WorldWideScience

Sample records for active south polar

  1. South Polar Polygons

    Science.gov (United States)

    2005-01-01

    4 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a polgyon-cracked surface, into which deep, somewhat kidney-bean-shaped pits have formed. These are landscapes of the martian south polar residual cap. This view was captured during May 2005. Location near: 86.9oS, 5.1oW Image width: 1.5 km (0.9 mi) Illumination from: upper left Season Southern Spring

  2. Semi-automatic measures of activity in selected south polar regions of Mars using morphological image analysis

    Science.gov (United States)

    Aye, Klaus-Michael; Portyankina, Ganna; Pommerol, Antoine; Thomas, Nicolas

    The High Resolution Imaging Science Experiment (HiRISE) onboard Mars Reconnaissance Orbiter (MRO) has been used to monitor the seasonal evolution of several regions at high southern latitudes. Of particular interest have been jet-like activities that may result from the process described by Kieffer (2007), involving translucent CO2 ice. These jets are assumed to create fan-shaped ground features, as studied e.g. in Hansen et.al. (2010) and Portyankina et.al. (2010). In Thomas et.al. (2009), a small region of interest (ROI) inside the south polar Inca City region (81° S, 296° E) was defined for which the seasonal change of the number of fans was determined. This ROI was chosen for its strong visual variability in ground features. The mostly manual counting work showed, that the number of apparent fans increases monotonously for a considerable amount of time from the beginning of the spring time observations at Ls of 178° until approx. 230° , following the increase of available solar energy for the aforementioned processes of the Kieffer model. This fact indicates that the number of visual fan features can be used as an activity measure for the seasonal evolution of this area, in addition to commonly used evolution studies of surface reflectance. Motivated by these results, we would like to determine the fan count evolution for more south polar areas like Ithaca, Manhattan, Giza and others. To increase the reproducibility of the results by avoiding potential variability in fan shape recognition by human eye and to increase the production efficiency, efforts are being undertaken to automise the fan counting procedure. The techniques used, cleanly separated in different stages of the procedure, the difficulties for each stage and an overview of the tools used at each step will be presented. After showing a proof of concept in Aye et.al. (2010), for a ROI that is comparable to the one previously used for manual counting in Thomas et.al. (2009), we now will show

  3. SOUTH POL: Revealing the Polarized Southern Sky

    Science.gov (United States)

    Magalhaes, Antonio Mario Mario; Ramírez, Edgar; Ribeiro, Nadili; Seriacopi, Daiane; Rubinho, Marcelo; Ferrari, Tiberio; Rodrigues, Claudia; Schoenell, William; Herpich, Fabio; Pereyra, Antonio

    2018-01-01

    SOUTH POL will be a survey of the Southern sky in optical polarized light. It will use a newly built polarimeter for T80-S, an 84 cm robotic telescope installed at Cerro Tololo (CTIO), Chile. It will initially cover the sky South of declination -15 deg with a polarimetric accuracy Solar System.The polarimeter has just been commissioned in mid-November, 2017. The data reduction pipeline has already been built. We will describe the instrument and the data reduction, as well as a few of the science cases. The survey is expected to begin midway through the 1st semester of 2018. Both catalog data and raw images will be made available.

  4. Curtain eruptions from Enceladus' south-polar terrain

    Science.gov (United States)

    Spitale, Joseph N.; Hurford, Terry A.; Rhoden, Alyssa R.; Berkson, Emily E.; Platts, Symeon S.

    2015-05-01

    Observations of the south pole of the Saturnian moon Enceladus revealed large rifts in the south-polar terrain, informally called `tiger stripes', named Alexandria, Baghdad, Cairo and Damascus Sulci. These fractures have been shown to be the sources of the observed jets of water vapour and icy particles and to exhibit higher temperatures than the surrounding terrain. Subsequent observations have focused on obtaining close-up imaging of this region to better characterize these emissions. Recent work examined those newer data sets and used triangulation of discrete jets to produce maps of jetting activity at various times. Here we show that much of the eruptive activity can be explained by broad, curtain-like eruptions. Optical illusions in the curtain eruptions resulting from a combination of viewing direction and local fracture geometry produce image features that were probably misinterpreted previously as discrete jets. We present maps of the total emission along the fractures, rather than just the jet-like component, for five times during an approximately one-year period in 2009 and 2010. An accurate picture of the style, timing and spatial distribution of the south-polar eruptions is crucial to evaluating theories for the mechanism controlling the eruptions.

  5. Drawing the Curtain on Enceladus' South-Polar Eruptions

    Science.gov (United States)

    Spitale, Joseph N.; Hurford, Terry A.; Rhoden, Alyssa R.; Berkson, Emily E.; Platts, Symeon S.

    2015-11-01

    For a comprehensive description of Enceladus' south-polar eruptions observed at high resolution, they must be represented as broad curtains rather than discrete jets. Meanders in the fractures from which the curtains of material erupt give rise to optical illusions that look like discrete jets, even along fractures with no local variations in eruptive activity, implying that many features previously identified as "jets" are in fact phantoms. By comparing Cassini images with model curtain eruptions, we are able to obtain maps of eruptive activity that are not biased by the presence of those phantom jets. The average of our activity maps over all times agrees well with thermal maps produced by Cassini CIRS. We can best explain the observed curtains by assuming spreading angles with altitude of up to 14° and zenith angles of up to 8°, for curtains observed in geometries that are sensitive to those quantities.

  6. Transient surface liquid in Titan's south polar region from Cassini

    Science.gov (United States)

    Hayes, A.G.; Aharonson, O.; Lunine, J.I.; Kirk, R.L.; Zebker, H.A.; Wye, L.C.; Lorenz, R.D.; Turtle, E.P.; Paillou, P.; Mitri, Giuseppe; Wall, S.D.; Stofan, E.R.; Mitchell, K.L.; Elachi, C.

    2011-01-01

    Cassini RADAR images of Titan's south polar region acquired during southern summer contain lake features which disappear between observations. These features show a tenfold increases in backscatter cross-section between images acquired one year apart, which is inconsistent with common scattering models without invoking temporal variability. The morphologic boundaries are transient, further supporting changes in lake level. These observations are consistent with the exposure of diffusely scattering lakebeds that were previously hidden by an attenuating liquid medium. We use a two-layer model to explain backscatter variations and estimate a drop in liquid depth of approximately 1-m-per-year. On larger scales, we observe shoreline recession between ISS and RADAR images of Ontario Lacus, the largest lake in Titan's south polar region. The recession, occurring between June 2005 and July 2009, is inversely proportional to slopes estimated from altimetric profiles and the exponential decay of near-shore backscatter, consistent with a uniform reduction of 4 ± 1.3 m in lake depth. Of the potential explanations for observed surface changes, we favor evaporation and infiltration. The disappearance of dark features and the recession of Ontario's shoreline represents volatile transport in an active methane-based hydrologic cycle. Observed loss rates are compared and shown to be consistent with available global circulation models. To date, no unambiguous changes in lake level have been observed between repeat images in the north polar region, although further investigation is warranted. These observations constrain volatile flux rates in Titan's hydrologic system and demonstrate that the surface plays an active role in its evolution. Constraining these seasonal changes represents the first step toward our understanding of longer climate cycles that may determine liquid distribution on Titan over orbital time periods.

  7. Monstrous Ice Cloud System in Titan's Present South Polar Stratosphere

    Science.gov (United States)

    Anderson, Carrie; Samuelson, Robert; McLain, Jason; Achterberg, Richard; Flasar, F. Michael; Milam, Stefanie

    2015-11-01

    During southern autumn when sunlight was still available, Cassini's Imaging Science Subsystem discovered a cloud around 300 km near Titan's south pole (West, R. A. et al., AAS/DPS Abstracts, 45, #305.03, 2013); the cloud was later determined by Cassini's Visible and InfraRed Mapping Spectrometer to contain HCN ice (de Kok et al., Nature, 514, pp 65-67, 2014). This cloud has proven to be only the tip of an extensive ice cloud system contained in Titan's south polar stratosphere, as seen through the night-vision goggles of Cassini's Composite InfraRed Spectrometer (CIRS). As the sun sets and the gloom of southern winter approaches, evidence is beginning to accumulate from CIRS far-IR spectra that a massive system of nitrile ice clouds is developing in Titan's south polar stratosphere. Even during the depths of northern winter, nothing like the strength of this southern system was evident in corresponding north polar regions.From the long slant paths that are available from limb-viewing CIRS far-IR spectra, we have the first definitive detection of the ν6 band of cyanoacetylene (HC3N) ice in Titan’s south polar stratosphere. In addition, we also see a strong blend of nitrile ice lattice vibration features around 160 cm-1. From these data we are able to derive ice abundances. The most prominent (and still chemically unidentified) ice emission feature, the Haystack, (at 220 cm-1) is also observed. We establish the vertical distributions of the ice cloud systems associated with both the 160 cm-1 feature and the Haystack. The ultimate aim is to refine the physical and possibly the chemical relationships between the two. Transmittance thin film spectra of nitrile ice mixtures obtained in our Spectroscopy for Planetary ICes Environments (SPICE) laboratory are used to support these analyses.

