01-01

Apparatus for monitoring for polar vapours in a gas consists of (i) a body member defining a passage through which a continuous stream of the gas passes; (ii) an ionising source associated with a region of the passage such that ionization of the gas stream takes place substantially only within the region and also any polar vapour molecules present therein will react with the gas formed to generate ion clusters; and (iii) an electrode for collecting ions carried by the gas stream, the electrode being positioned in the passage downstream of the region and separated from the region by a sufficient distance to ensure that no substantial number of the gas ions formed in said region remains in the gas stream at the collector electrode whilst ensuring that a substantial proportion of the ion clusters formed in the region does remain in the gas stream at the collector electrode. (author)

Optical properties of polarization-dependent geometrical phase elements with partially polarized light

International Nuclear Information System (INIS)

Gorodetski, Y.; Biener, G.; Niv, A.; Kleiner, V.; Hasman, E.

2005-01-01

Full Text:The behavior of geometrical phase elements illuminated with partially polarized monochromatic beams is being theoretically as well as experimentally investigated. The element discussed in this paper is composed of wave plates with retardation and space-variant orientation angle. We found that a beam emerging from such an element comprises two polarization orders of right and left-handed circularly polarized states with conjugate geometrical phase modification. This phase equals twice the orientation angle of the space-variant wave plate comprising the element. Apart from the two polarization orders, the emerging beam coherence polarization matrix comprises a matrix termed as the vectorial interference matrix. This matrix contains the information concerning the correlation between the two orthogonal circularly polarized portions of the incident beam. In this paper we measure this correlation by a simple interference experiment. Furthermore, we found that the equivalent mutual intensity of the emerging beam is being modulated according to the geometrical phase induced by the element. Other interesting phenomena along propagation will be discussed theoretically and experimentally demonstrated. We demonstrate experimentally our analysis by using a spherical geometrical phase element, which is realized by use of space-variant sub wavelength grating and illuminated with a CO 2 laser radiation of 10.6μm wavelength

Cdc42 is crucial for the establishment of epithelial polarity during early mammalian development

DEFF Research Database (Denmark)

Wu, Xunwei; Li, Shaohua; Chrostek-Grashoff, Anna

2007-01-01

To study the role of Cdc42 in the establishment of epithelial polarity during mammalian development, we generated murine Cdc42-null embryonic stem cells and analyzed peri-implantation development using embryoid bodies (EBs). Mutant EBs developed endoderm and underlying basement membrane, but exhi......To study the role of Cdc42 in the establishment of epithelial polarity during mammalian development, we generated murine Cdc42-null embryonic stem cells and analyzed peri-implantation development using embryoid bodies (EBs). Mutant EBs developed endoderm and underlying basement membrane...

A novel polarization demodulation method using polarization beam splitter (PBS) for dynamic pressure sensor

Science.gov (United States)

Su, Yang; Zhou, Hua; Wang, Yiming; Shen, Huiping

2018-03-01

In this paper we propose a new design to demodulate polarization properties induced by pressure using a PBS (polarization beam splitter), which is different with traditional polarimeter based on the 4-detector polarization measurement approach. The theoretical model is established by Muller matrix method. Experimental results confirm the validity of our analysis. Proportional relationships and linear fit are found between output signal and applied pressure. A maximum sensitivity of 0.092182 mv/mv is experimentally achieved and the frequency response exhibits a <0.14 dB variation across the measurement bandwidth. The sensitivity dependence on incident SOP (state of polarization) is investigated. The simple and all-fiber configuration, low-cost and high speed potential make it promising for fiber-based dynamic pressure sensing.

Classification of M1/M2-polarized human macrophages by label-free hyperspectral reflectance confocal microscopy and multivariate analysis.

Science.gov (United States)

Bertani, Francesca R; Mozetic, Pamela; Fioramonti, Marco; Iuliani, Michele; Ribelli, Giulia; Pantano, Francesco; Santini, Daniele; Tonini, Giuseppe; Trombetta, Marcella; Businaro, Luca; Selci, Stefano; Rainer, Alberto

2017-08-21

The possibility of detecting and classifying living cells in a label-free and non-invasive manner holds significant theranostic potential. In this work, Hyperspectral Imaging (HSI) has been successfully applied to the analysis of macrophagic polarization, given its central role in several pathological settings, including the regulation of tumour microenvironment. Human monocyte derived macrophages have been investigated using hyperspectral reflectance confocal microscopy, and hyperspectral datasets have been analysed in terms of M1 vs. M2 polarization by Principal Components Analysis (PCA). Following PCA, Linear Discriminant Analysis has been implemented for semi-automatic classification of macrophagic polarization from HSI data. Our results confirm the possibility to perform single-cell-level in vitro classification of M1 vs. M2 macrophages in a non-invasive and label-free manner with a high accuracy (above 98% for cells deriving from the same donor), supporting the idea of applying the technique to the study of complex interacting cellular systems, such in the case of tumour-immunity in vitro models.

Principal State Analysis for a Compact in-Line Fiber Polarization Controller

International Nuclear Information System (INIS)

Li Zheng-Yong; Wu Chong-Qing; Wang Zhi-Hao; Qin Tao; Wang Yi-Xu

2013-01-01

A compact in-line fiber-based polarization controller (FPC) made of a rotatable fiber squeezer is investigated in detail with the Mueller matrix model established based on the generalized principal state of polarization (PSP). The PSP caused by the fiber squeezing is in the equator plane, which turns around S 3 axis on the Poincaré sphere when rotating the squeezer. Subsequently, a programmable polarization control method is proposed to realize the polarization conversion between arbitrary polarization states, in which only two parameters of phase shift and rotation angle need to be controlled. This type of FPC, which has a highly compact structure, lower insertion loss, and can be directly embedded into any fiber devices without any extra delay, will be an ideal PC for high-speed optical communication and all-optical signal processing

Electromagnetic Fields at the Surface of Human-Body Cylinders

DEFF Research Database (Denmark)

Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren H.; Thaysen, Jesper

2016-01-01

transverse electric and transverse magnetic polarization. The results show that the material assumption when modeling the human body as a homogeneous material is very important. Furthermore, it is shown that one assumption might lead to higher fields for a specific polarization, angle of incidence...

Spin-polarized hydrogen, deuterium, and tritium : I

International Nuclear Information System (INIS)

Haugen, M.; Ostgaard, E.

1989-01-01

The ground-state energy of spin-polarized hydrogen, deuterium and tritium is calculated by means of a modified variational lowest order constrained-variation method, and the calculations are done for five different two-body potentials. Spin-polarized H is not self-bound according to our theoretical results for the ground-state binding energy. For spin-polarized D, however, we obtain theoretical results for the ground-state binding energy per particle from -0.4 K at an equilibrium particle density of 0.25 σ -3 or a molar volume of 121 cm 3 /mol to +0.32 K at an equilibrium particle density of 0.21 σ -3 or a molar volume of 142 cm 3 /mol, where σ = 3.69 A (1A = 10 -10 m). It is, therefore, not clear whether spin-polarized deuterium should be self-bound or not. For spin-polarized T, we obtain theoretical results for the ground-state binding energy per particle from -4.73 K at an equilibrium particle density of 0.41 σ -3 or a molar volume of 74 cm 3 /mol to -1.21 K at an equilibrium particle density of 0.28 σ -3 or a molar volume of 109 cm 3 /mol. (Author) 27 refs., 9 figs., tab

Analysis of the local worst-case SAR exposure caused by an MRI multi-transmit body coil in anatomical models of the human body

Energy Technology Data Exchange (ETDEWEB)

Neufeld, Esra; Gosselin, Marie-Christine; Murbach, Manuel; Christ, Andreas; Cabot, Eugenia; Kuster, Niels, E-mail: neufeld@itis.ethz.ch [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr. 43, 8004 Zuerich (Switzerland)

2011-08-07

Multi-transmit coils are increasingly being employed in high-field magnetic resonance imaging, along with a growing interest in multi-transmit body coils. However, they can lead to an increase in whole-body and local specific absorption rate (SAR) compared to conventional body coils excited in circular polarization for the same total incident input power. In this study, the maximum increase of SAR for three significantly different human anatomies is investigated for a large 3 T (128 MHz) multi-transmit body coil using numerical simulations and a (generalized) eigenvalue-based approach. The results demonstrate that the increase of SAR strongly depends on the anatomy. For the three models and normalization to the sum of the rung currents squared, the whole-body averaged SAR increases by up to a factor of 1.6 compared to conventional excitation and the peak spatial SAR (averaged over any 10 cm{sup 3} of tissue) by up to 13.4. For some locations the local averaged SAR goes up as much as 800 times (130 when looking only at regions where it is above 1% of the peak spatial SAR). The ratio of the peak spatial SAR to the whole-body SAR increases by a factor of up to 47 and can reach values above 800. Due to the potentially much larger power deposition, additional, preferably patient-specific, considerations are necessary to avoid injuries by such systems.

Salting out the polar polymorph: analysis by alchemical solvent transformation.

Science.gov (United States)

Duff, Nathan; Dahal, Yuba Raj; Schmit, Jeremy D; Peters, Baron

2014-01-07

We computationally examine how adding NaCl to an aqueous solution with α- and γ-glycine nuclei alters the structure and interfacial energy of the nuclei. The polar γ-glycine nucleus in pure aqueous solution develops a melted layer of amorphous glycine around the nucleus. When NaCl is added, a double layer is formed that stabilizes the polar glycine polymorph and eliminates the surface melted layer. In contrast, the non-polar α-glycine nucleus is largely unaffected by the addition of NaCl. To quantify the stabilizing effect of NaCl on γ-glycine nuclei, we alchemically transform the aqueous glycine solution into a brine solution of glycine. The alchemical transformation is performed both with and without a nucleus in solution and for nuclei of α-glycine and γ-glycine polymorphs. The calculations show that adding 80 mg/ml NaCl reduces the interfacial free energy of a γ-glycine nucleus by 7.7 mJ/m(2) and increases the interfacial free energy of an α-glycine nucleus by 3.1 mJ/m(2). Both results are consistent with experimental reports on nucleation rates which suggest: J(α, brine) transformation approach can predict the results for both polar and non-polar polymorphs. The results suggest a general "salting out" strategy for obtaining polar polymorphs and also a general approach to computationally estimate the effects of solvent additives on interfacial free energies for nucleation.

Polar bears at risk

Energy Technology Data Exchange (ETDEWEB)

Norris, S.; Rosentrater, L.; Eid, P.M. [WWF International Arctic Programme, Oslo (Norway)

2002-05-01

Polar bears, the world's largest terrestrial carnivore, spend much of their lives on the arctic sea ice. This is where they hunt and move between feeding, denning, and resting areas. The world population, estimated at 22,000 bears, is made up of 20 relatively distinct populations varying in size from a few hundred to a few thousand animals. About 60 per cent of all polar bears are found in Canada. In general, the status of this species is stable, although there are pronounced differences between populations. Reductions in the extent and thickness of sea ice has lead the IUCN Polar Bear Specialist Group to describe climate change as one of the major threats facing polar bears today. Though the long-term effects of climate change will vary in different areas of the Arctic, impacts on the condition and reproductive success of polar bears and their prey are likely to be negative. Longer ice-free periods resulting from earlier break-up of sea ice in the spring and later formation in the fall is already impacting polar bears in the southern portions of their range. In Canada's Hudson Bay, for example, bears hunt on the ice through the winter and into early summer, after which the ice melts completely, forcing bears ashore to fast on stored fat until freeze-up in the fall. The time bears have on the ice to hunt and build up their body condition is cut short when the ice melts early. Studies from Hudson Bay show that for every week earlier that ice break-up occurs, bears will come ashore 10 kg lighter and in poorer condition. It is likely that populations of polar bears dividing their time between land and sea will be severely reduced and local extinctions may occur as greenhouse gas emissions continue to rise and sea ice melts. Expected changes in regional weather patterns will also impact polar bears. Rain in the late winter can cause maternity dens to collapse before females and cubs have departed, thus exposing occupants to the elements and to predators. Such

How the embryo makes a limb: determination, polarity and identity.

Science.gov (United States)

Tickle, Cheryll

2015-10-01

The vertebrate limb with its complex anatomy develops from a small bud of undifferentiated mesoderm cells encased in ectoderm. The bud has its own intrinsic polarity and can develop autonomously into a limb without reference to the rest of the embryo. In this review, recent advances are integrated with classical embryology, carried out mainly in chick embryos, to present an overview of how the embryo makes a limb bud. We will focus on how mesoderm cells in precise locations in the embryo become determined to form a limb and express the key transcription factors Tbx4 (leg/hindlimb) or Tbx5 (wing/forelimb). These Tbx transcription factors have equivalent functions in the control of bud formation by initiating a signalling cascade involving Wnts and fibroblast growth factors (FGFs) and by regulating recruitment of mesenchymal cells from the coelomic epithelium into the bud. The mesoderm that will form limb buds and the polarity of the buds is determined with respect to both antero-posterior and dorso-ventral axes of the body. The position in which a bud develops along the antero-posterior axis of the body will also determine its identity - wing/forelimb or leg/hindlimb. Hox gene activity, under the influence of retinoic acid signalling, is directly linked with the initiation of Tbx5 gene expression in the region along the antero-posterior axis of the body that will form wings/forelimbs and determines antero-posterior polarity of the buds. In contrast, Tbx4 expression in the regions that will form legs/hindlimbs is regulated by the homeoprotein Pitx1 and there is no evidence that Hox genes determine antero-posterior polarity of the buds. Bone morphogenetic protein (BMP) signalling determines the region along the dorso-ventral axis of the body in which both wings/forelimbs and legs/hindlimbs develop and dorso-ventral polarity of the buds. The polarity of the buds leads to the establishment of signalling regions - the dorsal and ventral ectoderm, producing Wnts and BMPs

Polarization Effects in Attosecond Photoelectron Spectroscopy

DEFF Research Database (Denmark)

Baggesen, Jan Conrad; Madsen, Lars Bojer

2010-01-01

following the field instead. We show that polarization effects may lead to an apparent temporal shift that needs to be properly accounted for in the analysis. The effect may be isolated and studied by angle-resolved photoelectron spectroscopy from oriented polar molecules. We also show that polarization...... effects will lead to an apparent temporal shift of 50 as between photoelectrons from a 2p and 1s state in atomic hydrogen....

Continuous variable polarization entanglement, experiment and analysis

International Nuclear Information System (INIS)

Bowen, Warwick P; Treps, Nicolas; Schnabel, Roman; Ralph, Timothy C; Lam, Ping Koy

2003-01-01

We generate and characterize continuous variable polarization entanglement between two optical beams. We first produce quadrature entanglement, and by performing local operations we transform it into a polarization basis. We extend two entanglement criteria, the inseparability criteria proposed by Duan et al (2000 Phys. Rev. Lett. 84 2722) and the Einstein-Podolsky-Rosen (EPR) paradox criteria proposed by Reid and Drummond (1988 Phys. Rev. Lett. 60 2731), to Stokes operators; and use them to characterize the entanglement. Our results for the EPR paradox criteria are visualized in terms of uncertainty balls on the Poincare sphere. We demonstrate theoretically that using two quadrature entangled pairs it is possible to entangle three orthogonal Stokes operators between a pair of beams, although with a bound √3 times more stringent than for the quadrature entanglement

Continuous variable polarization entanglement, experiment and analysis

Energy Technology Data Exchange (ETDEWEB)

Bowen, Warwick P [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Treps, Nicolas [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Schnabel, Roman [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Ralph, Timothy C [Department of Physics, Centre for Quantum Computer Technology, University of Queensland, St Lucia, QLD 4072 (Australia); Lam, Ping Koy [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia)

2003-08-01

We generate and characterize continuous variable polarization entanglement between two optical beams. We first produce quadrature entanglement, and by performing local operations we transform it into a polarization basis. We extend two entanglement criteria, the inseparability criteria proposed by Duan et al (2000 Phys. Rev. Lett. 84 2722) and the Einstein-Podolsky-Rosen (EPR) paradox criteria proposed by Reid and Drummond (1988 Phys. Rev. Lett. 60 2731), to Stokes operators; and use them to characterize the entanglement. Our results for the EPR paradox criteria are visualized in terms of uncertainty balls on the Poincare sphere. We demonstrate theoretically that using two quadrature entangled pairs it is possible to entangle three orthogonal Stokes operators between a pair of beams, although with a bound {radical}3 times more stringent than for the quadrature entanglement.

Analysis of Resistive-Vee Dipole Antennas for Producing Polarization Diversity

Science.gov (United States)

2014-08-01

3 1.2 Existing Circular Polarization GPR Technologies . . . . . . . . . . . . . 4 1.2.1 Crossed-Dipole Antennas...8 1.3 Proposed Circular Polarization GPR System . . . . . . . . . . . . . . . . 10 1.4 Outline...reshaped RVD with the Kim resistive profile is marked by the square. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Figure 89

Comparative analysis of fecal microbiota and intestinal microbial metabolic activity in captive polar bears.

Science.gov (United States)

Schwab, Clarissa; Gänzle, Michael

2011-03-01

The composition of the intestinal microbiota depends on gut physiology and diet. Ursidae possess a simple gastrointestinal system composed of a stomach, small intestine, and indistinct hindgut. This study determined the composition and stability of fecal microbiota of 3 captive polar bears by group-specific quantitative PCR and PCR-DGGE (denaturing gradient gel electrophoresis) using the 16S rRNA gene as target. Intestinal metabolic activity was determined by analysis of short-chain fatty acids in feces. For comparison, other Carnivora and mammals were included in this study. Total bacterial abundance was approximately log 8.5 DNA gene copies·(g feces)-1 in all 3 polar bears. Fecal polar bear microbiota was dominated by the facultative anaerobes Enterobacteriaceae and enterococci, and the Clostridium cluster I. The detection of the Clostridium perfringens α-toxin gene verified the presence of C. perfringens. Composition of the fecal bacterial population was stable on a genus level; according to results obtained by PCR-DGGE, dominant bacterial species fluctuated. The total short-chain fatty acid content of Carnivora and other mammals analysed was comparable; lactate was detected in feces of all carnivora but present only in trace amounts in other mammals. In comparison, the fecal microbiota and metabolic activity of captive polar bears mostly resembled the closely related grizzly and black bears.

The Current State of Nanoparticle-Induced Macrophage Polarization and Reprogramming Research

Directory of Open Access Journals (Sweden)

Xiaoyuan Miao

2017-02-01

Full Text Available Macrophages are vital regulators of the host defense in organisms. In response to different local microenvironments, resting macrophages (M0 can be polarized into different phenotypes, pro-inflammatory (M1 or anti-inflammatory (M2, and perform different roles in different physiological or pathological conditions. Polarized macrophages can also be further reprogrammed by reversing their phenotype according to the changed milieu. Macrophage polarization and reprogramming play essential roles in maintaining the steady state of the immune system and are involved in the processes of many diseases. As foreign substances, nanoparticles (NPs mainly target macrophages after entering the body. NPs can perturb the polarization and reprogramming of macrophages, affect their immunological function and, therefore, affect the pathological process of disease. Optimally-designed NPs for the modulation of macrophage polarization and reprogramming might provide new solutions for treating diseases. Systematically investigating how NPs affect macrophage polarization is crucial for understanding the regulatory effects of NPs on immune cells in vivo. In this review, macrophage polarization by NPs is summarized and discussed.

Polarized neutron spectrometer for inelastic experiments at J-PARC

Directory of Open Access Journals (Sweden)

Yokoo Tetsuya

2015-01-01

Full Text Available Construction of the newly developed polarization analysis neutron chopper spectrometer (POLANO commenced in the Japan Proton Accelerator Research Complex (J-PARC, Materials and Life Science Experimental Facility (MLF. The POLANO is a direct geometry chopper spectrometer with neutron polarization analysis capability. In the suite of inelastic spectrometers, six instruments are now in operation. POLANO will be the only spectrometer dedicated to polarization analysis experiments. The primary phase of the construction will be completed by 2014 with beam commissioning scheduled for 2015.

Polarity analysis of GaN nanorods by photo-assisted Kelvin probe force microscopy

Energy Technology Data Exchange (ETDEWEB)

Wei, Jiandong; Neumann, Richard; Wang, Xue; Li, Shunfeng; Fuendling, Soenke; Merzsch, Stephan; Al-Suleiman, Mohamed A.M.; Soekmen, Uensal; Wehmann, Hergo-H.; Waag, Andreas [Institut fuer Halbleitertechnik, TU Braunschweig (Germany)

2011-07-15

Polarity dependence (N-polar (000-1) and Ga-polar (0001)) of surface photovoltage of epitaxially grown, vertically aligned GaN nanorods has been investigated by photo-assisted Kelvin probe force microscopy (KPFM). Commercial GaN substrates with known polarities are taken as reference samples. The polarity of GaN substrates can be well distinguished by the change in surface photovoltage upon UV illumination in air ambient. These different behaviors of Ga- and N-polar surfaces are attributed to the polarity-related surface-bound charges and photochemical reactivity. GaN nanorods were grown on patterned SiO{sub 2}/sapphire templates by metal-organic vapor phase epitaxy (MOVPE). In order to analyze the bottom surface of the grown GaN nanorods, a technique known from high power electronics and joining techniques is applied to remove the substrate. The top and bottom surfaces of the GaN nanorods are identified to be N-polar and Ga-polar according to the KPFM results, respectively. Our experiments demonstrate that KPFM is a simple and suitable method capable to identify the polarity of GaN nanorods. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

ImaEdge - a platform for quantitative analysis of the spatiotemporal dynamics of cortical proteins during cell polarization.

Science.gov (United States)

Zhang, Zhen; Lim, Yen Wei; Zhao, Peng; Kanchanawong, Pakorn; Motegi, Fumio

2017-12-15

Cell polarity involves the compartmentalization of the cell cortex. The establishment of cortical compartments arises from the spatial bias in the activity and concentration of cortical proteins. The mechanistic dissection of cell polarity requires the accurate detection of dynamic changes in cortical proteins, but the fluctuations of cell shape and the inhomogeneous distributions of cortical proteins greatly complicate the quantitative extraction of their global and local changes during cell polarization. To address these problems, we introduce an open-source software package, ImaEdge, which automates the segmentation of the cortex from time-lapse movies, and enables quantitative extraction of cortical protein intensities. We demonstrate that ImaEdge enables efficient and rigorous analysis of the dynamic evolution of cortical PAR proteins during Caenorhabditis elegans embryogenesis. It is also capable of accurate tracking of varying levels of transgene expression and discontinuous signals of the actomyosin cytoskeleton during multiple rounds of cell division. ImaEdge provides a unique resource for quantitative studies of cortical polarization, with the potential for application to many types of polarized cells.This article has an associated First Person interview with the first authors of the paper. © 2017. Published by The Company of Biologists Ltd.

A technique for measurement of vector and tensor polarization in solid spin one polarized targets

International Nuclear Information System (INIS)

Kielhorn, W.F.

1991-06-01

Vector and tensor polarizations are explicitly defined and used to characterize the polarization states of spin one polarized targets, and a technique for extracting these polarizations from nuclear magnetic resonance (NMR) data is developed. This technique is independent of assumptions about spin temperature, but assumes the target's crystal structure induces a quadrupole interaction with the spin one particles. Analysis of the NMR signals involves a computer curve fitting algorithm implemented with a fast Fourier transform method which speeds and simplifies curve fitting algorithms used previously. For accurate curve fitting, the NMR electronic circuit must be modeled by the fitting algorithm. Details of a circuit, its model, and data collected from this circuit are given for a solid deuterated ammonia target. 37 refs., 19 figs., 3 tabs

Decision-Making by Handball Referees: Design of an ad hoc Observation Instrument and Polar Coordinate Analysis.

Science.gov (United States)

Morillo, Juan P; Reigal, Rafael E; Hernández-Mendo, Antonio; Montaña, Alejandro; Morales-Sánchez, Verónica

2017-01-01

Referees are essential for sports such as handball. However, there are few tools available to analyze the activity of handball referees. The aim of this study was to design an instrument for observing the behavior of referees in handball competitions and to analyze the resulting data by polar coordinate analysis. The instrument contained 6 criteria and 18 categories and can be used to monitor and describe the actions of handball referees according to their role/position on the playing court. For the data quality control analysis, we calculated Pearson's (0.99), Spearman's (0.99), and Tau Kendall's (1.00) correlation coefficients and Cohen's kappa (entre 0.72 y 0.75) and Phi (entre 0.83 y 0.87) coefficients. In the generalizability analysis, the absolute and relative generalizability coefficients were 0.99 in both cases. Polar coordinate analysis of referee decisions showed that correct calls were more common for central court and 7-meter throw calls. Likewise, calls were more likely to be incorrect (in terms of both errors of omission and commission) when taken from the goal-line position.

Decision-Making by Handball Referees: Design of an ad hoc Observation Instrument and Polar Coordinate Analysis

Directory of Open Access Journals (Sweden)

Juan P. Morillo

2017-10-01

Full Text Available Referees are essential for sports such as handball. However, there are few tools available to analyze the activity of handball referees. The aim of this study was to design an instrument for observing the behavior of referees in handball competitions and to analyze the resulting data by polar coordinate analysis. The instrument contained 6 criteria and 18 categories and can be used to monitor and describe the actions of handball referees according to their role/position on the playing court. For the data quality control analysis, we calculated Pearson's (0.99, Spearman's (0.99, and Tau Kendall's (1.00 correlation coefficients and Cohen's kappa (entre 0.72 y 0.75 and Phi (entre 0.83 y 0.87 coefficients. In the generalizability analysis, the absolute and relative generalizability coefficients were 0.99 in both cases. Polar coordinate analysis of referee decisions showed that correct calls were more common for central court and 7-meter throw calls. Likewise, calls were more likely to be incorrect (in terms of both errors of omission and commission when taken from the goal-line position.

Turbulence in extended synchrotron radio sources. I. Polarization of turbulent sources. II. Power-spectral analysis

International Nuclear Information System (INIS)

Eilek, J.A.

1989-01-01

Recent theories of magnetohydrodynamic turbulence are used to construct microphysical turbulence models, with emphasis on models of anisotropic turbulence. These models have been applied to the determination of the emergent polarization from a resolved uniform source. It is found that depolarization alone is not a unique measure of the turbulence, and that the turblence will also affect the total-intensity distributions. Fluctuations in the intensity image can thus be employed to measure turbulence strength. In the second part, it is demonstrated that a power-spectral analysis of the total and polarized intensity images can be used to obtain the power spectra of the synchrotron emission. 81 refs

Detection of ULF electromagnetic emissions as a precursor to an earthquake in China with an improved polarization analysis

Directory of Open Access Journals (Sweden)

Y. Ida

2008-07-01

Full Text Available An improved analysis of polarization (as the ratio of vertical magnetic field component to the horizontal one has been developed, and applied to the approximately four years data (from 1 March 2003 to 31 December 2006 observed at Kashi station in China. It is concluded that the polarization ratio has exhibited an apparent increase only just before the earthquake on 1 September 2003 (magnitude = 6.1 and epicentral distance of 116 km.

Polarization of lanthanum nucleus by dynamic polarization method

International Nuclear Information System (INIS)

Adachi, Toshikazu; Ishimoto, Shigeru; Masuda, Yasuhiro; Morimoto, Kimio

1989-01-01

Preliminary studies have been carried out concerning the application of a dynamic polarization method to polarizing lanthanum fluoride single crystal to be employed as target in experiments with time reversal invariance. The present report briefly outlines the dynamic polarization method and describes some preliminary studies carried out so far. Dynamic polarization is of particular importance because no techniques are currently available that can produce highly polarized static nucleus. Spin interaction between electrons and protons (nuclei) plays a major role in the dynamic polarization method. In a thermal equilibrium state, electrons are polarized almost completely while most protons are not polarized. Positively polarized proton spin is produced by applying microwave to this system. The most hopeful candidate target material is single crystal of LaF 3 containing neodymium because the crystal is chemically stable and easy to handle. The spin direction is of great importance in experiments with time reversal invariance. The spin of neutrons in the target can be cancelled by adjusting the external magnetic field applied to a frozen polarized target. In a frozen spin state, the polarity decreases slowly with a relaxation time that depends on the external magnetic field and temperature. (N.K.)

A technique for measurement of vector and tensor polarization in solid spin one polarized targets

Energy Technology Data Exchange (ETDEWEB)

Kielhorn, W.F.

1991-06-01

Vector and tensor polarizations are explicitly defined and used to characterize the polarization states of spin one polarized targets, and a technique for extracting these polarizations from nuclear magnetic resonance (NMR) data is developed. This technique is independent of assumptions about spin temperature, but assumes the target's crystal structure induces a quadrupole interaction with the spin one particles. Analysis of the NMR signals involves a computer curve fitting algorithm implemented with a fast Fourier transform method which speeds and simplifies curve fitting algorithms used previously. For accurate curve fitting, the NMR electronic circuit must be modeled by the fitting algorithm. Details of a circuit, its model, and data collected from this circuit are given for a solid deuterated ammonia target. 37 refs., 19 figs., 3 tabs.

Production of positive pions from polarized protons by linearly polarized photons in the energy region 300--420 MeV

Energy Technology Data Exchange (ETDEWEB)

Get' man, V.A.; Gorbenko, V.G.; Grushin, V.F.; Derkach, A.Y.; Zhebrovskii, Y.V.; Karnaukhov, I.M.; Kolesnikov, L.Y.; Luchanin, A.A.; Rubashkin, A.L.; Sanin, V.M.; Sorokin, P.V.; Sporov, E.A.; Telegin, Y.N.; Shalatskii, S.V.

1980-10-01

A technique for measurement of the polarization observables ..sigma.., P, and T for the reaction ..gamma..p..-->..n..pi../sup +/ in a doubly polarized experiment (polarized proton target + linearly polarized photon beam) is described. Measurements of the angular distributions of these observables in the range of pion emission angles 30--150/sup 0/ are presented for four photon energies from 300 to 420 MeV. Inclusion of the new experimental data in an energy-independent multipole analysis of photoproduction from protons permits a more reliable selection of solutions to be made.

PolarBRDF: A general purpose Python package for visualization and quantitative analysis of multi-angular remote sensing measurements

Science.gov (United States)

Poudyal, R.; Singh, M.; Gautam, R.; Gatebe, C. K.

2016-12-01

The Bidirectional Reflectance Distribution Function (BRDF) is a fundamental concept for characterizing the reflectance property of a surface, and helps in the analysis of remote sensing data from satellite, airborne and surface platforms. Multi-angular remote sensing measurements are required for the development and evaluation of BRDF models for improved characterization of surface properties. However, multi-angular data and the associated BRDF models are typically multidimensional involving multi-angular and multi-wavelength information. Effective visualization of such complex multidimensional measurements for different wavelength combinations is presently somewhat lacking in the literature, and could serve as a potentially useful research and teaching tool in aiding both interpretation and analysis of BRDF measurements. This article describes a newly developed software package in Python (PolarBRDF) to help visualize and analyze multi-angular data in polar and False Color Composite (FCC) forms. PolarBRDF also includes functionalities for computing important multi-angular reflectance/albedo parameters including spectral albedo, principal plane reflectance and spectral reflectance slope. Application of PolarBRDF is demonstrated using various case studies obtained from airborne multi-angular remote sensing measurements using NASA's Cloud Absorption Radiometer (CAR)- http://car.gsfc.nasa.gov/. Our visualization program also provides functionalities for untangling complex surface/atmosphere features embedded in pixel-based remote sensing measurements, such as the FCC imagery generation of BRDF measurements of grasslands in the presence of wildfire smoke and clouds. Furthermore, PolarBRDF also provides quantitative information of the angular distribution of scattered surface/atmosphere radiation, in the form of relevant BRDF variables such as sunglint, hotspot and scattering statistics.

Recent on-beam tests of wide angle neutron polarization analysis with a 3He spin filter: Magic PASTIS on V20 at HZB

Science.gov (United States)

Babcock, E.; Salhi, Z.; Gainov, R.; Woracek, R.; Soltner, H.; Pistel, P.; Beule, F.; Bussmann, K.; Heynen, A.; Kämmerling, H.; Suxdorf, F.; Strobl, M.; Russina, M.; Voigt, J.; Ioffe, A.

2017-06-01

A complete XYZ polarization analysis solution is under development for the new thermal time of flight spectrometer TOPAS [1], to be operated in the coming east neutron guide hall at the MLZ. Polarization Analysis Studies on a Thermal Inelastic Spectrometer, commonly called PASTIS [2], is based on polarized 3He neutron spin filters and an XYZ field configuration for the sample environment and a polarization-preserving neutron guide field. The complete system was designed to provide adiabatic transport of the neutron polarization to the sample position while maintaining the homogeneity of the XYZ field. This system has now been tested on the polarized time-of-flight ESS test beam line V20 at HZB [3]. Down to the minimum wavelength of 1.6 Å on the instrument, the magnetic configuration worked ideally for neutron spin transport while giving full experimental freedom to change between the X, Y or Z field configuration. The 3He cell used was polarized at the 3He lab of the JCNS at the MLZ in Garching and transported to HZB in Berlin via car showing that such a transport is indeed feasible for such experiments. We present results of this test and the next steps forward.

Mathematical and numerical analysis of systems of compressible hydrodynamics and photonics with polar coordinates

International Nuclear Information System (INIS)

Meltz, Bertrand

2015-01-01

This thesis deals with the mathematical and numerical analysis of the systems of compressible hydrodynamics and radiative transfer. More precisely, we study the derivation of numerical methods with 2D polar coordinates (one for the radius, one for the angle) where equations are discretized on regular polar grids. On one hand, these methods are well-suited for the simulation of flows with polar symmetries since they preserve these symmetries by construction. On the other hand, such coordinates systems introduce geometrical singularities as well as geometrical source terms which must be carefully treated. The first part of this document is devoted to the study of hydrodynamics equations, or Euler equations. We propose a new class of arbitrary high-order numerical schemes in both space and time and rely on directional splitting methods for the resolution of 2D equations. Each sub-system is solved using a Lagrange+Remap solver. We study the influence of the r=0 geometrical singularities of the cylindrical and spherical coordinates systems on the precision of the 2D numerical solutions. The second part of this document is devoted to the study of radiative transfer equations. In these equations, the unknowns depend on a large number of variables and a stiff source term is involved. The main difficulty consists in capturing the correct asymptotic behavior on coarse grids. We first construct a class of models where the radiative intensity is projected on a truncated spherical harmonics basis in order to lower the number of mathematical dimensions. Then we propose an Asymptotic Preserving scheme built in polar coordinates and we show that the scheme capture the correct diffusion limit in the radial direction as well as in the polar direction. (author) [fr

SDP_mharwit_1: Demonstration of HIFI Linear Polarization Analysis of Spectral Features

Science.gov (United States)

Harwit, M.

2010-03-01

We propose to observe the polarization of the 621 GHz water vapor maser in VY Canis Majoris to demonstrate the capability of HIFI to make polarization observations of Far-Infrared/Submillimeter spectral lines. The proposed Demonstration Phase would: - Show that HIFI is capable of interesting linear polarization measurements of spectral lines; - Test out the highest spectral resolving power to sort out closely spaced Doppler components; - Determine whether the relative intensities predicted by Neufeld and Melnick are correct; - Record the degree and direction of linear polarization for the closely-Doppler shifted peaks.

Full Polarization Analysis of Resonant Superlattice and Forbidden x-ray Reflections in Magnetite

International Nuclear Information System (INIS)

Wilkins, S.B.; Bland, S.R.; Detlefs, B.; Beale, T.A.W.; Mazzoli, C.; Joly, Y.; Hatton, P.D.; Lorenzo, J.E.; Brabers, V.A.M.

2009-01-01

Despite being one of the oldest known magnetic materials, and the classic mixed valence compound, thought to be charge ordered, the structure of magnetite below the Verwey transition is complex and the presence and role of charge order is still being debated. Here, we present resonant x-ray diffraction data at the iron K-edge on forbidden (0, 0, 2n+1) C and superlattice (0, 0, 2n+1/2)C reflections. Full linear polarization analysis of the incident and scattered light was conducted in order to explore the origins of the reflections. Through simulation of the resonant spectra we have confirmed that a degree of charge ordering takes place, while the anisotropic tensor of susceptibility scattering is responsible for the superlattice reflections below the Verwey transition. We also report the surprising result of the conversion of a significant proportion of the scattered light from linear to nonlinear polarization.

6-C polarization analysis using point measurements of translational and rotational ground-motion: theory and applications

Science.gov (United States)

Sollberger, David; Greenhalgh, Stewart A.; Schmelzbach, Cedric; Van Renterghem, Cédéric; Robertsson, Johan O. A.

2018-04-01

We provide a six-component (6-C) polarization model for P-, SV-, SH-, Rayleigh-, and Love-waves both inside an elastic medium as well as at the free surface. It is shown that single-station 6-C data comprised of three components of rotational motion and three components of translational motion provide the opportunity to unambiguously identify the wave type, propagation direction, and local P- and S-wave velocities at the receiver location by use of polarization analysis. To extract such information by conventional processing of three-component (3-C) translational data would require large and dense receiver arrays. The additional rotational components allow the extension of the rank of the coherency matrix used for polarization analysis. This enables us to accurately determine the wave type and wave parameters (propagation direction and velocity) of seismic phases, even if more than one wave is present in the analysis time window. This is not possible with standard, pure-translational 3-C recordings. In order to identify modes of vibration and to extract the accompanying wave parameters, we adapt the multiple signal classification algorithm (MUSIC). Due to the strong nonlinearity of the MUSIC estimator function, it can be used to detect the presence of specific wave types within the analysis time window at very high resolution. We show how the extracted wavefield properties can be used, in a fully automated way, to separate the wavefield into its different wave modes using only a single 6-C recording station. As an example, we apply the method to remove surface wave energy while preserving the underlying reflection signal and to suppress energy originating from undesired directions, such as side-scattered waves.

Lyapunov vs. geometrical stability analysis of the Kepler and the restricted three body problems

International Nuclear Information System (INIS)

Yahalom, A.; Levitan, J.; Lewkowicz, M.; Horwitz, L.

2011-01-01

In this Letter we show that although the application of standard Lyapunov analysis predicts that completely integrable Kepler motion is unstable, the geometrical analysis of Horwitz et al. predicts the observed stability. This seems to us to provide evidence for both the incompleteness of the standard Lyapunov analysis and the strength of the geometrical analysis. Moreover, we apply this approach to the three body problem in which the third body is restricted to move on a circle of large radius which induces an adiabatic time dependent potential on the second body. This causes the second body to move in a very interesting and intricate but periodic trajectory; however, the standard Lyapunov analysis, as well as methods based on the parametric variation of curvature associated with the Jacobi metric, incorrectly predict chaotic behavior. The geometric approach predicts the correct stable motion in this case as well. - Highlights: → Lyapunov analysis predicts Kepler motion to be unstable. → Geometrical analysis predicts the observed stability. → Lyapunov analysis predicts chaotic behavior in restricted three body problem. → The geometric approach predicts the correct stable motion in restricted three body problem.

Body Movement Music Score – Introduction of a newly developed model for the analysis and description of body qualities, movement and music in music therapy

Directory of Open Access Journals (Sweden)

Hanna Agnieszka Skrzypek

2017-01-01

Full Text Available Background In music therapy, there is a range of music therapy concepts that, in addition to music, describe and analyse the body and movement. A model that equally examines the body, movement and music has not been developed. The Body Movement Music Score (BMMS is a newly developed and evaluated music therapy model for analysing body qualities, movement, playing style of musical instruments and music and to describe body behaviour and body expression, movement behaviour and movement expression, playing behaviour and musical expression in music therapy treatment. The basis for the development of the Body Movement Music Score was the evaluation of the analytical movement model Emotorics-Emotive Body Movement Mind Paradigm (Emotorics-EBMMP by Yona Shahar Levy for the analysis and description of the emotive-motor behaviour and movement expression of schizophrenic patients in music therapy treatment. Participants and procedure The application of the Body Movement Music Score is presented in a videotaped example from the music therapy treatment of one schizophrenic patient. Results The results of applying the Body Movement Music Score are presented in the form of Body Qualities I Analysis, Body Qualities II Analysis, Movement Analysis, Playing Style Analysis and Music Analysis Profiles. Conclusions The Body Movement Music Score has been developed and evaluated for the music therapy treatment of schizophrenic patients. For the development of the model, a proof of reliability is necessary to verify the reliability and limitations of the model in practice and show that the Body Movement Music Score could be used for both practical and clinical work, for documentation purposes and to impact research in music therapy.

Theory and analysis of a large field polarization imaging system with obliquely incident light.

Science.gov (United States)

Lu, Xiaotian; Jin, Weiqi; Li, Li; Wang, Xia; Qiu, Su; Liu, Jing

2018-02-05

Polarization imaging technology provides information about not only the irradiance of a target but also the polarization degree and angle of polarization, which indicates extensive application potential. However, polarization imaging theory is based on paraxial optics. When a beam of obliquely incident light passes an analyser, the direction of light propagation is not perpendicular to the surface of the analyser and the applicability of the traditional paraxial optical polarization imaging theory is challenged. This paper investigates a theoretical model of a polarization imaging system with obliquely incident light and establishes a polarization imaging transmission model with a large field of obliquely incident light. In an imaging experiment with an integrating sphere light source and rotatable polarizer, the polarization imaging transmission model is verified and analysed for two cases of natural light and linearly polarized light incidence. Although the results indicate that the theoretical model is consistent with the experimental results, the theoretical model distinctly differs from the traditional paraxial approximation model. The results prove the accuracy and necessity of the theoretical model and the theoretical guiding significance for theoretical and systematic research of large field polarization imaging.

Analysis of selenium in body fluids: A review

International Nuclear Information System (INIS)

Alaejos, M.S.; Romero, C.D.

1995-01-01

This article reviews numerous analytical techniques for determining trace amounts of selenium in body fluids. In addition, sampling storage and treatment procedures are evaluated. The analytical techniques reviewed include the following: spectrofluorometry and spectrophotometry; atomic absorption spectrometry; fluorescence and atomic emission spectroscopy; mass spectroscopy; X-ray spectrometric analysis; neutron activation analysis; chromatographic methods; and electrochemical methods. 469 refs

Multiband Circular Polarizer Based on Fission Transmission of Linearly Polarized Wave for X-Band Applications

Directory of Open Access Journals (Sweden)

Farman Ali Mangi

2016-01-01

Full Text Available A multiband circular polarizer based on fission transmission of linearly polarized wave for x-band application is proposed, which is constructed of 2 × 2 metallic strips array. The linear-to-circular polarization conversion is obtained by decomposing the linearly incident x-polarized wave into two orthogonal vector components of equal amplitude and 90° phase difference between them. The innovative approach of “fission transmission of linear-to-circular polarized wave” is firstly introduced to obtain giant circular dichroism based on decomposition of orthogonal vector components through the structure. It means that the incident linearly polarized wave is converted into two orthogonal components through lower printed metallic strips layer and two transmitted waves impinge on the upper printed strips layer to convert into four orthogonal vector components at the end of structure. This projection and transmission sequence of orthogonal components sustain the chain transmission of electromagnetic wave and can achieve giant circular dichroism. Theoretical analysis and microwave experiments are presented to validate the performance of the structure. The measured results are in good agreement with simulation results. In addition, the proposed circular polarizer exhibits the optimal performance with respect to the normal incidence. The right handed circularly polarized wave is emitted ranging from 10.08 GHz to 10.53 GHz and 10.78 GHz to 11.12 GHz, while the left handed circular polarized wave is excited at 10.54 GHz–10.70 GHz and 11.13 GHz–11.14 GHz, respectively.

Measurement of polarization observables in the reaction {gamma}p{yields} p{pi}{sup 0}{pi}{sup 0} using linearly polarized photons with the CBELSA/TAPS experiment

Energy Technology Data Exchange (ETDEWEB)

Sokhoyan, Vahe

2012-07-27

The spectrum and the properties of baryon resonances can be studied using photons with energies appropriate to excite baryonic states. Double meson photoproduction allows access to cascading resonance decays via other excited states. Also, at higher energies the importance of the double meson photoproduction increases due to higher cross-sections in comparison to single meson photoproduction. To study baryon resonances, the measurement of polarization observables as well as the measurement of differential cross-sections plays a very important role. In this work the three-body polarization observables I{sup s}, I{sup c} and the respective twobody asymmetry {Sigma} were measured for the reaction {gamma}p {yields} p{pi}{sup 0}{pi}{sup 0} in an incoming photon energy range of E{sub {gamma}} = 970 - 1650 MeV. The data were acquired with the CBELSA/TAPS experiment located at the ELSA accelerator in Bonn, using a linearly polarized photon beam impinging on a liquid hydrogen target. The observables I{sup s} and I{sup c} which occur in two-meson final states are measured for the first time in the reaction {gamma}p {yields} p{pi}{sup 0}{pi}{sup 0}. The corresponding two-body asymmetry {Sigma} is measured in an extended energy range in comparison to already existing data. A comparison with theoretical models shows that the polarization observables provide valuable input to study resonance contributions and their decay modes. The D{sub 33}(1700) {yields} {Delta}{pi} decay is studied based on the comparison of the Bonn-Gatchina Partial Wave Analysis (PWA) predictions with the data. Furthermore, a comparison of the data with the Bonn-Gatchina PWA and the Fix isobar model predictions allows to distinguish between these two models. Additionally, band-like structures and peaks are observed in the mass ranges of {Delta}(1232), D{sub 13}(1520), F{sub 15}(1680), f{sub 0}(980) and f{sub 2}(1270) in the according Dalitz plots and invariant mass distributions. The contributions of these

Workshop on polarized neutron filters and polarized pulsed neutron experiments

International Nuclear Information System (INIS)

Itoh, Shinichi

2004-07-01

The workshop was held in KEK by thirty-three participants on April 26, 2004. The polarized neutron filter method was only discussed. It consists of three parts; the first part was discussed on the polarized neutron methods, the second part on the polarized neutron experiments and the third on the pulse neutron spectrometer and polarized neutron experiments. The six papers were presented such as the polarized 3 He neutron spin filter, neutron polarization by proton polarized filter, soft master and neutron scattering, polarized neutron in solid physics, polarization experiments by chopper spectroscope and neutron polarization system in superHRPD. (S.Y.)

NNLO QCD corrections to the polarized top quark decay t (↑)→Xb+W+

Science.gov (United States)

Czarnecki, A.; Groote, S.; Körner, J. G.; Piclum, J. H.

2018-05-01

We compute the next-to-next-to-leading order (NNLO) QCD corrections to the decay t (↑)→Xb+W+ of a polarized top quark. The spin-momentum correlation in this quasi two-body decay is described by the polar angle distribution d Γ /d cos θP=Γ/2 (1 +PtαPcos θP) , where Pt is the polarization of the top quark and αP denotes the asymmetry parameter of the decay. For the latter we find αPNNLO=0.3792 ±0.0037 .

Titan Polar Landscape Evolution

Science.gov (United States)

Moore, Jeffrey M.

2016-01-01

With the ongoing Cassini-era observations and studies of Titan it is clear that the intensity and distribution of surface processes (particularly fluvial erosion by methane and Aeolian transport) has changed through time. Currently however, alternate hypotheses substantially differ among specific scenarios with respect to the effects of atmospheric evolution, seasonal changes, and endogenic processes. We have studied the evolution of Titan's polar region through a combination of analysis of imaging, elevation data, and geomorphic mapping, spatially explicit simulations of landform evolution, and quantitative comparison of the simulated landscapes with corresponding Titan morphology. We have quantitatively evaluated alternate scenarios for the landform evolution of Titan's polar terrain. The investigations have been guided by recent geomorphic mapping and topographic characterization of the polar regions that are used to frame hypotheses of process interactions, which have been evaluated using simulation modeling. Topographic information about Titan's polar region is be based on SAR-Topography and altimetry archived on PDS, SAR-based stereo radar-grammetry, radar-sounding lake depth measurements, and superposition relationships between geomorphologic map units, which we will use to create a generalized topographic map.

Neutron polarization in polarized 3He targets

International Nuclear Information System (INIS)

Friar, J.L.; Gibson, B.F.; Payne, G.L.; Bernstein, A.M.; Chupp, T.E.

1990-01-01

Simple formulas for the neutron and proton polarizations in polarized 3 He targets are derived assuming (1) quasielastic final states; (2) no final-state interactions; (3) no meson-exchange currents; (4) large momentum transfers; (5) factorizability of 3 He SU(4) response-function components. Numerical results from a wide variety of bound-state solutions of the Faddeev equations are presented. It is found that this simple model predicts the polarization of neutrons in a fully polarized 3 He target to be 87%, while protons should have a slight residual polarization of -2.7%. Numerical studies show that this model works very well for quasielastic electron scattering

Relationships between POPs, biometrics and circulating steroids in male polar bears (Ursus maritimus) from Svalbard

DEFF Research Database (Denmark)

Ciesielski, Tomasz M; Hansen, Ingunn Tjelta; Bytingsvik, Jenny

2017-01-01

), progesterone (PRO), androstenedione (AN), dehydroepiandrosterone (DHEA), testosterone (TS), dihydrotestosterone (DHT), estrone (E1), 17α-estradiol (αE2) and 17β-estradiol (βE2) were quantified in polar bear serum by gas chromatography tandem mass spectrometry (GC-MS/MS), while POPs were measured in plasma....../estrogen ratios being approximately 60 times higher in adult males than in subadult males. PCA plots and OPLS models indicated that TS was positively related to biometrics, such as body condition index in male polar bears. A negative relationship was also observed between POPs and DHT. Consequently, POPs and body...

Molecular MRI based on hyper-polarized xenon

International Nuclear Information System (INIS)

Tassali, Nawal

2012-01-01

Magnetic Resonance Imaging (MRI) has a high importance in medicine as it enables the observation of the organs inside the body without the use of radiative or invasive techniques. However it is known to suffer from poor sensitivity. To circumvent this limitation, a key solution resides in the use of hyper-polarized species. Among the entities with which we can drastically increase nuclear polarization, xenon has very specific properties through its interactions with its close environment that lead to a wide chemical shift bandwidth. The goal is thus to use it as a tracer. This PhD thesis focuses on the concept of 129 Xe MRI-based sensors for the detection of biological events. In this approach, hyper-polarized xenon is vectorized to biological targets via functionalized host systems, and then localized thanks to fast dedicated MRI sequences. The conception and set-up of a spin-exchange optical pumping device is first described. Then studies about the interaction of the hyper-polarized noble gas with new cryptophanes susceptible to constitute powerful host molecules are detailed. Also the implementation of recent MRI sequences optimized for the transient character of the hyper-polarization and taking profit of the xenon in-out exchange is described. Applications of this approach for the detection of metallic ions and cellular receptors are studied. Finally, our first in vivo results on a small animal model are presented. (author) [fr

When measured spin polarization is not spin polarization

International Nuclear Information System (INIS)

Dowben, P A; Wu Ning; Binek, Christian

2011-01-01

Spin polarization is an unusually ambiguous scientific idiom and, as such, is rarely well defined. A given experimental methodology may allow one to quantify a spin polarization but only in its particular context. As one might expect, these ambiguities sometimes give rise to inappropriate interpretations when comparing the spin polarizations determined through different methods. The spin polarization of CrO 2 and Cr 2 O 3 illustrate some of the complications which hinders comparisons of spin polarization values. (viewpoint)

Polarized neutron scattering on HYSPEC: the HYbrid SPECtrometer at SNS

OpenAIRE

Zaliznyak, Igor A; Savici, Andrei T.; Garlea, V. Ovidiu; Winn, Barry; Filges, Uwe; Schneeloch, John; Tranquada, John M.; Gu, Genda; Wang, Aifeng; Petrovic, Cedomir

2016-01-01

We describe some of the first polarized neutron scattering measurements performed at HYSPEC spectrometer at the Spallation Neutron Source, Oak Ridge National Laboratory. We discuss details of the instrument setup and the experimental procedures in the mode with full polarization analysis. Examples of polarized neutron diffraction and polarized inelastic neutron data obtained on single crystal samples are presented.

Comparison of two software versions for assessment of body-composition analysis by DXA

DEFF Research Database (Denmark)

Vozarova, B; Wang, J; Weyer, C

2001-01-01

To compare two software versions provided by Lunar CO: for assessment of body composition analysis by DXA.......To compare two software versions provided by Lunar CO: for assessment of body composition analysis by DXA....

The Rho GTPase Cdc42 regulates hair cell planar polarity and cellular patterning in the developing cochlea

Directory of Open Access Journals (Sweden)

Anna Kirjavainen

2015-03-01

Full Text Available Hair cells of the organ of Corti (OC of the cochlea exhibit distinct planar polarity, both at the tissue and cellular level. Planar polarity at tissue level is manifested as uniform orientation of the hair cell stereociliary bundles. Hair cell intrinsic polarity is defined as structural hair bundle asymmetry; positioning of the kinocilium/basal body complex at the vertex of the V-shaped bundle. Consistent with strong apical polarity, the hair cell apex displays prominent actin and microtubule cytoskeletons. The Rho GTPase Cdc42 regulates cytoskeletal dynamics and polarization of various cell types, and, thus, serves as a candidate regulator of hair cell polarity. We have here induced Cdc42 inactivation in the late-embryonic OC. We show the role of Cdc42 in the establishment of planar polarity of hair cells and in cellular patterning. Abnormal planar polarity was displayed as disturbances in hair bundle orientation and morphology and in kinocilium/basal body positioning. These defects were accompanied by a disorganized cell-surface microtubule network. Atypical protein kinase C (aPKC, a putative Cdc42 effector, colocalized with Cdc42 at the hair cell apex, and aPKC expression was altered upon Cdc42 depletion. Our data suggest that Cdc42 together with aPKC is part of the machinery establishing hair cell planar polarity and that Cdc42 acts on polarity through the cell-surface microtubule network. The data also suggest that defects in apical polarization are influenced by disturbed cellular patterning in the OC. In addition, our data demonstrates that Cdc42 is required for stereociliogenesis in the immature cochlea.

Challenges and opportunities for tissue-engineering polarized epithelium.

Science.gov (United States)

Paz, Ana C; Soleas, John; Poon, James C H; Trieu, Dennis; Waddell, Thomas K; McGuigan, Alison P

2014-02-01

The epithelium is one of the most important tissue types in the body and the specific organization of the epithelial cells in these tissues is important for achieving appropriate function. Since many tissues contain an epithelial component, engineering functional epithelium and understanding the factors that control epithelial maturation and organization are important for generating whole artificial organ replacements. Furthermore, disruption of the cellular organization leads to tissue malfunction and disease; therefore, engineered epithelium could provide a valuable in vitro model to study disease phenotypes. Despite the importance of epithelial tissues, a surprisingly limited amount of effort has been focused on organizing epithelial cells into artificial polarized epithelium with an appropriate structure that resembles that seen in vivo. In this review, we provide an overview of epithelial tissue organization and highlight the importance of cell polarization to achieve appropriate epithelium function. We next describe the in vitro models that exist to create polarized epithelium and summarize attempts to engineer artificial epithelium for clinical use. Finally, we highlight the opportunities that exist to translate strategies from tissue engineering other tissues to generate polarized epithelium with a functional structure.

CLASSIFICATION FOR ANGLE-DEPENDENT POLARIZED PHOTOEMISSION SPECTRA USING MAGNETIC-MOMENTS ANALYSIS

NARCIS (Netherlands)

VANDERLAAN, G; THOLE, BT

The angular distribution of photoelectrons from a core level or localized valence level excited with circularly or linearly polarized Xrays is shown to contain the complete one-electron information of the ground state of a magnetic polarized atom. We generalize the definition of the fundamental

Analysis of polarization in hydrogen bonded complexes: An asymptotic projection approach

Science.gov (United States)

Drici, Nedjoua

2018-03-01

The asymptotic projection technique is used to investigate the polarization effect that arises from the interaction between the relaxed, and frozen monomeric charge densities of a set of neutral and charged hydrogen bonded complexes. The AP technique based on the resolution of the original Kohn-Sham equations can give an acceptable qualitative description of the polarization effect in neutral complexes. The significant overlap of the electron densities, in charged and π-conjugated complexes, impose further development of a new functional, describing the coupling between constrained and non-constrained electron densities within the AP technique to provide an accurate representation of the polarization effect.

Physics with polarized beams. Report of the ANL Technical Advisory Panel. [Research with polarized proton beams

Energy Technology Data Exchange (ETDEWEB)

1975-11-01

Experimental directions which will be the most useful in developing underlying theories of hadronic collisions are outlined. As a pedagogical device to accomplish this, approximate percentages of a total program which could be devoted to different areas have been quoted. Findings are presented in the form of a short basic report with several long detailed appendices. In the basic report our opinion as to the amount of polarized beam experimental effort that should be applied to the following areas is stated: nucleon-nucleon scattering, quasi-two-body processes, inclusive production, and new or unexplored areas (such as large p/sub T/ and invariance principles). Our reasoning is discussed briefly, however, the details are left for the appendices. Members of the panel present certain aspects of the above areas, which should be useful for planning and/or performing polarized beam experiments. The seven presentations are abstracted separately in ERA.

Spin-polarized neutron matter at different orders of chiral effective field theory

OpenAIRE

Sammarruca, F.; Machleidt, R.; Kaiser, N.

2015-01-01

Spin-polarized neutron matter is studied using chiral two- and three-body forces. We focus, in particular, on predictions of the energy per particle in ferromagnetic neutron matter at different orders of chiral effective field theory and for different choices of the resolution scale. We discuss the convergence pattern of the predictions and their cutoff dependence. We explore to which extent fully polarized neutron matter behaves (nearly) like a free Fermi gas. We also consider the more gener...

Polarized neutron scattering on HYSPEC: the HYbrid SPECtrometer at SNS

Energy Technology Data Exchange (ETDEWEB)

Zaliznyak, Igor [Brookhaven National Laboratory (BNL); Savici, Andrei T [ORNL; Garlea, Vasile O [ORNL; Winn, Barry L [ORNL; Schneelock, John [Brookhaven National Laboratory (BNL); Tranquada, John M. [Brookhaven National Laboratory (BNL); Gu, G. D. [Brookhaven National Laboratory (BNL); Wang, Aifeng [Brookhaven National Laboratory (BNL); Petrovic, C [Brookhaven National Laboratory (BNL)

2017-01-01

We describe some of the first polarized neutron scattering measurements performed at HYSPEC spectrometer at the Spallation Neutron Source, Oak Ridge National Laboratory. We discuss details of the instrument setup and the experimental procedures in the mode with the full polarization analysis. Examples of the polarized neutron diffraction and the polarized inelastic neutron data obtained on single crystal samples are presented.

A Novel Human Body Area Network for Brain Diseases Analysis.

Science.gov (United States)

Lin, Kai; Xu, Tianlang

2016-10-01

Development of wireless sensor and mobile communication technology provide an unprecedented opportunity for realizing smart and interactive healthcare systems. Designing such systems aims to remotely monitor the health and diagnose the diseases for users. In this paper, we design a novel human body area network for brain diseases analysis, which is named BABDA. Considering the brain is one of the most complex organs in the human body, the BABDA system provides four function modules to ensure the high quality of the analysis result, which includes initial data collection, data correction, data transmission and comprehensive data analysis. The performance evaluation conducted in a realistic environment with several criteria shows the availability and practicability of the BABDA system.

Effects of capturing and collaring on polar bears: findings from long-term research on the southern Beaufort Sea population

Science.gov (United States)

Rode, Karyn D.; Pagano, Anthony M.; Bromaghin, Jeffrey F.; Atwood, Todd C.; Durner, George M.; Simac, Kristin S.; Amstrup, Steven C.

2014-01-01

Context: The potential for research methods to affect wildlife is an increasing concern among both scientists and the public. This topic has a particular urgency for polar bears because additional research is needed to monitor and understand population responses to rapid loss of sea ice habitat.Aims: This study used data collected from polar bears sampled in the Alaska portion of the southern Beaufort Sea to investigate the potential for capture to adversely affect behaviour and vital rates. We evaluated the extent to which capture, collaring and handling may influence activity and movement days to weeks post-capture, and body mass, body condition, reproduction and survival over 6 months or more.Methods: We compared post-capture activity and movement rates, and relationships between prior capture history and body mass, body condition and reproductive success. We also summarised data on capture-related mortality.Key results: Individual-based estimates of activity and movement rates reached near-normal levels within 2–3 days and fully normal levels within 5 days post-capture. Models of activity and movement rates among all bears had poor fit, but suggested potential for prolonged, lower-level rate reductions. Repeated captures was not related to negative effects on body condition, reproduction or cub growth or survival. Capture-related mortality was substantially reduced after 1986, when immobilisation drugs were changed, with only 3 mortalities in 2517 captures from 1987–2013.Conclusions: Polar bears in the southern Beaufort Sea exhibited the greatest reductions in activity and movement rates 3.5 days post-capture. These shorter-term, post-capture effects do not appear to have translated into any long-term effects on body condition, reproduction, or cub survival. Additionally, collaring had no effect on polar bear recovery rates, body condition, reproduction or cub survival.Implications: This study provides empirical evidence that current capture

Wavelet analysis of polarization azimuths maps for laser images of myocardial tissue for the purpose of diagnosing acute coronary insufficiency

Science.gov (United States)

Wanchuliak, O. Ya.; Peresunko, A. P.; Bakko, Bouzan Adel; Kushnerick, L. Ya.

2011-09-01

This paper presents the foundations of a large scale - localized wavelet - polarization analysis - inhomogeneous laser images of histological sections of myocardial tissue. Opportunities were identified defining relations between the structures of wavelet coefficients and causes of death. The optical model of polycrystalline networks of myocardium protein fibrils is presented. The technique of determining the coordinate distribution of polarization azimuth of the points of laser images of myocardium histological sections is suggested. The results of investigating the interrelation between the values of statistical (statistical moments of the 1st-4th order) parameters are presented which characterize distributions of wavelet - coefficients polarization maps of myocardium layers and death reasons.

Freely tunable broadband polarization rotator for terahertz waves.

Science.gov (United States)

Fan, Ren-Hao; Zhou, Yu; Ren, Xiao-Ping; Peng, Ru-Wen; Jiang, Shang-Chi; Xu, Di-Hu; Xiong, Xiang; Huang, Xian-Rong; Wang, Mu

2015-02-18

A freely tunable polarization rotator for broadband terahertz waves is demonstrated using a three-rotating-layer metallic grating structure, which can conveniently rotate the polarization of a linearly polarized terahertz wave to any desired direction with nearly perfect conversion efficiency. This low-cost, high-efficiency, and freely tunable device has potential applications as material analysis, wireless communication, and THz imaging. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Research on generating various polarization-modes in polarized illumination system

Science.gov (United States)

Huang, Jinping; Lin, Wumei; Fan, Zhenjie

2013-08-01

With the increase of the numerical aperture (NA), the polarization of light affects the imaging quality of projection lens more significantly. On the contrary, according to the mask pattern, the resolution of projection lens can be improved by using the polarized illumination. That is to say, using the corresponding polarized beam (or polarization-mode) along with the off-axis illumination will improve the resolution and the imaging quality of the of projection lens. Therefore, the research on the generation of various polarization modes and its conversion methods become more and more important. In order to realize various polarization modes in polarized illumination system, after read a lot of references, we provide a way that fitting for the illumination system with the wavelength of 193nm.Six polarization-modes and a depolarized mode are probably considered. Wave-plate stack is used to generate linearly polarization-mode, which have a higher degree polarization. In order to generate X-Y and Y-X polarization mode, the equipment consisting of four sectors of λ/2 wave plate was used. We combined 16 sectors of λ/2 wave plate which have different orientations of the "slow" axis to generate radial and azimuthal polarization. Finally, a multi-polarization control device was designed. Using the kind of multi-polarization control device which applying this method could help to choose the polarization modes conveniently and flexibility for the illumination system.

Polarization properties of linearly polarized parabolic scaling Bessel beams

Energy Technology Data Exchange (ETDEWEB)

Guo, Mengwen; Zhao, Daomu, E-mail: zhaodaomu@yahoo.com

2016-10-07

The intensity profiles for the dominant polarization, cross polarization, and longitudinal components of modified parabolic scaling Bessel beams with linear polarization are investigated theoretically. The transverse intensity distributions of the three electric components are intimately connected to the topological charge. In particular, the intensity patterns of the cross polarization and longitudinal components near the apodization plane reflect the sign of the topological charge. - Highlights: • We investigated the polarization properties of modified parabolic scaling Bessel beams with linear polarization. • We studied the evolution of transverse intensity profiles for the three components of these beams. • The intensity patterns of the cross polarization and longitudinal components can reflect the sign of the topological charge.

Evaluating the Role of First Polar Body Morphology on Rates of Fertilization and Embryo Development in ICSI Cycles

Directory of Open Access Journals (Sweden)

Iman Halvaei

2011-01-01

Full Text Available Background: Recent studies have demonstrated that morphology of the first polar body (1st PBis related to oocyte viability, which can be used as a prognostic tool to predict oocyte performanceand pregnancy outcomes in an intracytoplasmic sperm injection (ICSI program. According to somestudies, there is a correlation between oocyte performance and 1st PB morphology, while others havenot reported any correlation. The objective of this study is to evaluate the role of 1st PB morphologyon rates of fertilization and embryo development in ICSI cases.Materials and Methods: In this prospective study morphological characteristics of 470 metaphaseII (MII oocytes were assessed in 80 ICSI cycles. The women were ages 21-42 years (mean 32.6 ±0.2. Their oocytes were retrieved after a hyperstimulation protocol. After denudation, all oocyteswere evaluated for 1st PB morphology. The oocytes were divided into two groups of A (normal 1stPB and B (abnormal fragmented 1st PB. In addition, other abnormalities, such as refractile bodies(RF, wide previtelline space (wPVS, central and general granulation, bull’s eye, vacuole, smoothendoplasmic reticulum cluster (SERc, debris in PVS, shape and dark oocyte were checked. Forverifying of fertilization, about 18-19 hours post-ICSI, oocytes were checked for two-pronuclear.Assessments of embryo quality, development and embryo transfer were done at day two. Chisquare,Fisher’s exact and independent sample t tests were chosen for statistical analysis.Results: Twenty-seven percent of oocytes had fragmented 1st PB, while the remainder was associatedwith other morphological abnormalities. A total of 46.1% and 26.9% of oocytes showed double andmultiple defects, respectively. RF was the most common abnormality observed in group B. Nosignificant differences in women’s’ ages between groups A and B were noted (p=0.3. A total of 179and 107 oocytes (61.5% vs. 59.8% were fertilized in groups A and B, respectively (p=0.7. Therates of

Spin-dependent electron many-body effects in GaAs

Science.gov (United States)

Nemec, P.; Kerachian, Y.; van Driel, H. M.; Smirl, Arthur L.

2005-12-01

Time- and polarization-resolved differential transmission measurements employing same and oppositely circularly polarized 150fs optical pulses are used to investigate spin characteristics of conduction band electrons in bulk GaAs at 295K . Electrons and holes with densities in the 2×1016cm-3-1018cm-3 range are generated and probed with pulses whose center wavelength is between 865 and 775nm . The transmissivity results can be explained in terms of the spin sensitivity of both phase-space filling and many-body effects (band-gap renormalization and screening of the Coulomb enhancement factor). For excitation and probing at 865nm , just above the band-gap edge, the transmissivity changes mainly reflect spin-dependent phase-space filling which is dominated by the electron Fermi factors. However, for 775nm probing, the influence of many-body effects on the induced transmission change are comparable with those from reduced phase space filling, exposing the spin dependence of the many-body effects. If one does not take account of these spin-dependent effects one can misinterpret both the magnitude and time evolution of the electron spin polarization. For suitable measurements we find that the electron spin relaxation time is 130ps .