  8. 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.

  9. 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.

  10. Stratigraphy of the south polar region of Ganymede

    Science.gov (United States)

    Dehon, R. A.

    1987-01-01

    A preliminary assessment is made of the stratigraphy and geology in the south polar region of the Jovian satellite, Ganymede. Geologic mapping is based on inspection of Voyager images and compilation on an airbrush base map at a scale of 1:5M. Illumination and resolution vary greatly in the region. Approximately half of the quadripole is beyond the terminator. Low angle illumination over a large part of the area precludes distinction of some units by albedo characteristics. Several types of grooved terrain and groove related terrain occur in the southern polar region. Grooves typically occur in straight to curvilinear sets or lanes. Bright lanes and grooved lanes intersect at high angles outlining polygons of dark cratered terrain. Groove sets exhibit a range of ages as shown by superposition or truncation and by crater superposition ages.

  11. Complete mitochondrial genome of the South Polar Skua Stercorarius maccormicki (Charadriiformes, Stercorariidae) in Antarctica.

    Science.gov (United States)

    Han, Yeong-Deok; Baek, Ye-Seul; Kim, Jeong-Hoon; Choi, Han-Gu; Kim, Sanghee

    2016-05-01

    The South Polar Skua, gull-like seabirds is the most fascinating Antarctic seabirds that lay two eggs at sites free of snow and ice and predominantly hunt pelagic fish and penguins. Blood samples of the South Polar Skua Stercorarius maccormicki was collected during the summer activity near King Sejong station in Antarctica. The complete mitochondrial DNA sequence of S. maccormicki was 16,669 bp, showing conserved genome structure and orientation found in other avian species. The control region of S. maccormicki was 93- and 80 bp shorter compared to those of Chroicocephalus saundersi and Synthliboramphus antiquus respectively. Interestingly, there is a (CAACAAACAA)6 repeat sequence in the control region. Our results of S. maccormicki mt genome including the repeat sequence, may provide useful genetic information for phylogenetic and phylogeographic histories of the southern skua complex.

  12. A study of auroral activity in the nightside polar cap

    International Nuclear Information System (INIS)

    Wu, Q.

    1989-01-01

    Using various ground observations at South Pole, Antarctica (invariant magnetic latitude -74 degree) and its conjugate point, Frobisher Bay, Canada, the author has studied the following aspects of nightside polar cap auroral activity: the appearance and disappearance of polar cap auroras (diffuse and discrete) associated with substorms and interplanetary magnetic field (IMF) variations; auroral optical emission line intensities; and the seasonal variation of auroral conjugacy. The observations show that the polar cap auroras usually fade away before the expansive phase of a substorm and bright auroral arcs reach high latitude (-74 degree) near the recovery phase. Just before the auroras fade away the discrete polar cap auroral arcs, which are usually on the poleward boundary of the diffuse aurora, intensify for 1 to 2 minutes. The observations also indicate the IMF may have stronger control over polar cap auroral activity than do substorms. A search for energy spectral variation of precipitating electrons using the intensities of 630.0 nm (0) and 427 nm (N 2 + ) auroral emission lines reveals no dramatic changes in the energy spectrum; instead, the data show possible atmospheric scattering and geometric effects on the photometric measurements while the bright auroral arc is moving into the polar cap. The conjugate observations show that the stormtime auroral electrojet current, which is associated with the bright auroral arc, in most cases reaches higher (lower) latitudes in the winter (summer) hemisphere. An asymmetric plasma sheet (with respect to the neutral sheet) is proposed, which expands deeper into the winter lobe, under a tilted geomagnetic dipole. Accordingly, the winter polar cap would have smaller area and the auroral electrojet would be at higher latitude

  13. Active Polar Two-Fluid Macroscopic Dynamics

    Science.gov (United States)

    Pleiner, Harald; Svensek, Daniel; Brand, Helmut R.

    2014-03-01

    We study the dynamics of systems with a polar dynamic preferred direction. Examples include the pattern-forming growth of bacteria (in a solvent, shoals of fish (moving in water currents), flocks of birds and migrating insects (flying in windy air). Because the preferred direction only exists dynamically, but not statically, the macroscopic variable of choice is the macroscopic velocity associated with the motion of the active units. We derive the macroscopic equations for such a system and discuss novel static, reversible and irreversible cross-couplings connected to this second velocity. We find a normal mode structure quite different compared to the static descriptions, as well as linear couplings between (active) flow and e.g. densities and concentrations due to the genuine two-fluid transport derivatives. On the other hand, we get, quite similar to the static case, a direct linear relation between the stress tensor and the structure tensor. This prominent ``active'' term is responsible for many active effects, meaning that our approach can describe those effects as well. In addition, we also deal with explicitly chiral systems, which are important for many active systems. In particular, we find an active flow-induced heat current specific for the dynamic chiral polar order.

  14. Time activity patterns: a case of south Durban, South Africa

    CSIR Research Space (South Africa)

    Matooane, M

    2010-08-01

    Full Text Available Exposure modelling in south Durban is constrained by a lack of population specific time-activity patterns data. We argue that the application of time-activity patterns from elsewhere in the world in exposure modelling in south Durban would...

  15. 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.

  16. Atmospheric Modeling of the Martian Polar Regions: CRISM EPF Coverage During the South Polar Spring Recession

    Science.gov (United States)

    Brown, A. J.; McGuire, P.; Wolff, M. J.

    2008-03-01

    We describe efforts to model dust and ice aerosols content and soils and icy surface reflectance in the Martian southern polar region during spring recession (Ls = 152-320) using CRISM emission phase function (EPF) observations.

  17. Dayside aurorae and polar arcs under south-east IMF orientation

    Directory of Open Access Journals (Sweden)

    P. E. Sandholt

    2006-12-01

    Full Text Available We document a characteristic spatial and temporal structure of the aurora in the postnoon sector present during a 10-h-long interval of very steady southeast IMF orientation (clock angle=135° ending in a sharp south-to-north transition. Focus is placed on the detailed morphology of auroral forms/activities corresponding to merging and lobe convection cells obtained from SuperDARN convection data and Greenland magnetograms. The ground optical instruments at Ny Ålesund, Svalbard (76° MLAT recorded different auroral forms/activities as the station moved to higher magnetic local times (MLTs in the 13:00–17:00 MLT sector. Whereas the 13:00–15:00 MLT sector is characterized by classical poleward moving auroral forms (PMAFs associated with merging cell transients, the aurora in the 15:00–17:00 MLT sector shows instead a characteristic latitudinal bifurcation consisting of standard oval forms and polar arcs, and a corresponding composite pattern of merging and lobe convection cells. The merging and lobe cells respond to the southward and northward IMF transitions by activation/fading and fading/activation, respectively. A sequence of brightening events is characterized by successive activations progressing in latitude from the merging cell regime to the lobe cell regime. Emphasis is placed on the association between polar arc brightenings and the activation of the channel of enhanced sunward flow in the lobe cell. The observations are discussed in relation to recent work on solar wind-magnetosphere-ionosphere interconnection topology.

  18. Investigating Mercury's South Polar Deposits: Arecibo Radar Observations and High-Resolution Determination of Illumination Conditions

    Science.gov (United States)

    Chabot, Nancy L.; Shread, Evangela E.; Harmon, John K.

    2018-02-01

    There is strong evidence that Mercury's polar deposits are water ice hosted in permanently shadowed regions. In this study, we present new Arecibo radar observations of Mercury's south pole, which reveal numerous radar-bright deposits and substantially increase the radar imaging coverage. We also use images from MESSENGER's full mission to determine the illumination conditions of Mercury's south polar region at the same spatial resolution as the north polar region, enabling comparisons between the two poles. The area of radar-bright deposits in Mercury's south is roughly double that found in the north, consistent with the larger permanently shadowed area in the older, cratered terrain at the south relative to the younger smooth plains at the north. Radar-bright features are strongly associated with regions of permanent shadow at both poles, consistent with water ice being the dominant component of the deposits. However, both of Mercury's polar regions show that roughly 50% of permanently shadowed regions lack radar-bright deposits, despite some of these locations having thermal environments that are conducive to the presence of water ice. The observed uneven distribution of water ice among Mercury's polar cold traps may suggest that the source of Mercury's water ice was not a steady, regular process but rather that the source was an episodic event, such as a recent, large impact on the innermost planet.

  19. 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.

  20. IR SPECTRAL MAPPING OF THE MARTIAN SOUTH POLAR RESIDUAL CAP USING CRISM

    Directory of Open Access Journals (Sweden)

    J. Campbell

    2016-06-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are considered to be important in theories of abiogenesis (Allamandola, 2011 . There is evidence that PAHs have been detected on two icy Saturnian satellites using the Visual and Infrared Mapping Spectrometer (VIMS on the Cassini spacecraft (Cruikshank et al., 2007. The hypothesised presence of PAHs in Mars south polar cap has not been systematically examined even though the Mars south polar cap may allow the preservation of organic molecules that are typically destroyed at the Martian surface by UV radiation (Dartnell et al. 2012. This hypothesis is supported by recent analyses of South Polar Residual Cap (SPRC structural evolution (Thomas et al., 2009 that suggest the possibility that seasonal and long term sublimation may excavate dust particles from within the polar ice. Periodic sublimation is believed to be responsible for the formation of so-called “Swiss Cheese Terrain”, a unique surface feature found only in the Martian south polar residual cap consisting of flat floored, circular depressions (Byrne, 2009. We show the first examples of work towards the detection of PAHs in Swiss Cheese Terrain, using data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM, on board NASA’s Mars Reconnaissance Orbiter (MRO. CRISM is designed to search for mineralogical indications of past and present water, thus providing extensive coverage of the south polar cap. In this work, we discuss whether CRISM infrared spectra can be used to detect PAHs in Swiss Cheese Terrain and demonstrate a number of maps showing shifts in spectral profiles over the SPRC.

  1. Marine foraging and annual fish consumption of a south polar Skua population in the maritime Antarctic

    NARCIS (Netherlands)

    Hahn, S.M.; Ritz, M.S.; Reinhardt, K.

    2008-01-01

    Pelagic fish are an important component of Antarctic food webs but few quantitative data exist on energy transfer from fish to seabirds for the Seasonal Pack-ice Zone. We studied a local population of south polar, skuas Catharacta maccormicki during a whole breeding cycle and estimated its entire

  2. Active polarization imaging system based on optical heterodyne balanced receiver

    Science.gov (United States)

    Xu, Qian; Sun, Jianfeng; Lu, Zhiyong; Zhou, Yu; Luan, Zhu; Hou, Peipei; Liu, liren

    2017-08-01

    Active polarization imaging technology has recently become the hot research field all over the world, which has great potential application value in the military and civil area. By introducing active light source, the Mueller matrix of the target can be calculated according to the incident light and the emitted or reflected light. Compared with conventional direct detection technology, optical heterodyne detection technology have higher receiving sensitivities, which can obtain the whole amplitude, frequency and phase information of the signal light. In this paper, an active polarization imaging system will be designed. Based on optical heterodyne balanced receiver, the system can acquire the horizontal and vertical polarization of reflected optical field simultaneously, which contain the polarization characteristic of the target. Besides, signal to noise ratio and imaging distance can be greatly improved.

  3. Tracking the Polar Front south of New Zealand using penguin dive data

    Science.gov (United States)

    Sokolov, Serguei; Rintoul, Stephen R.; Wienecke, Barbara

    2006-04-01

    Nearly 36,000 vertical temperature profiles collected by 15 king penguins are used to map oceanographic fronts south of New Zealand. There is good correspondence between Antarctic Circumpolar Current (ACC) front locations derived from temperatures sampled in the upper 150 m along the penguin tracks and front positions inferred using maps of sea surface height (SSH). Mesoscale features detected in the SSH maps from this eddy-rich region are also reproduced in the individual temperature sections based on dive data. The foraging strategy of Macquarie Island king penguins appears to be influenced strongly by oceanographic structure: almost all the penguin dives are confined to the region close to and between the northern and southern branches of the Polar Front. Surface chlorophyll distributions also reflect the influence of the ACC fronts, with the northern branch of the Polar Front marking a boundary between low surface chlorophyll to the north and elevated values to the south.

  4. Buried CO2 Ice traces in South Polar Layered Deposits of Mars detected by radar sounder

    Science.gov (United States)

    Castaldo, L.; Mège, D.; Orosei, R.; Séjourné, A.

    2014-12-01

    SHARAD (SHAllow RADar) is the subsurface sounding radar provided by the Italian Space Agency (ASI) as a facility instrument to NASA's 2005 Mars Reconnaissance Orbiter (MRO). The Reduced Data Record of SHARAD data covering the area of the South Polar Layered Deposits (SPLD), has been used. The elaboration and interpretation of the data, aimed to estimate electromagnetic properties of surface layers, has been performed in terms of permittivity. The theory of electromagnetic scattering from fractal surfaces, and the estimation of geometric parameters from topographic data by Mars Orbiter Laser Altimeter (MOLA) which was one of five instruments on board the Mars Global Surveyor (MGS) spacecraft, has been used. A deep analysis of inversion has been made on all Mars and extended to the South Polar Caps in order to extract the area with a permittivity constant of CO2 ice. Several corrections have been applied to the data, moreover the calibration of the signal requires the determination of a constant that takes into account the power gain due to the radar system and the surface in order to compensate the power losses due to the orbitographic phenomena. The determination of regions with high probability of buried CO2 ice in the first layer of the Martian surface, is obtained extracting the real part of the permittivity constant of the CO2 ice (~2), estimated by other means. The permittivity of CO2ice is extracted from the Global Permittivity Map of Mars using the global standard deviation of itself as following: ɛCO2ice=ɛCO2ice+ Σ (1)where Σ=±std(ɛMapMars)/2Figure 1(a) shows the south polar areas where the values of the permittivity point to the possibility of a CO2 ice layer. Figure 1(b) is the corresponding geologic map. The comparison between the two maps indicates that the area with probable buried CO2 overlaps Hesperian and Amazonian polar units (Hp, Hesperian plains-forming deposits marked by narrow sinuous, anabranching ridges and irregular depressions, and

  5. Zeno inhibition of polarization rotation in an optically active medium

    International Nuclear Information System (INIS)

    Gonzalo, Isabel; Luis, Alfredo; Porras, Miguel A

    2015-01-01

    We describe an experiment in which the rotation of the polarization of light propagating in an optically active water solution of D-fructose tends to be inhibited by frequent monitoring whether the polarization remains unchanged. This is an example of the Zeno effect that has remarkable pedagogical interest because of its conceptual simplicity, easy implementation, low cost, and because the same the Zeno effect holds at classical and quantum levels. An added value is the demonstration of the Zeno effect beyond typical idealized assumptions in a practical setting with real polarizers. (paper)

  6. IDENTIFYING SURFACE CHANGES ON HRSC IMAGES OF THE MARS SOUTH POLAR RESIDUAL CAP (SPRC

    Directory of Open Access Journals (Sweden)

    A. R. D. Putri

    2016-06-01

    Full Text Available The surface of Mars has been an object of interest for planetary research since the launch of Mariner 4 in 1964. Since then different cameras such as the Viking Visual Imaging Subsystem (VIS, Mars Global Surveyor (MGS Mars Orbiter Camera (MOC, and Mars Reconnaissance Orbiter (MRO Context Camera (CTX and High Resolution Imaging Science Experiment (HiRISE have been imaging its surface at ever higher resolution. The High Resolution Stereo Camera (HRSC on board of the European Space Agency (ESA Mars Express, has been imaging the Martian surface, since 25th December 2003 until the present-day. HRSC has covered 100 % of the surface of Mars, about 70 % of the surface with panchromatic images at 10-20 m/pixel, and about 98 % at better than 100 m/pixel (Neukum et. al., 2004, including the polar regions of Mars. The Mars polar regions have been studied intensively recently by analysing images taken by the Mars Express and MRO missions (Plaut et al., 2007. The South Polar Residual Cap (SPRC does not change very much in volume overall but there are numerous examples of dynamic phenomena associated with seasonal changes in the atmosphere. In particular, we can examine the time variation of layers of solid carbon dioxide and water ice with dust deposition (Bibring, 2004, spider-like channels (Piqueux et al., 2003 and so-called Swiss Cheese Terrain (Titus et al., 2004. Because of seasonal changes each Martian year, due to the sublimation and deposition of water and CO2 ice on the Martian south polar region, clearly identifiable surface changes occur in otherwise permanently icy region. In this research, good quality HRSC images of the Mars South Polar region are processed based on previous identification as the optimal coverage of clear surfaces (Campbell et al., 2015. HRSC images of the Martian South Pole are categorized in terms of quality, time, and location to find overlapping areas, processed into high quality Digital Terrain Models (DTMs and

  7. Polarization ray tracing in anisotropic optically active media. I. Algorithms

    International Nuclear Information System (INIS)

    McClain, S.C.; Hillman, L.W.; Chipman, R.A.