Molecular electron recollision dynamics in intense circularly polarized laser pulses

Science.gov (United States)

Bandrauk, André D.; Yuan, Kai-Jun

2018-04-01

Extreme UV and x-ray table top light sources based on high-order harmonic generation (HHG) are focused now on circular polarization for the generation of circularly polarized attosecond pulses as new tools for controlling electron dynamics, such as charge transfer and migration and the generation of attosecond quantum electron currents for ultrafast magneto-optics. A fundamental electron dynamical process in HHG is laser induced electron recollision with the parent ion, well established theoretically and experimentally for linear polarization. We discuss molecular electron recollision dynamics in circular polarization by theoretical analysis and numerical simulation. The control of the polarization of HHG with circularly polarized ionizing pulses is examined and it is shown that bichromatic circularly polarized pulses enhance recollision dynamics, rendering HHG more efficient, especially in molecules because of their nonspherical symmetry. The polarization of the harmonics is found to be dependent on the compatibility of the rotational symmetry of the net electric field created by combinations of bichromatic circularly polarized pulses with the dynamical symmetry of molecules. We show how the field and molecule symmetry influences the electron recollision trajectories by a time-frequency analysis of harmonics. The results, in principle, offer new unique controllable tools in the study of attosecond molecular electron dynamics.

Lambda polarization feasibility study at BM@N

Directory of Open Access Journals (Sweden)

Suvarieva Dilyna

2017-01-01

In this analysis, the possibility to measure at BM@N the polarization of the lightest strange hyperon Λ is studied in Monte Carlo event samples produced with the DCM-QGSM generator. It is shown that the detector will allow to measure Λ polarization with a precision required to check the model predictions.

Analysis of modal frequency optimization of railway vehicle car body

Directory of Open Access Journals (Sweden)

Wenjing Sun

2016-04-01

Full Text Available High structural modal frequencies of car body are beneficial as they ensure better vibration control and enhance ride quality of railway vehicles. Modal sensitivity optimization and elastic suspension parameters used in the design of equipment beneath the chassis of the car body are proposed in order to improve the modal frequencies of car bodies under service conditions. Modal sensitivity optimization is based on sensitivity analysis theory which considers the thickness of the body frame at various positions as variables in order to achieve optimization. Equipment suspension design analyzes the influence of suspension parameters on the modal frequencies of the car body through the use of an equipment-car body coupled model. Results indicate that both methods can effectively improve the modal parameters of the car body. Modal sensitivity optimization increases vertical bending frequency from 9.70 to 10.60 Hz, while optimization of elastic suspension parameters increases the vertical bending frequency to 10.51 Hz. The suspension design can be used without alteration to the structure of the car body while ensuring better ride quality.

Polarization of Cosmic Microwave Background

International Nuclear Information System (INIS)

Buzzelli, A; Cabella, P; De Gasperis, G; Vittorio, N

2016-01-01

In this work we present an extension of the ROMA map-making code for data analysis of Cosmic Microwave Background polarization, with particular attention given to the inflationary polarization B-modes. The new algorithm takes into account a possible cross- correlated noise component among the different detectors of a CMB experiment. We tested the code on the observational data of the BOOMERanG (2003) experiment and we show that we are provided with a better estimate of the power spectra, in particular the error bars of the BB spectrum are smaller up to 20% for low multipoles. We point out the general validity of the new method. A possible future application is the LSPE balloon experiment, devoted to the observation of polarization at large angular scales. (paper)

Polarized nuclear target based on parahydrogen induced polarization

OpenAIRE

Budker, D.; Ledbetter, M. P.; Appelt, S.; Bouchard, L. S.; Wojtsekhowski, B.

2012-01-01

We discuss a novel concept of a polarized nuclear target for accelerator fixed-target scattering experiments, which is based on parahydrogen induced polarization (PHIP). One may be able to reach a 33% free-proton polarization in the ethane molecule. The potential advantages of such a target include operation at zero magnetic field, fast ($\\sim$100 Hz) polarization reversal, and operation with large intensity of an electron beam.

Statistical mechanics of dense plasmas and implications for the plasma polarization shift

International Nuclear Information System (INIS)

Rogers, F.J.

1984-01-01

A brief description of the statistical mechanics of reacting, dense, plasmas is given. The results do not support a Debye-like polarization shift at low density. It is shown that the electronic charge density factors into a strongly quantum mechanical part, that is not much affected by many body correlations and a weakly quantum mechanical part, that is considerably effected by many body correlations. The few body charge density is obtained from direct solution of the Schroedinger equation and the many body charge density is obtained from the hypernetted chain equation through the introduction of a pseudopotential

Simulation and Automation of Microwave Frequency Control in Dynamic Nuclear Polarization for Solid Polarized Targets

Science.gov (United States)

Perera, Gonaduwage; Johnson, Ian; Keller, Dustin

2017-09-01

Dynamic Nuclear Polarization (DNP) is used in most of the solid polarized target scattering experiments. Those target materials must be irradiated using microwaves at a frequency determined by the difference in the nuclear Larmor and electron paramagnetic resonance (EPR) frequencies. But the resonance frequency changes with time as a result of radiation damage. Hence the microwave frequency should be adjusted accordingly. Manually adjusting the frequency can be difficult, and improper adjustments negatively impact the polarization. In order to overcome these difficulties, two controllers were developed which automate the process of seeking and maintaining the optimal frequency: one being a standalone controller for a traditional DC motor and the other a LabVIEW VI for a stepper motor configuration. Further a Monte-Carlo simulation was developed which can accurately model the polarization over time as a function of microwave frequency. In this talk, analysis of the simulated data and recent improvements to the automated system will be presented. DOE.

Magnetic excitations and polarized neutrons

International Nuclear Information System (INIS)

Shirane, G.

1985-01-01

We review the historical development of polarized beam techniques for studies of condensed matter physics. In particular we describe, in some detail, the recent advance of the triple axis technique with polarization analysis. It is now possible to carry out quantitative characterization of magnetic cross sections S(Q,ω), in absolute units, for a wide range of energy and momentum transfers. We will discuss some examples of recent inelastic measurements on 3d ferromagnets and heavy Fermions. 35 refs., 11 figs., 2 tabs

Spin-polarized scanning electron microscopy

International Nuclear Information System (INIS)

Kohashi, Teruo

2014-01-01

Spin-Polarized Scanning Electron Microscopy (Spin SEM) is one way for observing magnetic domain structures taking advantage of the spin polarization of the secondary electrons emitted from a ferromagnetic sample. This principle brings us several excellent capabilities such as high-spatial resolution better than 10 nm, and analysis of magnetization direction in three dimensions. In this paper, the principle and the structure of the spin SEM is briefly introduced, and some examples of the spin SEM measurements are shown. (author)

The near infrared polarization of NGC 7023

International Nuclear Information System (INIS)

Sellgren, K.

1984-01-01

NGC 7023 is a visual reflection nebula whose low optical depth at near infrared wavelengths suggests it may be well-suited to analysis of the near infrared scattering properties of dust. While processes other than scattered light dominate the near infrared emission of NGC 7023, a detectable scattered light component remains, as can be demonstrated by polarization measurements. Polarization at 2.2 μm has been detected at two positions in NGC 7023. The polarization angles at these two positions are perpendicular to the line between each nebular position and the star which illuminates the visual reflection nebulosity, indicating that the polarization mechanism is most likely the scattering of starlight from this star. (author)

Ground-based Polarization Remote Sensing of Atmospheric Aerosols and the Correlation between Polarization Degree and PM2.5

International Nuclear Information System (INIS)

Cheng, Chen; Zhengqiang, Li; Weizhen, Hou; Yisong, Xie; Donghui, Li; Kaitao, Li; Ying, Zhang

2014-01-01

The ground-based polarization remote sensing adds the polarization dimension information to traditional intensity detection, which provides a new method to detect atmospheric aerosols properties. In this paper, the polarization measurements achieved by a new multi-wavelength sun photometer, CE318-DP, are used for the ground-based remote sensing of atmospheric aerosols. In addition, a polarized vector radiative transfer model is introduced to simulate the DOLP (Degree Of Linear Polarization) under different sky conditions. At last, the correlative analysis between mass density of PM 2.5 and multi-wavelength and multi-angular DOLP is carried out. The result shows that DOLP has a high correlation with mass density of PM 2.5 , R 2 >0.85. As a consequence, this work provides a new method to estimate the mass density of PM 2.5 by using the comprehensive network of ground-based sun photometer

Polarization observables in Virtual Compton Scattering

Energy Technology Data Exchange (ETDEWEB)

Doria, Luca

2007-10-15

Virtual Compton Scattering (VCS) is an important reaction for understanding nucleon structure at low energies. By studying this process, the generalized polarizabilities of the nucleon can be measured. These observables are a generalization of the already known polarizabilities and will permit theoretical models to be challenged on a new level. More specifically, there exist six generalized polarizabilities and in order to disentangle them all, a double polarization experiment must be performed. Within this work, the VCS reaction p(e,e'p){gamma} was measured at MAMI using the A1 Collaboration three spectrometer setup with Q{sup 2}=0.33 (GeV/c){sup 2}. Using the highly polarized MAMI beam and a recoil proton polarimeter, it was possible to measure both the VCS cross section and the double polarization observables. Already in 2000, the unpolarized VCS cross section was measured at MAMI. In this new experiment, we could confirm the old data and furthermore the double polarization observables were measured for the first time. The data were taken in five periods between 2005 and 2006. In this work, the data were analyzed to extract the cross section and the proton polarization. For the analysis, a maximum likelihood algorithm was developed together with the full simulation of all the analysis steps. The experiment is limited by the low statistics due mainly to the focal plane proton polarimeter efficiency. To overcome this problem, a new determination and parameterization of the carbon analyzing power was performed. The main result of the experiment is the extraction of a new combination of the generalized polarizabilities using the double polarization observables. (orig.)

Polarization observables in Virtual Compton Scattering

International Nuclear Information System (INIS)

Doria, Luca

2007-10-01

Virtual Compton Scattering (VCS) is an important reaction for understanding nucleon structure at low energies. By studying this process, the generalized polarizabilities of the nucleon can be measured. These observables are a generalization of the already known polarizabilities and will permit theoretical models to be challenged on a new level. More specifically, there exist six generalized polarizabilities and in order to disentangle them all, a double polarization experiment must be performed. Within this work, the VCS reaction p(e,e'p)γ was measured at MAMI using the A1 Collaboration three spectrometer setup with Q 2 =0.33 (GeV/c) 2 . Using the highly polarized MAMI beam and a recoil proton polarimeter, it was possible to measure both the VCS cross section and the double polarization observables. Already in 2000, the unpolarized VCS cross section was measured at MAMI. In this new experiment, we could confirm the old data and furthermore the double polarization observables were measured for the first time. The data were taken in five periods between 2005 and 2006. In this work, the data were analyzed to extract the cross section and the proton polarization. For the analysis, a maximum likelihood algorithm was developed together with the full simulation of all the analysis steps. The experiment is limited by the low statistics due mainly to the focal plane proton polarimeter efficiency. To overcome this problem, a new determination and parameterization of the carbon analyzing power was performed. The main result of the experiment is the extraction of a new combination of the generalized polarizabilities using the double polarization observables. (orig.)

Cosmic microwave background polarization results from QUIET

International Nuclear Information System (INIS)

Buder, I.

2014-01-01

Despite the success of precision cosmology, cosmologists cannot fully explain the initial conditions of the Universe. Inflation, an exponential expansion in the first ∼ 10 -36 s, is a promising potential explanation. A generic prediction of inflation is odd-parity (B-mode) polarization in the cosmic microwave background (CMB). Q/U Imaging Experiment (QUIET) aimed at limiting or detecting this polarization. We built a pseudo-correlation microwave polarimeter as an array of mass-produced modules in the focal plane of a 1.4 m telescope. We used rotation around the absorbing ground screen, a new time-stream double-demodulation technique, and optimized optics in the design to reduce instrumental polarization. We observed with this instrument at the Atacama Plateau in Chile between October 2008 and December 2010. This paper describes the analysis and results of these observations from one of 2 parallel pipelines. We developed noise modeling, filtering and data selection following a blind-analysis strategy. Central to this strategy was a suite of null test, each motivated by a possible instrumental problem or systematic effect. We evaluated the systematic errors in the blind stage of the analysis before the result was known. We calculated the CMB power spectra using a pseudo-C l cross-correlation technique that suppressed contamination and made the result insensitive to noise bias. We measured the first 3 peaks of the E-mode spectrum at high significance and limited B-mode polarization. We measured the CMB polarization power at 25 ≤ l ≤ 975. We found no statistically significant deviation from ΛCDM model, and our results are consistent with zero BB and EB power. Systematic errors were well below our B-mode polarization limits. This systematic-error reduction was a strong demonstration of technology for application in more sensitive, next generation CMB experiments. (author)

Applications of polarized neutrons

International Nuclear Information System (INIS)

Mezei, F.

1993-01-01

The additional spin degree of freedom of the neutron can be made use of in neutron scattering work in two fundamental ways: (a) directly for the identification of magnetic scattering effects and (b) indirectly as a spectroscopic tool for modulating and analysing beams. Although strong magnetic scattering contributions can often be studied by unpolarized neutrons, a fully unambiguous separation of nuclear and magnetic phenomena can only be achieved by the additional information provided by polarized neutrons, especially if one of the two kinds of contributions is weak compared to the other. In the most general case a sample with both magnetic and nuclear features can be characterized by as many as 16 independent dynamic correlation functions instead of the single well known S(q, ω) for non-magnetic nuclear scattering only. Polarization analysis in principle allows one to determine all these 16 functions. The indirect applications of polarized neutrons are also steadily gaining importance. The most widely used method of this kind, the application of Larmor precessions for high resolution energy analysis in Neutron Spin Echo spectroscopy opened up a whole new domain in inelastic neutron scattering which was not accessible to any other spectroscopic method with or without neutrons before. (author)

Structural analysis of the JT-60SA cryostat vessel body

Energy Technology Data Exchange (ETDEWEB)

Botija, José, E-mail: jose.botija@ciemat.es [Association EURATOM – CIEMAT, Avda. Complutense 40, 28040 Madrid (Spain); Alonso, Javier; Fernández, Pilar; Medrano, Mercedes; Ramos, Francisco; Rincon, Esther; Soleto, Alfonso [Association EURATOM – CIEMAT, Avda. Complutense 40, 28040 Madrid (Spain); Davis, Sam; Di Pietro, Enrico; Tomarchio, Valerio [Fusion for Energy, JT-60SA European Home Team, 85748 Garching bei Munchen (Germany); Masaki, Kei; Sakasai, Akira; Shibama, Yusuke [JAEA – Japan Atomic Energy Agency, Naka Fusion Institute, Ibaraki 311-0193 (Japan)

2013-10-15

Highlights: ► Structural analysis to validate the JT-60SA cryostat vessel body design. ► Design code ASME 2007 “Boiler and Pressure Vessel Code. Section VIII”. ► First buckling mode: load multiplier of 10.644, higher than the minimum factor 4.7. ► Elastic and elastic–plastic stress analysis meets ASME against plastic collapse. ► Bolted fasteners have been analyzed showing small gaps closed by strong welding. -- Abstract: The JT-60SA cryostat is a stainless steel vacuum vessel (14 m diameter, 16 m height) which encloses the Tokamak providing the vacuum environment (10{sup −3} Pa) necessary to limit the transmission of thermal loads to the components at cryogenic temperature. It must withstand both external atmospheric pressure during normal operation and internal overpressure in case of an accident. The paper summarizes the structural analyses performed in order to validate the JT-60SA cryostat vessel body design. It comprises several analyses: a buckling analysis to demonstrate stability under the external pressure; an elastic and an elastic–plastic stress analysis according to ASME VIII rules, to evaluate resistance to plastic collapse including localized stress concentrations; and, finally, a detailed analysis with bolted fasteners in order to evaluate the behavior of the flanges, assuring the integrity of the vacuum sealing welds of the cryostat vessel body.

Scaling of the polarization amplitude in quantum many-body systems in one dimension

Science.gov (United States)

Kobayashi, Ryohei; Nakagawa, Yuya O.; Fukusumi, Yoshiki; Oshikawa, Masaki

2018-04-01

Resta proposed a definition of the electric polarization in one-dimensional systems in terms of the ground-state expectation value of the large gauge transformation operator. Vanishing of the expectation value in the thermodynamic limit implies that the system is a conductor. We study Resta's polarization amplitude (expectation value) in the S =1 /2 XXZ chain and its several generalizations, in the gapless conducting Tomonaga-Luttinger liquid phase. We obtain an analytical expression in the lowest-order perturbation theory about the free fermion point (XY chain) and an exact result for the Haldane-Shastry model with long-range interactions. We also obtain numerical results, mostly using the exact diagonalization method. We find that the amplitude exhibits a power-law scaling in the system size (chain length) and vanishes in the thermodynamic limit. On the other hand, the exponent depends on the model even when the low-energy limit is described by the Tomonaga-Luttinger liquid with the same Luttinger parameter. We find that a change in the exponent occurs when the Umklapp term(s) are eliminated, suggesting the importance of the Umklapp terms.

Characterization of polarized THP-1 macrophages and polarizing ability of LPS and food compounds.

Science.gov (United States)

Chanput, Wasaporn; Mes, Jurriaan J; Savelkoul, Huub F J; Wichers, Harry J

2013-02-01

Little is known about the polarizing potential of currently used human macrophage cell lines, while a better understanding phenomena can support the prediction of effects in vivo based on in vitro analysis. To test the polarization capability of PMA differentiated-THP-1 macrophages (M0), cells were stimulated with 20 ng ml(-1) IFNγ + 1 μg ml(-1) LPS and 20 ng ml(-1) IL-4, which are known to influence macrophage polarization in vivo and ex vivo into the M1 and M2 state, respectively. Apart from several well-known M1 and M2 markers, also new possible markers for M1 and M2 polarization were analysed in this study. The expression of M1 marker genes was up-regulated in IFNγ + LPS stimulated-M0 THP-1 macrophages. The IL-4 stimulated-M0 THP-1 macrophages expressed M2 cell membrane receptor genes. However, M2 chemokine and their receptor genes were only slightly up-regulated which might be due to the complexity of the secondary cell-cell interaction of the chemokine system. Lipopolysaccharides from E. coli (LPS) and food compounds [lentinan, vitamin D3 (vD3) and the combination of lentinan + vitamin D3 (Len + vD3)] were investigated for their polarizing ability on M0 THP-1 macrophages towards either the M1 or M2 state. LPS (700 ng ml(-1)) was able to skew M0 THP-1 macrophages towards the M1 direction since all analysed M1 marker genes were strongly expressed. Lentinan, vD3 and Len + vD3 did not induce expression of either M1 or M2 markers, indicating no polarizing ability of these compounds. Based on the expression of M1 and M2 marker genes we concluded that THP-1 macrophages could be successfully polarized into either the M1 or M2 state. Therefore, they can be used as a new macrophage polarizing model to estimate the polarizing/switching ability of test food compounds.

Dishevelled links basal body docking and orientation in ciliated epithelial cells

Science.gov (United States)

Vladar, Eszter K.; Axelrod, Jeffrey D.

2014-01-01

Some epithelia contain cells with multiple, motile cilia that beat in a concerted fashion. New tools and experimental systems have facilitated molecular studies of cilium biogenesis and of the coordinated planar polarization of cilia that leads to their concerted motility. Recent, elegant work by Park and colleagues, using embryonic frog epidermis, demonstrates that Dishevelled (Dvl), a key regulator of both the Wnt/β-catenin and Planar Cell Polarity (PCP) pathways, controls both the docking and planar polarization of ciliary basal bodies. PMID:18819800

Fusion of a polarized projectile with a polarized target

International Nuclear Information System (INIS)

Christley, J.A.; Johnson, R.C.; Thompson, I.J.

1995-01-01

The fusion cross sections for a polarized target with both unpolarized and polarized projectiles are studied. Expressions for the observables are given for the case when both nuclei are polarized. Calculations for fusion of an aligned 165 Ho target with 16 O and polarized 7 Li beams are presented

T -odd correlations in polarized top quark decays in the sequential decay t (↑)→Xb+W+(→ℓ++νℓ) and in the quasi-three-body decay t (↑)→ Xb+ℓ++νℓ

Science.gov (United States)

Fischer, M.; Groote, S.; Körner, J. G.

2018-05-01

We identify the T -odd structure functions that appear in the description of polarized top quark decays in the sequential decay t (↑)→Xb+W+(→ℓ++νℓ) (two structure functions) and the quasi-three-body decay t (↑)→X b+ℓ++νℓ (one structure function). A convenient measure of the magnitude of the T -odd structure functions is the contribution of the imaginary part Im gR of the right-chiral tensor coupling gR to the T -odd structure functions which we work out. Contrary to the case of QCD, the NLO electroweak corrections to polarized top quark decays admit absorptive one-loop vertex contributions. We analytically calculate the imaginary parts of the relevant four electroweak one-loop triangle vertex diagrams and determine their contributions to the T -odd helicity structure functions that appear in the description of polarized top quark decays.

Ring-element analysis of layered orthotropic bodies

DEFF Research Database (Denmark)

Jørgensen, O.

1993-01-01

For the analysis of arbitrarily laminated circular bodies, a displacement-based ring-element is presented. The analysis is performed in a cylindrical coordinate system. The method of analysis requires the boundary conditions as well as the external forces to be pi-periodic. The element formulation...... accounts for a desired degree of approximation of the displacement field in the direction of the circumference. This is done by a truncated Fourier expansion of the angular dependence of the displacements in terms of trigonometric functions. Thus the Fourier expansion coefficients are the unknowns...... to that of solutions obtained by traditional 3D elements. A scheme for analytical integration of the angular dependence of the stiffness matrix is given....

Wnt signaling and polarity in freshwater sponges.

Science.gov (United States)

Windsor Reid, Pamela J; Matveev, Eugueni; McClymont, Alexandra; Posfai, Dora; Hill, April L; Leys, Sally P

2018-02-02

The Wnt signaling pathway is uniquely metazoan and used in many processes during development, including the formation of polarity and body axes. In sponges, one of the earliest diverging animal groups, Wnt pathway genes have diverse expression patterns in different groups including along the anterior-posterior axis of two sponge larvae, and in the osculum and ostia of others. We studied the function of Wnt signaling and body polarity formation through expression, knockdown, and larval manipulation in several freshwater sponge species. Sponge Wnts fall into sponge-specific and sponge-class specific subfamilies of Wnt proteins. Notably Wnt genes were not found in transcriptomes of the glass sponge Aphrocallistes vastus. Wnt and its signaling genes were expressed in archaeocytes of the mesohyl throughout developing freshwater sponges. Osculum formation was enhanced by GSK3 knockdown, and Wnt antagonists inhibited both osculum development and regeneration. Using dye tracking we found that the posterior poles of freshwater sponge larvae give rise to tissue that will form the osculum following metamorphosis. Together the data indicate that while components of canonical Wnt signaling may be used in development and maintenance of osculum tissue, it is likely that Wnt signaling itself occurs between individual cells rather than whole tissues or structures in freshwater sponges.

Body composition of two human cadavers by neutron activation and chemical analysis

International Nuclear Information System (INIS)

Knight, G.S.; Beddoe, A.H.; Streat, S.J.; Hill, G.L.

1986-01-01

In vivo neutron activation analysis (NAA) is currently used to measure body composition in metabolic and nutritional studies in many clinical situations, but has not previously been validated by comparison with chemical analysis of human cadavers. Total body nitrogen (TBN) and chlorine (TBCl) were measured in two human cadavers by NAA before homogenization and chemical analysis (CHEM) after (cadaver 1: TBN, 1.47 NAA, 1.51 CHEM; TBCl, 0.144 NAA, 0.147 CHEM; cadaver 2: TBN, 0.576 NAA, 0.572 CHEM; TBCl, 0.0227 NAA, 0.0250 CHEM). The homogenates were also analyzed by NAA, and no significant differences were found, indicating that the effects of elemental inhomogeneity on the measurement of TBN and TBCl are insignificant. Total body water, fat, protein, minerals, and carbohydrates were measured chemically for each cadaver and compared with estimates for these compartments obtained from a body composition model, which when used in vivo involves NAA and tritium dilution. The agreement found justifies the use of the model for the measurement of changes in total body protein, water, and fat in sequential studies in groups of patients

Measurements and amplitude analysis of small angle pp polarization between 398 and 572 MeV

CERN Document Server

Aebischer, D; Greeniaus, L G; Hess, R; Junod, A; Lechanoine-Leluc, C; Nikles, J C; Rapin, D; Werren, D W

1976-01-01

Results are reported of an experiment performed at CERN in which a 38% polarized beam of protons was scattered on a carbon target and the measurements were made at 398, 455, 530 and 572 MeV in the CM angular range 4 degrees < Theta *<22 degrees . It is shown that the data are in good agreement with phase shift analysis predictions. (7 refs).

Exploring Science Through Polar Exploration

Science.gov (United States)

Pfirman, S. L.; Bell, R. E.; Zadoff, L.; Kelsey, R.

2003-12-01

Exploring the Poles is a First Year Seminar course taught at Barnard College, Columbia University. First Year Seminars are required of incoming students and are designed to encourage critical analysis in a small class setting with focused discussion. The class links historical polar exploration with current research in order to: introduce non-scientists to the value of environmental science through polar literature; discuss issues related to venturing into the unknown that are of relevance to any discipline: self-reliance, leadership, preparation, decisions under uncertainty; show students the human face of science; change attitudes about science and scientists; use data to engage students in exploring/understanding the environment and help them learn to draw conclusions from data; integrate research and education. These goals are met by bringing analysis of early exploration efforts together with a modern understanding of the polar environment. To date to class has followed the efforts of Nansen in the Fram, Scott and Amundsen in their race to the pole, and Shackleton's Endurance. As students read turn-of-the-century expedition journals, expedition progress is progressively revealed on an interactive map showing the environmental context. To bring the exploration process to life, students are assigned to expedition teams for specific years and the fates of the student "expeditions" are based on their own decisions. For example, in the Arctic, they navigate coastal sea ice and become frozen into the ice north of Siberia, re-creating Nansen's polar drift. Fates of the teams varied tremendously: some safely emerged at Fram Strait in 4 years, while others nearly became hopelessly lost in the Beaufort Gyre. Students thus learn about variability in the current polar environment through first hand experience, enabling them to appreciate the experiences, decisions, and, in some cases, the luck, of polar explorers. Evaluation by the Columbia Center for New Media, Teaching

Update of the Polar SWIFT model for polar stratospheric ozone loss (Polar SWIFT version 2)

Science.gov (United States)

Wohltmann, Ingo; Lehmann, Ralph; Rex, Markus

2017-07-01

The Polar SWIFT model is a fast scheme for calculating the chemistry of stratospheric ozone depletion in polar winter. It is intended for use in global climate models (GCMs) and Earth system models (ESMs) to enable the simulation of mutual interactions between the ozone layer and climate. To date, climate models often use prescribed ozone fields, since a full stratospheric chemistry scheme is computationally very expensive. Polar SWIFT is based on a set of coupled differential equations, which simulate the polar vortex-averaged mixing ratios of the key species involved in polar ozone depletion on a given vertical level. These species are O3, chemically active chlorine (ClOx), HCl, ClONO2 and HNO3. The only external input parameters that drive the model are the fraction of the polar vortex in sunlight and the fraction of the polar vortex below the temperatures necessary for the formation of polar stratospheric clouds. Here, we present an update of the Polar SWIFT model introducing several improvements over the original model formulation. In particular, the model is now trained on vortex-averaged reaction rates of the ATLAS Chemistry and Transport Model, which enables a detailed look at individual processes and an independent validation of the different parameterizations contained in the differential equations. The training of the original Polar SWIFT model was based on fitting complete model runs to satellite observations and did not allow for this. A revised formulation of the system of differential equations is developed, which closely fits vortex-averaged reaction rates from ATLAS that represent the main chemical processes influencing ozone. In addition, a parameterization for the HNO3 change by denitrification is included. The rates of change of the concentrations of the chemical species of the Polar SWIFT model are purely chemical rates of change in the new version, whereas in the original Polar SWIFT model, they included a transport effect caused by the

Undulator-Based Production of Polarized Photons

International Nuclear Information System (INIS)

McDonald, Kirk

2008-01-01

'Project Title: Undulator-Based Production of Polarized Photons' DOE Contract Number: FG02-04ER41355 Principal Investigator: Prof. Kirk McDonald Period of Performance: 09/10/2004 thru 08/31/2006 This award was to fund Princeton's activity on SLAC experiment E166, 'Undulator-Based Production of Polarized Positrons' which was performed at SLAC during June and September 2005. Princeton U. fabricated a magnetic spectrometer for this experiment, and participated in the commissioning, operation, and analysis of the experiment, for which Prof. McDonald was a co-spokesperson. The experiment demonstrated that an intense positron beam with 80% longitudinal polarization could be generated by conversion of MeVenergy circularly polarized photons in a thin target, which photons were generated by passage of high-energy electrons through a helical undulator. This technique has since been adopted as the baseline for the polarized positron source of the proposed International Linear Collider. Results of the experiment have been published in Physical Review Letters, vol 100, p 210801 (2008) (see attached .pdf file), and a longer paper is in preparation.

Study on provenance of ancient Yaozhou porcelain bodies by fingerprint elements scatter analysis

International Nuclear Information System (INIS)

Zhao Weijuan; Guo Min; Gao Zhengyao; Li Guoxia; Xie Jianzhong

2004-01-01

25 samples of Yaozhou porcelain bodies, 3 samples of the tri-color pottery bodies during the Tang Dynasty, 1 samples of Saggar material during Song Dynasty and 4 samples of clay mineral taken from the place near Yaozhou Kiln Museum was selected. The technique of neutron activation analysis (NAA) has been employed to measure the content of 29 kinds of elements in the samples. 8 elements of them were selected as fingerprint elements to make scatter analysis. The conclusion is that the ancient Yaozhou porcelain bodies produced by different kilns have long shared a stable and concentrated raw material sources. Both the tri-colored pottery bodies made in Yaozhou Kilns during the Tang Dynasty and the Yaozhou porcelain bodies are from the same provenance. (authors)

Analysis of the neutralino system in three-body leptonic decays of neutralinos

International Nuclear Information System (INIS)

Choi, S.Y.; Chung, B.C.; Kalinowski, J.; Rolbiecki, K.; Kim, Y.G.

2006-01-01

Neutralinos χ 0 in supersymmetric theories, the spin-1/2 Majorana-type superpartners of the U(1) and SU(2) neutral electroweak gauge bosons and SU(2) neutral Higgs bosons, are expected to be among light supersymmetric particles so that they can be produced copiously via direct pair production and/or from cascade decays of other sparticles such as sleptons at the planned Large Hadron Collider and the prospective International Linear Collider. Considering the prospects of having both highly polarized neutralinos and possibility of reconstructing their decay rest frames, we provide a systematic investigation of the three-body leptonic decays of the neutralinos in the minimal supersymmetric standard model and demonstrate alternative ways for probing the Majorana nature of the neutralinos and CP violation in the neutralino system. (orig.)

Effect-directed analysis to explore the polar bear exposome: identification of thyroid hormone disrupting compounds in plasma.

Science.gov (United States)

Simon, Eszter; van Velzen, Martin; Brandsma, Sicco H; Lie, Elisabeth; Løken, Katharina; de Boer, Jacob; Bytingsvik, Jenny; Jenssen, Bjørn M; Aars, Jon; Hamers, Timo; Lamoree, Marja H

2013-08-06

Compounds with transthyretin (TTR)-binding potency in the blood plasma of polar bear cubs were identified with effect-directed analysis (EDA). This approach contributes to the understanding of the thyroid disrupting exposome of polar bears. The selection of these samples for in-depth EDA was based on the difference between the observed TTR-binding potency on the one hand and the calculated potency (based on known concentrations of TTR-binding compounds and their relative potencies) on the other. A library-based identification was applied to the liquid chromatography-time-of-flight-mass spectrometry (LC-ToF-MS) data by screening for matches between compound lists and the LC-ToF-MS data regarding accurate mass and isotope pattern. Then, isotope cluster analysis (ICA) was applied to the LC-ToF-MS data allowing specific screening for halogen isotope patterns. The presence of linear and branched nonylphenol (NP) was observed for the first time in polar bears. Furthermore, the presence of one di- and two monohydroxylated octachlorinated biphenyls (octaCBs) was revealed in the extracts. Linear and branched NP, 4'-OH-CB201 and 4,4'-OH-CB202 could be successfully confirmed with respect to their retention time in the analytical system. In addition, branched NP, mono- and dihydroxylated-octaCBs showed TTR-binding potencies and could explain another 32 ± 2% of the total measured activities in the extracts.

Neutron polarization

International Nuclear Information System (INIS)

Firk, F.W.K.

1976-01-01

Some recent experiments involving polarized neutrons are discussed; they demonstrate how polarization studies provide information on fundamental aspects of nuclear structure that cannot be obtained from more traditional neutron studies. Until recently, neutron polarization studies tended to be limited either to very low energies or to restricted regions at higher energies, determined by the kinematics of favorable (p, vector n) and (d, vector n) reactions. With the advent of high intensity pulsed electron and proton accelerators and of beams of vector polarized deuterons, this is no longer the case. One has entered an era in which neutron polarization experiments are now being carried out, in a routine way, throughout the entire range from thermal energies to tens-of-MeV. The significance of neutron polarization studies is illustrated in discussions of a wide variety of experiments that include the measurement of T-invariance in the β-decay of polarized neutrons, a search for the effects of meson exchange currents in the photo-disintegration of the deuteron, the determination of quantum numbers of states in the fission of aligned 235 U and 237 Np induced by polarized neutrons, and the double- and triple-scattering of fast neutrons by light nuclei

Unexpected attraction of polarotactic water-leaving insects to matt black car surfaces: mattness of paintwork cannot eliminate the polarized light pollution of black cars.