    1993-01-01

    Procedures for performing polarization ray tracing through birefringent media are presented in a form compatible with the standard methods of geometrical ray tracing. The birefringent materials treated include the following: anisotropic optically active materials such as quartz, non-optically active uniaxial materials such as calcite, and isotropic optically active materials such as mercury sulfide and organic liquids. Refraction and reflection algorithms are presented that compute both ray directions and wave directions. Methods for computing polarization modes, refractive indices, optical path lengths, and Fresnel transmission and reflection coefficients are also specified. A numerical example of these algorithms is given for analyzing the field of view of a quartz rotator. 37 refs., 3 figs

  8. Antimicrobial Activity Investigation on Wuyiencin Fractions of Different Polarity

    Directory of Open Access Journals (Sweden)

    Zengjie Cui

    2010-04-01

    Full Text Available The aim of this study was to evaluate the antimicrobial activity of Wuyiencin fractions with different polarities against six indicator microorganisms: Rhodotorula rubra, Bacillus subtilis, Bacillus megaterium, Escherichia coli, Cladosporium fulvum and Staphylococcus aureus. The fermentation broth of Wuyiencin was submitted to AB-8 macroporous adsorptive resin and fractionated with solvents of different polarity. The fraction eluted with water had remarkably antimicrobial activity against all the microorganisms investigated except for C. fulvum and S. aureus (MIC ≤ 0.0625 mg/mL, probably due to the presence of active components. The fraction eluted with methanol showed potential antimicrobial activity against all the test microorganisms except for R.rubra, with MIC values of0.5 and 2 mg/mL. In conclusion, fractions eluted with water and methanol, respectively, represent the main active-part of Wuyiencin, and could be emphasized for agricultural applications in the future.

  9. Circularly polarized antennas for active holographic imaging through barriers

    Science.gov (United States)

    McMakin, Douglas L [Richland, WA; Severtsen, Ronald H [Richland, WA; Lechelt, Wayne M [West Richland, WA; Prince, James M [Kennewick, WA

    2011-07-26

    Circularly-polarized antennas and their methods of use for active holographic imaging through barriers. The antennas are dielectrically loaded to optimally match the dielectric constant of the barrier through which images are to be produced. The dielectric loading helps to remove barrier-front surface reflections and to couple electromagnetic energy into the barrier.

  10. Massive CO2 Ice Deposits Sequestered in the South Polar Layered Deposits of Mars

    Science.gov (United States)

    Phillips, Roger J.; Davis, Brian J.; Tanaka, Kenneth L.; Byrne, Shane; Mellon, Michael T.; Putzig, Nathaniel E.; Haberle, Robert M.; Kahre, Melinda A.; Campbell, Bruce A.; Carter, Lynn M.; Smith, Isaac B.; Holt, John W.; Smrekar, Suzanne E.; Nunes, Daniel C.; Plaut, Jeffrey J.; Egan, Anthony F.; Titus, Timothy N.; Seu, Roberto

    2011-01-01

    Shallow Radar soundings from the Mars Reconnaissance Orbiter reveal a buried deposit of carbon dioxide (CO2) ice within the south polar layered deposits of Mars with a volume of 9500 to 12,500 cubic kilometers, about 30 times that previously estimated for the south pole residual cap. The deposit occurs within a stratigraphic unit that is uniquely marked by collapse features and other evidence of interior CO2 volatile release. If released into the atmosphere at times of high obliquity, the CO2 reservoir would increase the atmospheric mass by up to 80%, leading to more frequent and intense dust storms and to more regions where liquid water could persist without boiling.

  11. Three-dimensional thermal structure of the South Polar Vortex of Venus

    Science.gov (United States)

    Hueso, Ricardo; Garate-Lopez, Itziar; Garcia-Muñoz, Antonio; Sánchez-Lavega, Agustín

    2014-11-01

    We have analyzed thermal infrared images provided by the VIRTIS-M instrument aboard Venus Express (VEX) to obtain high resolution thermal maps of the Venus south polar region between 55 and 85 km altitudes. The maps investigate three different dynamical configurations of the polar vortex including its classical dipolar shape, a regularly oval shape and a transition shape between the different configurations of the vortex. We apply the atmospheric model described by García Muñoz et al. (2013) and a variant of the retrieval algorithm detailed in Grassi et al. (2008) to obtain maps of temperature over the Venus south polar region in the quoted altitude range. These maps are discussed in terms of cloud motions and relative vorticity distribution obtained previously (Garate-Lopez et al. 2013). Temperature maps retrieved at 55 - 63 km show the same structures that are observed in the ~5 µm radiance images. This altitude range coincides with the optimal expected values of the cloud top altitude at polar latitudes and magnitudes derived from the analysis of ~5 µm images are measured at this altitude range. We also study the imprint of the vortex on the thermal field above the cloud level which extends up to 80 km. From the temperature maps, we also study the vertical stability of different atmospheric layers. The cold collar is clearly the most statically stable structure at polar latitudes, while the vortex and subpolar latitudes show lower stability values. Furthermore, the hot filaments present within the vortex at 55-63 km exhibit lower values of static stability than their immediate surroundings.ReferencesGarate-Lopez et al. Nat. Geosci. 6, 254-257 (2013).García Muñoz et al. Planet. Space Sci. 81, 65-73 (2013).Grassi, D. et al. J. Geophys. Res. 113, 1-12 (2008).AcknowledgementsWe thank ESA for supporting Venus Express, ASI, CNES and the other national space agencies supporting VIRTIS on VEX and their principal investigators G. Piccioni and P. Drossart. This work

  12. Polarized electrons and the origin of optical activity

    International Nuclear Information System (INIS)

    Bonner, W.A.; Dort, M.A. Van; Yearian, M.R.; Zeman, H.D.; Li, G.C.; Stanford Univ., Calif.

    1976-01-01

    The history of experiments bearing on the origin of optical acitivity in nature by parity non-conservation during the β-decay of radioactive isotopes is briefly reviewed. Following this, we present a more detailed description of our recent published and unpublished data and calculations regarding the generation of optical activity in DL-leucine by means of artificially produced longitudinally polarized electrons from a linear accelerator

  13. Subsidence of the South Polar Terrain and global tectonic of Enceladus

    Science.gov (United States)

    Czechowski, Leszek

    2016-04-01

    Introduction: Enceladus is the smallest celestial body in the Solar System where volcanic and tectonic activities are observed. Every second, the mass of ˜200 kg is ejected into space from the South Polar Terrain (SPT) - [1]. The loss of matter from the body's interior should lead to global compression of the crust (like on Mercury). Typical effects of compression are: thrust faults, folding and subduction. However, such forms are not dominant on Enceladus. We propose here special dynamical process that could explain this paradox. Our hypothesis states that the mass loss from SPT is the main driving mechanism of the following tectonic processes: subsidence of SPT, flow in the mantle and motion of adjacent tectonic plates. The hypothesis is presented in [2] and [3]. We suggest that the loss of the volatiles results in a void, an instability, and motion of solid matter to fill the void. The motion includes: Subsidence of the 'lithosphere' of SPT. Flow of the matter in the mantle. Motion of plates adjacent to SPT towards the active region. Methods and results: The numerical model of the subsidence process is developed. It is based on the model of thermal convection in the mantle. Special boundary conditions are applied, that could simulate subsidence of SPT. If emerging void is being filled by the subsidence of SPT only, then the velocity of subsidence is ˜0.05 mmṡyr-1. However, numerical calculations indicate that all three types of motion are usually important. The role of a given motion depends on the viscosity distribution. Generally, for most of the models the subsidence is ˜0.02 mmṡyr-1, but mantle flow and plates' motion also play a role in filling the void. The preliminary results of the numerical model indicate also that the velocity of adjacent plates could be ˜0.02 mmṡyr-1 for the Newtonian rheology. Note that in our model the reduction of the crust area is not a result of compression but it is a result of the plate sinking. Therefore the

  14. How the geysers, tidal stresses, and thermal emission across the south polar terrain of enceladus are related

    International Nuclear Information System (INIS)

    Porco, Carolyn; DiNino, Daiana; Nimmo, Francis

    2014-01-01

    We present the first comprehensive examination of the geysering, tidal stresses, and anomalous thermal emission across the south pole of Enceladus and discuss the implications for the moon's thermal history and interior structure. A 6.5 yr survey of the moon's south polar terrain (SPT) by the Cassini imaging experiment has located ∼100 jets or geysers erupting from four prominent fractures crossing the region. Comparing these results with predictions of diurnally varying tidal stresses and with Cassini low resolution thermal maps shows that all three phenomena are spatially correlated. The coincidence of individual jets with very small (∼10 m) hot spots detected in high resolution Cassini VIMS data strongly suggests that the heat accompanying the geysers is not produced by shearing in the upper brittle layer but rather is transported, in the form of latent heat, from a sub-ice-shell sea of liquid water, with vapor condensing on the near-surface walls of the fractures. Normal stresses modulate the geysering activity, as shown in the accompanying paper; we demonstrate here they are capable of opening water-filled cracks all the way down to the sea. If Enceladus' eccentricity and heat production are in steady state today, the currently erupting material and anomalous heat must have been produced in an earlier epoch. If regional tidal heating is occurring today, it may be responsible for some of the erupting water and heat. Future Cassini observations may settle the question.

  15. Atmospheric Modeling of the Martian Polar Regions: One Mars Year of CRISM EPF Observations of the South Pole

    Science.gov (United States)

    Brown, A. J.; Wolff, M. J.

    2009-03-01

    We have used CRISM Emission Phase Function gimballed observations to investigate atmospheric dust/ice opacity and surface albedo in the south polar region for the first Mars year of MRO operations. This covers the MY28 "dust event" and cap recession.

  16. Collective motion of active Brownian particles with polar alignment.

    Science.gov (United States)

    Martín-Gómez, Aitor; Levis, Demian; Díaz-Guilera, Albert; Pagonabarraga, Ignacio

    2018-04-04

    We present a comprehensive computational study of the collective behavior emerging from the competition between self-propulsion, excluded volume interactions and velocity-alignment in a two-dimensional model of active particles. We consider an extension of the active brownian particles model where the self-propulsion direction of the particles aligns with the one of their neighbors. We analyze the onset of collective motion (flocking) in a low-density regime (10% surface area) and show that it is mainly controlled by the strength of velocity-alignment interactions: the competition between self-propulsion and crowding effects plays a minor role in the emergence of flocking. However, above the flocking threshold, the system presents a richer pattern formation scenario than analogous models without alignment interactions (active brownian particles) or excluded volume effects (Vicsek-like models). Depending on the parameter regime, the structure of the system is characterized by either a broad distribution of finite-sized polar clusters or the presence of an amorphous, highly fluctuating, large-scale traveling structure which can take a lane-like or band-like form (and usually a hybrid structure which is halfway in between both). We establish a phase diagram that summarizes collective behavior of polar active brownian particles and propose a generic mechanism to describe the complexity of the large-scale structures observed in systems of repulsive self-propelled particles.

  17. Habitat degradation affects the summer activity of polar bears.

    Science.gov (United States)

    Ware, Jasmine V; Rode, Karyn D; Bromaghin, Jeffrey F; Douglas, David C; Wilson, Ryan R; Regehr, Eric V; Amstrup, Steven C; Durner, George M; Pagano, Anthony M; Olson, Jay; Robbins, Charles T; Jansen, Heiko T

    2017-05-01

    Understanding behavioral responses of species to environmental change is critical to forecasting population-level effects. Although climate change is significantly impacting species' distributions, few studies have examined associated changes in behavior. Polar bear (Ursus maritimus) subpopulations have varied in their near-term responses to sea ice decline. We examined behavioral responses of two adjacent subpopulations to changes in habitat availability during the annual sea ice minimum using activity data. Location and activity sensor data collected from 1989 to 2014 for 202 adult female polar bears in the Southern Beaufort Sea (SB) and Chukchi Sea (CS) subpopulations were used to compare activity in three habitat types varying in prey availability: (1) land; (2) ice over shallow, biologically productive waters; and (3) ice over deeper, less productive waters. Bears varied activity across and within habitats with the highest activity at 50-75% sea ice concentration over shallow waters. On land, SB bears exhibited variable but relatively high activity associated with the use of subsistence-harvested bowhead whale carcasses, whereas CS bears exhibited low activity consistent with minimal feeding. Both subpopulations had fewer observations in their preferred shallow-water sea ice habitats in recent years, corresponding with declines in availability of this substrate. The substantially higher use of marginal habitats by SB bears is an additional mechanism potentially explaining why this subpopulation has experienced negative effects of sea ice loss compared to the still-productive CS subpopulation. Variability in activity among, and within, habitats suggests that bears alter their behavior in response to habitat conditions, presumably in an attempt to balance prey availability with energy costs.

  18. Do polar faculae terminate or commence an extended cycle of solar activity?

    International Nuclear Information System (INIS)

    Bumba, V.

    1990-01-01

    From the local as well as from the global points of view, polar magnetic fields are formed from successively developed trailing polarity fields expelled from the main activity zone. Polar faculae observed during the 20th and the 21st cycles of activity fill in the areas covered by the most intense unipolar fields distributed in the convection network. These polar regions formed from magnetic fields of an old activity cycle are sharply separated from low-latitude magnetic fields and from fields developed by a new cycle of activity. The polarity distribution in polar faculae seems to follow from unipolarity of their magnetic fields - the prevailing polarity becomes the main leading polarity. The greatest part of the main activity zone, the most intense faculae shifting equatorwards are connected with the zone of the prevailing leading polarity magnetic fields. Some of these faculae - the weak and inhomogeneously distributed ones, bordering the main faculae butterflies polewards - are related again to the trailing polarity fields shifting polewards. The main characteristic of the latitudinal distribution of solar faculae is the existence of their two latitudinal types: the polar faculae shifting polewards are related to the trailing polarity fields of the old cycle, the faculae of the main activity zone shifting equatorwards are related mainly (from the global point of view) to the leading polarity fields, and their activity ends several years earlier than that of the polar ones. The polar faculae with their magnetic fields represent the last phase of the magnetic activity cycle lasting 15-17 years. (author). 6 figs., 21 refs

  19. Active Polar Gels: a Paradigm for Cytoskeletal Dynamics

    Science.gov (United States)

    Julicher, Frank

    2006-03-01

    The cytoskeleton of eucaryotic cells is an intrinsically dynamic network of rod-like filaments. Active processes on the molecular scale such as the action of motor proteins and the polymerization and depolymerization of filaments drive active dynamic behaviors while consuming chemical energy in the form of a fuel. Such emergent dynamics is regulated by the cell and is important for many cellular processes such as cell locomotion and cell division. From a general point of view the cytoskeleton represents an active gel-like material with interesting material properties. We present a general theory of active viscoelastic materials made of polar filaments which is motivated by the the cytoskeleton. The continuous consumption of a fuel generates a non- equilibrium state characterized by the generation of flows and stresses. Our theory can be applied to experiments in which cytoskeletal patterns are set in motion by active processes such as those which are at work in cells. It can also capture generic aspects of the flows and stress profiles which occur during cell locomotion.

  20. Identification of tectonic deformations on the south polar surface of the moon

    Science.gov (United States)

    Mukherjee, Saumitra; Singh, Priyadarshini

    2015-07-01

    Recent extensional and contractional tectonic features present globally over the lunar surface have been studied to infer lunar crustal tectonism. Investigation of indicators of recent crustal tectonics, such as fault lines, thrust fault scarps, and dislocation of debris along the identified fault planes, primarily using data from the miniature-synthetic aperture radar (mini-SAR) aboard CHANDRAYAAN-1 mission and Narrow angle camera (NAC) images, are the focus of this study. Spatial orientation of these tectonic features helps to elucidate the change in the interior geological dynamics of any planetary body with time. The ability of microwave sensors to penetrate the lunar regolith, along with application of m-χ decomposition method on Mini-SAR data has been used to reveal unique features indicative of hidden tectonics. The m-χ decomposition derived radar images expose hidden lineaments and lobate scarps present within shadowed crater floors as well as over the illuminated regions of the lunar surface. The area around and within Cabeus B crater in the South Polar Region contains lobate scarps, hidden lineaments and debris avalanches (associated with the identified lineaments) indicative of relatively recent crustal tectonism.