Directory of Open Access Journals (Sweden)

Miklos Blaho

Full Text Available The horizontally polarizing surface parts of shiny black cars (the reflection-polarization characteristics of which are similar to those of water surfaces attract water-leaving polarotactic insects. Thus, shiny black cars are typical sources of polarized light pollution endangering water-leaving insects. A new fashion fad is to make car-bodies matt black or grey. Since rough (matt surfaces depolarize the reflected light, one of the ways of reducing polarized light pollution is to make matt the concerned surface. Consequently, matt black/grey cars may not induce polarized light pollution, which would be an advantageous feature for environmental protection. To test this idea, we performed field experiments with horizontal shiny and matt black car-body surfaces laid on the ground. Using imaging polarimetry, in multiple-choice field experiments we investigated the attractiveness of these test surfaces to various water-leaving polarotactic insects and obtained the following results: (i The attractiveness of black car-bodies to polarotactic insects depends in complex manner on the surface roughness (shiny, matt and species (mayflies, dolichopodids, tabanids. (ii Non-expectedly, the matt dark grey car finish is much more attractive to mayflies (being endangered and protected in many countries than matt black finish. (iii The polarized light pollution of shiny black cars usually cannot be reduced with the use of matt painting. On the basis of these, our two novel findings are that (a matt car-paints are highly polarization reflecting, and (b these matt paints are not suitable to repel polarotactic insects. Hence, the recent technology used to make matt the car-bodies cannot eliminate or even can enhance the attractiveness of black/grey cars to water-leaving insects. Thus, changing shiny black car painting to matt one is a disadvantageous fashion fad concerning the reduction of polarized light pollution of black vehicles.

Unexpected attraction of polarotactic water-leaving insects to matt black car surfaces: mattness of paintwork cannot eliminate the polarized light pollution of black cars.

Science.gov (United States)

Blaho, Miklos; Herczeg, Tamas; Kriska, Gyorgy; Egri, Adam; Szaz, Denes; Farkas, Alexandra; Tarjanyi, Nikolett; Czinke, Laszlo; Barta, Andras; Horvath, Gabor

2014-01-01

The horizontally polarizing surface parts of shiny black cars (the reflection-polarization characteristics of which are similar to those of water surfaces) attract water-leaving polarotactic insects. Thus, shiny black cars are typical sources of polarized light pollution endangering water-leaving insects. A new fashion fad is to make car-bodies matt black or grey. Since rough (matt) surfaces depolarize the reflected light, one of the ways of reducing polarized light pollution is to make matt the concerned surface. Consequently, matt black/grey cars may not induce polarized light pollution, which would be an advantageous feature for environmental protection. To test this idea, we performed field experiments with horizontal shiny and matt black car-body surfaces laid on the ground. Using imaging polarimetry, in multiple-choice field experiments we investigated the attractiveness of these test surfaces to various water-leaving polarotactic insects and obtained the following results: (i) The attractiveness of black car-bodies to polarotactic insects depends in complex manner on the surface roughness (shiny, matt) and species (mayflies, dolichopodids, tabanids). (ii) Non-expectedly, the matt dark grey car finish is much more attractive to mayflies (being endangered and protected in many countries) than matt black finish. (iii) The polarized light pollution of shiny black cars usually cannot be reduced with the use of matt painting. On the basis of these, our two novel findings are that (a) matt car-paints are highly polarization reflecting, and (b) these matt paints are not suitable to repel polarotactic insects. Hence, the recent technology used to make matt the car-bodies cannot eliminate or even can enhance the attractiveness of black/grey cars to water-leaving insects. Thus, changing shiny black car painting to matt one is a disadvantageous fashion fad concerning the reduction of polarized light pollution of black vehicles.

Three-photon polarization ququarts: polarization, entanglement and Schmidt decompositions

International Nuclear Information System (INIS)

Fedorov, M V; Miklin, N I

2015-01-01

We consider polarization states of three photons, propagating collinearly and having equal given frequencies but with arbitrary distributed horizontal or vertical polarizations of photons. A general form of such states is a superposition of four basic three-photon polarization modes, to be referred to as the three-photon polarization ququarts (TPPQ). All such states can be considered as consisting of one- and two-photon parts, which can be entangled with each other. The degrees of entanglement and polarization, as well as the Schmidt decomposition and Stokes vectors of TPPQ are found and discussed. (paper)

On Classical Dynamics of Affinely-Rigid Bodies Subject to the Kirchhoff-Love Constraints

Directory of Open Access Journals (Sweden)

Vasyl Kovalchuk

2010-04-01

Full Text Available In this article we consider the affinely-rigid body moving in the three-dimensional physical space and subject to the Kirchhoff-Love constraints, i.e., while it deforms homogeneously in the two-dimensional central plane of the body it simultaneously performs one-dimensional oscillations orthogonal to this central plane. For the polar decomposition we obtain the stationary ellipsoids as special solutions of the general, strongly nonlinear equations of motion. It is also shown that these solutions are conceptually different from those obtained earlier for the two-polar (singular value decomposition.

The use of bioelectrical impedance analysis for body composition in epidemiological studies

DEFF Research Database (Denmark)

Böhm, A; Heitmann, B L

2013-01-01

BACKGROUND/OBJECTIVES: Bioelectrical impedance analysis (BIA) is a relatively simple, inexpensive and non-invasive technique to measure body composition and is therefore suitable in field studies and larger surveys. SUBJECTS/METHODS: We performed an overview of BIA-derived body fat percentages (BF......%) from 55 published studies of healthy populations aged 6-80 years. In addition, the relationship between body mass index (BMI) and body composition is documented in the context of BIA as a good alternative to closely differentiate which composition of the body better relates to the risk...

Convex Bodies With Minimal Volume Product in R^2 --- A New Proof

OpenAIRE

Lin, Youjiang

2010-01-01

In this paper, a new proof of the following result is given: The product of the volumes of an origin symmetric convex bodies $K$ in R^2 and of its polar body is minimal if and only if $K$ is a parallelogram.

Analysis by Mass Spectrometry of the Polar Lipids from the Cellular Membrane of Thermophilic Lactic Acid Bacteria

Directory of Open Access Journals (Sweden)

A. M. Seldes

2000-03-01

Full Text Available Fast atom bombardment (FAB technique was employed to determine the structure of polar lipids from the cellular membrane of Lactobacillus delbruekii ssp. bulgaricus and Streptococcus salivarius ssp. thermophilus. Analysis of spectra provided useful information about the molecular species and aminoacids constituents of the samples.

Polarization splitter and polarization rotator designs based on transformation optics.

Science.gov (United States)

Kwon, Do-Hoon; Werner, Douglas H

2008-11-10

The transformation optics technique is employed in this paper to design two optical devices - a two-dimensional polarization splitter and a three-dimensional polarization rotator for propagating beams. The polarization splitter translates the TM- and the TE-polarized components of an incident beam in opposite directions (i.e., shifted up or shifted down). The polarization rotator rotates the polarization state of an incoming beam by an arbitrary angle. Both optical devices are reflectionless at the entry and exit interfaces. Design details and full-wave simulation results are provided.

Analysis of Urine as Indicators of Specific Body Conditions

Science.gov (United States)

Dey, Souradeep; Saha, Triya; Narendrakumar, Uttamchand

2017-11-01

Urinalysis can be defined as a procedure for examining various factors of urine, which include physical properties, particulate matter, cells, casts, crystals, organisms and solutes. Urinalysis is recommended to be a part of the initial examination of all patients as its cheap, feasible and gives productive results. This paper focuses on the analysis of urine collected at specific body conditions. Here we illustrate the urine profile of different persons having various body conditions, which include, having urinary tract infection, undergoing strenuous exercise, having back pain regularly, having very low urine output and a person who is on 24 hours of diet. Examination of urine collected from different persons having specific body conditions usually helps us in the diagnosis of various diseases, which it indicates.

Analysis of polarized photoluminescence emission of ordered III–V semiconductor quaternary alloys

Energy Technology Data Exchange (ETDEWEB)

Prutskij, Tatiana, E-mail: tatiana.prutskij@correo.buap.mx [Instituto de Ciencias, BUAP, Privada 17 Norte, No 3417, Col. San Miguel Huyeotlipan, 72050 Puebla, Pue., México (Mexico); Makarov, Nykolay, E-mail: nykolay.makarov@correo.buap.mx [Instituto de Ciencias, BUAP, Privada 17 Norte, No 3417, Col. San Miguel Huyeotlipan, 72050 Puebla, Pue., México (Mexico); Attolini, Giovanni, E-mail: giovanni@imem.cnr.it [IMEM/CNR, Parco Area delle Scienze 37/A, 43010 Parma (Italy)

2016-04-15

Ternary and quaternary III–V alloys obtained by metal-organic vapor-phase epitaxy (MOVPE) grow very often with some degree of atomic ordering. Atomic ordering reduces the symmetry of the crystal lattice and thus drastically changes optical properties of the alloy. Moreover, the photoluminescence (PL) emission becomes polarized and its study helps to understand the atomic arrangement within the crystal lattice. In this work we experimentally studied the polarization of the PL emission from different crystallographic planes of several quaternary III–V semiconductor alloys grown on GaAs substrates by MOVPE. We compare the measured PL emission polarization angular patterns with those calculated with a model made for ternary alloys and discuss the limits of application of this model for quaternaries. It is found that the experimentally obtained polarization patterns are consistent with the existence of different ordering crystallographic planes for III- and for V-group atoms.

Nontarget analysis of polar contaminants in freshwater sediments influenced by pharmaceutical industry using ultra-high-pressure liquid chromatography-quadrupole time-of-flight mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Terzic, Senka, E-mail: terzic@irb.h [Division of Marine and Environmental Research, Rudjer Boskovic Institute, 10000 Zagreb (Croatia); Ahel, Marijan [Division of Marine and Environmental Research, Rudjer Boskovic Institute, 10000 Zagreb (Croatia)

2011-02-15

A comprehensive analytical procedure for a reliable identification of nontarget polar contaminants in aquatic sediments was developed, based on the application of ultra-high-pressure liquid chromatography (UHPLC) coupled to hybrid quadrupole time-of-flight mass spectrometry (QTOFMS). The procedure was applied for the analysis of freshwater sediment that was highly impacted by wastewater discharges from the pharmaceutical industry. A number of different contaminants were successfully identified owing to the high mass accuracy of the QTOFMS system, used in combination with high chromatographic resolution of UHPLC. The major compounds, identified in investigated sediment, included a series of polypropylene glycols (n = 3-16), alkylbenzene sulfonate and benzalkonium surfactants as well as a number of various pharmaceuticals (chlorthalidone, warfarin, terbinafine, torsemide, zolpidem and macrolide antibiotics). The particular advantage of the applied technique is its capability to detect less known pharmaceutical intermediates and/or transformation products, which have not been previously reported in freshwater sediments. - Research highlights: UHPLC-QTOFMS coupling was applied for nontarget analysis of polar contaminants. Wide spectrum of polar contaminants was identified in polluted sediments. Pharmaceuticals and their intermediates were present in high concentrations. - Comprehensive analysis of freshwater sediments by UPLC/QTOF indicated importance of pharmaceutically-derived polar contaminants.

Can polar bears use terrestrial foods to offset lost ice-based hunting opportunities?

Science.gov (United States)

Rode, Karyn D.; Robbins, Charles T.; Nelson, Lynne; Amstrup, Steven C.

2015-01-01

Increased land use by polar bears (Ursus maritimus) due to climate-change-induced reduction of their sea-ice habitat illustrates the impact of climate change on species distributions and the difficulty of conserving a large, highly specialized carnivore in the face of this global threat. Some authors have suggested that terrestrial food consumption by polar bears will help them withstand sea-ice loss as they are forced to spend increasing amounts of time on land. Here, we evaluate the nutritional needs of polar bears as well as the physiological and environmental constraints that shape their use of terrestrial ecosystems. Only small numbers of polar bears have been documented consuming terrestrial foods even in modest quantities. Over much of the polar bear's range, limited terrestrial food availability supports only low densities of much smaller, resident brown bears (Ursus arctos), which use low-quality resources more efficiently and may compete with polar bears in these areas. Where consumption of terrestrial foods has been documented, polar bear body condition and survival rates have declined even as land use has increased. Thus far, observed consumption of terrestrial food by polar bears has been insufficient to offset lost ice-based hunting opportunities but can have ecological consequences for other species. Warming-induced loss of sea ice remains the primary threat faced by polar bears.

Validity of PEC Approximation for On-Body Propagation

DEFF Research Database (Denmark)

Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren Helstrup; Thaysen, Jesper

2016-01-01

Many articles on on-body propagation assumes that the human body can be approximated by a perfect electric conductor (PEC) instead of the actual constitutive parameters of the human body, which is that of a lossy dielectric. This assumption is investigated in this article through comparison...... of the scattering of a plane wave at oblique incidence by a PEC and a lossy dielectric cylinder. The investigation shows that the validity of the assumption depends on the polarization of the plane wave, the angle of incidence, and the region of interest....

Polarization dynamics and polarization time of random three-dimensional electromagnetic fields

International Nuclear Information System (INIS)

Voipio, Timo; Setaelae, Tero; Shevchenko, Andriy; Friberg, Ari T.

2010-01-01

We investigate the polarization dynamics of random, stationary three-dimensional (3D) electromagnetic fields. For analyzing the time evolution of the instantaneous polarization state, two intensity-normalized polarization autocorrelation functions are introduced, one based on a geometric approach with the Poincare vectors and the other on energy considerations with the Jones vectors. Both approaches lead to the same conclusions on the rate and strength of the polarization dynamics and enable the definition of a polarization time over which the state of polarization remains essentially unchanged. For fields obeying Gaussian statistics, the two correlation functions are shown to be expressible in terms of quantities characterizing partial 3D polarization and electromagnetic coherence. The 3D degree of polarization is found to have the same meaning in the 3D polarization dynamics as the usual two-dimensional (2D) degree of polarization does with planar fields. The formalism is demonstrated with several examples, and it is expected to be useful in applications dealing with polarization fluctuations of 3D light.

Strategic Polarization.

Science.gov (United States)

Kalai, Adam; Kalai, Ehud

2001-08-01

In joint decision making, similarly minded people may take opposite positions. Consider the example of a marriage in which one spouse gives generously to charity while the other donates nothing. Such "polarization" may misrepresent what is, in actuality, a small discrepancy in preferences. It may be that the donating spouse would like to see 10% of their combined income go to charity each year, while the apparently frugal spouse would like to see 8% donated. A simple game-theoretic analysis suggests that the spouses will end up donating 10% and 0%, respectively. By generalizing this argument to a larger class of games, we provide strategic justification for polarization in many situations such as debates, shared living accommodations, and disciplining children. In some of these examples, an arbitrarily small disagreement in preferences leads to an arbitrarily large loss in utility for all participants. Such small disagreements may also destabilize what, from game-theoretic point of view, is a very stable equilibrium. Copyright 2001 Academic Press.

Polarized electron sources

Energy Technology Data Exchange (ETDEWEB)

Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

1994-12-01

The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

Polarized electron sources

International Nuclear Information System (INIS)

Prepost, R.

1994-01-01

The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented

Grading the "good" body: a poststructural feminist analysis of body mass index initiatives.

Science.gov (United States)

Gerbensky-Kerber, Anne

2011-06-01

This article analyzes discourse surrounding Arkansas's legislation requiring public schools to measure students' body mass index (BMI) annually and to send the scores to parents on children's report cards. Using poststructural feminist sensibilities, I explore the tensions experienced by parents, children, educators, and policymakers as this mandate was debated and implemented. The discourse illuminates salient issues about disproportionate disparities in health status that exist in communities with fewer resources, and the potentially unintended gendered consequences of health policies. I explain three dominant threads of discourse: How the economic costs of childhood obesity opened a policy window for the legislation; the presence of tensions between freedom and social control; and how BMI discourses inscribe ideological visions of bodies. Ultimately, the analysis offers insight into the discursive nature of policymaking and how class and gender are implicated in health interventions.

Moment analysis of hadronic vacuum polarization

Directory of Open Access Journals (Sweden)

Eduardo de Rafael

2014-09-01

Full Text Available I suggest a new approach to the determination of the hadronic vacuum polarization (HVP contribution to the anomalous magnetic moment of the muon aμHVP in lattice QCD. It is based on properties of the Mellin transform of the hadronic spectral function and their relation to the HVP self-energy in the Euclidean. I show how aμHVP is very well approximated by a few moments associated to this Mellin transform and how these moments can be evaluated in lattice QCD, providing thus a series of tests when compared with the corresponding determinations using experimental data.

Moment analysis of hadronic vacuum polarization

International Nuclear Information System (INIS)

Rafael, Eduardo de

2014-01-01

I suggest a new approach to the determination of the hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment of the muon a μ HVP in lattice QCD. It is based on properties of the Mellin transform of the hadronic spectral function and their relation to the HVP self-energy in the Euclidean. I show how a μ HVP is very well approximated by a few moments associated to this Mellin transform and how these moments can be evaluated in lattice QCD, providing thus a series of tests when compared with the corresponding determinations using experimental data

Moment analysis of hadronic vacuum polarization

Energy Technology Data Exchange (ETDEWEB)

Rafael, Eduardo de

2014-09-07

I suggest a new approach to the determination of the hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment of the muon a{sub μ}{sup HVP} in lattice QCD. It is based on properties of the Mellin transform of the hadronic spectral function and their relation to the HVP self-energy in the Euclidean. I show how a{sub μ}{sup HVP} is very well approximated by a few moments associated to this Mellin transform and how these moments can be evaluated in lattice QCD, providing thus a series of tests when compared with the corresponding determinations using experimental data.

Update of the Polar SWIFT model for polar stratospheric ozone loss (Polar SWIFT version 2

Directory of Open Access Journals (Sweden)

I. Wohltmann

2017-07-01

Full Text Available The Polar SWIFT model is a fast scheme for calculating the chemistry of stratospheric ozone depletion in polar winter. It is intended for use in global climate models (GCMs and Earth system models (ESMs to enable the simulation of mutual interactions between the ozone layer and climate. To date, climate models often use prescribed ozone fields, since a full stratospheric chemistry scheme is computationally very expensive. Polar SWIFT is based on a set of coupled differential equations, which simulate the polar vortex-averaged mixing ratios of the key species involved in polar ozone depletion on a given vertical level. These species are O3, chemically active chlorine (ClOx, HCl, ClONO2 and HNO3. The only external input parameters that drive the model are the fraction of the polar vortex in sunlight and the fraction of the polar vortex below the temperatures necessary for the formation of polar stratospheric clouds. Here, we present an update of the Polar SWIFT model introducing several improvements over the original model formulation. In particular, the model is now trained on vortex-averaged reaction rates of the ATLAS Chemistry and Transport Model, which enables a detailed look at individual processes and an independent validation of the different parameterizations contained in the differential equations. The training of the original Polar SWIFT model was based on fitting complete model runs to satellite observations and did not allow for this. A revised formulation of the system of differential equations is developed, which closely fits vortex-averaged reaction rates from ATLAS that represent the main chemical processes influencing ozone. In addition, a parameterization for the HNO3 change by denitrification is included. The rates of change of the concentrations of the chemical species of the Polar SWIFT model are purely chemical rates of change in the new version, whereas in the original Polar SWIFT model, they included a transport effect

Dynamic exposure model analysis of continuous laser direct writing in Polar-coordinate

Science.gov (United States)

Zhang, Shan; Lv, Yingjun; Mao, Wenjie

2018-01-01

In order to exactly predict the continuous laser direct writing quality in Polar-coordinate, we take into consideration the effect of the photoresist absorbing beam energy, the Gaussian attribute of the writing beam and the dynamic exposure process, and establish a dynamic exposure model to describe the influence of the tangential velocity of the normal incident facular center and laser power on the line width and sidewall angle. Numerical simulation results indicate that while writing velocity remains unchanged, the line width and sidewall angle are all increased as the laser power increases; while laser power remains unchanged, the line width and sidewall angle are all decreased as the writing velocity increases; at the same time the line profile in the exposure section is asymmetry and the center of the line has tiny excursion toward the Polar-coordinate origin compared with the facular center. Then it is necessary to choose the right writing velocity and laser power to obtain the ideal line profile. The model makes up the shortcomings of traditional models that can only predict line width or estimate the profile of the writing line in the absence of photoresist absorption, and can be considered as an effect analysis method for optimizing the parameters of fabrication technique of laser direct writing.

Polarization holograms allow highly efficient generation of complex light beams.

Science.gov (United States)

Ruiz, U; Pagliusi, P; Provenzano, C; Volke-Sepúlveda, K; Cipparrone, Gabriella

2013-03-25

We report a viable method to generate complex beams, such as the non-diffracting Bessel and Weber beams, which relies on the encoding of amplitude information, in addition to phase and polarization, using polarization holography. The holograms are recorded in polarization sensitive films by the interference of a reference plane wave with a tailored complex beam, having orthogonal circular polarizations. The high efficiency, the intrinsic achromaticity and the simplicity of use of the polarization holograms make them competitive with respect to existing methods and attractive for several applications. Theoretical analysis, based on the Jones formalism, and experimental results are shown.

Analysis of measured data of human body based on error correcting frequency

Science.gov (United States)

Jin, Aiyan; Peipei, Gao; Shang, Xiaomei

2014-04-01

Anthropometry is to measure all parts of human body surface, and the measured data is the basis of analysis and study of the human body, establishment and modification of garment size and formulation and implementation of online clothing store. In this paper, several groups of the measured data are gained, and analysis of data error is gotten by analyzing the error frequency and using analysis of variance method in mathematical statistics method. Determination of the measured data accuracy and the difficulty of measured parts of human body, further studies of the causes of data errors, and summarization of the key points to minimize errors possibly are also mentioned in the paper. This paper analyses the measured data based on error frequency, and in a way , it provides certain reference elements to promote the garment industry development.

Spin-polarized ballistic conduction through correlated Au-NiMnSb-Au heterostructures

KAUST Repository

Morari, C.; Appelt, W. H.; Ö stlin, A.; Prinz-Zwick, A.; Schwingenschlö gl, Udo; Eckern, U.; Chioncel, L.

2017-01-01

calculations with local electronic interactions, of Hubbard-type on the Mn sites, leads to a hybridization between the interface and many-body states. The significant reduction of the spin polarization seen in the density of states is not apparent in the spin

Polar bear attacks on humans: Implications of a changing climate

Science.gov (United States)

Wilder, James; Vongraven, Dag; Atwood, Todd C.; Hansen, Bob; Jessen, Amalie; Kochnev, Anatoly A.; York, Geoff; Vallender, Rachel; Hedman, Daryll; Gibbons, Melissa

2017-01-01

Understanding causes of polar bear (Ursus maritimus) attacks on humans is critical to ensuring both human safety and polar bear conservation. Although considerable attention has been focused on understanding black (U. americanus) and grizzly (U. arctos) bear conflicts with humans, there have been few attempts to systematically collect, analyze, and interpret available information on human-polar bear conflicts across their range. To help fill this knowledge gap, a database was developed (Polar Bear-Human Information Management System [PBHIMS]) to facilitate the range-wide collection and analysis of human-polar bear conflict data. We populated the PBHIMS with data collected throughout the polar bear range, analyzed polar bear attacks on people, and found that reported attacks have been extremely rare. From 1870–2014, we documented 73 attacks by wild polar bears, distributed among the 5 polar bear Range States (Canada, Greenland, Norway, Russia, and United States), which resulted in 20 human fatalities and 63 human injuries. We found that nutritionally stressed adult male polar bears were the most likely to pose threats to human safety. Attacks by adult females were rare, and most were attributed to defense of cubs. We judged that bears acted as a predator in most attacks, and that nearly all attacks involved ≤2 people. Increased concern for both human and bear safety is warranted in light of predictions of increased numbers of nutritionally stressed bears spending longer amounts of time on land near people because of the loss of their sea ice habitat. Improved conflict investigation is needed to collect accurate and relevant data and communicate accurate bear safety messages and mitigation strategies to the public. With better information, people can take proactive measures in polar bear habitat to ensure their safety and prevent conflicts with polar bears. This work represents an important first step towards improving our understanding of factors influencing

Atacama Cosmology Telescope: Polarization calibration analysis for CMB measurements with ACTPol and Advanced ACTPol

Science.gov (United States)

Koopman, Brian; ACTPol Collaboration

2015-04-01

The Atacama Cosmology Telescope Polarimeter (ACTPol) is a polarization sensitive upgrade for the Atacama Cosmology Telescope, located at an elevation of 5190 m on Cerro Toco in Chile. Achieving first light in 2013, ACTPol is entering its third observation season. Advanced ACTPol is a next generation upgrade for ACTPol, with additional frequencies, polarization modulation, and new detector arrays, that will begin in 2016. I will first present an overview of the two projects and then focus on describing the methods used for polarization angle calibration of the ACTPol detectors. These methods utilize polarization ray tracing in the optical design software CODEV together with detector positions determined from planet observations and represent a critical input for mapping the polarization of the CMB.

Promoting Diversity Through Polar Interdisciplinary Coordinated Education (Polar ICE)

Science.gov (United States)

McDonnell, J. D.; Hotaling, L. A.; Garza, C.; Van Dyk, P. B.; Hunter-thomson, K. I.; Middendorf, J.; Daniel, A.; Matsumoto, G. I.; Schofield, O.

2017-12-01

Polar Interdisciplinary Coordinated Education (ICE) is an education and outreach program designed to provide public access to the Antarctic and Arctic regions through polar data and interactions with the scientists. The program provides multi-faceted science communication training for early career scientists that consist of a face-to face workshop and opportunities to apply these skills. The key components of the scientist training workshop include cultural competency training, deconstructing/decoding science for non-expert audiences, the art of telling science stories, and networking with members of the education and outreach community and reflecting on communication skills. Scientists partner with educators to provide professional development for K-12 educators and support for student research symposia. Polar ICE has initiated a Polar Literacy initiative that provides both a grounding in big ideas in polar science and science communication training designed to underscore the importance of the Polar Regions to the public while promoting interdisciplinary collaborations between scientists and educators. Our ultimate objective is to promote STEM identity through professional development of scientists and educators while developing career awareness of STEM pathways in Polar science.

Polarization-independent broadband meta-holograms via polarization-dependent nanoholes.

Science.gov (United States)

Zhang, Xiaohu; Li, Xiong; Jin, Jinjin; Pu, Mingbo; Ma, Xiaoliang; Luo, Jun; Guo, Yinghui; Wang, Changtao; Luo, Xiangang

2018-05-17

Composed of ultrathin metal or dielectric nanostructures, metasurfaces can manipulate the phase, amplitude and polarization of electromagnetic waves at a subwavelength scale, which is promising for flat optical devices. In general, metasurfaces composed of space-variant anisotropic units are sensitive to the incident polarization due to the inherent polarization dependent geometric phase. Here, we implement polarization-independent broadband metasurface holograms constructed by polarization-dependent anisotropic elliptical nanoholes by elaborate design of complex amplitude holograms. The fabricated meta-hologram exhibits a polarization insensitive feature with an acceptable image quality. We verify the feasibility of the design algorithm for three-dimensional (3D) meta-holograms with simulation and the feasibility for two-dimensional (2D) meta-holograms is experimentally demonstrated at a broadband wavelength range from 405 nm to 632.8 nm. The effective polarization-independent broadband complex wavefront control with anisotropic elliptical nanoholes proposed in this paper greatly promotes the practical applications of the metasurface in technologies associated with wavefront manipulation, such as flat lens, colorful holographic displays and optical storage.

Primordial gravitational waves measurements and anisotropies of CMB polarization rotation

Directory of Open Access Journals (Sweden)

Si-Yu Li

2015-12-01

Full Text Available Searching for the signal of primordial gravitational waves in the B-modes (BB power spectrum is one of the key scientific aims of the cosmic microwave background (CMB polarization experiments. However, this could be easily contaminated by several foreground issues, such as the interstellar dust grains and the galactic cyclotron electrons. In this paper we study another mechanism, the cosmic birefringence, which can be introduced by a CPT-violating interaction between CMB photons and an external scalar field. Such kind of interaction could give rise to the rotation of the linear polarization state of CMB photons, and consequently induce the CMB BB power spectrum, which could mimic the signal of primordial gravitational waves at large scales. With the recently released polarization data of BICEP2 and the joint analysis data of BICEP2/Keck Array and Planck, we perform a global fitting analysis on constraining the tensor-to-scalar ratio r by considering the polarization rotation angle [α(nˆ] which can be separated into a background isotropic part [α¯] and a small anisotropic part [Δα(nˆ]. Since the data of BICEP2 and Keck Array experiments have already been corrected by using the “self-calibration” method, here we mainly focus on the effects from the anisotropies of CMB polarization rotation angle. We find that including Δα(nˆ in the analysis could slightly weaken the constraints on the tensor-to-scalar ratio r, when using current CMB polarization measurements. We also simulate the mock CMB data with the BICEP3-like sensitivity. Very interestingly, we find that if the effects of the anisotropic polarization rotation angle could not be taken into account properly in the analysis, the constraints on r will be dramatically biased. This implies that we need to break the degeneracy between the anisotropies of the CMB polarization rotation angle and the CMB primordial tensor perturbations, in order to measure the signal of primordial

One directional polarized neutron reflectometry with optimized reference layer method

International Nuclear Information System (INIS)

Masoudi, S. Farhad; Jahromi, Saeed S.

2012-01-01

In the past decade, several neutron reflectometry methods for determining the modulus and phase of the complex reflection coefficient of an unknown multilayer thin film have been worked out among which the method of variation of surroundings and reference layers are of highest interest. These methods were later modified for measurement of the polarization of the reflected beam instead of the measurement of the intensities. In their new architecture, these methods not only suffered from the necessity of change of experimental setup but also another difficulty was added to their experimental implementations. This deficiency was related to the limitations of the technology of the neutron reflectometers that could only measure the polarization of the reflected neutrons in the same direction as the polarization of the incident beam. As the instruments are limited, the theory has to be optimized so that the experiment could be performed. In a recent work, we developed the method of variation of surroundings for one directional polarization analysis. In this new work, the method of reference layer with polarization analysis has been optimized to determine the phase and modulus of the unknown film with measurement of the polarization of the reflected neutrons in the same direction as the polarization of the incident beam.

Ocean color remote sensing using polarization properties of reflected sunlight

Science.gov (United States)

Frouin, R.; Pouliquen, E.; Breon, F.-M.

1994-01-01

The effects of the atmosphere and surface on sunlight backscattered to space by the ocean may be substantially reduced by using the unpolarized component of reflectance instead of total reflectance. At 450 nm, a wavelength of interest in ocean color remote sensing, and for typical conditions, 45% of the unpolarized reflectance may originate from the water body instead of 20% of the total reflectance, which represents a gain of a factor 2.2 in useful signal for water composition retrieval. The best viewing geometries are adjacent to the glitter region; they correspond to scattering angles around 100 deg, but they may change slightly depending on the polarization characteristics of the aerosols. As aerosol optical thickness increases, the atmosphere becomes less efficient at polarizing sunlight, and the enhancement of the water body contribution to unpolarized reflectance is reduced. Since the perturbing effects are smaller on unpolarized reflectance, at least for some viewing geometries, they may be more easily corrected, leading to a more accurate water-leaving signal and, therefore, more accurate estimates of phytoplankton pigment concentration.

Polarization digital holographic microscopy using low-cost liquid crystal polarization rotators

Science.gov (United States)

Dovhaliuk, Rostyslav Yu

2018-02-01

Polarization imaging methods are actively used to study anisotropic objects. A number of methods and systems, such as imaging polarimeters, were proposed to measure the state of polarization of light that passed through the object. Digital holographic and interferometric approaches can be used to quantitatively measure both amplitude and phase of a wavefront. Using polarization modulation optics, the measurement capabilities of such interference-based systems can be extended to measure polarization-dependent parameters, such as phase retardation. Different kinds of polarization rotators can be used to alternate the polarization of a reference beam. Liquid crystals are used in a rapidly increasing number of different optoelectronic devices. Twisted nematic liquid crystals are widely used as amplitude modulators in electronic displays and light valves or shutter glass. Such devices are of particular interest for polarization imaging, as they can be used as polarization rotators, and due to large-scale manufacturing have relatively low cost. A simple Mach-Zehnder polarized holographic setup that uses modified shutter glass as a polarization rotator is demonstrated. The suggested approach is experimentally validated by measuring retardation of quarter-wave film.

Polarization properties of below-threshold harmonics from aligned molecules H2+ in linearly polarized laser fields.

Science.gov (United States)

Dong, Fulong; Tian, Yiqun; Yu, Shujuan; Wang, Shang; Yang, Shiping; Chen, Yanjun

2015-07-13

We investigate the polarization properties of below-threshold harmonics from aligned molecules in linearly polarized laser fields numerically and analytically. We focus on lower-order harmonics (LOHs). Our simulations show that the ellipticity of below-threshold LOHs depends strongly on the orientation angle and differs significantly for different harmonic orders. Our analysis reveals that this LOH ellipticity is closely associated with resonance effects and the axis symmetry of the molecule. These results shed light on the complex generation mechanism of below-threshold harmonics from aligned molecules.

The Online Body Breaks Out? Asence, Ghosts, Cyborgs, Gender, Polarity and Politics

Directory of Open Access Journals (Sweden)

Jonathan Marshall

2004-01-01

Full Text Available Online bodies, or cyber-bodies, seem to be constantly involved in issues of boundaries. This paper explores some of those issues. A brief outline of some offline boundary anxieties is given, such as being overwhelmed by germs, work or the foreign. It is then argued that boundaries online are even more porous and unclear. The term 'asence' is introduced to point to an existential anxiety about the ambiguities of being suspended between presence and absence. It is shown that asence and the problems around the sustaining of mood, explain some aspects of online life including flame, netsex, and the intensity of mourning. A sense of online presence may only be able to arise through asencing of the offline body and its discomforts. Ethnographic examples come from the Mailing List Cybermind. The vagueness of the virtual body is compared with other common western constructions of virtual bodies such as ghosts, and it is suggested that such constructions still have strength despite widespread cynicism about mind (online and body (offline splits. Computers seem to have become a place for haunting and disembodiment, which produces confusions when it becomes time to act offline. Other useful metaphors may not be able to be used. Haraway's model of the Cyborg is often claimed to overcome these problems, collapsing borders between human and machine, human and animal, sentient and non-sentient, female and male. However it seems to fail in these tasks because the cyborg myth has its own directions independent of our intentions, and this myth is directed by the discourse of techno-capitalism. It may prove more useful to strategically exaggerate oppositions, or to explore their ambiguities, than to dampen them by theoretical hybridisation.