  1. Gravitational spreading, bookshelf faulting, and tectonic evolution of the South Polar Terrain of Saturn's moon Enceladus

    Science.gov (United States)

    Yin, An; Pappalardo, Robert T.

    2015-11-01

    Despite a decade of intense research the mechanical origin of the tiger-stripe fractures (TSF) and their geologic relationship to the hosting South Polar Terrain (SPT) of Enceladus remain poorly understood. Here we show via systematic photo-geological mapping that the semi-squared SPT is bounded by right-slip, left-slip, extensional, and contractional zones on its four edges. Discrete deformation along the edges in turn accommodates translation of the SPT as a single sheet with its transport direction parallel to the regional topographic gradient. This parallel relationship implies that the gradient of gravitational potential energy drove the SPT motion. In map view, internal deformation of the SPT is expressed by distributed right-slip shear parallel to the SPT transport direction. The broad right-slip shear across the whole SPT was facilitated by left-slip bookshelf faulting along the parallel TSF. We suggest that the flow-like tectonics, to the first approximation across the SPT on Enceladus, is best explained by the occurrence of a transient thermal event, which allowed the release of gravitational potential energy via lateral viscous flow within the thermally weakened ice shell.

  2. Hyperspectral characterisation of the Martian south polar residual cap using CRISM

    Science.gov (United States)

    Campbell, J. D.; Sidiropoulos, P.; Muller, J.-P.

    2017-09-01

    We present our research on hyperspectral characterization of the Martian South Polar Residual Cap (SPRC), with a focus on the detection of organic signatures within the dust content of the ice. The SPRC exhibits unique CO2 ice sublimation features known colloquially as 'Swiss Cheese Terrain' (SCT). These flat floored, circular depressions are highly dynamic, and may expose dust particles previously trapped within the ice in the depression walls and partially on the floors. Here we identify suitable regions for potential dust exposure on the SPRC, and utilise data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on board NASA's Mars Reconnaissance Orbiter (MRO) satellite to examine infrared spectra of dark regions to establish their mineral composition, to eliminate the effects of ices on sub-pixel dusty features, and to assess whether ther might be signatures indicative of Polycyclic Aromatic Hydrocarbons (PAHs). Spectral mapping has identified compositional differences between depression rims and the majority of the SPRC and CRISM spectra have been corrected to minimise the influence of CO2 and H2O ice. Whilst no conclusive evidence for PAHs has been found, depression rims are shown to have higher water content than regions of featureless ice, and there are indications of magnesium carbonate within the dark, dusty regions.

  3. Active Color Control in a Metasurface by Polarization Rotation

    Directory of Open Access Journals (Sweden)

    Minkyung Kim

    2018-06-01

    Full Text Available Generating colors by employing metallic nanostructures has attracted intensive scientific attention recently, because one can easily realize higher spatial resolution and highly robust colors compared to conventional pigment. However, since the scattering spectra and thereby the resultant colors are determined by the nanostructure geometries, only one fixed color can be produced by one design and a whole new sample is required to generate a different color. In this paper, we demonstrate active metasurface, which shows a range of colors dependent on incident polarization by selectively exciting three different plasmonic nanorods. The metasurface, which does not include any tunable materials or external stimuli, will be beneficial in real-life applications especially in the display applications.

  4. Interfacial behavior of polar, weakly polar, and nonpolar compounds bound to activated carbons.

    Science.gov (United States)

    Gun'ko, V M; Turov, V V; Zarko, V I; Goncharuk, O V; Nychiporuk, Yu M; Kozynchenko, O P; Skubiszewska-Zięba, J; Leboda, R; Charmas, B; Balakin, D Yu; Ptushinskii, Yu G

    2013-08-15

    Detailed analysis of the interfacial behavior of water and weakly polar or nonpolar organics adsorbed alone or co-adsorbed onto activated carbons (AC) at different temperatures is a complex problem important for practical applications of adsorbents. Interaction of water, 1-decanol, and n-decane with AC possessing highly developed porosity (pore volume Vp≈1.4-2.3 cm(3)/g, specific surface area S(BET)≈1500-3500 m(2)/g) was studied over a broad temperature range using differential scanning calorimetry (DSC), thermoporometry, (1)H NMR spectroscopy, cryoporometry, and temperature-programmed desorption with mass-spectrometry control methods. Comparison of the pore size distributions (PSD) calculated using the DSC thermoporometry, NMR cryoporometry, and nitrogen adsorption isotherms allows us to determine localization of adsorbates in different pores, as well as changes in the PSD of AC due to freezing of adsorbates in pores. Theoretical calculations (using ab initio HF/6-31G(d,p), DFT B3LYP/6-31G(d,p), and PM7 methods) explain certain aspects of the interfacial behavior of water, decane, and decanol adsorbed onto AC that appear in the experimental data. Obtained results show strong temperature dependence (above and below the freezing point, Tf, of bulk liquids) of the interfacial behavior of adsorbates on the textural characteristics and hydrophilic/hydrophobic properties of AC and the adsorbate amounts that affect the distributions of adsorbates unfrozen at T

  5. Mass balance of Mars' residual south polar cap from CTX images and other data

    Science.gov (United States)

    Thomas, P. C.; Calvin, W.; Cantor, B.; Haberle, R.; James, P. B.; Lee, S. W.

    2016-04-01

    Erosion of pits in the residual south polar cap (RSPC) of Mars concurrent with deposition and fluctuating cap boundaries raises questions about the mass balance and long term stability of the cap. Determining a mass balance by measurement of a net gain or loss of atmospheric CO2 by direct pressure measurements (Haberle, R.M. et al. [2014]. Secular climate change on Mars: An update using one Mars year of MSL pressure data. American Geophysical Union (Fall). Abstract 3947), although perhaps the most direct method, has so far given ambiguous results. Estimating volume changes from imaging data faces challenges, and has previously been attempted only in isolated areas of the cap. In this study we use 6 m/pixel Context Imager (CTX) data from Mars year 31 to map all the morphologic units of the RSPC, expand the measurement record of pit erosion rates, and use high resolution images to place limits on vertical changes in the surface of the residual cap. We find the mass balance in Mars years 9-31 to be -6 to +4 km3/♂y, or roughly -0.039% to +0.026% of the mean atmospheric CO2 mass/♂y. The indeterminate sign results chiefly from uncertainty in the amounts of deposition or erosion on the upper surfaces of deposits (as opposed to scarp retreat). Erosion and net deposition in this period appear to be controlled by summertime planetary scale dust events, the largest occurring in MY 9, another, smaller one in MY 28. The rates of erosion and the deposition observed since MY 9 appear to be consistent with the types of deposits and erosional behavior found in most of the residual cap. However, small areas (100 ♂y) of depositional and/or erosional conditions different from those occurring in the period since MY 9, although these environmental differences could be subtle.

  6. Research status of large mode area single polarization active fiber

    Science.gov (United States)

    Xiao, Chun; Zhang, Ge; Yang, Bin-hua; Cheng, Wei-feng; Gu, Shao-yi

    2018-03-01

    As high power fiber laser used more and more widely, to increase the output power of fiber laser and beam quality improvement have become an important goal for the development of high power fiber lasers. The use of large mode fiber is the most direct and effective way to solve the nonlinear effect and fiber damage in the fiber laser power lifting process. In order to reduce the effect of polarization of the fiber laser system, the study found that when introduces a birefringence in the single-mode fiber, the polarization state changes caused by the birefringence is far greater than the random polarization state changes, then the external disturbance is completely submerged, finally the polarization can be controlled and stabilized. Through the fine design of the fiber structure, if the birefringence is high enough to achieve the separation of the two polarization states, the fiber will have a different cut-off mechanism to eliminate polarization which is not need, which will realize single mode single polarization transmission in a band. In this paper, different types of single polarization fiber design are presented and the application of these fibers are also discussed.

  7. Literature Review Lifestyles and routine activities of South African ...

    African Journals Online (AJOL)

    Journal of Child and Adolescent Mental Health ... Lifestyles and routine activities of South African teenagers at risk of being trafficked for involuntary prostitution. Thozama ... Actual lifestyle and routine activities of South African teenagers and risky behaviours (substance abuse, intergenerational sex and child prostitution) are ...

  8. Robotics and automation activities in South Africa

    CSIR Research Space (South Africa)

    Utete, S

    2013-09-01

    Full Text Available Second in the series of articles focusing on the state of robotics and automation in the BRICS countries: Brazil, Russia, India, China, and South Africa, this article provides an overview on South Africa written by researchers from the Council...

  9. Dynamics of Venus' Southern hemisphere and South Polar Vortex from VIRTIS data obtained during the Venus Expres Mission

    Science.gov (United States)

    Hueso, R.; Garate-Lopez, I.; Sanchez-Lavega, A.

    2011-12-01

    The VIRTIS instrument onboard Venus Express observes Venus in two channels (visible and infrared) obtaining spectra and multi-wavelength images of the planet. The images have been used to trace the motions of the atmosphere at different layers of clouds [1-3]. We review the VIRTIS cloud image data and wind results obtained by different groups [1-3] and we present new results concerning the morphology and evolution of the South Polar Vortex at the upper and lower cloud levels with data covering the first 900 days of the mission. We present wind measurements of the South hemisphere obtained by cloud tracking individual cloud features and higher-resolution wind results of the polar region covering the evolution of the South polar vortex. The later were obtained by an image correlation algorithm run under human supervision to validate the data. We present day-side data of the upper clouds obtained at 380 and 980 nm sensitive to altitudes of 66-70 km, night-side data in the near infrared at 1.74 microns of the lower cloud (45-50 km) and day and night-side data obtained in the thermal infrared (wavelengths of 3.8 and 5.1 microns) which covers the dynamical evolution of Venus South Polar vortex at the cloud tops (66-70 km). We explore the different dynamics associated to the varying morphology of the vortex, its dynamical structure at different altitudes, the variability of the global wind data of the southern hemisphere and the interrelation of the polar vortex dynamics with the wind dynamics at subpolar and mid-latitudes. Acknowledgements: Work funded by Spanish MICIIN AYA2009-10701 with FEDER support and Grupos Gobierno Vasco IT-464-07. References [1] A. Sánchez-Lavega et al., Geophys. Res. Lett. 35, L13204, (2008). [2] D. Luz et al., Science, 332, 577-580 (2011). [3] R. Hueso, et al., Icarus doi:10.1016/j.icarus.2011.04.020 (2011)

  10. Roots of women's union activism : South Africa 1973-2003

    NARCIS (Netherlands)

    Tshoaedi, Cynthia Malehoko

    2008-01-01

    This study examines the mobilisation of South African women into trade union activities between the period 1973 and 2003. Firstly, it underscores the role of South African women in fighting for workers’ rights in the workplace and their contributions in the building of the labour movement at the

  11. South Polar Skua breeding populations in the Ross Sea assessed from demonstrated relationship with Adélie Penguin numbers

    Science.gov (United States)

    Wilson, Deborah J.; Lyver, Phil O'B.; Greene, Terry C.; Whitehead, Amy L.; Dugger, Catherine; Karl, Brian J.; Barringer, James R. F.; McGarry, Roger; Pollard, Annie M.; Ainley, David G.

    2017-01-01

    In the Ross Sea region, most South Polar Skuas (Stercorarius maccormicki) nest near Adélie Penguin (Pygoscelis adeliae) colonies, preying and scavenging on fish, penguins, and other carrion. To derive a relationship to predict skua numbers from better-quantified penguin numbers, we used distance sampling to estimate breeding skua numbers within 1000 m of 5 penguin nesting locations (Cape Crozier, Cape Royds, and 3 Cape Bird locations) on Ross Island in 3 consecutive years. Estimated numbers of skua breeding pairs were highest at Cape Crozier (270,000 penguin pairs; 1099 and 1347 skua pairs in 2 respective years) and lowest at Cape Royds (3000 penguin pairs; 45 skua pairs). The log–log linear relationship (R2 = 0.98) between pairs of skuas and penguins was highly significant, and most historical estimates of skua and penguin numbers in the Ross Sea were within 95 % prediction intervals of the regression. Applying our regression model to current Adélie Penguin colony sizes at 23 western Ross Sea locations predicted that 4635 pairs of skuas now breed within 1000 m of penguin colonies in the Ross Island metapopulation (including Beaufort Island) and northern Victoria Land. We estimate, using published skua estimates for elsewhere in Antarctica, that the Ross Sea South Polar Skua population comprises ~50 % of the world total, although this may be an overestimate because of incomplete data elsewhere. To improve predictions and enable measurement of future skua population change, we recommend additional South Polar Skua surveys using consistent distance-sampling methods at penguin colonies of a range of sizes.

  12. Metabolic profile and biological activities of Lavandula pedunculata subsp. lusitanica (Chaytor) Franco: studies on the essential oil and polar extracts.

    Science.gov (United States)

    Costa, Patrícia; Gonçalves, Sandra; Valentão, Patrícia; Andrade, Paula B; Almeida, Carlos; Nogueira, José M F; Romano, Anabela

    2013-12-01

    We investigated the metabolic profile and biological activities of the essential oil and polar extracts of Lavandula pedunculata subsp. lusitanica (Chaytor) Franco collected in south Portugal. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that oxygen-containing monoterpenes was the principal group of compounds identified in the essential oil. Camphor (40.6%) and fenchone (38.0%) were found as the major constituents. High-performance liquid chromatography with diode array detection (HPLC-DAD) analysis allowed the identification of hydroxycinnamic acids (3-O-caffeoylquinic, 4-O-caffeoylquinic, 5-O-caffeoylquinic and rosmarinic acids) and flavones (luteolin and apigenin) in the polar extracts, with rosmarinic acid being the main compound in most of them. The bioactive compounds from L. pedunculata polar extracts were the most efficient free-radical scavengers, Fe(2+) chelators and inhibitors of malondialdehyde production, while the essential oil was the most active against acetylcholinesterase. Our results reveal that the subspecies of L. pedunculata studied is a potential source of active metabolites with a positive effect on human health. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Antibacterial activity of the five South African Erythroxylaceae species

    African Journals Online (AJOL)

    Administrator

    2011-09-21

    Sep 21, 2011 ... emarginatum against Klebsiella pneumoniae; E. pictum against Bacillus ... Key words: Antimicrobial activity, Erythroxylaceae, medicinal uses, South Africa. .... concentration at which the plant extract inhibited bacterial growth.

  14. Paleomagnetism of a well-dated marine succession in South China: A possible Late Cambrian true polar wander (TPW)

    Science.gov (United States)

    Jiao, Wen-Jun; Li, Yong-Xiang; Yang, Zhen-Yu

    2018-04-01

    The Cambrian true polar wander (TPW) hypothesis remains controversial largely because of the uncertainties in the quality and/or fidelity of the paleomagnetic data as well as their chronological control. Testing the TPW hypothesis requires high-quality paleomagnetic data of sufficient spatial and temporal resolutions. Here, we present paleomagnetic results of a continuous Cambrian shallow marine succession from South China where available detailed biostratigraphy provides exceptional chronological constraints. Forty-three sites of paleomagnetic samples were collected from this limestone-dominated succession. Stepwise thermal demagnetization generally reveals three-component magnetizations. Low- and intermediate-temperature components can be cleaned by ∼330 °C, and the high-temperature component (HTC) was isolated typically from ∼350 to ∼450 °C. A positive fold test and the presence of reversed polarity in the strata, together with rock magnetic data as well as the scanning electron microscopic (SEM) and transmission electron microscopic (TEM) results, collectively suggest that the HTCs are likely primary. A directional shift of the HTCs occurs between the lower-middle Cambrian and the upper Cambrian strata in the succession and is tentatively interpreted to indicate a ∼57° polar wander from ∼500.5 to 494 Ma. Because the rate of polar wander is too fast to be a tectonic origin, this polar wander is interpreted to represent a Late Cambrian TPW. This TPW appears coeval with the Steptoean positive carbon isotope excursion (SPICE) and the major trilobite mass extinctions, suggesting a potential link between the TPW and the Late Cambrian biotic and climatic changes. Because the proposed TPW event is exceptionally well-dated, it should be testable through examination of other worldwide sections.

  15. Detection of B-mode polarization in the cosmic microwave background with data from the South Pole Telescope.

    Science.gov (United States)

    Hanson, D; Hoover, S; Crites, A; Ade, P A R; Aird, K A; Austermann, J E; Beall, J A; Bender, A N; Benson, B A; Bleem, L E; Bock, J J; Carlstrom, J E; Chang, C L; Chiang, H C; Cho, H-M; Conley, A; Crawford, T M; de Haan, T; Dobbs, M A; Everett, W; Gallicchio, J; Gao, J; George, E M; Halverson, N W; Harrington, N; Henning, J W; Hilton, G C; Holder, G P; Holzapfel, W L; Hrubes, J D; Huang, N; Hubmayr, J; Irwin, K D; Keisler, R; Knox, L; Lee, A T; Leitch, E; Li, D; Liang, C; Luong-Van, D; Marsden, G; McMahon, J J; Mehl, J; Meyer, S S; Mocanu, L; Montroy, T E; Natoli, T; Nibarger, J P; Novosad, V; Padin, S; Pryke, C; Reichardt, C L; Ruhl, J E; Saliwanchik, B R; Sayre, J T; Schaffer, K K; Schulz, B; Smecher, G; Stark, A A; Story, K T; Tucker, C; Vanderlinde, K; Vieira, J D; Viero, M P; Wang, G; Yefremenko, V; Zahn, O; Zemcov, M

    2013-10-04

    Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable.