Electromagnetic torques in the core and resonant excitation of decadal polar motion

Science.gov (United States)

Mound, Jon E.

2005-02-01

Motion of the rotation axis of the Earth contains decadal variations with amplitudes on the order of 10 mas. The origin of these decadal polar motions is unknown. A class of rotational normal modes of the core-mantle system termed torsional oscillations are known to affect the length of day (LOD) at decadal periods and have also been suggested as a possible excitation source for the observed decadal polar motion. Torsional oscillations involve relative motion between the outer core and the surrounding solid bodies, producing electromagnetic torques at the inner-core boundary (ICB) and core-mantle boundary (CMB). It has been proposed that the ICB torque can explain the excitation of the approximately 30-yr-period polar motion termed the Markowitz wobble. This paper uses the results of a torsional oscillation model to calculate the torques generated at Markowitz and other decadal periods and finds, in contrast to previous results, that electromagnetic torques at the ICB can not explain the observed polar motion.

Large meta-analysis of genome-wide association studies identifies five loci for lean body mass

DEFF Research Database (Denmark)

Zillikens, M Carola; Demissie, Serkalem; Hsu, Yi-Hsiang

2017-01-01

Lean body mass, consisting mostly of skeletal muscle, is important for healthy aging. We performed a genome-wide association study for whole body (20 cohorts of European ancestry with n = 38,292) and appendicular (arms and legs) lean body mass (n = 28,330) measured using dual energy X-ray absorpt...... a meta-analysis of genome-wide association studies for whole body lean body mass and find five novel genetic loci to be significantly associated.......-ray absorptiometry or bioelectrical impedance analysis, adjusted for sex, age, height, and fat mass. Twenty-one single-nucleotide polymorphisms were significantly associated with lean body mass either genome wide (p 

Assessment of body composition by dual-energy X-ray absorptiometry, bioimpedance analysis and anthropometrics in children

DEFF Research Database (Denmark)

Tompuri, Tuomo T; Lakka, Timo A; Hakulinen, Mikko

2015-01-01

We compared InBody720 segmental multifrequency bioimpedance analysis (SMF-BIA) with Lunar Prodigy Advance dual-energy X-ray absorptiometry (DXA) in assessment of body composition among 178 predominantly prepubertal children. Segmental agreement analysis of body compartments was carried out...

Planning for a new polarized source

International Nuclear Information System (INIS)

Clegg, T.B.

1985-01-01

In anticipation of obtaining funds for a new polarized source, the authors have tried to stay abreast of new source technological developments. In particular, the authors have worked to try to understand methods for improving the atomic beam polarized source. It seems interesting to consider whether the large ionization efficiency of an electron-cyclotron-resonance source could be maintained if such a source were used as an ionizer for the polarized atomic beam. An analysis of this application suggests that such an ECR ionizer might produce outgoing ion-beam intensities which are up to five times larger than those presently achieved with electron bombardment ionizers. Furthermore, the concern previously expressed that the ECR ionizer would cause resonant depolarization of the atomic beam before ionization seems unlikely

Long-Lifetime Low-Scatter Neutron Polarization Target

International Nuclear Information System (INIS)

Richardson, Jonathan M.

2004-01-01

Polarized neutrons scattering is an important technology for characterizing magnetic and other materials. Polarized helium three (P-3He) is a novel technology for creating polarized beams and, perhaps more importantly, for the analysis of polarization in highly divergent scattered beams. Analysis of scattered beams requires specialized targets with complex geometries to ensure accurate results. Special materials and handling procedures are required to give the targets a long useful lifetime. In most cases, the targets must be shielded from stray magnetic fields from nearby equipment. SRL has developed and demonstrated hybrid targets made from glass and aluminum. We have also developed and calibrated a low-field NMR system for measuring polarization lifetimes. We have demonstrated that our low-field system is able to measure NMR signals in the presence of conducting (metallic) cell elements. We have also demonstrated a non-magnetic valve that can be used to seal the cells. We feel that these accomplishments in Phase I are sufficient to ensure a successful Phase II program. The commercial market for this technology is solid. There are over nine neutron scattering centers in the US and Canada and over 22 abroad. Currently, the US plans to build a new $1.4B scattering facility called the Spallation Neutron Source (SNS). The technology developed in this project will allow SRL to supply targets to both existing and future facilities. SRL is also involved with the application of P-3He to medical imaging

Physical activity and body image among men and boys: A meta-analysis.

Science.gov (United States)

Bassett-Gunter, Rebecca; McEwan, Desmond; Kamarhie, Aria

2017-09-01

Three meta-analytic reviews have concluded that physical activity is positively related to body image. Historically, research regarding physical activity and body image has been disproportionately focused on female samples. For example, the most recent meta-analysis (2009) extracted 56 effect sizes for women and only 12 for men. The current paper provides an update to the literature regarding the relationship between physical activity and body image among men and boys across 84 individual effect sizes. The analysis also provides insight regarding moderator variables including participant age, and physical activity type and intensity. Overall, physical activity was positively related to body image among men and boys with various moderator variables warranting further investigation. Pragmatic implications are discussed as well as the limitations within existing research and need for additional research to further understand moderator and mediator variables. Copyright © 2017 Elsevier Ltd. All rights reserved.

Classifying lipoproteins based on their polar profiles.

Science.gov (United States)

Polanco, Carlos; Castañón-González, Jorge Alberto; Buhse, Thomas; Uversky, Vladimir N; Amkie, Rafael Zonana

2016-01-01

The lipoproteins are an important group of cargo proteins known for their unique capability to transport lipids. By applying the Polarity index algorithm, which has a metric that only considers the polar profile of the linear sequences of the lipoprotein group, we obtained an analytical and structural differentiation of all the lipoproteins found in UniProt Database. Also, the functional groups of lipoproteins, and particularly of the set of lipoproteins relevant to atherosclerosis, were analyzed with the same method to reveal their structural preference, and the results of Polarity index analysis were verified by an alternate test, the Cumulative Distribution Function algorithm, applied to the same groups of lipoproteins.

Polarization holography

DEFF Research Database (Denmark)

Nikolova, L.; Ramanujam, P.S.

Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

Daple Coordinates Planar Polarized Microtubule Dynamics in Ependymal Cells and Contributes to Hydrocephalus

Directory of Open Access Journals (Sweden)

Maki Takagishi

2017-07-01

Full Text Available Motile cilia in ependymal cells, which line the cerebral ventricles, exhibit a coordinated beating motion that drives directional cerebrospinal fluid (CSF flow and guides neuroblast migration. At the apical cortex of these multi-ciliated cells, asymmetric localization of planar cell polarity (PCP proteins is required for the planar polarization of microtubule dynamics, which coordinates cilia orientation. Daple is a disheveled-associating protein that controls the non-canonical Wnt signaling pathway and cell motility. Here, we show that Daple-deficient mice present hydrocephalus and their ependymal cilia lack coordinated orientation. Daple regulates microtubule dynamics at the anterior side of ependymal cells, which in turn orients the cilial basal bodies required for the directional cerebrospinal fluid flow. These results demonstrate an important role for Daple in planar polarity in motile cilia and provide a framework for understanding the mechanisms and functions of planar polarization in the ependymal cells.

PolarTrack: Optical Outside-In Device Tracking that Exploits Display Polarization

DEFF Research Database (Denmark)

Rädle, Roman; Jetter, Hans-Christian; Fischer, Jonathan

2018-01-01

PolarTrack is a novel camera-based approach to detecting and tracking mobile devices inside the capture volume. In PolarTrack, a polarization filter continuously rotates in front of an off-the-shelf color camera, which causes the displays of observed devices to periodically blink in the camera feed....... The periodic blinking results from the physical characteristics of current displays, which shine polarized light either through an LC overlay to produce images or through a polarizer to reduce light reflections on OLED displays. PolarTrack runs a simple detection algorithm on the camera feed to segment...... displays and track their locations and orientations, which makes PolarTrack particularly suitable as a tracking system for cross-device interaction with mobile devices. Our evaluation of PolarTrack's tracking quality and comparison with state-of-the-art camera-based multi-device tracking showed a better...

Body image after mastectomy: A thematic analysis of younger women's written accounts.

Science.gov (United States)

Grogan, Sarah; Mechan, Jayne

2017-09-01

This study investigated younger women's body image after mastectomy. In all, 49 women, aged 29-53 years (mean age: 39 years) who had had bilateral ( n = 8) or unilateral ( n = 41) mastectomy responded to open-ended questions online. Inductive thematic analysis revealed that aesthetics were less important than survival between diagnosis and mastectomy. Following mastectomy, women negotiated new body identities. Treatment effects such as weight gain were significant concerns. However, impacts on body confidence varied, and some participants rejected mainstream body shape ideals and reported feeling proud of their scars. Implications for supporting younger women post-mastectomy, including promotion of body acceptance, are discussed.

Media Representation of the Human Body: Discourse Analysis of Advertisements

Directory of Open Access Journals (Sweden)

Marija Lončar

2015-09-01

Full Text Available Even though advertisements represent a world of its own, they are an inevitable part of different kinds of media. The purpose of advertising is not only to promote a product but also to transfer messages, values and ideas in order to make emotional connections with brands. By building emotional attachment, advertisers increase and strengthen consumers’ responses. The promoting of the advertisements’ images becomes much more important than promoting the product itself. Nowadays, an increasing interest in representing a human body along with different kinds of products and services has become a commonplace among advertisers. Representation of the body is a socially constructed phenomenon. In other words, social processes shape perceptions of our bodies and these perceptions (recreate human experiences of the body. The authors’ approach includes qualitative discourse analysis of advertisements. The objective was to identify the relationship between the human body and textual messages as integral components of the advertised item taken in consideration, as well as the ways in which they interact with the reader’s overall experience. For this purpose, different advertisements that contain visual and textual messages representing human bodies have been analysed. They were all published in the following lifestyle magazines: Cosmopolitan, Playboy, Men’s Health, during 2012 and 2013. The authors conclude that media representations of a human body as social phenomena perceive value and treat the body in different ways depending on the relationship between the advertisement, the textual message and the human body.

Nontarget analysis of polar contaminants in freshwater sediments influenced by pharmaceutical industry using ultra-high-pressure liquid chromatography-quadrupole time-of-flight mass spectrometry

International Nuclear Information System (INIS)

Terzic, Senka; Ahel, Marijan

2011-01-01

A comprehensive analytical procedure for a reliable identification of nontarget polar contaminants in aquatic sediments was developed, based on the application of ultra-high-pressure liquid chromatography (UHPLC) coupled to hybrid quadrupole time-of-flight mass spectrometry (QTOFMS). The procedure was applied for the analysis of freshwater sediment that was highly impacted by wastewater discharges from the pharmaceutical industry. A number of different contaminants were successfully identified owing to the high mass accuracy of the QTOFMS system, used in combination with high chromatographic resolution of UHPLC. The major compounds, identified in investigated sediment, included a series of polypropylene glycols (n = 3-16), alkylbenzene sulfonate and benzalkonium surfactants as well as a number of various pharmaceuticals (chlorthalidone, warfarin, terbinafine, torsemide, zolpidem and macrolide antibiotics). The particular advantage of the applied technique is its capability to detect less known pharmaceutical intermediates and/or transformation products, which have not been previously reported in freshwater sediments. - Research highlights: → UHPLC-QTOFMS coupling was applied for nontarget analysis of polar contaminants. → Wide spectrum of polar contaminants was identified in polluted sediments. → Pharmaceuticals and their intermediates were present in high concentrations. - Comprehensive analysis of freshwater sediments by UPLC/QTOF indicated importance of pharmaceutically-derived polar contaminants.

Seasonal variability in physicochemical characteristics of small water bodies across a High Arctic wetland, Polar Bear Pass, Bathurst Island, Nunavut, Canada

Science.gov (United States)

Abnizova, A.; Miller, E.; Shakil, S.; Young, K. L.

2012-12-01

Small water bodies (lakes, ponds) in permafrost environments make up roughly half of the total area of surface water, but their relevance to nutrient and carbon fluxes on a landscape scale still remains largely unknown. Small variations in pond water balance as a result of seasonal changes in precipitation, evaporation, or drainage processes have the potential to produce considerable changes in the carbon and nutrient budgets as small changes in the water level can have a major effect on volumes and surface areas of ponds. The aims of this study were (1) to identify the main characteristics in pond hydrology both seasonally and between years; (2) to identify factors controlling variation in measured physicochemical variables; and (3) to detect seasonal trends in the hydrological and chemical characteristics of ponds located in an extensive low-gradient High Arctic wetland. We conducted detailed limnological surveys of 50 wetland ponds located at Polar Bear Pass (PBP), Bathurst Island, Nunavut, Canada during 2007-2010. The results indicate large seasonal variability in physicochemical parameters that is associated with pond water budget changes, especially for ponds with steady water levels vs. dynamic ponds (fluctuating water levels). Principal component analysis (PCA) of the datasets indicated that major ion content, specifically calcium (Ca2+), was responsible for much of the variability among the ponds in both 2008 and 2009. Additionally in 2009 most of the variability was also due to specific conductivity in the summer and magnesium (Mg2+) in the fall. These trends are typically identified as a result of dilution or evapo-concentration processes in small water bodies. In 2007, a warm and dry year, pH and potassium (K+) were responsible for much of variation between ponds. This is attributed to high vegetation growth in ponds and a longer growing season. While no trend was identified in 2010 (PCA analysis), calculations of greenhouse gas (GHG) emissions from 50

Analysis of the polarization characteristic of a satellite-to-ground laser communication optical system

Science.gov (United States)

Wang, Chao; Jiang, Lun; An, Yan; Doug, Ke-yan; Zhang, Ya-lin

2015-10-01

We present three rotation symmetric planar metamaterials and consist of 3, 4 and 6 split resonant rings (SRRs) respectively, proved that they are polarization-insensitive. The modulation characters constructed by the three planar metamaterials are also studied and compared to demonstrate that the structure with more even rotation symmetry is much more beneficial to be polarization-independence. Furthermore, the influencing rules of the electrodes on the polarization character of metamaterials are obtained. The polarization character can be converted by tailoring the electrodes which provides a guide to construct and design novel terahertz polarimetirc devices for potential applications.

Design and Performance Analysis of 2D OCDMA System with Polarization States

Science.gov (United States)

Bharti, Manisha; Sharma, Ajay K.; Kumar, Manoj

2016-12-01

This paper focuses on increasing the number of subscribers in optical code-division multiple access (OCDMA) system by using one of the features of light signal that it can be propagated in two polarization states. The performance of two-dimensional (2D) OCDMA system based on wavelength-time coding scheme by adding polarization state is investigated at varying data rates from 1 GHz to 6 GHz and for various modulation formats. It is reported that with increase in data rate of system, the performance of the system deteriorates due to polarization mode dispersion. Non-return to-zero (RZ), return to-zero (RZ), carrier suppressed return-to-zero (CSRZ) and differential phase shift keying (DPSK) modulation formats are simulated for a single user system with polarization. Investigations reveal that differential phase shift keying (DPSK) modulation format suits best to the proposed system and exhibit the potential to improve the flexibility of system for more number of users. The investigations are reported in terms of Q-factor, BER, received optical power (ROP) and eye diagrams.

Psychrophilic and Psychrotolerant Microbial Extremophiles in Polar Environments

Science.gov (United States)

Hoover, Richard B.; Pikuta, Elena V.

2010-01-01

The microbial extremophiles that inhabit the polar regions of our planet are of tremendous significance. The psychrophilic and psychrotolerant microorganisms, which inhabit all of the cold environments on Earth have important applications to Bioremediation, Medicine, Pharmaceuticals, and many other areas of Biotechnology. Until recently, most of the research on polar microorganisms was confined to studies of polar diatoms, yeast, fungi and cyanobacteria. However, within the past three decades, extensive studies have been conducted to understand the bacteria and archaea that inhabit the Arctic and Antarctic sea-ice, glaciers, ice sheets, permafrost and the cryptoendolithic, cryoconite and ice-bubble environments. These investigations have resulted in the discovery of many new genera and species of anaerobic and aerobic microbial extremophiles. Exotic enzymes, cold-shock proteins and pigments produced by some of the extremophiles from polar environments have the potential to be of great benefit to Mankind. Knowledge about microbial life in the polar regions is crucial to understanding the limitations and biodiversity of life on Earth and may provide valuable clues to the Origin of Life on Earth. The discovery of viable microorganisms in ancient ice from the Fox Tunnel, Alaska and the deep Vostok Ice has shown that microorganisms can remain alive while cryopreserved in ancient ice. The psychrophilic lithoautotrophic homoacetogen isolated from the deep anoxic trough of Lake Untersee is an ideal candidate for life that might inhabit comets or the polar caps of Mars. The spontaneous release of gas from within the Anuchin Glacier above Lake Untersee may provide clues to the ice geysers that erupt from the tiger stripe regions of Saturn s moon Enceladus. The methane productivity in the lower regimes of Lake Untersee may also provide insights into possible mechanisms for the recently discovered methane releases on Mars. Since most of the other water bearing bodies of our

Measurement of total-body oxygen, nitrogen, and carbon in vivo by photon activation analysis

International Nuclear Information System (INIS)

Ulin, K.

1984-01-01

With the aim of assessing nutritional status, the feasibility of measuring the total body quantities of the major body elements, i.e. oxygen, nitrogen, and carbon, using the photon beam of a 45 MV betatron and a whole-body counter, has been evaluated in detail. Following photon activation a single energy γ-radiation (.511 MeV) is observed from all three elements to be measured. The half-lives of 15 O, 13 N, and 11 C, however, are sufficiently different (20.5 min, 10.0 min, and 20.4 min. respectively) to permit their measurement from an analysis of the measured decay curve. Following corrections for interfering reactions, a computer curve-fitting algorithm is used to resolve the data into 15 O, 13 N, and 11 C components. Measurements of O, N, and C have been made both in phantoms and in live and dead rats. A comparison of the body composition results from this technique with results from chemical analysis indicates that measured carbon can quite accurately predict total body fat. The comparison of the total body nitrogen measurement by photon activation with total body protein by chemical analysis was inconclusive and suggests that further work be done to verify the estimated accuracy of the nitrogen measurement

Dual-band high-efficiency polarization converter using an anisotropic metasurface

Science.gov (United States)

Lin, Baoqin; Wang, Buhong; Meng, Wen; Da, Xinyu; Li, Wei; Fang, Yingwu; Zhu, Zihang

2016-05-01

In this work, a dual-band and high-efficiency reflective cross-polarization converter based on an anisotropic metasurface for linearly polarized electromagnetic waves is proposed. Its unit cell is composed of an elliptical disk-ring mounted on grounded dielectric substrate, which is an anisotropic structure with a pair of mutually perpendicular symmetric axes u and v along ± 45 ° directions with respect to y-axis direction. Both the simulation and measured results show that the polarization converter can convert x- or y-polarized incident wave to its cross polarized wave in the two frequency bands (6.99-9.18 GHz, 11.66-20.40 GHz) with the conversion efficiency higher than 90%; moreover, the higher frequency band is an ultra-wide one with a relative bandwidth of 54.5% for multiple plasmon resonances. In addition, we present a detailed analysis for the polarization conversion of the polarization converter, and derive a formula to calculate the cross- and co-polarization reflections at y-polarized incidence according to the phase differences between the two reflected coefficients at u-polarized and v-polarized incidences. The simulated, calculated, and measured results are all in agreement with the entire frequency regions.

Inadequacy of Body Weight-Based Recommendations for Individual Protein Intake-Lessons from Body Composition Analysis.

Science.gov (United States)

Geisler, Corinna; Prado, Carla M; Müller, Manfred J

2016-12-31

Current body weight-based protein recommendations are ignoring the large variability in body composition, particularly lean mass (LM), which drives protein requirements. We explored and highlighted the inter-individual variability of weight versus body composition-adjusted protein intakes by secondary analysis in three cohorts of (1) 574 healthy adults (mean ± SD age: 41.4 ± 15.2 years); (2) 403 cirrhotic patients (age: 44.7 ± 12.3 years) and (3) 547 patients with lung cancer (age: 61.3 ± 8.2 years). LM was assessed using different devices (magnetic resonance imaging, dual-energy X-ray absorptiometry, computer tomography, total body potassium and bioelectrical impedance), body weight-based protein intake, its ratio (per kg LM) and mean protein requirement were calculated. Variability in protein intake in all cohorts ranged from 0.83 to 1.77 g protein per kg LM per day using (theoretical protein intake of 60 g protein per day). Calculated mean protein requirement was 1.63 g protein per kg LM per day; consequently, 95.3% of healthy subjects, 100% of cirrhotic and 97.4% of cancer patients would present with a low protein intake per kg LM. Weight-adjusted recommendations are inadequate to address the LM specific differences in protein needs of healthy subjects or clinical populations. Absolute protein intake seems to be more relevant compared to the relative proportion of protein, which in turn changes with different energy needs.

Inadequacy of Body Weight-Based Recommendations for Individual Protein Intake—Lessons from Body Composition Analysis

Directory of Open Access Journals (Sweden)

Corinna Geisler

2016-12-01

Full Text Available Current body weight-based protein recommendations are ignoring the large variability in body composition, particularly lean mass (LM, which drives protein requirements. We explored and highlighted the inter-individual variability of weight versus body composition-adjusted protein intakes by secondary analysis in three cohorts of (1 574 healthy adults (mean ± SD age: 41.4 ± 15.2 years; (2 403 cirrhotic patients (age: 44.7 ± 12.3 years and (3 547 patients with lung cancer (age: 61.3 ± 8.2 years. LM was assessed using different devices (magnetic resonance imaging, dual-energy X-ray absorptiometry, computer tomography, total body potassium and bioelectrical impedance, body weight-based protein intake, its ratio (per kg LM and mean protein requirement were calculated. Variability in protein intake in all cohorts ranged from 0.83 to 1.77 g protein per kg LM per day using (theoretical protein intake of 60 g protein per day. Calculated mean protein requirement was 1.63 g protein per kg LM per day; consequently, 95.3% of healthy subjects, 100% of cirrhotic and 97.4% of cancer patients would present with a low protein intake per kg LM. Weight-adjusted recommendations are inadequate to address the LM specific differences in protein needs of healthy subjects or clinical populations. Absolute protein intake seems to be more relevant compared to the relative proportion of protein, which in turn changes with different energy needs.

Enhanced biological processes associated with alopecia in polar bears (Ursus maritimus)

Science.gov (United States)

Bowen, Lizabeth; Miles, A. Keith; Stott, Jeffrey L.; Waters, Shannon C.; Atwood, Todd C.

2015-01-01

Populations of wildlife species worldwide experience incidents of mass morbidity and mortality. Primary or secondary drivers of these events may escape classical detection methods for identifying microbial insults, toxin exposure, or additional stressors. In 2012, 28% of polar bears sampled in a study in the southern Beaufort Sea region of Alaska had varying degrees of alopecia that was concomitant with reduced body condition. Concurrently, elevated numbers of sick or dead ringed seals were detected in the southern Beaufort, Chukchi, and Bering seas in 2012, resulting in the declaration of an unusual mortality event (UME) by the National Oceanic and Atmospheric Administration (NOAA). The primary and possible ancillary causative stressors of these events are unknown, and related physiological changes within individual animals have been undetectable using classical diagnostic methods. Here we present an emerging technology as a potentially guiding investigative approach aimed at elucidating the circumstances responsible for the susceptibility of certain polar bears to observed conditions. Using transcriptomic analysis we identified enhanced biological processes including immune response, viral defense, and response to stress in polar bears with alopecia. Our results support an alternative mechanism of investigation into the causative agents that, when used proactively, could serve as an early indicator for populations and species at risk. We suggest that current or classical methods for investigation into events of unusual morbidity and mortality can be costly, sometimes unfocused, and often inconclusive. Advances in technology allow for implementation of a holistic system of surveillance and investigation that could provide early warning of health concerns in wildlife species important to humans.

Enhanced biological processes associated with alopecia in polar bears (Ursus maritimus).

Science.gov (United States)

Bowen, Lizabeth; Miles, A Keith; Stott, Jeffrey; Waters, Shannon; Atwood, Todd

2015-10-01

Populations of wildlife species worldwide experience incidents of mass morbidity and mortality. Primary or secondary drivers of these events may escape classical detection methods for identifying microbial insults, toxin exposure, or additional stressors. In 2012, 28% of polar bears sampled in a study in the southern Beaufort Sea region of Alaska had varying degrees of alopecia that was concomitant with reduced body condition. Concurrently, elevated numbers of sick or dead ringed seals were detected in the southern Beaufort, Chukchi, and Bering seas in 2012, resulting in the declaration of an unusual mortality event (UME) by the National Oceanic and Atmospheric Administration (NOAA). The primary and possible ancillary causative stressors of these events are unknown, and related physiological changes within individual animals have been undetectable using classical diagnostic methods. Here we present an emerging technology as a potentially guiding investigative approach aimed at elucidating the circumstances responsible for the susceptibility of certain polar bears to observed conditions. Using transcriptomic analysis we identified enhanced biological processes including immune response, viral defense, and response to stress in polar bears with alopecia. Our results support an alternative mechanism of investigation into the causative agents that, when used proactively, could serve as an early indicator for populations and species at risk. We suggest that current or classical methods for investigation into events of unusual morbidity and mortality can be costly, sometimes unfocused, and often inconclusive. Advances in technology allow for implementation of a holistic system of surveillance and investigation that could provide early warning of health concerns in wildlife species important to humans. Published by Elsevier B.V.

Surface chemistry and electronic structure of nonpolar and polar GaN films

Energy Technology Data Exchange (ETDEWEB)

Mishra, Monu; Krishna, T.C. Shibin; Aggarwal, Neha; Gupta, Govind, E-mail: govind@nplindia.org

2015-08-01

Highlights: • Surface chemistry and electronic structure of polar and nonpolar GaN is reported. • Influence of polarization on electron affinity of p & np GaN films is investigated. • Correlation between surface morphology and polarity has been deduced. - Abstract: Photoemission and microscopic analysis of nonpolar (a-GaN/r-Sapphire) and polar (c-GaN/c-Sapphire) epitaxial gallium nitride (GaN) films grown via RF-Molecular Beam Epitaxy is reported. The effect of polarization on surface properties like surface states, electronic structure, chemical bonding and morphology has been investigated and correlated. It was observed that polarization lead to shifts in core level (CL) as well as valence band (VB) spectra. Angle dependent X-ray Photoelectron Spectroscopic analysis revealed higher surface oxide in polar GaN film compared to nonpolar GaN film. On varying the take off angle (TOA) from 0° to 60°, the Ga−O/Ga−N ratio varied from 0.11–0.23 for nonpolar and 0.17–0.36 for polar GaN film. The nonpolar film exhibited N-face polarity while Ga-face polarity was perceived in polar GaN film due to the inherent polarization effect. Polarization charge compensated surface states were observed on the polar GaN film and resulted in downward band bending. Ultraviolet photoelectron spectroscopic measurements revealed electron affinity and ionization energy of 3.4 ± 0.1 eV and 6.8 ± 0.1 eV for nonpolar GaN film and 3.8 ± 0.1 eV and 7.2 ± 0.1 eV for polar GaN film respectively. Field Emission Scanning Electron Microscopy measurements divulged smooth morphology with pits on polar GaN film. The nonpolar film on the other hand showed pyramidal structures having facets all over the surface.

Development of high-polarization Fe/Ge neutron polarizing supermirror: Possibility of fine-tuning of scattering length density in ion beam sputtering

Science.gov (United States)

Maruyama, R.; Yamazaki, D.; Akutsu, K.; Hanashima, T.; Miyata, N.; Aoki, H.; Takeda, M.; Soyama, K.

2018-04-01

The multilayer structure of Fe/Si and Fe/Ge systems fabricated by ion beam sputtering (IBS) was investigated using X-ray and polarized neutron reflectivity measurements and scanning transmission electron microscopy with energy-dispersive X-ray analysis. The obtained result revealed that the incorporation of sputtering gas particles (Ar) in the Ge layer gives rise to a marked reduction in the neutron scattering length density (SLD) and contributes to the SLD contrast between the Fe and Ge layers almost vanishing for spin-down neutrons. Bundesmann et al. (2015) have shown that the implantation of primary Ar ions backscattered at the target is responsible for the incorporation of Ar particles and that the fraction increases with increasing ion incidence angle and increasing polar emission angle. This leads to a possibility of fine-tuning of the SLD for the IBS, which is required to realize a high polarization efficiency of a neutron polarizing supermirror. Fe/Ge polarizing supermirror with m = 5 fabricated under the same condition showed a spin-up reflectivity of 0.70 at the critical momentum transfer. The polarization was higher than 0.985 for the qz range where the correction for the polarization inefficiencies of the beamline works properly. The result of the polarized neutron reflectivity measurement suggests that the "magnetically-dead" layers formed at both sides of the Fe layer, together with the SLD contrast, play a critical role in determining the polarization performance of a polarizing supermirror.

Polarized proton beams

International Nuclear Information System (INIS)

Roser, T.

1995-01-01

The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

A Fuzzy Computing Model for Identifying Polarity of Chinese Sentiment Words.

Science.gov (United States)

Wang, Bingkun; Huang, Yongfeng; Wu, Xian; Li, Xing

2015-01-01

With the spurt of online user-generated contents on web, sentiment analysis has become a very active research issue in data mining and natural language processing. As the most important indicator of sentiment, sentiment words which convey positive and negative polarity are quite instrumental for sentiment analysis. However, most of the existing methods for identifying polarity of sentiment words only consider the positive and negative polarity by the Cantor set, and no attention is paid to the fuzziness of the polarity intensity of sentiment words. In order to improve the performance, we propose a fuzzy computing model to identify the polarity of Chinese sentiment words in this paper. There are three major contributions in this paper. Firstly, we propose a method to compute polarity intensity of sentiment morphemes and sentiment words. Secondly, we construct a fuzzy sentiment classifier and propose two different methods to compute the parameter of the fuzzy classifier. Thirdly, we conduct extensive experiments on four sentiment words datasets and three review datasets, and the experimental results indicate that our model performs better than the state-of-the-art methods.

Analysis of whole-body vibration on rheological models for tissues

Science.gov (United States)

Neamţu, A.; Simoiu, D.; Nyaguly, E.; Crastiu, I.; Bereteu, L.

2018-01-01

Whole body vibrations have become a very popular method in recent years, both in physical therapy and in sports. This popularity is due to the fact that, as a result of analyzing the groups of subjects, the effects of small amplitude vibration and low frequency vibration, it was found an increase in the force developed by the feet, a hardening of bone strength or an increase in bone density. In this paper we propose to give a possible explanation of the stress relieving in muscle and/or bone after whole body vibration treatment. To do this we consider some rheological models which after whole body vibrations and after the analysis of their response lead to various experiments.

Few body problems in nuclear and particle physics

International Nuclear Information System (INIS)

Slobodrian, R.J.; Cujec, B.; Ramavataram, K.

1975-01-01

Nucleon-nucleon interactions at all energies, meson-nucleon and meson-deuteron interactions, nuclear bremsstrahlung, on-shell and off-shell interactions, final-state interactions, bound and scattering states, few-body forces, polarization phenomena, short range correlations, quasi-free scattering, composite hadron models, subnucleon structure, multiparticle and coherent production processes, break-up reactions, electrodisintegration, relativistic effects and future resources in nuclear and particle physics are discussed in relation to the state of few-body physics in 1974. (B.F.G.)

Heme and non-heme iron transporters in non-polarized and polarized cells

Directory of Open Access Journals (Sweden)

Yasui Yumiko

2010-06-01

Full Text Available Abstract Background Heme and non-heme iron from diet, and recycled iron from hemoglobin are important products of the synthesis of iron-containing molecules. In excess, iron is potentially toxic because it can produce reactive oxygen species through the Fenton reaction. Humans can absorb, transport, store, and recycle iron without an excretory system to remove excess iron. Two candidate heme transporters and two iron transporters have been reported thus far. Heme incorporated into cells is degraded by heme oxygenases (HOs, and the iron product is reutilized by the body. To specify the processes of heme uptake and degradation, and the reutilization of iron, we determined the subcellular localizations of these transporters and HOs. Results In this study, we analyzed the subcellular localizations of 2 isoenzymes of HOs, 4 isoforms of divalent metal transporter 1 (DMT1, and 2 candidate heme transporters--heme carrier protein 1 (HCP1 and heme responsive gene-1 (HRG-1--in non-polarized and polarized cells. In non-polarized cells, HCP1, HRG-1, and DMT1A-I are located in the plasma membrane. In polarized cells, they show distinct localizations: HCP1 and DMT1A-I are located in the apical membrane, whereas HRG-1 is located in the basolateral membrane and lysosome. 16Leu at DMT1A-I N-terminal cytosolic domain was found to be crucial for plasma membrane localization. HOs are located in smooth endoplasmic reticulum and colocalize with NADPH-cytochrome P450 reductase. Conclusions HCP1 and DMT1A-I are localized to the apical membrane, and HRG-1 to the basolateral membrane and lysosome. These findings suggest that HCP1 and DMT1A-I have functions in the uptake of dietary heme and non-heme iron. HRG-1 can transport endocytosed heme from the lysosome into the cytosol. These localization studies support a model in which cytosolic heme can be degraded by HOs, and the resulting iron is exported into tissue fluids via the iron transporter ferroportin 1, which is

Biomagnification of polybrominated diphenyl ether and hexabromocyclododecane flame retardants in the polar bear food chain in Svalbard, Norway.

Science.gov (United States)

Sørmo, Eugen Gravningen; Salmer, Maria Pettersvik; Jenssen, Bjørn Munro; Hop, Haakon; Baek, Kine; Kovacs, Kit Maureen; Lydersen, Christian; Falk-Petersen, Stig; Gabrielsen, Geir Wing; Lie, Elisabeth; Skaare, Janneche Utne

2006-09-01

Concentrations of brominated flame retardants (BFRs), including polybrominated diphenylethers (PBDEs) and hexabromocyclododecane (HBCD), were investigated in an arctic marine food chain consisting of four invertebrate species: polar cod (Boreogadus saida), ringed seals (Pusa hispida), and polar bears (Ursus maritimus). The most abundant BFR, brominated diphenyl ether (BDE)-47, was found in detectable concentrations even in zooplankton, the lowest trophic level examined in this study. Most of the investigated BFRs biomagnified as function of tropic level in the food chain. A noticeable exception occurred at the highest trophic level, the polar bear, in which only BDE-153 was found to increase from its main prey, the ringed seal, indicating that polar bears appear to be able to metabolize and biodegrade most BFRs. In contrast, lower-brominated PBDEs, particularly BDE-47, showed clear signs of bioaccumulation in zooplankton, polar cod, and ringed seals. We suggest that this discrepancy in the fate of BFRs among the different species may be related to greater induction of oxidative detoxification activities in the polar bear. Absorption and debromination rates may be more important for bioaccumulation rates of BFRs in zooplankton, polar cod, and ringed seals. Lipid weight-based concentrations (LWCs) and whole body-based concentrations (WBCs) of BFRs were used to assess biomagnification factors (BMFs). Whole-body concentrations gave the most realistic BMFs, as BMFs derived from LWCs seem to be confounded by the large variability in lipid content of tissues from the investigated species. This study demonstrates that PBDEs and HBCD have reached measurable concentrations even in the lower trophic levels (invertebrates and fish) in the Arctic and biomagnifies in the polar bear food chain.

Polarizing aperture stereoscopic cinema camera

Science.gov (United States)

Lipton, Lenny

2012-07-01

The art of stereoscopic cinematography has been held back because of the lack of a convenient way to reduce the stereo camera lenses' interaxial to less than the distance between the eyes. This article describes a unified stereoscopic camera and lens design that allows for varying the interaxial separation to small values using a unique electro-optical polarizing aperture design for imaging left and right perspective views onto a large single digital sensor, the size of the standard 35 mm frame, with the means to select left and right image information. Even with the added stereoscopic capability, the appearance of existing camera bodies will be unaltered.

Investigation of the polarization state of dual APPLE-II undulators

International Nuclear Information System (INIS)

Hand, Matthew; Wang, Hongchang; Dhesi, Sarnjeet S.; Sawhney, Kawal

2016-01-01

Complete polarization analysis of the photon beam produced by a dual APPLE-II undulator configuration using a multilayer-based soft X-ray polarimeter is given. The use of an APPLE II undulator is extremely important for providing a high-brilliance X-ray beam with the capability to switch between various photon beam polarization states. A high-precision soft X-ray polarimeter has been used to systematically investigate the polarization characteristics of the two helical APPLE II undulators installed on beamline I06 at Diamond Light Source. A simple data acquisition and processing procedure has been developed to determine the Stokes polarization parameters for light polarized at arbitrary linear angles emitted from a single undulator, and for circularly polarized light emitted from both undulators in conjunction with a single-period undulator phasing unit. The purity of linear polarization is found to deteriorate as the polarization angle moves away from the horizontal and vertical modes. Importantly, a negative correlation between the degree of circular polarization and the photon flux has been found when the phasing unit is used

Investigation of the polarization state of dual APPLE-II undulators

Energy Technology Data Exchange (ETDEWEB)

Hand, Matthew; Wang, Hongchang, E-mail: hongchang.wang@diamond.ac.uk; Dhesi, Sarnjeet S.; Sawhney, Kawal [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE (United Kingdom)

2016-01-01

Complete polarization analysis of the photon beam produced by a dual APPLE-II undulator configuration using a multilayer-based soft X-ray polarimeter is given. The use of an APPLE II undulator is extremely important for providing a high-brilliance X-ray beam with the capability to switch between various photon beam polarization states. A high-precision soft X-ray polarimeter has been used to systematically investigate the polarization characteristics of the two helical APPLE II undulators installed on beamline I06 at Diamond Light Source. A simple data acquisition and processing procedure has been developed to determine the Stokes polarization parameters for light polarized at arbitrary linear angles emitted from a single undulator, and for circularly polarized light emitted from both undulators in conjunction with a single-period undulator phasing unit. The purity of linear polarization is found to deteriorate as the polarization angle moves away from the horizontal and vertical modes. Importantly, a negative correlation between the degree of circular polarization and the photon flux has been found when the phasing unit is used.

Differential sensitivity of epithelial cells to extracellular matrix in polarity establishment.

Directory of Open Access Journals (Sweden)

Shigenobu Yonemura

Full Text Available Establishment of apical-basal polarity is crucial for epithelial sheets that form a compartment in the body, which function to maintain the environment in the compartment. Effects of impaired polarization are easily observed in three-dimensional (3-D culture systems rather than in two-dimensional (2-D culture systems. Although the mechanisms for establishing the polarity are not completely understood, signals from the extracellular matrix (ECM are considered to be essential for determining the basal side and eventually generating polarity in the epithelial cells. To elucidate the common features and differences in polarity establishment among various epithelial cells, we analyzed the formation of epithelial apical-basal polarity using three cell lines of different origin: MDCK II cells (dog renal tubules, EpH4 cells (mouse mammary gland, and R2/7 cells (human colon expressing wild-type α-catenin (R2/7 α-Cate cells. These cells showed clear apical-basal polarity in 2-D cultures. In 3-D cultures, however, each cell line displayed different responses to the same ECM. In MDCK II cells, spheroids with a single lumen formed in both Matrigel and collagen gel. In R2/7 α-Cate cells, spheroids showed similar apical-basal polarity as that seen in MDCK II cells, but had multiple lumens. In EpH4 cells, the spheroids displayed an apical-basal polarity that was opposite to that seen in the other two cell types in both ECM gels, at least during the culture period. On the other hand, the three cell lines showed the same apical-basal polarity both in 2-D cultures and in 3-D cultures using the hanging drop method. The three lines also had similar cellular responses to ECM secreted by the cells themselves. Therefore, appropriate culture conditions should be carefully determined in advance when using various epithelial cells to analyze cell polarity or 3-D morphogenesis.

Charge transport in non-polar and semi-polar III-V nitride heterostructures

International Nuclear Information System (INIS)

Konar, Aniruddha; Verma, Amit; Fang, Tian; Zhao, Pei; Jana, Raj; Jena, Debdeep

2012-01-01

Compared to the intense research focus on the optical properties, the transport properties in non-polar and semi-polar III-nitride semiconductors remain relatively unexplored to date. The purpose of this paper is to discuss charge-transport properties in non-polar and semi-polar orientations of GaN in a comparative fashion to what is known for transport in polar orientations. A comprehensive approach is adopted, starting from an investigation of the differences in the electronic bandstructure along different polar orientations of GaN. The polarization fields along various orientations are then discussed, followed by the low-field electron and hole mobilities. A number of scattering mechanisms that are specific to non-polar and semi-polar GaN heterostructures are identified, and their effects are evaluated. Many of these scattering mechanisms originate due to the coupling of polarization with disorder and defects in various incarnations depending on the crystal orientation. The effect of polarization orientation on carrier injection into quantum-well light-emitting diodes is discussed. This paper ends with a discussion of orientation-dependent high-field charge-transport properties including velocity saturation, instabilities and tunneling transport. Possible open problems and opportunities are also discussed. (paper)

6C polarization analysis - seismic direction finding in coherent noise, automated event identification, and wavefield separation

Science.gov (United States)

Schmelzbach, C.; Sollberger, D.; Greenhalgh, S.; Van Renterghem, C.; Robertsson, J. O. A.

2017-12-01

Polarization analysis of standard three-component (3C) seismic data is an established tool to determine the propagation directions of seismic waves recorded by a single station. A major limitation of seismic direction finding methods using 3C recordings, however, is that a correct propagation-direction determination is only possible if the wave mode is known. Furthermore, 3C polarization analysis techniques break down in the presence of coherent noise (i.e., when more than one event is present in the analysis time window). Recent advances in sensor technology (e.g., fibre-optical, magnetohydrodynamic angular rate sensors, and ring laser gyroscopes) have made it possible to accurately measure all three components of rotational ground motion exhibited by seismic waves, in addition to the conventionally recorded three components of translational motion. Here, we present an extension of the theory of single station 3C polarization analysis to six-component (6C) recordings of collocated translational and rotational ground motions. We demonstrate that the information contained in rotation measurements can help to overcome some of the main limitations of standard 3C seismic direction finding, such as handling multiple arrivals simultaneously. We show that the 6C polarisation of elastic waves measured at the Earth's free surface does not only depend on the seismic wave type and propagation direction, but also on the local P- and S-wave velocities just beneath the recording station. Using an adaptation of the multiple signal classification algorithm (MUSIC), we demonstrate how seismic events can univocally be identified and characterized in terms of their wave type. Furthermore, we show how the local velocities can be inferred from single-station 6C data, in addition to the direction angles (inclination and azimuth) of seismic arrivals. A major benefit of our proposed 6C method is that it also allows the accurate recovery of the wave type, propagation directions, and phase

Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations.

Science.gov (United States)

Rode, Karyn D; Regehr, Eric V; Douglas, David C; Durner, George; Derocher, Andrew E; Thiemann, Gregory W; Budge, Suzanne M

2014-01-01

Polar bears (Ursus maritimus) have experienced substantial changes in the seasonal availability of sea ice habitat in parts of their range, including the Beaufort, Chukchi, and Bering Seas. In this study, we compared the body size, condition, and recruitment of polar bears captured in the Chukchi and Bering Seas (CS) between two periods (1986-1994 and 2008-2011) when declines in sea ice habitat occurred. In addition, we compared metrics for the CS population 2008-2011 with those of the adjacent southern Beaufort Sea (SB) population where loss in sea ice habitat has been associated with declines in body condition, size, recruitment, and survival. We evaluated how variation in body condition and recruitment were related to feeding ecology. Comparing habitat conditions between populations, there were twice as many reduced ice days over continental shelf waters per year during 2008-2011 in the SB than in the CS. CS polar bears were larger and in better condition, and appeared to have higher reproduction than SB bears. Although SB and CS bears had similar diets, twice as many bears were fasting in spring in the SB than in the CS. Between 1986-1994 and 2008-2011, body size, condition, and recruitment indices in the CS were not reduced despite a 44-day increase in the number of reduced ice days. Bears in the CS exhibited large body size, good body condition, and high indices of recruitment compared to most other populations measured to date. Higher biological productivity and prey availability in the CS relative to the SB, and a shorter recent history of reduced sea ice habitat, may explain the maintenance of condition and recruitment of CS bears. Geographic differences in the response of polar bears to climate change are relevant to range-wide forecasts for this and other ice-dependent species. © 2013 John Wiley & Sons Ltd.

Variation in the response of an Arctic top predator experiencing habitat loss: Feeding and reproductive ecology of two polar bear populations

Science.gov (United States)

Rode, Karyn D.; Regehr, Eric V.; Douglas, David C.; Durner, George M.; Derocher, Andrew E.; Thiemann, Gregory W.; Budge, Suzanne M.

2014-01-01

Polar bears (Ursus maritimus) have experienced substantial changes in the seasonal availability of sea ice habitat in parts of their range, including the Beaufort, Chukchi, and Bering Seas. In this study, we compared the body size, condition, and recruitment of polar bears captured in the Chukchi and Bering Seas (CS) between two periods (1986–1994 and 2008–2011) when declines in sea ice habitat occurred. In addition, we compared metrics for the CS population 2008–2011 with those of the adjacent southern Beaufort Sea (SB) population where loss in sea ice habitat has been associated with declines in body condition, size, recruitment, and survival. We evaluated how variation in body condition and recruitment were related to feeding ecology. Comparing habitat conditions between populations, there were twice as many reduced ice days over continental shelf waters per year during 2008–2011 in the SB than in the CS. CS polar bears were larger and in better condition, and appeared to have higher reproduction than SB bears. Although SB and CS bears had similar diets, twice as many bears were fasting in spring in the SB than in the CS. Between 1986–1994 and 2008–2011, body size, condition, and recruitment indices in the CS were not reduced despite a 44-day increase in the number of reduced ice days. Bears in the CS exhibited large body size, good body condition, and high indices of recruitment compared to most other populations measured to date. Higher biological productivity and prey availability in the CS relative to the SB, and a shorter recent history of reduced sea ice habitat, may explain the maintenance of condition and recruitment of CS bears. Geographic differences in the response of polar bears to climate change are relevant to range-wide forecasts for this and other ice-dependent species.

Polarization measurement by use of discrete space-variant sub wavelength dielectric gratings

International Nuclear Information System (INIS)

Biener, G.; Niv, A.; Gorodetski, Yu.; Kleiner, V.; Hasman, E.

2004-01-01

Full Text:Polarization measurement has been widely used for a large range of applications such as ellipsometry bio-imaging, imaging polarimetry and optical communications. A commonly used method is measuring of the time-dependent signal once the beam is transmitted through a photoelastic modulator or a rotating quarter-wave plate followed by an analyzer. The polarization state of the beam can be derived by Fourier analysis of the detected signal. This method, however, requires a sequence of consecutive measurements, thus making it impractical for real-time polarization measurement in an application such as adaptive polarization-mode dispersion compensation in optical communications. Recently, we developed a novel method for real-time polarization measurement by use of a discrete space-variant sub wavelength dielectric grating (DSG). The formation of the grating is done by discrete orientation of the local sub wavelength grooves. The complete polarization analysis of the incident beam is determined by spatial Fourier transform of the near-field intensity distribution transmitted through the DSG followed by a sub wavelength metal polarizer. We realized the gratings for CO 2 laser radiation at a wavelength of 10.6 micron on GaAs substrate utilizing advanced photo lithographic and etching techniques. We experimentally demonstrated the ability of our method to measure the polarization state for fully and partially polarized light. Unlike other methods based on Fourier analysis, no active elements are required. It is possible to integrate our polarimeter on a two-dimensional detector array for lab-on chip applications to achieve a high-throughput and low-cost commercial polarimeter for bio sensing. Currently we are investigating the possibility of using far-field measurement of the beam emerging from a DSG for polarization measurement

[A Concept Analysis for Mind-Body Interaction].

Science.gov (United States)

Chen, Hsing-Wen; Yeh, Mei-Ling; Rong, Jiin-Ru

2015-08-01

Mind-body interaction (MBI) refers the holistic association and interactive process between wisdom, thinking, belief, and physiological reaction, which critically affects health. The main goal of nursing is to maintain mind and body in a healthy state of well being. Few reports in the literatures have addressed the evaluation and application of MBI. Thus, a conceptual analysis of this subject is worth exploring in depth. This paper analyzes the MBI concept step by step based on the procedures of Walker and Avant. The result defines the characteristics of MBI as (1) being aware of psychosomatic effects, (2) interacting between psychology, neurology, immunology and others, and (3) turning out a bio-psycho-social status. Antecedents include geography, culture, race, gender, age, education, profession, values, personality, experience, and health status. Consequences of MBI include well-being, illness, and death. This paper provides new information on MBI that clarifies its meaning, provides comprehensive cognition, and suggests useful applications.

Polarization-sensitive color in butterfly scales: polarization conversion from ridges with reflecting elements.

Science.gov (United States)

Zhang, Ke; Tang, Yiwen; Meng, Jinsong; Wang, Ge; Zhou, Han; Fan, Tongxiang; Zhang, Di

2014-11-03

Polarization-sensitive color originates from polarization-dependent reflection or transmission, exhibiting abundant light information, including intensity, spectral distribution, and polarization. A wide range of butterflies are physiologically sensitive to polarized light, but the origins of polarized signal have not been fully understood. Here we systematically investigate the colorful scales of six species of butterfly to reveal the physical origins of polarization-sensitive color. Microscopic optical images under crossed polarizers exhibit their polarization-sensitive characteristic, and micro-structural characterizations clarify their structural commonality. In the case of the structural scales that have deep ridges, the polarization-sensitive color related with scale azimuth is remarkable. Periodic ridges lead to the anisotropic effective refractive indices in the parallel and perpendicular grating orientations, which achieves form-birefringence, resulting in the phase difference of two different component polarized lights. Simulated results show that ridge structures with reflecting elements reflect and rotate the incident p-polarized light into s-polarized light. The dimensional parameters and shapes of grating greatly affect the polarization conversion process, and the triangular deep grating extends the outstanding polarization conversion effect from the sub-wavelength period to the period comparable to visible light wavelength. The parameters of ridge structures in butterfly scales have been optimized to fulfill the polarization-dependent reflection for secret communication. The structural and physical origin of polarization conversion provides a more comprehensive perspective on the creation of polarization-sensitive color in butterfly wing scales. These findings show great potential in anti-counterfeiting technology and advanced optical material design.

COMPASS polarized Drell-Yan experiment

CERN Document Server

Doshita, Norihiro

2016-01-01

The COMPASS II started at 2012 that includes polarized Drell-Yan program with a polarized solid target. The availability of pion beam provides an access to the Drell-Yan physics throughout the process where quark(target)-antiquark(beam) pair annihilates electromagnetically with a production of dilepton pair. Study of angular dependencies of the Drell-Yan process cross-section allows us to access to parton distribution functions (PDFs) or, more precisely, a convolutions of various PDFs. The transversely polarized target together with negative pion beam is an important feature of the COMPASS Drell-Yan experiment, that provides us with unique data on transverse momentum dependent (TMD) PDFs. After a plot run in 2014, the experiment has just started in 2015. The role of the Drell-Yan experiment at COMPASS in TMD PDFs study, with a comparison to semi-inclusive deep inelastic scattering experiment, is described. The experimental set-up, the status of the data taking in 2015 and preliminary analysis results in the 2...

Non-commutativity in polar coordinates

Energy Technology Data Exchange (ETDEWEB)

Edwards, James P. [Universidad Michoacana de San Nicolas de Hidalgo, Ciudad Universitaria, Instituto de Fisica y Matematicas, Morelia, Michoacan (Mexico)

2017-05-15

We reconsider the fundamental commutation relations for non-commutative R{sup 2} described in polar coordinates with non-commutativity parameter θ. Previous analysis found that the natural transition from Cartesian coordinates to the traditional polar system led to a representation of [r, φ] as an everywhere diverging series. In this article we compute the Borel resummation of this series, showing that it can subsequently be extended throughout parameter space and hence provide an interpretation of this commutator. Our analysis provides a complete solution for arbitrary r and θ that reproduces the earlier calculations at lowest order and benefits from being generally applicable to problems in a two-dimensional non-commutative space. We compare our results to previous literature in the (pseudo-)commuting limit, finding a surprising spatial dependence for the coordinate commutator when θ >> r{sup 2}. Finally, we raise some questions for future study in light of this progress. (orig.)

System for measuring the proton polarization in a polarized target

International Nuclear Information System (INIS)

Karnaukhov, I.M.; Lukhanin, A.A.; Telegin, Yu.N.; Trotsenko, V.I.; Chechetenko, V.F.

1984-01-01

The system for measuring the proton polarization in a polarized target representing the high-sensitivity nuclear magnetic resonance (NMR) is described Q-meter with series connection and a circuit for measuring system resonance characteristic is used for NMR-absorption signal recording. Measuring coil is produced of a strip conductor in order to obtain uniform system sensitivity to polarization state in all target volume and improve signal-to-noise ratio. Polarization measuring system operates ion-line with the M-6000 computer. The total measuring error for the value of free proton polarization in target taking into account the error caused by local depolarization of working substance under irradiation by high-intense photon beam is <= 6%. Long-term application of the described system for measuring the proton polarization in the LUEh-20000 accelerator target used in the pion photoproduction experiments has demonstrated its high reliability

Sources of polarized neutrons

International Nuclear Information System (INIS)

Walter, L.

1983-01-01

Various sources of polarized neutrons are reviewed. Monoenergetic source produced with unpolarized or polarized beams, white sources of polarized neutrons, production by transmissions through polarized hydrogen targets and polarized thermal neutronsare discussed, with appropriate applications included. (U.K.)

THE SMALL BODY GEOPHYSICAL ANALYSIS TOOL

Science.gov (United States)

Bercovici, Benjamin; McMahon, Jay

2017-10-01

The Small Body Geophysical Analysis Tool (SBGAT) that we are developing aims at providing scientists and mission designers with a comprehensive, easy to use, open-source analysis tool. SBGAT is meant for seamless generation of valuable simulated data originating from small bodies shape models, combined with advanced shape-modification properties.The current status of SBGAT is as follows:The modular software architecture that was specified in the original SBGAT proposal was implemented in the form of two distinct packages: a dynamic library SBGAT Core containing the data structure and algorithm backbone of SBGAT, and SBGAT Gui which wraps the former inside a VTK, Qt user interface to facilitate user/data interaction. This modular development facilitates maintenance and addi- tion of new features. Note that SBGAT Core can be utilized independently from SBGAT Gui.SBGAT is presently being hosted on a GitHub repository owned by SBGAT’s main developer. This repository is public and can be accessed at https://github.com/bbercovici/SBGAT. Along with the commented code, one can find the code documentation at https://bbercovici.github.io/sbgat-doc/index.html. This code documentation is constently updated in order to reflect new functionalities.SBGAT’s user’s manual is available at https://github.com/bbercovici/SBGAT/wiki. This document contains a comprehensive tutorial indicating how to retrieve, compile and run SBGAT from scratch.Some of the upcoming development goals are listed hereafter. First, SBGAT's dynamics module will be extented: the PGM algorithm is the only type of analysis method currently implemented. Future work will therefore consists in broadening SBGAT’s capabilities with the Spherical Harmonics Expansion of the gravity field and the calculation of YORP coefficients. Second, synthetic measurements will soon be available within SBGAT. The software should be able to generate synthetic observations of different type (radar, lightcurve, point clouds

PolarHub: A Global Hub for Polar Data Discovery

Science.gov (United States)

Li, W.

2014-12-01

This paper reports the outcome of a NSF project in developing a large-scale web crawler PolarHub to discover automatically the distributed polar dataset in the format of OGC web services (OWS) in the cyberspace. PolarHub is a machine robot; its goal is to visit as many webpages as possible to find those containing information about polar OWS, extract this information and store it into the backend data repository. This is a very challenging task given huge data volume of webpages on the Web. Three unique features was introduced in PolarHub to make it distinctive from earlier crawler solutions: (1) a multi-task, multi-user, multi-thread support to the crawling tasks; (2) an extensive use of thread pool and Data Access Object (DAO) design patterns to separate persistent data storage and business logic to achieve high extendibility of the crawler tool; (3) a pattern-matching based customizable crawling algorithm to support discovery of multi-type geospatial web services; and (4) a universal and portable client-server communication mechanism combining a server-push and client pull strategies for enhanced asynchronous processing. A series of experiments were conducted to identify the impact of crawling parameters to the overall system performance. The geographical distribution pattern of all PolarHub identified services is also demonstrated. We expect this work to make a major contribution to the field of geospatial information retrieval and geospatial interoperability, to bridge the gap between data provider and data consumer, and to accelerate polar science by enhancing the accessibility and reusability of adequate polar data.

Collective effects in spin polarized plasmas

International Nuclear Information System (INIS)

Coppi, B.; Cowley, S.; Detragiache, P.; Kulsrud, R.; Pegoraro, F.

1984-10-01

A fusing plasma with coherently polarized spin nuclei can be subject to instabilities due to the anisotropy of the reaction product distributions in velocity space, which is a result of their polarization. The characteristics of these instabilities depend strongly on the plasma spatial inhomogeneities and a significant rate of spin depolarization can be produced by them if adequate fluctuation amplitudes are reached. The results of the relevant analysis are, in addition, of interest for plasma heating processes with frequencies in the range of the cyclotron frequencies of the considered nuclei

Polarization extinction ratio of the polarization crosstalk caused by point pressure force in the polarization-maintaining fiber

Science.gov (United States)

Mukhtubayev, Azamat B.; Aksarin, Stanislav M.; Strigalev, Vladimir E.

2017-11-01

A study of the orthogonal polarization modes crosstalk changes in the point of different mechanical actions (pressure force) in the polarization-maintaining fiber with straining elliptical cladding is presented. It was found that by increasing of the pressure force the polarization extinction ratio increases nonlinearly. Also revealed the dependence of the extinction coefficient and the angle between vector of the mechanical action and polarization axes of the test fiber, which leads to change the extinction coefficient variable from -57 dB to -25 dB under the pressure force of 0.7 N. Also it was found that the cross angle of the fiber axes doesn't influence on the extinction ratio value of the mechanical induced polarization crosstalk.

Polarized secondary radioactive beams

International Nuclear Information System (INIS)

Zaika, N.I.

1992-01-01

Three methods of polarized radioactive nuclei beam production: a) a method nuclear interaction of the non-polarized or polarized charged projectiles with target nuclei; b) a method of polarization of stopped reaction radioactive products in a special polarized ion source with than following acceleration; c) a polarization of radioactive nuclei circulating in a storage ring are considered. Possible life times of the radioactive ions for these methods are determined. General schemes of the polarization method realizations and depolarization problems are discussed

Performance study of the gamma-ray bursts polarimeter POLAR

Science.gov (United States)

Sun, J. C.; Wu, B. B.; Bao, T. W.; Batsch, T.; Bernasconi, T.; Britvitch, I.; Cadoux, F.; Cernuda, I.; Chai, J. Y.; Dong, Y. W.; Gauvin, N.; Hajdas, W.; He, J. J.; Kole, M.; Kong, M. N.; Kong, S. W.; Lechanoine-Leluc, C.; Li, Lu; Liu, J. T.; Liu, X.; Marcinkowski, R.; Orsi, S.; Pohl, M.; Produit, N.; Rapin, D.; Rutczynska, A.; Rybka, D.; Shi, H. L.; Song, L. M.; Szabelski, J.; Wang, R. J.; Wen, X.; Xiao, H. L.; Xiong, S. L.; Xu, H. H.; Xu, M.; Zhang, L.; Zhang, L. Y.; Zhang, S. N.; Zhang, X. F.; Zhang, Y. J.; Zwolinska, A.

2016-07-01

The Gamma-ray Burst Polarimeter-POLAR is a highly sensitive detector which is dedicated to the measurement of GRB's polarization with a large effective detection area and a large field of view (FOV). The optimized performance of POLAR will contribute to the capture and measurement of the transient sources like GRBs and Solar Flares. The detection energy range of POLAR is 50 keV 500 keV, and mainly dominated by the Compton scattering effect. POLAR consists of 25 detector modular units (DMUs), and each DMU is composed of low Z material Plastic Scintillators (PS), multi-anode photomultipliers (MAPMT) and multi-channel ASIC Front-end Electronics (FEE). POLAR experiment is an international collaboration project involving China, Switzerland and Poland, and is expected to be launched in September in 2016 onboard the Chinese space laboratory "Tiangong-2 (TG-2)". With the efforts from the collaborations, POLAR has experienced the Demonstration Model (DM) phase, Engineering and Qualification Model (EQM) phase, Qualification Model (QM) phase, and now a full Flight Model (FM) of POLAR has been constructed. The FM of POLAR has passed the environmental acceptance tests (thermal cycling, vibration, shock and thermal vacuum tests) and experienced the calibration tests with both radioactive sources and 100% polarized Gamma-Ray beam at ESRF after its construction. The design of POLAR, Monte-Carlo simulation analysis, as well as the performance test results will all be introduced in this paper.

Scattering of polarized electrons from polarized targets: Coincidence reactions and prescriptions for polarized half-off-shell single-nucleon cross sections

International Nuclear Information System (INIS)

Caballero, J.A.; Massachusetts Inst. of Tech., Cambridge, MA; Donnelly, T.W.; Massachusetts Inst. of Tech., Cambridge, MA; Poulis, G.I.; Massachusetts Inst. of Tech., Cambridge, MA

1993-01-01

Coincidence reactions of the type vector A( vector e, e'N)B involving the scattering of polarized electrons from polarized targets are discussed within the context of the plane-wave impulse approximation. Prescriptions are developed for polarized half-off single-nucleon cross sections; the different prescriptions are compared for typical quasi-free kinematics. Illustrative results are presented for coincidence polarized electron scattering from typical polarized nuclei. (orig.)

Genome-wide association analysis identifies three new susceptibility loci for childhood body mass index

NARCIS (Netherlands)

J.F. Felix (Janine); J.P. Bradfield (Jonathan); C. Monnereau; R.J.P. van der Valk (Ralf); E. Stergiakouli (Evie); A. Chesi (Alessandra); R. Gaillard (Romy); B. Feenstra (Bjarke); E. Thiering (Elisabeth); E. Kreiner-Møller (Eskil); A. Mahajan (Anubha); Niina Pitkänen; R. Joro (Raimo); A. Cavadino (Alana); V. Huikari (Ville); S. Franks (Steve); M. Groen-Blokhuis (Maria); D.L. Cousminer (Diana); J.A. Marsh (Julie); T. Lehtimäki (Terho); J.A. Curtin (John); J. Vioque (Jesus); T.S. Ahluwalia (Tarunveer Singh); R. Myhre (Ronny); T.S. Price (Thomas); Natalia Vilor-Tejedor; L. Yengo (Loic); N. Grarup (Niels); I. Ntalla (Ioanna); W.Q. Ang (Wei); M. Atalay (Mustafa); H. Bisgaard (Hans); A.I.F. Blakemore (Alexandra); A. Bonnefond (Amélie); L. Carstensen (Lisbeth); J.G. Eriksson (Johan G.); C. Flexeder (Claudia); L. Franke (Lude); F. Geller (Frank); M. Geserick (Mandy); A.L. Hartikainen; C.M.A. Haworth (Claire M.); J.N. Hirschhorn (Joel N.); A. Hofman (Albert); J.-C. Holm (Jens-Christian); M. Horikoshi (Momoko); J.J. Hottenga (Jouke Jan); J. Huang (Jian); H.N. Kadarmideen (Haja N.); M. Kähönen (Mika); W. Kiess (Wieland); T.A. Lakka (Timo); T.A. Lakka (Timo); A. Lewin (Alex); L. Liang (Liming); L.-P. Lyytikäinen (Leo-Pekka); B. Ma (Baoshan); P. Magnus (Per); S.E. McCormack (Shana E.); G. Mcmahon (George); F.D. Mentch (Frank); C.M. Middeldorp (Christel); C.S. Murray (Clare S.); K. Pahkala (Katja); T.H. Pers (Tune); R. Pfäffle (Roland); D.S. Postma (Dirkje); C. Power (Christine); A. Simpson (Angela); V. Sengpiel (Verena); C. Tiesler (Carla); M. Torrent (Maties); A.G. Uitterlinden (André); J.B.J. van Meurs (Joyce); R. Vinding (Rebecca); J. Waage (Johannes); J. Wardle (Jane); E. Zeggini (Eleftheria); B.S. Zemel (Babette S.); G.V. Dedoussis (George); O. Pedersen (Oluf); P. Froguel (Philippe); J. Sunyer (Jordi); R. Plomin (Robert); B. Jacobsson (Bo); T. Hansen (Torben); J.R. Gonzalez (Juan R.); A. Custovic; O.T. Raitakari (Olli T.); C.E. Pennell (Craig); Elisabeth Widén; D.I. Boomsma (Dorret); G.H. Koppelman (Gerard); S. Sebert (Sylvain); M.-R. Jarvelin (Marjo-Riitta); E. Hypponen (Elina); M.I. McCarthy (Mark); V. Lindi (Virpi); N. Harri (Niinikoski); A. Körner (Antje); K. Bønnelykke (Klaus); J. Heinrich (Joachim); M. Melbye (Mads); F. Rivadeneira Ramirez (Fernando); H. Hakonarson (Hakon); S.M. Ring (Susan); G.D. Smith; T.I.A. Sørensen (Thorkild I.A.); N.J. Timpson (Nicholas); S.F.A. Grant (Struan); V.W.V. Jaddoe (Vincent); H.J. Kalkwarf (Heidi J.); J.M. Lappe (Joan M.); V. Gilsanz (Vicente); S.E. Oberfield (Sharon E.); J.A. Shepherd (John A.); A. Kelly (Andrea)

2016-01-01

textabstractA large number of genetic loci are associated with adult body mass index. However, the genetics of childhood body mass index are largely unknown.We performed a meta-analysis of genome-wide association studies of childhood body mass index, using sex- and age-adjusted standard deviation

Ortho-Babinet polarization-interrogating filter: an interferometric approach to polarization measurement.

Science.gov (United States)

Van Delden, Jay S

2003-07-15

A novel, interferometric, polarization-interrogating filter assembly and method for the simultaneous measurement of all four Stokes parameters across a partially polarized irradiance image in a no-moving-parts, instantaneous, highly sensitive manner is described. In the reported embodiment of the filter, two spatially varying linear retarders and a linear polarizer comprise an ortho-Babinet, polarization-interrogating (OBPI) filter. The OBPI filter uniquely encodes the incident ensemble of electromagnetic wave fronts comprising a partially polarized irradiance image in a controlled, deterministic, spatially varying manner to map the complete state of polarization across the image to local variations in a superposed interference pattern. Experimental interferograms are reported along with a numerical simulation of the method.

Three-body recombination of cold fermionic atoms

International Nuclear Information System (INIS)

Suno, H; Esry, B D; Greene, Chris H

2003-01-01

Recombination of identical, spin-polarized fermions in cold three-body collisions is investigated. We parametrize the mechanisms for recombination in terms of the 'scattering volume' V p and another length scale r 0 . Model two-body interactions were used within the framework of the adiabatic hyperspherical representation. We examine the recombination rate K 3 as a function of the collision energy E for various values of V p . Not only do we consider the dominant J Π = 1 + case, but also the next-leading order contributions from J Π = 1 - and 3 - . We discuss the behaviour near a two-body resonance and the expected universality of fermionic recombination. Comparisons with boson recombination are considered in detail

Performance Analysis of CRC Codes for Systematic and Nonsystematic Polar Codes with List Decoding

Directory of Open Access Journals (Sweden)

Takumi Murata

2018-01-01

Full Text Available Successive cancellation list (SCL decoding of polar codes is an effective approach that can significantly outperform the original successive cancellation (SC decoding, provided that proper cyclic redundancy-check (CRC codes are employed at the stage of candidate selection. Previous studies on CRC-assisted polar codes mostly focus on improvement of the decoding algorithms as well as their implementation, and little attention has been paid to the CRC code structure itself. For the CRC-concatenated polar codes with CRC code as their outer code, the use of longer CRC code leads to reduction of information rate, whereas the use of shorter CRC code may reduce the error detection probability, thus degrading the frame error rate (FER performance. Therefore, CRC codes of proper length should be employed in order to optimize the FER performance for a given signal-to-noise ratio (SNR per information bit. In this paper, we investigate the effect of CRC codes on the FER performance of polar codes with list decoding in terms of the CRC code length as well as its generator polynomials. Both the original nonsystematic and systematic polar codes are considered, and we also demonstrate that different behaviors of CRC codes should be observed depending on whether the inner polar code is systematic or not.

Nonlinear analysis of 0-3 polarized PLZT microplate based on the new modified couple stress theory

Science.gov (United States)

Wang, Liming; Zheng, Shijie

2018-02-01

In this study, based on the new modified couple stress theory, the size- dependent model for nonlinear bending analysis of a pure 0-3 polarized PLZT plate is developed for the first time. The equilibrium equations are derived from a variational formulation based on the potential energy principle and the new modified couple stress theory. The Galerkin method is adopted to derive the nonlinear algebraic equations from governing differential equations. And then the nonlinear algebraic equations are solved by using Newton-Raphson method. After simplification, the new model includes only a material length scale parameter. In addition, numerical examples are carried out to study the effect of material length scale parameter on the nonlinear bending of a simply supported pure 0-3 polarized PLZT plate subjected to light illumination and uniform distributed load. The results indicate the new model is able to capture the size effect and geometric nonlinearity.

Experiments with Fermilab polarized proton and polarized antiproton beams

International Nuclear Information System (INIS)

Yokosawa, A.

1990-01-01

We summarize activities concerning the Fermilab polarized beams. They include a brief description of the polarized-beam facility, measurements of beam polarization by polarimeters, asymmetry measurements in the π degree production at high p perpendicular and in the Λ (Σ degree), π ± , π degree production at large x F , and Δσ L (pp, bar pp) measurements. 18 refs

Testing statistical isotropy in cosmic microwave background polarization maps

Science.gov (United States)

Rath, Pranati K.; Samal, Pramoda Kumar; Panda, Srikanta; Mishra, Debesh D.; Aluri, Pavan K.

2018-04-01

We apply our symmetry based Power tensor technique to test conformity of PLANCK Polarization maps with statistical isotropy. On a wide range of angular scales (l = 40 - 150), our preliminary analysis detects many statistically anisotropic multipoles in foreground cleaned full sky PLANCK polarization maps viz., COMMANDER and NILC. We also study the effect of residual foregrounds that may still be present in the Galactic plane using both common UPB77 polarization mask, as well as the individual component separation method specific polarization masks. However, some of the statistically anisotropic modes still persist, albeit significantly in NILC map. We further probed the data for any coherent alignments across multipoles in several bins from the chosen multipole range.

Body composition of chronic renal patients: anthropometry and bioimpedance vector analysis

Directory of Open Access Journals (Sweden)

Viviane Soares

2013-12-01

Full Text Available OBJECTIVE: to compare the body composition of patients undergoing hemodialysis with that of healthy individuals using different methods. METHOD: cross-sectional study assessing male individuals using anthropometric markers, electrical bioimpedance and vector analysis. RESULTS: the healthy individuals presented larger triceps skinfold and arm circumference (p<0.001. The bioimpedance variables also presented significant higher values in this group. Significant difference was found in the confidence interval of the vector analysis performed for both the patients and healthy individuals (p<0.0001. The tolerance intervals showed that 55.20% of the patients were dehydrated, 10.30% presented visible edema, and 34.50% were within normal levels of hydration. Bioimpedance and vector analysis revealed that 52% of the patients presented decreased cell mass while 14.00% presented increased cell mass. CONCLUSIONS: the differences in the body composition of patients and healthy individuals were revealed through bioimpedance and vector analysis but not through their measures of arm circumference and arm muscle area.

Oxygen hypothesis of polar gigantism not supported by performance of Antarctic pycnogonids in hypoxia

Science.gov (United States)

Woods, H. Arthur; Moran, Amy L.; Arango, Claudia P.; Mullen, Lindy; Shields, Chris

2008-01-01

Compared to temperate and tropical relatives, some high-latitude marine species are large-bodied, a phenomenon known as polar gigantism. A leading hypothesis on the physiological basis of gigantism posits that, in polar water, high oxygen availability coupled to low metabolic rates relieves constraints on oxygen transport and allows the evolution of large body size. Here, we test the oxygen hypothesis using Antarctic pycnogonids, which have been evolving in very cold conditions (−1.8–0°C) for several million years and contain spectacular examples of gigantism. Pycnogonids from 12 species, spanning three orders of magnitude in body mass, were collected from McMurdo Sound, Antarctica. Individual sea spiders were forced into activity and their performance was measured at different experimental levels of dissolved oxygen (DO). The oxygen hypothesis predicts that, all else being equal, large pycnogonids should perform disproportionately poorly in hypoxia, an outcome that would appear as a statistically significant interaction between body size and oxygen level. In fact, although we found large effects of DO on performance, and substantial interspecific variability in oxygen sensitivity, there was no evidence for size×DO interactions. These data do not support the oxygen hypothesis of Antarctic pycnogonid gigantism and suggest that explanations must be sought in other ecological or evolutionary processes. PMID:19129117

Recent advance in polar seismology: Global impact of the International Polar Year

Science.gov (United States)

Kanao, Masaki; Zhao, Dapeng; Wiens, Douglas A.; Stutzmann, Éléonore

2015-03-01

The most exciting initiative for the recent polar studies was the International Polar Year (IPY) in 2007-2008. The IPY has witnessed a growing community of seismologists who have made considerable efforts to acquire high-quality data in polar regions. It also provided an excellent opportunity to make significant advances in seismic instrumentation of the polar regions to achieve scientific targets involving global issues. Taking these aspects into account, we organize and publish a special issue in Polar Science on the recent advance in polar seismology and cryoseismology as fruitful achievements of the IPY.

Possible Effects of Climate Warming on Selected Populations of Polar Bears (Ursus maritimus) in the Canadian Arctic

Science.gov (United States)

Parkinson, Claire L.; Stirling Ian

2006-01-01

Polar bears are dependent on sea ice for survival. Climate warming in the Arctic has caused significant declines in coverage and thickness of sea ice in the polar basin and progressively earlier breakup in some areas. In four populations of polar bears in the eastern Canadian Arctic (including Western Hudson Bay), Inuit hunters report more bears near settlements during the open water period in recent years. These observations have been interpreted as evidence of increasing population size, resulting in increases in hunting quotas. However, long-term data on the population size and condition of polar bears in Western Hudson Bay, and population and harvest data from Baffin Bay, make it clear that those two populations at least are declining, not increasing. While the details vary in different arctic regions, analysis of passive-microwave satellite imagery, beginning in the late 1970s, indicates that the sea ice is breaking up at progressively earlier dates, so that bears must fast for longer periods during the open water season. Thus, at least part of the explanation for the appearance of more bears in coastal communities is likely that they are searching for alternative food sources because their stored body fat depots are being exhausted. We hypothesize that, if the climate continues to warm as projected by the IPCC, then polar bears in all five populations discussed in this paper will be stressed and are likely to decline in numbers, probably significantly so. As these populations decline, there will likely also be continuing, possibly increasing, numbers of problem interactions between bears and humans as the bears seek alternate food sources. Taken together, the data reported in this paper suggest that a precautionary approach be taken to the harvesting of polar bears and that the potential effects of climate warming be incorporated into planning for the management and conservation of this species throughout the Arctic.

Kinetic-limited etching of magnesium doping nitrogen polar GaN in potassium hydroxide solution

Science.gov (United States)

Jiang, Junyan; Zhang, Yuantao; Chi, Chen; Yang, Fan; Li, Pengchong; Zhao, Degang; Zhang, Baolin; Du, Guotong

2016-01-01

KOH based wet etchings were performed on both undoped and Mg-doped N-polar GaN films grown by metal-organic chemical vapor deposition. It is found that the etching rate for Mg-doped N-polar GaN gets slow obviously compared with undoped N-polar GaN. X-ray photoelectron spectroscopy analysis proved that Mg oxide formed on N-polar GaN surface is insoluble in KOH solution so that kinetic-limited etching occurs as the etching process goes on. The etching process model of Mg-doped N-polar GaN in KOH solution is tentatively purposed using a simplified ideal atomic configuration. Raman spectroscopy analysis reveals that Mg doping can induce tensile strain in N-polar GaN films. Meanwhile, p-type N-polar GaN film with a hole concentration of 2.4 ÿ 1017 cm⿿3 was obtained by optimizing bis-cyclopentadienyl magnesium flow rates.

Study of excess carrier dynamics in polar, semi-polar, and non-polar (In,Ga)N epilayers and QWs

Energy Technology Data Exchange (ETDEWEB)

Aleksiejunas, R. [Institute of Applied Research, Vilnius University, Sauletekio Ave. 9-III, 10222 Vilnius (Lithuania); Laser Research Center, Vilnius University, Sauletekio Ave. 10, 10222 Vilnius (Lithuania); Lubys, L.; Jarasiunas, K. [Institute of Applied Research, Vilnius University, Sauletekio Ave. 9-III, 10222 Vilnius (Lithuania); Vengris, M. [Laser Research Center, Vilnius University, Sauletekio Ave. 10, 10222 Vilnius (Lithuania); Wernicke, T.; Hoffmann, V.; Netzel, C.; Knauer, A.; Weyers, M. [Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12498 Berlin (Germany); Kneissl, M. [Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12498 Berlin (Germany); Institute of Solid State Physics, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany)

2011-07-15

We studied carrier recombination and diffusion in GaN/sapphire templates, (In,Ga)N layers, and (In,Ga)N quantum well structures oriented along the polar [0001], semi-polar [11-22], and non-polar [11-20] orientations by means of light induced transient grating, differential transmission, and photoluminescence optical techniques. We show that the lifetime of excess carriers drops by orders of magnitude when changing the orientation from polar to non-polar, both in GaN templates and (In,Ga)N layers. We attribute the shorter lifetime to carrier trapping by extended structural defects that are more abundant in non-polar grown samples. In addition, we observe pronounced carrier localization effects in the semi- and non-polar layers. We show that thick (In,Ga)N layers inherit the properties of the GaN templates. However, the thin quantum well structures show a lower carrier trapping activity. So, a better electrical quality can be assumed as compared to the thick (In,Ga)N layers. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

A Fuzzy Computing Model for Identifying Polarity of Chinese Sentiment Words

Directory of Open Access Journals (Sweden)

Bingkun Wang

2015-01-01

Full Text Available With the spurt of online user-generated contents on web, sentiment analysis has become a very active research issue in data mining and natural language processing. As the most important indicator of sentiment, sentiment words which convey positive and negative polarity are quite instrumental for sentiment analysis. However, most of the existing methods for identifying polarity of sentiment words only consider the positive and negative polarity by the Cantor set, and no attention is paid to the fuzziness of the polarity intensity of sentiment words. In order to improve the performance, we propose a fuzzy computing model to identify the polarity of Chinese sentiment words in this paper. There are three major contributions in this paper. Firstly, we propose a method to compute polarity intensity of sentiment morphemes and sentiment words. Secondly, we construct a fuzzy sentiment classifier and propose two different methods to compute the parameter of the fuzzy classifier. Thirdly, we conduct extensive experiments on four sentiment words datasets and three review datasets, and the experimental results indicate that our model performs better than the state-of-the-art methods.

A Fuzzy Computing Model for Identifying Polarity of Chinese Sentiment Words

Science.gov (United States)

Huang, Yongfeng; Wu, Xian; Li, Xing

2015-01-01

With the spurt of online user-generated contents on web, sentiment analysis has become a very active research issue in data mining and natural language processing. As the most important indicator of sentiment, sentiment words which convey positive and negative polarity are quite instrumental for sentiment analysis. However, most of the existing methods for identifying polarity of sentiment words only consider the positive and negative polarity by the Cantor set, and no attention is paid to the fuzziness of the polarity intensity of sentiment words. In order to improve the performance, we propose a fuzzy computing model to identify the polarity of Chinese sentiment words in this paper. There are three major contributions in this paper. Firstly, we propose a method to compute polarity intensity of sentiment morphemes and sentiment words. Secondly, we construct a fuzzy sentiment classifier and propose two different methods to compute the parameter of the fuzzy classifier. Thirdly, we conduct extensive experiments on four sentiment words datasets and three review datasets, and the experimental results indicate that our model performs better than the state-of-the-art methods. PMID:26106409

A 3D model of polarized dust emission in the Milky Way

Science.gov (United States)

Martínez-Solaeche, Ginés; Karakci, Ata; Delabrouille, Jacques

2018-05-01

We present a three-dimensional model of polarized galactic dust emission that takes into account the variation of the dust density, spectral index and temperature along the line of sight, and contains randomly generated small-scale polarization fluctuations. The model is constrained to match observed dust emission on large scales, and match on smaller scales extrapolations of observed intensity and polarization power spectra. This model can be used to investigate the impact of plausible complexity of the polarized dust foreground emission on the analysis and interpretation of future cosmic microwave background polarization observations.

Normal levels of total body sodium and chlorine by neutron activation analysis

International Nuclear Information System (INIS)

Kennedy, N.S.J.; Eastell, R.; Smith, M.A.; Tothill, P.

1983-01-01

In vivo neutron activation analysis was used to measure total body sodium and chlorine in 18 male and 18 female normal adults. Corrections for body size were developed. Normalisation factors were derived which enable the prediction of the normal levels of sodium and chlorine in a subject. The coefficient of variation of normalised sodium was 5.9% in men and 6.9% in women, and of normalised chlorine 9.3% in men and 5.5% in women. In the range examined (40-70 years) no significant age dependence was observed for either element. Total body sodium was correlated with total body chlorine and total body calcium. Sodium excess, defined as the amount of body sodium in excess of that associated with chlorine, also correlated well with total body calcium. In females there was a mean annual loss of sodium excess of 1.2% after the menopause, similar to the loss of calcium. (author)

Polarized targets and beams

International Nuclear Information System (INIS)

Meyer, W.

1985-01-01

First the experimental situation of the single-pion photoproduction and the photodisintegration of the deuteron is briefly discussed. Then a description of the Bonn polarization facilities is given. The point of main effort is put on the polarized target which plays a vital role in the program. A facility for photon induced double polarization experiments at ELSA will be presented in section 4. Properties of a tensor polarized deuteron target are discussed in section 5. The development in the field of polarized targets, especially on new target materials, enables a new generation of polarized target experiments with (polarized) electrons. Some comments on the use of a polarized target in combination with electron beams will be discussed in section 6. Electron deuteron scattering from a tensor polarized deuteron target is considered and compared with other experimental possibilities. (orig./HSI)

Study of Body Composition by Impedance Analysis

Science.gov (United States)

González-Solís, J. L.; Vargas-Luna, M.; Sosa-Aquino, M.; Bernal-Alvarado, J.; Gutiérrez-Juárez, G.; Huerta-Franco, R.; Sanchis-Sabater, A.

2002-08-01

This work presents a set of impedance measurements and preliminary results on the analysis of body composition using impedance spectroscopy. This study is made using a pork meat sample and spectra from fat and flesh region were independently obtained using the same electrodes array. From these measurements, and theoretical considerations, it is possible to explain the behavior of the composite sample flesh-fat-flesh and, fitting the electrical parameters of the model, it shows the plausibility of a physical and quantitative application to human corporal composition.

Elliptic Fourier Analysis of body shape variation of Hippocampus spp. (seahorse in Danajon Bank, Philippines

Directory of Open Access Journals (Sweden)

S. R. M. Tabugo-Rico

2017-12-01

Full Text Available Seahorses inhabit various ecosystems hence, had become a flagship species of the marine environment. The Philippines as a hot spot of biodiversity in Asia holds a number of species of seahorses. This serve as an exploratory study to describe body shape variation of selected common seahorse species: Hippocampus comes, Hippocampus histrix, Hippocampus spinosissimus and Hippocampus kuda from Danajon bank using Elliptic Fourier Analysis. The method was done to test whether significant yet subtle differences in body shape variation can be species-specific, habitat-influenced and provide evidence of sexual dimorphism. It is hypothesized that phenotypic divergence may provide evidence for genetic differentiation or mere adaptations to habitat variation. Results show significant considerable differences in the body shapes of the five populations based on the canonical variate analysis (CVA and multivariate analysis of variance (MANOVA with significant p values. Populations were found to be distinct from each other suggesting that body shape variation is species-specific, habitat-influenced and provided evidence for sexual dimorphism. Results of discriminant analysis show further support for species specific traits and sexual dimorphism. This study shows the application of the method of geometric morphometrics specifically elliptic fourier analysis in describing subtle body shape variation of selected Hippocampus species.

Large meta-analysis of genome-wide association studies identifies five loci for lean body mass.

Science.gov (United States)

Zillikens, M Carola; Demissie, Serkalem; Hsu, Yi-Hsiang; Yerges-Armstrong, Laura M; Chou, Wen-Chi; Stolk, Lisette; Livshits, Gregory; Broer, Linda; Johnson, Toby; Koller, Daniel L; Kutalik, Zoltán; Luan, Jian'an; Malkin, Ida; Ried, Janina S; Smith, Albert V; Thorleifsson, Gudmar; Vandenput, Liesbeth; Hua Zhao, Jing; Zhang, Weihua; Aghdassi, Ali; Åkesson, Kristina; Amin, Najaf; Baier, Leslie J; Barroso, Inês; Bennett, David A; Bertram, Lars; Biffar, Rainer; Bochud, Murielle; Boehnke, Michael; Borecki, Ingrid B; Buchman, Aron S; Byberg, Liisa; Campbell, Harry; Campos Obanda, Natalia; Cauley, Jane A; Cawthon, Peggy M; Cederberg, Henna; Chen, Zhao; Cho, Nam H; Jin Choi, Hyung; Claussnitzer, Melina; Collins, Francis; Cummings, Steven R; De Jager, Philip L; Demuth, Ilja; Dhonukshe-Rutten, Rosalie A M; Diatchenko, Luda; Eiriksdottir, Gudny; Enneman, Anke W; Erdos, Mike; Eriksson, Johan G; Eriksson, Joel; Estrada, Karol; Evans, Daniel S; Feitosa, Mary F; Fu, Mao; Garcia, Melissa; Gieger, Christian; Girke, Thomas; Glazer, Nicole L; Grallert, Harald; Grewal, Jagvir; Han, Bok-Ghee; Hanson, Robert L; Hayward, Caroline; Hofman, Albert; Hoffman, Eric P; Homuth, Georg; Hsueh, Wen-Chi; Hubal, Monica J; Hubbard, Alan; Huffman, Kim M; Husted, Lise B; Illig, Thomas; Ingelsson, Erik; Ittermann, Till; Jansson, John-Olov; Jordan, Joanne M; Jula, Antti; Karlsson, Magnus; Khaw, Kay-Tee; Kilpeläinen, Tuomas O; Klopp, Norman; Kloth, Jacqueline S L; Koistinen, Heikki A; Kraus, William E; Kritchevsky, Stephen; Kuulasmaa, Teemu; Kuusisto, Johanna; Laakso, Markku; Lahti, Jari; Lang, Thomas; Langdahl, Bente L; Launer, Lenore J; Lee, Jong-Young; Lerch, Markus M; Lewis, Joshua R; Lind, Lars; Lindgren, Cecilia; Liu, Yongmei; Liu, Tian; Liu, Youfang; Ljunggren, Östen; Lorentzon, Mattias; Luben, Robert N; Maixner, William; McGuigan, Fiona E; Medina-Gomez, Carolina; Meitinger, Thomas; Melhus, Håkan; Mellström, Dan; Melov, Simon; Michaëlsson, Karl; Mitchell, Braxton D; Morris, Andrew P; Mosekilde, Leif; Newman, Anne; Nielson, Carrie M; O'Connell, Jeffrey R; Oostra, Ben A; Orwoll, Eric S; Palotie, Aarno; Parker, Stephen C J; Peacock, Munro; Perola, Markus; Peters, Annette; Polasek, Ozren; Prince, Richard L; Räikkönen, Katri; Ralston, Stuart H; Ripatti, Samuli; Robbins, John A; Rotter, Jerome I; Rudan, Igor; Salomaa, Veikko; Satterfield, Suzanne; Schadt, Eric E; Schipf, Sabine; Scott, Laura; Sehmi, Joban; Shen, Jian; Soo Shin, Chan; Sigurdsson, Gunnar; Smith, Shad; Soranzo, Nicole; Stančáková, Alena; Steinhagen-Thiessen, Elisabeth; Streeten, Elizabeth A; Styrkarsdottir, Unnur; Swart, Karin M A; Tan, Sian-Tsung; Tarnopolsky, Mark A; Thompson, Patricia; Thomson, Cynthia A; Thorsteinsdottir, Unnur; Tikkanen, Emmi; Tranah, Gregory J; Tuomilehto, Jaakko; van Schoor, Natasja M; Verma, Arjun; Vollenweider, Peter; Völzke, Henry; Wactawski-Wende, Jean; Walker, Mark; Weedon, Michael N; Welch, Ryan; Wichmann, H-Erich; Widen, Elisabeth; Williams, Frances M K; Wilson, James F; Wright, Nicole C; Xie, Weijia; Yu, Lei; Zhou, Yanhua; Chambers, John C; Döring, Angela; van Duijn, Cornelia M; Econs, Michael J; Gudnason, Vilmundur; Kooner, Jaspal S; Psaty, Bruce M; Spector, Timothy D; Stefansson, Kari; Rivadeneira, Fernando; Uitterlinden, André G; Wareham, Nicholas J; Ossowski, Vicky; Waterworth, Dawn; Loos, Ruth J F; Karasik, David; Harris, Tamara B; Ohlsson, Claes; Kiel, Douglas P

2017-07-19

Lean body mass, consisting mostly of skeletal muscle, is important for healthy aging. We performed a genome-wide association study for whole body (20 cohorts of European ancestry with n = 38,292) and appendicular (arms and legs) lean body mass (n = 28,330) measured using dual energy X-ray absorptiometry or bioelectrical impedance analysis, adjusted for sex, age, height, and fat mass. Twenty-one single-nucleotide polymorphisms were significantly associated with lean body mass either genome wide (p lean body mass and in 45,090 (42,360 of European ancestry) subjects from 25 cohorts for appendicular lean body mass was successful for five single-nucleotide polymorphisms in/near HSD17B11, VCAN, ADAMTSL3, IRS1, and FTO for total lean body mass and for three single-nucleotide polymorphisms in/near VCAN, ADAMTSL3, and IRS1 for appendicular lean body mass. Our findings provide new insight into the genetics of lean body mass.Lean body mass is a highly heritable trait and is associated with various health conditions. Here, Kiel and colleagues perform a meta-analysis of genome-wide association studies for whole body lean body mass and find five novel genetic loci to be significantly associated.

Reduction of coating induced polarization aberrations by controlling the polarization state variation

International Nuclear Information System (INIS)

Li, Yanghui; Shen, Weidong; Zheng, Zhenrong; Zhang, Yueguang; Liu, Xu; Hao, Xiang

2011-01-01

The mechanism of coating induced polarization state variation is analysed by the Jones matrix. Pauli spin matrices are used to establish the relationship between coating induced polarization state variation and polarization aberrations. To reduce coating induced polarization aberrations, we propose that δ = 0 and T s = T p at arbitrary incident angle should be appended as two additional optimization goals of optical coating design when the requirements of transmittance are met. Two typical anti-reflection (AR) coatings are designed and the polarization state variation induced by them is simulated. The MTF (modulation transfer function) calculated by polarization ray tracing is applied to evaluate the polarization aberrations of the practical lithography objective system with the two AR coatings. All the obtained results show that the coating induced polarization aberrations can be reduced by optimizing the angle dependent properties of the optical coating without additional optical elements

Effect of 3D Polarization profiles on polarization measurements and colliding beam experiments

Energy Technology Data Exchange (ETDEWEB)

Fischer, W.; Bazilevsky, A.

2011-08-18

The development of polarization profiles are the primary reason for the loss of average polarization. Polarization profiles have been parametrized with a Gaussian distribution. We derive the effect of 3-dimensional polarization profiles on the measured polarization in polarimeters, as well as the observed polarization and the figure of merit in single and double spin experiments. Examples from RHIC are provided. The Relativistic Heavy Ion Collider (RHIC) is the only collider of spin polarized protons. During beam acceleration and storage profiles of the polarization P develop, which affect the polarization measured in a polarimeter, and the polarization and figure of merit (FOM) in colliding beam experiments. We calculate these for profiles in all dimensions, and give examples for RHIC. Like in RHIC we call the two colliding beams Blue and Yellow. We use the overbar to designate intensity-weighted averages in polarimeters (e.g. {bar P}), and angle brackets to designate luminosity-weighted averages in colliding beam experiments (e.g.

).

Effect of 3D Polarization profiles on polarization measurements and colliding beam experiments

International Nuclear Information System (INIS)

Fischer, W.; Bazilevsky, A.

2011-01-01

The development of polarization profiles are the primary reason for the loss of average polarization. Polarization profiles have been parametrized with a Gaussian distribution. We derive the effect of 3-dimensional polarization profiles on the measured polarization in polarimeters, as well as the observed polarization and the figure of merit in single and double spin experiments. Examples from RHIC are provided. The Relativistic Heavy Ion Collider (RHIC) is the only collider of spin polarized protons. During beam acceleration and storage profiles of the polarization P develop, which affect the polarization measured in a polarimeter, and the polarization and figure of merit (FOM) in colliding beam experiments. We calculate these for profiles in all dimensions, and give examples for RHIC. Like in RHIC we call the two colliding beams Blue and Yellow. We use the overbar to designate intensity-weighted averages in polarimeters (e.g. (bar P)), and angle brackets to designate luminosity-weighted averages in colliding beam experiments (e.g. ).

Acquired umbilical hernias in four captive polar bears (Ursus maritimus).

Science.gov (United States)

Velguth, Karen E; Rochat, Mark C; Langan, Jennifer N; Backues, Kay

2009-12-01

Umbilical hernias are a common occurrence in domestic animals and humans but have not been well documented in polar bears. Surgical reduction and herniorrhaphies were performed to correct acquired hernias in the region of the umbilicus in four adult captive polar bears (Ursus maritimus) housed in North American zoos. Two of the four bears were clinically unaffected by their hernias prior to surgery. One bear showed signs of severe discomfort following acute enlargement of the hernia. In another bear, re-herniation led to acute abdominal pain due to gastric entrapment and strangulation. The hernias in three bears were surgically repaired by debridement of the hernia ring and direct apposition of the abdominal wall, while the large defect in the most severely affected bear was closed using polypropylene mesh to prevent excessive tension. The cases in this series demonstrate that while small hernias may remain clinically inconsequential for long periods of time, enlargement or recurrence of the defect can lead to incarceration and acute abdominal crisis. Umbilical herniation has not been reported in free-ranging polar bears, and it is suspected that factors such as body condition, limited exercise, or enclosure design potentially contribute to the development of umbilical hernias in captive polar bears.

Low-Entropy States of Neutral Atoms in Polarization-Synthesized Optical Lattices.

Science.gov (United States)

Robens, Carsten; Zopes, Jonathan; Alt, Wolfgang; Brakhane, Stefan; Meschede, Dieter; Alberti, Andrea

2017-02-10

We create low-entropy states of neutral atoms by utilizing a conceptually new optical-lattice technique that relies on a high-precision, high-bandwidth synthesis of light polarization. Polarization-synthesized optical lattices provide two fully controllable optical lattice potentials, each of them confining only atoms in either one of the two long-lived hyperfine states. By employing one lattice as the storage register and the other one as the shift register, we provide a proof of concept using four atoms that selected regions of the periodic potential can be filled with one particle per site. We expect that our results can be scaled up to thousands of atoms by employing an atom-sorting algorithm with logarithmic complexity, which is enabled by polarization-synthesized optical lattices. Vibrational entropy is subsequently removed by sideband cooling methods. Our results pave the way for a bottom-up approach to creating ultralow-entropy states of a many-body system.

Responses of invertebrates to temperature and water stress: A polar perspective.

Science.gov (United States)

Everatt, Matthew J; Convey, Pete; Bale, Jeffrey S; Worland, M Roger; Hayward, Scott A L

2015-12-01

As small bodied poikilothermic ectotherms, invertebrates, more so than any other animal group, are susceptible to extremes of temperature and low water availability. In few places is this more apparent than in the Arctic and Antarctic, where low temperatures predominate and water is unusable during winter and unavailable for parts of summer. Polar terrestrial invertebrates express a suite of physiological, biochemical and genomic features in response to these stressors. However, the situation is not as simple as responding to each stressor in isolation, as they are often faced in combination. We consider how polar terrestrial invertebrates manage this scenario in light of their physiology and ecology. Climate change is also leading to warmer summers in parts of the polar regions, concomitantly increasing the potential for drought. The interaction between high temperature and low water availability, and the invertebrates' response to them, are therefore also explored. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nuclear polarization and neutrons

International Nuclear Information System (INIS)

Glaettli, H.

1985-01-01

Different possibilities for the use of polarized nuclei in thermal neutron scattering on condensed matter are reviewed. Highly polarized nuclei are the starting point for studying dipolar magnetic order. Systematic measurement of spin-dependent scattering lengths is possible on samples with polarized nuclei. Highly polarized hydrogen should help to unravel complicated structures in chemistry and biology. The use of polarized proton targets as an energy-independent neutron polarizer in the thermal and epithermal region should be considered afresh. (author)

Antidiabetic activity of medium-polar extract from the leaves of Stevia rebaudiana Bert. (Bertoni on alloxan-induced diabetic rats

Directory of Open Access Journals (Sweden)

Himanshu Misra

2011-01-01

Full Text Available Objective: To investigate the medicative effects of medium-polar (benzene:acetone, 1:1, v/v extract of leaves from Stevia rebaudiana (family Asteraceae on alloxan-induced diabetic rats. Materials and Methods: Diabetes was induced in adult albino Wistar rats by intraperitoneal (i.p. injection of alloxan (180 mg/kg. Medium-polar extract was administered orally at daily dose of 200 and 400 mg/kg body wt. basis for 10 days. The control group received normal saline (0.9% for the same duration. Glibenclamide was used as positive control reference drug against Stevia extract. Results: Medium-polar leaf extract of S. rebaudiana (200 and 400 mg/kg produced a delayed but significant (P < 0.01 decrease in the blood glucose level, without producing condition of hypoglycemia after treatment, together with lesser loss in the body weight as compared with standard positive control drug glibenclamide. Conclusions: Treatment of diabetes with sulfonylurea drugs (glibenclamide causes hypoglycemia followed by greater reduction in body weight, which are the most worrisome effects of these drugs. Stevia extract was found to antagonize the necrotic action of alloxan and thus had a re-vitalizing effect on β-cells of pancreas.

Polarization measurements of the Bok globule B361

Energy Technology Data Exchange (ETDEWEB)

Williams, I P; Vedi, K [Queen Mary Coll., London (UK); Griffiths, W K [Leeds Univ. (UK); Bhatt, H C; Kulkarni, P V; Ashok, N M [Physical Research Lab., Ahmedabad (India); Wallis, R E [Royal Greenwich Observatory, Hailsham (UK)

1985-01-01

The results of the first measurements of the polarization of light from background stars passing through B361 are described. Nearly all the stars show that the direction of the polarized light is approximately north-south. If the polarization is caused by aligned grains within the globule then a magnetic field of the order of 50-100 ..mu..G is required. Both polarimetry and photometry confirm that two of the stars studied are very distant background stars while three of these stars were found to be foreground stars. The analysis indicates that the globule is not further away than 650 pc, but can only establish an approximate upper limit.

Comparison of Chlamydia trachomatis serovar L2 growth in polarized genital epithelial cells grown in three-dimensional culture with non-polarized cells.

Science.gov (United States)

Dessus-Babus, Sophie; Moore, Cheryl G; Whittimore, Judy D; Wyrick, Priscilla B

2008-04-01

A common model for studying Chlamydia trachomatis and growing chlamydial stocks uses Lymphogranuloma venereum serovar L2 and non-polarized HeLa cells. However, recent publications indicate that the growth rate and progeny yields can vary considerably for a particular strain depending on the cell line/type used, and seem to be partially related to cell tropism. In the present study, the growth of invasive serovar L2 was compared in endometrial HEC-1B and endocervical HeLa cells polarized on collagen-coated microcarrier beads, as well as in HeLa cells grown in tissue culture flasks. Microscopy analysis revealed no difference in chlamydial attachment/entry patterns or in inclusion development throughout the developmental cycle between cell lines. Very comparable growth curves in both cell lines were also found using real-time PCR analysis, with increases in chlamydial DNA content of 400-500-fold between 2 and 36 h post-inoculation. Similar progeny yields with comparable infectivity were recovered from HEC-1B and HeLa cell bead cultures, and no difference in chlamydial growth was found in polarized vs. non-polarized HeLa cells. In conclusion, unlike other C. trachomatis strains such as urogenital serovar E, invasive serovar L2 grows equally well in physiologically different endometrial and endocervical environments, regardless of the host cell polarization state.

Long-term analysis of ionospheric polar patches based on CHAMP TEC data

DEFF Research Database (Denmark)

Noja, M.; Stolle, Claudia; Park, J.

2013-01-01

Total electron content (TEC) from LEO satellites offers great possibility to sound the upper ionosphere and plasmasphere. This paper describes a method to derive absolute TEC observations aboard CHAMP considering multipath effects and receiver differential code bias. The long-term data set of 9...... years GPS observations is used to investigate the climatological behavior of high-latitude plasma patches in both hemispheres. The occurrence of polar patches has a clear correlation with the solar cycle, which is less pronounced in the Southern Hemisphere (SH). Summed over all years, we observed...... a higher number of patches in the SH. The maximum occurrence rate of patches has been found at the dayside polar cusp during 12:00-18:00 MLT (magnetic local time) supporting the mechanisms for patch creation by local particle precipitation and by intrusion of subauroral plasma into the polar cap through...

Superconducting polarizing magnet for a movable polarized target

International Nuclear Information System (INIS)

Anishchenko, N.G.; Bartenev, V.D.; Blinov, N.A.

1998-01-01

The superconducting polarizing magnet was constructed for the JINR (Dubna) movable polarized target (MPT) with working volume 200 mm long and 30 mm in diameter. The magnet provides a polarizing magnetic field up to 6 T in the centre with the uniformity of 4.5 x 10 -4 in the working volume of the target. The magnet contains a main solenoidal winding 558 mm long and 206/144 mm in diameters, and compensating and correcting winding placed at its ends. The windings are made of a NbTi wire, impregnated with the epoxy resin and placed in the horizontal cryostat. The diameter of the 'warm' aperture of the magnet cryostat is 96 mm. The design and technology of the magnet winding are described. Results of the magnetic field map measurements, using a NMR-magnetometer are given. A similar magnet constructed at DAPNIA, CEA/Saclay (France), represented a model for the present development. The MPT array is installed in the beam line of polarized neutrons produced by break-up of polarized deuterons extracted from the synchrophasotron of the Laboratory of High Energies (LHE), JINR (Dubna)

Photonic crystal based polarization insensitive flat lens

International Nuclear Information System (INIS)

Turduev, M; Bor, E; Kurt, H

2017-01-01

The paper proposes a new design of an inhomogeneous artificially created photonic crystal lens structure consisting of annular dielectric rods to efficiently focus both transverse electric and transverse magnetic polarizations of light into the same focal point. The locations of each individual cell that contains the annular dielectric rods are determined according to a nonlinear distribution function. The inner and outer radii of the annular photonic dielectric rods are optimized with respect to the polarization insensitive frequency response of the transmission spectrum of the lens structure. The physical background of the polarization insensitive focusing mechanism is investigated in both spatial and frequency domains. Moreover, polarization independent wavefront transformation/focusing has been explored in detail by investigating the dispersion relation of the structure. Corresponding phase index distribution of the lens is attained for polarization insensitive normalized frequency range of a / λ   =  0.280 and a / λ   =  0.300, where a denotes the lattice constant of the designed structure and λ denotes the wavelength of the incident light. We show the wave transformation performance and focal point movement dynamics for both polarizations of the lens structure by specially adjusting the length of the structure. The 3D finite-difference time domain numerical analysis is also performed to verifiy that the proposed design is able to focus the wave regardless of polarization into approximately the same focal point (difference between focal distances of both polarizations stays below 0.25 λ ) with an operating bandwidth of 4.30% between 1476 nm and 1541 nm at telecom wavelengths. The main superiorities of the proposed lens structure are being all dielectric and compact, and having flat front and back surfaces, rendering the proposed lens design more practical in the photonic integration process in various applications such as optical switch

Optical characterization and polarization calibration for rigid endoscopes

Science.gov (United States)

Garcia, Missael; Gruev, Viktor

2017-02-01

Polarization measurements give orthogonal information to spectral images making them a great tool in the characterization of environmental parameters in nature. Thus, polarization imagery has proven to be remarkably useful in a vast range of biomedical applications. One such application is the early diagnosis of flat cancerous lesions in murine colorectal tumor models, where polarization data complements NIR fluorescence analysis. Advances in nanotechnology have led to compact and precise bio-inspired imaging sensors capable of accurately co-registering multidimensional spectral and polarization information. As more applications emerge for these imagers, the optics used in these instruments get very complex and can potentially compromise the original polarization state of the incident light. Here we present a complete optical and polarization characterization of three rigid endoscopes of size 1.9mm x 10cm (Karl Storz, Germany), 5mm x 30cm, and 10mm x 33cm (Olympus, Germany), used in colonoscopy for the prevention of colitis-associated cancer. Characterization results show that the telescope optics act as retarders and effectively depolarize the linear component. These incorrect readings can cause false-positives or false-negatives leading to an improper diagnosis. In this paper, we offer a polarization calibration scheme for these endoscopes based on Mueller calculus. By modeling the optical properties from training data as real-valued Mueller matrices, we are able to successfully reconstruct the initial polarization state acquired by the imaging system.

Giessen polarization facility. III. Multi-detector analyzing system

Energy Technology Data Exchange (ETDEWEB)

Krause, H H; Stock, R; Arnold, W; Berg, H; Huttel, E; Ulbricht, J; Clausnitzer, G [Giessen Univ. (Germany, F.R.). Strahlenzentrum

1977-06-15

An analyzing system with a PDP 11 computer and a digital multiplexer is described. It allows to accept signals from 16 detectors with individual ADCs simultaneously. For measurements of analyzing powers the polarization of the ion beam can be switched to zero with a frequency of 1 kHz. The switching operation additionally controls the handling of the detector pulses. The software contains special programs for the analysis of polarization experiments.

Results on Double-polarization Asymmetries in Quasielastic Scattering from Polarized 3He

Directory of Open Access Journals (Sweden)

Sulkosky Vincent A.

2016-01-01

Full Text Available The 3He nucleus has become extremely important in the investigation of the neutron’s spin structure. When polarized, 3He acts as an effective polarized neutron target and hence facilitates our understanding of the neutron’s internal structure. However, to be used in this manner, our understanding of the internal structure of 3He is of extreme importance. As the precision of experiments has improved, the extraction of polarized neutron information from 3He leads to an ever larger share of the systematic uncertainty for these experiments. In these proceedings, I present a precise measurement of beam-target asymmetries in the He→3(e→ ,e′d${}^3\\overrightarrow {He} (\\vec e,e'd$ and He→3(e→,e′p${}^3\\overrightarrow {He} (\\vec e,e'p$ reactions. The former process is a uniquely sensitive probe of hadron dynamics in 3He and the structure of the underlying electromagnetic currents. The measurements have been performed around the quasi-elastic peak at Q2 = 0.25 (GeV/c2 and 0.35 (GeV/c2 for recoil momenta up to 270 MeV/c. The experimental apparatus, analysis and results were presented together with a comparison to state-of-the art Faddeev calculations.

High-energy, high-fat lifestyle challenges an Arctic apex predator, the polar bear.

Science.gov (United States)

Pagano, A M; Durner, G M; Rode, K D; Atwood, T C; Atkinson, S N; Peacock, E; Costa, D P; Owen, M A; Williams, T M

2018-02-02

Regional declines in polar bear ( Ursus maritimus ) populations have been attributed to changing sea ice conditions, but with limited information on the causative mechanisms. By simultaneously measuring field metabolic rates, daily activity patterns, body condition, and foraging success of polar bears moving on the spring sea ice, we found that high metabolic rates (1.6 times greater than previously assumed) coupled with low intake of fat-rich marine mammal prey resulted in an energy deficit for more than half of the bears examined. Activity and movement on the sea ice strongly influenced metabolic demands. Consequently, increases in mobility resulting from ongoing and forecasted declines in and fragmentation of sea ice are likely to increase energy demands and may be an important factor explaining observed declines in body condition and survival. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Analysis of aerosol optical depth evaluation in polar regions and associated uncertainties

Directory of Open Access Journals (Sweden)

P. Ortiz de Galisteo

2008-04-01

Full Text Available Some available processing algorithms used to calculate the aerosol optical depth from radiometric measurements were tested. The aim was to evaluate the associated uncertainties in polar regions due to the data processing, in order to adjust the methodology of the calculation and illustrate the importance of these error sources. The measurements were obtained during a sun photometer campaign in Ny-Ålesund within the framework of the POLAR-AOD project.

CP-sensitive observables in chargino production with transverse e± beam polarization

International Nuclear Information System (INIS)

Bartl, A.; Hohenwarter-Sodek, K.; Kernreiter, T.; Rud, H.

2004-01-01

We consider the process e + e - →χ + i χ - j at a linear collider with transverse e ± beam polarization. We investigate the influence of the CP phases on azimuthal asymmetries in e + e - →χ + i χ - j with subsequent two-body decays χ - j →ν l l - and χ - j →W - χ 0 1 . We show that triple product correlations involving the transverse e ± beam polarization vanish if at least one subsequent chargino decay is not observed. We derive this result within the minimal supersymmetric standard model (MSSM) with complex parameters; however, it holds also in the general MSSM with SUSY flavor violation. (orig.)

Atmospheric Polarization Imaging with Variable Aerosols, Clouds, and Surface Albedo

Science.gov (United States)

2013-07-01

values found in this region only during episodes of intense wildfire smoke. Detailed analysis of the aerosols in this smoke plume and their effect...Continuous outdoor operation of an all-sky polarization imager,” Proc. SPIE 7672 (Polarization: Measurement, Analysis , and Remote Sensing IX), 76720A-1-7, 7...Pust, “ Lunar corona in ice wave cloud,” 10th International Meeting on Light and Color in Nature, St. Mary’s College of Maryland, 16-20 June 2010. 2

Relation between sensory analysis and rheology of body lotions.

Science.gov (United States)

Moravkova, T; Filip, P

2016-12-01

Evaluation of sensory attributes of cosmetic products is traditionally based on sensory panels. However, in some cases, a suitable candidate method that can reduce time and costs is the use of instrumental analysis that can detect relatively very small changes of entry ingredients. Such approach has been already applied for emollients, salt content, stabilizers, etc. The aim of this contribution is to apply the relations between sensory analysis and rheology to a series of body lotions differing in the contents of emulsifiers and viscosity regulators. Sensory and rheological analyses are related. Rheological analysis can represent a good alternative to basic orientation in chosen customer's feelings. A rotational rheometer is the only instrumental device required for the measurements. An empirical rheological model was proposed by means of which the selected sensory attributes were evaluated using the numerical values of adjustable model parameters. This approach exhibited a very good agreement with the results obtained by the sensory panel. It was shown that a description of chosen sensory attributes can be responsibly carried out by rheological measurements, that is through the attained numerical values of the parameters appearing in a proposed empirical model characterizing shear viscosity of body lotions. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Evaluation of direct analysis in real time for the determination of highly polar pesticides in lettuce and celery using modified Quick Polar Pesticides Extraction method.

Science.gov (United States)

Lara, Francisco J; Chan, Danny; Dickinson, Michael; Lloyd, Antony S; Adams, Stuart J

2017-05-05

Direct analysis in real time (DART) was evaluated for the determination of a number of highly polar pesticides using the Quick Polar Pesticides Extraction (QuPPe) method. DART was hyphenated to high resolution mass spectrometry (HRMS) in order to get the required selectivity that allows the determination of these compounds in complex samples such as lettuce and celery. Experimental parameters such as desorption temperature, scanning speed, and distances between the DART ion source and MS inlet were optimized. Two different mass analyzers (Orbitrap and QTOF) and two accessories for sample introduction (Dip-it ® tips and QuickStrip™ sample cards) were evaluated. An extra clean-up step using primary-secondary amine (PSA) was included in the QuPPe method to improve sensitivity. The main limitation found was in-source fragmentation, nevertheless QuPPe-DART-HRMS proved to be a fast and reliable tool with quantitative capabilities for at least seven compounds: amitrole, cyromazine, propamocarb, melamine, diethanolamine, triethanolamine and 1,2,4-triazole. The limits of detection ranged from 20 to 60μg/kg. Recoveries for fortified samples ranged from 71 to 115%, with relative standard deviations <18%. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-period polar rain variations, solar wind and hemispherically symmetric polar rain

International Nuclear Information System (INIS)

Makita, K.; Meng, C.

1987-01-01

On the basic of electron data obtained by the Defense Meteorological Satellite Program (DMSP) F2 satellite the long-period variations of the polar rain flux are examined for four consecutive solar rotations. It is clearly demonstrated that the asymmetric enhancement of the polar rain flux is strongly controlled by the sector structure of the interplanetary magnetic field (IMF). However, the orbit-to-orbit and day-to-day variations of the polar rain flux are detected even during a very stable sector period, and the polar rain flux does not have any clear relationship to the magnitude of the IMF B/sub x/ or B/sub y/. Thus the polarity of B/sub x/ controls only the accessibility of a polar region. It is also noticed that the intensity of polar rain fluxes does not show any relationship to the density of the solar wind, suggesting that the origin of the polar rain electrons is different from the commonly observed part of the solar wind electron distribution function. In addition to the asymmetric polar rain distribution, increasing polar rain fluxes of similar high intensity are sometimes detected over both polar caps. An examination of more than 1 year's data from the DMSP F2 and F4 satellites shows that simultaneous intense uniform precipitations (>10 7 electrons/cm 2 s sr) over both polar caps are not coincidental; it also shows that the spectra are similar. The occurrence of hemispherically symmetric events is not common. They generally are observed after an IMF sector transition period, during unstable periods in the sector structure, and while the solar wind density is high. copyright American Geophysical Union 1987

Measurement of the polarization correlation coefficient in elastic pp scattering at 610 MeV

International Nuclear Information System (INIS)

Borisov, N.S.; Glonti, L.N.; Kazarinov, M.Yu.

1977-01-01

The polarization correlation coefficient Csub(nn) for elastic pp scattering at 610+-10 MeV was measured for four scattering angles: 40, 67, 78 and 90 deg (c.m.s.). A polarized proton beam with a maximum polarization of 0.39+-0.02 and a polarized proton target of the frozen type were used. The maximum polarization of the target was 0.97+-0.04. The experimental procedure is described in detail. The Csub(nn) measured are compared with the results of a phase analysis and the findings at 575 MeV obtained elsewhere. The Csub(nn) coefficients are shown to be valuable to discriminate alternative solutions of the phase analysis. The polarized proton targets of the frozen type, no accounting the complexity of their design, are emphasized to be rather reliable and convenient devices for conducting experiments at accelerators

Light in Condensed Matter in the Upper Atmosphere as the Origin of Homochirality: Circularly Polarized Light from Rydberg Matter

Science.gov (United States)

Holmlid, Leif

2009-08-01

Clouds of the condensed excited Rydberg matter (RM) exist in the atmospheres of comets and planetary bodies (most easily observed at Mercury and the Moon), where they surround the entire bodies. Vast such clouds are recently proposed to exist in the upper atmosphere of Earth (giving rise to the enormous features called noctilucent clouds, polar mesospheric clouds, and polar mesospheric summer radar echoes). It has been shown in experiments with RM that linearly polarized visible light scattered from an RM layer is transformed to circularly polarized light with a probability of approximately 50%. The circular Rydberg electrons in the magnetic field in the RM may be chiral scatterers. The magnetic and anisotropic RM medium acts as a circular polarizer probably by delaying one of the perpendicular components of the light wave. The delay process involved is called Rabi-flopping and gives delays of the order of femtoseconds. This strong effect thus gives intense circularly polarized visible and UV light within RM clouds. Amino acids and other chiral molecules will experience a strong interaction with this light field in the upper atmospheres of planets. The interaction will vary with the stereogenic conformation of the molecules and in all probability promote the survival of one enantiomer. Here, this strong effect is proposed to be the origin of homochirality. The formation of amino acids in the RM clouds is probably facilitated by the catalytic effect of RM.

Light in condensed matter in the upper atmosphere as the origin of homochirality: circularly polarized light from Rydberg matter.

Science.gov (United States)

Holmlid, Leif

2009-01-01

Clouds of the condensed excited Rydberg matter (RM) exist in the atmospheres of comets and planetary bodies (most easily observed at Mercury and the Moon), where they surround the entire bodies. Vast such clouds are recently proposed to exist in the upper atmosphere of Earth (giving rise to the enormous features called noctilucent clouds, polar mesospheric clouds, and polar mesospheric summer radar echoes). It has been shown in experiments with RM that linearly polarized visible light scattered from an RM layer is transformed to circularly polarized light with a probability of approximately 50%. The circular Rydberg electrons in the magnetic field in the RM may be chiral scatterers. The magnetic and anisotropic RM medium acts as a circular polarizer probably by delaying one of the perpendicular components of the light wave. The delay process involved is called Rabi-flopping and gives delays of the order of femtoseconds. This strong effect thus gives intense circularly polarized visible and UV light within RM clouds. Amino acids and other chiral molecules will experience a strong interaction with this light field in the upper atmospheres of planets. The interaction will vary with the stereogenic conformation of the molecules and in all probability promote the survival of one enantiomer. Here, this strong effect is proposed to be the origin of homochirality. The formation of amino acids in the RM clouds is probably facilitated by the catalytic effect of RM.

Electromagnetic Radiation Efficiency of Body-Implanted Devices

Science.gov (United States)

Nikolayev, Denys; Zhadobov, Maxim; Karban, Pavel; Sauleau, Ronan

2018-02-01

Autonomous wireless body-implanted devices for biotelemetry, telemedicine, and neural interfacing constitute an emerging technology providing powerful capabilities for medicine and clinical research. We study the through-tissue electromagnetic propagation mechanisms, derive the optimal frequency range, and obtain the maximum achievable efficiency for radiative energy transfer from inside a body to free space. We analyze how polarization affects the efficiency by exciting TM and TE modes using a magnetic dipole and a magnetic current source, respectively. Four problem formulations are considered with increasing complexity and realism of anatomy. The results indicate that the optimal operating frequency f for deep implantation (with a depth d ≳3 cm ) lies in the (108- 109 )-Hz range and can be approximated as f =2.2 ×107/d . For a subcutaneous case (d ≲3 cm ), the surface-wave-induced interference is significant: within the range of peak radiation efficiency (about 2 ×108 to 3 ×109 Hz ), the max-to-min ratio can reach a value of 6.5. For the studied frequency range, 80%-99% of radiation efficiency is lost due to the tissue-air wave-impedance mismatch. Parallel polarization reduces the losses by a few percent; this effect is inversely proportional to the frequency and depth. Considering the implantation depth, the operating frequency, the polarization, and the directivity, we show that about an order-of-magnitude efficiency improvement is achievable compared to existing devices.

The Impact Analysis of Water Body Landscape Pattern on Urban Heat Island: A Case Study of Wuhan City

Directory of Open Access Journals (Sweden)

Bohan Yang

2015-01-01

Full Text Available Based on the LST and the landscape metrics of water body with remote sensing technique and spatial analysis, the relationship between the mean LST and the attributes of water body was revealed via Pearson’s correlation analysis and multiple stepwise regression analysis. Result showed that, in 32 class-based metrics we selected, the proportion of water body, average water body size, the isolation and fragmentation of water body, and other eight metrics have high correlation with the LST. As a resultant force, the quantity, shape, and spatial distribution of water body affect the forming of temperature. We found that the quantity and spatial pattern of city water body could be allocated reasonably to maximize its cooling effect.

LAP-ND: a new instrument for vector polarization analysis and neutron depolarization measurements at FRJ-2

International Nuclear Information System (INIS)

Ioffe, Alexander; Bussmann, Klaus; Dohmen, Ludwig; Axelrod, Leonid; Gordeev, Gennadi; Brueckel, Thomas

2004-01-01

The method of vector analysis of the neutron polarization allows for the determination of both the magnitude and the direction of the magnetization vector in the sample. A directional distribution of the magnetization in a sample results in a spread of the direction of the polarization vector in space and thus in the depolarization of the incident beam. A new neutron depolarization set up is installed at the research reactor FRJ-2 of the Forschungszentrum Juelich. The main feature of the set up is the use of rather long wavelength, λ=(4-6.5) A, neutrons thus allowing for a significant increase in the sensitivity of depolarization measurements. The set up uses a non-cryogenic zero-field sample chamber with the residual magnetic field of about 1 mG. It will be used for the determination of the sample magnetization at mesoscopic and macroscopic levels and for the study of magnetic phase transitions, magnetic nanostructures, magnetic glasses, etc

Constraints on CPT violation from Wilkinson Microwave Anisotropy Probe three year polarization data: A wavelet analysis

International Nuclear Information System (INIS)

Cabella, Paolo; Silk, Joseph; Natoli, Paolo

2007-01-01

We perform a wavelet analysis of the temperature and polarization maps of the cosmic microwave background (CMB) delivered by the Wilkinson Microwave Anisotropy Probe experiment in search for a parity-violating signal. Such a signal could be seeded by new physics beyond the standard model, for which the Lorentz and CPT symmetries may not hold. Under these circumstances, the linear polarization direction of a CMB photon may get rotated during its cosmological journey, a phenomenon also called cosmological birefringence. Recently, Feng et al. have analyzed a subset of the Wilkinson Microwave Anisotropy Probe and BOOMERanG 2003 angular power spectra of the CMB, deriving a constraint that mildly favors a nonzero rotation. By using wavelet transforms we set a tighter limit on the CMB photon rotation angle Δα=-2.5±3.0 (Δα=-2.5±6.0) at the one (two) σ level, consistent with a null detection

LAP-ND: a new instrument for vector polarization analysis and neutron depolarization measurements at FRJ-2

Energy Technology Data Exchange (ETDEWEB)

Ioffe, Alexander; Bussmann, Klaus; Dohmen, Ludwig; Axelrod, Leonid; Gordeev, Gennadi; Brueckel, Thomas

2004-07-15

The method of vector analysis of the neutron polarization allows for the determination of both the magnitude and the direction of the magnetization vector in the sample. A directional distribution of the magnetization in a sample results in a spread of the direction of the polarization vector in space and thus in the depolarization of the incident beam. A new neutron depolarization set up is installed at the research reactor FRJ-2 of the Forschungszentrum Juelich. The main feature of the set up is the use of rather long wavelength, {lambda}=(4-6.5) A, neutrons thus allowing for a significant increase in the sensitivity of depolarization measurements. The set up uses a non-cryogenic zero-field sample chamber with the residual magnetic field of about 1 mG. It will be used for the determination of the sample magnetization at mesoscopic and macroscopic levels and for the study of magnetic phase transitions, magnetic nanostructures, magnetic glasses, etc.

Polarization developments

International Nuclear Information System (INIS)

Prescott, C.Y.

1993-07-01

Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist

Geographical Income Polarization

DEFF Research Database (Denmark)

Azhar, Hussain; Jonassen, Anders Bruun

inter municipal income inequality. Counter factual simulations show that rising property prices to a large part explain the rise in polarization. One side-effect of polarization is tendencies towards a parallel polarization of residence location patterns, where low skilled individuals tend to live...

Line scan analysis of the component of Ru porcelain by SRXRF method

International Nuclear Information System (INIS)

Zhu Jian; Mao Zhenwei; Yang Yimin; Feng Min; Wang Changsui; Sun Xinmin; Guo Musen; Huang Yuying; He Wei

2002-01-01

The technique of the SRXRF line scan analysis was used to measure contents of 11 elements at the broken plane of the Ru porcelain from porcelain glaze to body. It is found that there exists a great different layer of contents of elements between the porcelain glaze and body. The mechanism may be that in the process of firing the porcelain, materials of glass-glaze of porcelain glaze infiltrate into the surface of porcelain body, that could fit the phenomenon of observation by different microscopes (stereomicroscope, polarizing microscope and scanning electron microscope)

Perceiving polarization with the naked eye: characterization of human polarization sensitivity

Science.gov (United States)

Temple, Shelby E.; McGregor, Juliette E.; Miles, Camilla; Graham, Laura; Miller, Josie; Buck, Jordan; Scott-Samuel, Nicholas E.; Roberts, Nicholas W.

2015-01-01

Like many animals, humans are sensitive to the polarization of light. We can detect the angle of polarization using an entoptic phenomenon called Haidinger's brushes, which is mediated by dichroic carotenoids in the macula lutea. While previous studies have characterized the spectral sensitivity of Haidinger's brushes, other aspects remain unexplored. We developed a novel methodology for presenting gratings in polarization-only contrast at varying degrees of polarization in order to measure the lower limits of human polarized light detection. Participants were, on average, able to perform the task down to a threshold of 56%, with some able to go as low as 23%. This makes humans the most sensitive vertebrate tested to date. Additionally, we quantified a nonlinear relationship between presented and perceived polarization angle when an observer is presented with a rotatable polarized light field. This result confirms a previous theoretical prediction of how uniaxial corneal birefringence impacts the perception of Haidinger's brushes. The rotational dynamics of Haidinger's brushes were then used to calculate corneal retardance. We suggest that psychophysical experiments, based upon the perception of polarized light, are amenable to the production of affordable technologies for self-assessment and longitudinal monitoring of visual dysfunctions such as age-related macular degeneration. PMID:26136441

COST meeting - Polarization and AGN II - Abstracts and slides

International Nuclear Information System (INIS)

Kishimoto, M.; Rouan, D.; Tadhunter, C.; Lopez Rodriguez, E.; Braibant, L.; Pasetto, A.; Matt, G.; Afanasiev, V.; Lira, P.; Hutsemekers, D.; Sluse, D.; Marin, F.; Tamborra, F.; Yankova, K.; Laing, R.; Lico, R.; Agudo, I.; Hovatta, T.; Jermak, H.; Chen, X.; Myserlis, I.; Cellone, S.A.; Chidiac, C.; Chakraborty, N.; Bozhilov, V.

2016-01-01

This meeting is the 2. COST workshop on Polarization and Active Galactic Nuclei (AGN). Accreting supermassive black holes in active galactic nuclei are the most powerful, long-lasting sources in the universe. Emitting over ten orders of magnitude in photon energy or more, the radiation of AGN encodes information about a multitude of astrophysical processes: accretion, thermal and non-thermal radiative transfer, acceleration of outflows and jets, shock physics, special and general relativity. Observationally, AGN appear as numerous types and polarization studies have played a key role in establishing the idea of a unifying AGN geometry. The topics covered at the meeting include the following: 1) Polarimetry of AGN from the radio to gamma-rays; 2) Tools for modeling and data analysis of AGN polarization; 3) Polarization due to magnetic fields and dust in AGN; 4) Polarization of AGN inflows, outflows and jets; 5) Spectropolarimetry and polarization variability of AGN; and 6) From Sgr A* to the most luminous quasars: what can polarimetry do for AGN (super-)unification? This document is made up of the abstracts and slides of the presentations

Measurement of total body chlorine by prompt gamma in vivo neutron activation analysis

International Nuclear Information System (INIS)

Beddoe, A.H.; Streat, S.J.; Hill, G.L.

1987-01-01

A method of measuring total body chlorine (TBCl) by prompt gamma in vivo neutron activation analysis is described depending on the same NaI(Tl) spectra used for determinations of total body nitrogen. Ratios of chlorine to hydrogen are derived and TBCl determined using a model of body composition depending on measured body weight, total body water (by tritium dilution) and protein (6.25 x nitrogen) as well as estimated body minerals and glycogen. The precision of the method based on scanning an anthropomorphic phantom is approximately 9% (SD), for a patient dose equivalent of less than 0.30 mSv. Spectra collected from 67 normal volunteers (32 male, 35 female) yielded mean values of TBCl of 72 +- 19 (SD) g in males and 53.6 +- 15 g in females, in broad agreement with values reported by workers using delayed gamma methods. Results are presented for two human cadavers analysed by neutron activation and conventional chemical analysis; the ratios of TBCl (neutron activation) to TBCl (chemical) were 0.980 +- 0.028 (SEM) and 0.91 +- 0.09. It is suggested that an improvement in precision will be achieved by increasing the scanning time (thereby increasing the radiation dose equivalent) and by adding two more detectors. (author)

Measurement of the polarized neutron---polarized 3He total cross section

International Nuclear Information System (INIS)

Keith, C.D.; Gould, C.R.; Haase, D.G.; Seely, M.L.; Huffman, P.R.; Roberson, N.R.; Tornow, W.; Wilburn, W.S.

1995-01-01

The first measurements of polarized neutron--polarized 3 He scattering in the few MeV energy region are reported. The total cross section difference Δσ T for transversely polarized target and beam has been measured for neutron energies between 1.9 and 7.5 MeV. Comparison is made to predictions of Δσ T using various descriptions of the 4 He continuum. A brute-force polarized target of solid 3 He has been developed for these measurements. The target is 4.3x10 22 atoms/cm 2 thick and is polarized to 38% at 7 Telsa and 12 mK. copyright 1995 American Institute of Physics

Dynamics of cell polarity in tissue morphogenesis: a comparative view from Drosophila and Ciona [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Michael T. Veeman

2016-06-01

Full Text Available Tissues in developing embryos exhibit complex and dynamic rearrangements that shape forming organs, limbs, and body axes. Directed migration, mediolateral intercalation, lumen formation, and other rearrangements influence the topology and topography of developing tissues. These collective cell behaviors are distinct phenomena but all involve the fine-grained control of cell polarity. Here we review recent findings in the dynamics of polarized cell behavior in both the Drosophila ovarian border cells and the Ciona notochord. These studies reveal the remarkable reorganization of cell polarity during organ formation and underscore conserved mechanisms of developmental cell polarity including the Par/atypical protein kinase C (aPKC and planar cell polarity pathways. These two very different model systems demonstrate important commonalities but also key differences in how cell polarity is controlled in tissue morphogenesis. Together, these systems raise important, broader questions on how the developmental control of cell polarity contributes to morphogenesis of diverse tissues across the metazoa.

Polarization Change in Face-Centered Cubic Opal Films

Science.gov (United States)

Wolff, Christian; Romanov, Sergei; Küchenmeister, Jens; Peschel, Ulf; Busch, Kurt

2011-10-01

Artificial opals are a popular platform for investigating fundamental properties of Photonic Crystals (PhC). In this work, we provide a theoretical analysis of polarization-resolved transmission experiments through thin opal films. Despite the full cubic symmetry of the PhC, this system provides a very efficient mechanism for manipulating the polarization state of light. Based on band structure calculations and Bloch mode analysis, we find that this effect closely resembles classical birefringence. Due to the cubic symmetry, however, a description using tensorial quantities is not possible. This indicates fundamental limitations of effective material models for Photonic Crystals and demonstrates the importance of accurately modelling the microscopic geometry of such systems.

Dynamically polarized hydrogen target as a broadband, wavelength-independent thermal neutron spin polarizer

International Nuclear Information System (INIS)

Zhao Jinkui; Garamus, Vasil M.; Mueller, Wilhelm; Willumeit, Regine

2005-01-01

A hydrogen-rich sample with dynamically polarized hydrogen nuclei was tested as a wavelength-independent neutron transmission spin polarizer. The experiment used a modified setup of the dynamic nuclear polarization target station at the GKSS research center. The standard solvent sample at the GKSS DNP station was used. It is 2.8mm thick and consists of 43.4wt% water, 54.6wt% glycerol, and 2wt% of EHBA-Cr(v) complex. The wavelength of the incident neutrons for the transmission experiment was λ=8.1A with Δλ/λ=10%. The polarization of neutron beam after the target sample was analyzed with a supermirror analyzer. A neutron polarization of -52% was achieved at the hydrogen polarization of -69%. Further experiments will test the feasibility of other hydrogen-rich materials, such as methane, as the polarizer. A theoretical calculation shows that a polarized methane target would allow over 95% neutron polarizations with more than 30% transmission

Directional cell migration establishes the axes of planar polarity in the posterior lateral-line organ of the zebrafish.

Science.gov (United States)

López-Schier, Hernán; Starr, Catherine J; Kappler, James A; Kollmar, Richard; Hudspeth, A J

2004-09-01

The proper orientation of mechanosensory hair cells along the lateral-line organ of a fish or amphibian is essential for the animal's ability to sense directional water movements. Within the sensory epithelium, hair cells are polarized in a stereotyped manner, but the mechanisms that control their alignment relative to the body axes are unknown. We have found, however, that neuromasts can be oriented either parallel or perpendicular to the anteroposterior body axis. By characterizing the strauss mutant zebrafish line and by tracking labeled cells, we have demonstrated that neuromasts of these two orientations originate from, respectively, the first and second primordia. Furthermore, altering the migratory pathway of a primordium reorients a neuromast's axis of planar polarity. We propose that the global orientation of hair cells relative to the body axes is established through an interaction between directional movement by primordial cells and the timing of neuromast maturation.

Optical Field-Strength Polarization of Two-Mode Single-Photon States

Science.gov (United States)

Linares, J.; Nistal, M. C.; Barral, D.; Moreno, V.

2010-01-01

We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of…

Lagrange and Noether analysis of polarization laws of conservation for electromagnetic field

International Nuclear Information System (INIS)

Krivskij, I.Yu.; Simulik, V.M.

1988-01-01

Both well-known Bessel-Hagen conservation laws and conservation laws of polarized character are derived for electromagnetic field in the Lagrange approach to electrodynamics in terms of intensities (without using the A μ potentials as variation variables). The laws mentioned are derived according to Noether theorem because symmetry to which such concervation laws correspond is lost during the transition from intensities to potentials. Based on Noether theorem (and its generalization for Naeik's symmetries) and Lagrange function scalar in relation to complete Poincare group in terms of intensity tensor, a convenient formula for calculating and values conserved for electromagnetic field is derived which sets up a physically adequate symmetry operator -conservation law correlation and thus links the presence of conservation laws of polarized character with symmetry properties of Maxwell equations. Adiabaticity of conservation laws of polarized character under the presence of interaction with currents and charges is indicated

Kinetic-limited etching of magnesium doping nitrogen polar GaN in potassium hydroxide solution

International Nuclear Information System (INIS)

Jiang, Junyan; Zhang, Yuantao; Chi, Chen; Yang, Fan; Li, Pengchong; Zhao, Degang; Zhang, Baolin; Du, Guotong

2016-01-01

Graphical abstract: - Highlights: • Effects of Mg doping on wet etching of N-polar GaN are illustrated and analysed. • Etching process model of Mg-doped N-polar GaN in KOH solution is purposed. • It is found that Mg doping can induce tensile strain in N-polar GaN film. • N-polar p-GaN film with a hole concentration of 2.4 × 10"1"7 cm"−"3 is obtained. - Abstract: KOH based wet etchings were performed on both undoped and Mg-doped N-polar GaN films grown by metal-organic chemical vapor deposition. It is found that the etching rate for Mg-doped N-polar GaN gets slow obviously compared with undoped N-polar GaN. X-ray photoelectron spectroscopy analysis proved that Mg oxide formed on N-polar GaN surface is insoluble in KOH solution so that kinetic-limited etching occurs as the etching process goes on. The etching process model of Mg-doped N-polar GaN in KOH solution is tentatively purposed using a simplified ideal atomic configuration. Raman spectroscopy analysis reveals that Mg doping can induce tensile strain in N-polar GaN films. Meanwhile, p-type N-polar GaN film with a hole concentration of 2.4 × 10"1"7 cm"−"3 was obtained by optimizing bis-cyclopentadienyl magnesium flow rates.