  16. Interannual observations and quantification of summertime H2O ice deposition on the Martian CO2 ice south polar cap

    Science.gov (United States)

    Brown, Adrian J.; Piqueux, Sylvain; Titus, Timothy N.

    2014-01-01

    The spectral signature of water ice was observed on Martian south polar cap in 2004 by the Observatoire pour l'Mineralogie, l'Eau les Glaces et l'Activite (OMEGA) ( Bibring et al., 2004). Three years later, the OMEGA instrument was used to discover water ice deposited during southern summer on the polar cap ( Langevin et al., 2007). However, temporal and spatial variations of these water ice signatures have remained unexplored, and the origins of these water deposits remains an important scientific question. To investigate this question, we have used observations from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument on the Mars Reconnaissance Orbiter (MRO) spacecraft of the southern cap during austral summer over four Martian years to search for variations in the amount of water ice. We report below that for each year we have observed the cap, the magnitude of the H2O ice signature on the southern cap has risen steadily throughout summer, particularly on the west end of the cap. The spatial extent of deposition is in disagreement with the current best simulations of deposition of water ice on the south polar cap (Montmessin et al., 2007). This increase in water ice signatures is most likely caused by deposition of atmospheric H2O ice and a set of unusual conditions makes the quantification of this transport flux using CRISM close to ideal. We calculate a ‘minimum apparent‘ amount of deposition corresponding to a thin H2O ice layer of 0.2 mm (with 70% porosity). This amount of H2O ice deposition is 0.6–6% of the total Martian atmospheric water budget. We compare our ‘minimum apparent’ quantification with previous estimates. This deposition process may also have implications for the formation and stability of the southern CO2 ice cap, and therefore play a significant role in the climate budget of modern day Mars.

  17. Roots of women's union activism: South Africa 1973-2003

    OpenAIRE

    Tshoaedi, Cynthia Malehoko

    2008-01-01

    This study examines the mobilisation of South African women into trade union activities between the period 1973 and 2003. Firstly, it underscores the role of South African women in fighting for workers’ rights in the workplace and their contributions in the building of the labour movement at the national level. In explaining the mobilisation of women, this research focuses on their social biography. It explores women’s experiences in society, the family (or personal relationships), the workpl...

  18. Laser propulsion activity in South Africa

    CSIR Research Space (South Africa)

    Michaelis, MM

    2006-07-01

    Full Text Available hemisphere are becoming excited at the prospect of a considerable reduction in the cost of launch to low Earth orbit (LEO) by means of laser propulsion (LP) (see ref. 1). We argue here that developing nations also should assess the potential of a cheaper... of the grandiose scheme of ‘Space Port Kilimanjaro’ (Fig. 5), envis- aged by various authors becoming a reality, South African scien- tists, engineers and financiers would benefit. Kilimanjaro is regarded by some13 as the prime location for laser propulsion...

  19. Nonequilibrium phase transitions, fluctuations and correlations in an active contractile polar fluid.

    Science.gov (United States)

    Gowrishankar, Kripa; Rao, Madan

    2016-02-21

    We study the patterning, fluctuations and correlations of an active polar fluid consisting of contractile polar filaments on a two-dimensional substrate, using a hydrodynamic description. The steady states generically consist of arrays of inward pointing asters and show a continuous transition from a moving lamellar phase, a moving aster street, to a stationary aster lattice with no net polar order. We next study the effect of spatio-temporal athermal noise, parametrized by an active temperature TA, on the stability of the ordered phases. In contrast to its equilibrium counterpart, we find that the active crystal shows true long range order at low TA. On increasing TA, the asters dynamically remodel, concomitantly we find novel phase transitions characterized by bond-orientational and polar order upon "heating".

  20. The origin of the mid-infrared nuclear polarization of active galactic nuclei

    Science.gov (United States)

    Lopez-Rodriguez, E.; Alonso-Herrero, A.; Diaz-Santos, T.; Gonzalez-Martin, O.; Ichikawa, K.; Levenson, N. A.; Martinez-Paredes, M.; Nikutta, R.; Packham, C.; Perlman, E.; Almeida, C. Ramos; Rodriguez-Espinosa, J. M.; Telesco, C. M.

    2018-05-01

    We combine new (NGC 1275, NGC 4151, and NGC 5506) and previously published (Cygnus A, Mrk 231, and NGC 1068) sub-arcsecond resolution mid-infrared (MIR; 8-13 μm) imaging- and spectro-polarimetric observations of six Seyfert galaxies using CanariCam on the 10.4-m Gran Telescopio CANARIAS. These observations reveal a diverse set of physical processes responsible for the nuclear polarization, and permit characterization of the origin of the MIR nuclear polarimetric signature of active galactic nuclei (AGN). For all radio quiet objects, we found that the nuclear polarization is low (sensitivity to detect such extended emission (i.e., NGC 1068 and NGC 4151). We suggest that the higher degree of polarization previously found in lower resolution data arises only on the larger-than-nuclear scales. Only the radio-loud Cygnus A exhibits significant nuclear polarization (˜11 per cent), attributable to synchrotron emission from the pc-scale jet close to the core. We present polarization models that suggest that the MIR nuclear polarization for highly obscured objects arises from a self-absorbed MIR polarized clumpy torus and/or dichroism from the host galaxy, while for unabsorbed cores, MIR polarization arises from dust scattering in the torus and/or surrounding nuclear dust.

  1. A Small Ku-Band Polarization Tracking Active Phased Array for Mobile Satellite Communications

    Directory of Open Access Journals (Sweden)

    Wei Shi

    2013-01-01

    Full Text Available A compact polarization tracking active phased array for Ku-band mobile satellite signal reception is presented. In contrast with conventional mechanically tracking antennas, the approach presented here meets the requirements of beam tracking and polarization tracking simultaneously without any servo components. The two-layer stacked square patch fed by two probes is used as antenna element. The impedance bandwidth of 16% for the element covers the operating frequency range from 12.25 GHz to 12.75 GHz. In the presence of mutual coupling, the dimensional parameters for each element of the small 7 × 7 array are optimized during beam scanning and polarization tracking. The compact polarization tracking modules based on the low-temperature cofired ceramic (LTCC system-in-package (SiP technology are proposed. A small active phased array prototype with the size of 120 mm (length × 120 mm (width × 55 mm (height is developed. The measured polarization tracking patterns of the prototype are given. The polarization tracking beam can be steered in the elevation up to 50°. The gain of no less than 16.0 dBi and the aperture efficiency of more than 50% are obtained. The measured and simulated polarization tracking patterns agreed well.

  2. Polarized excitons and optical activity in single-wall carbon nanotubes

    Science.gov (United States)

    Chang, Yao-Wen; Jin, Bih-Yaw

    2018-05-01

    The polarized excitons and optical activity of single-wall carbon nanotubes (SWNTs) are studied theoretically by π -electron Hamiltonian and helical-rotational symmetry. By taking advantage of the symmetrization, the single-particle energy and properties of a SWNT are characterized with the corresponding helical band structure. The dipole-moment matrix elements, magnetic-moment matrix elements, and the selection rules can also be derived. Based on different selection rules, the optical transitions can be assigned as the parallel-polarized, left-handed circularly-polarized, and right-handed circularly-polarized transitions, where the combination of the last two gives the cross-polarized transition. The absorption and circular dichroism (CD) spectra are simulated by exciton calculation. The calculated results are well comparable with the reported measurements. Built on the foundation, magnetic-field effects on the polarized excitons and optical activity of SWNTs are studied. Dark-bright exciton splitting and interband Faraday effect in the CD spectrum of SWNTs under an axial magnetic field are predicted. The Faraday rotation dispersion can be analyzed according to the selection rules of circular polarizations and the helical band structure.

  3. A Classroom Activity for Teaching Electric Polarization of Insulators and Conductors

    Science.gov (United States)

    Deligkaris, Christos

    2018-04-01

    The phenomenon of electric polarization is crucial to student understanding of forces exerted between charged objects and insulators or conductors, the process of charging by induction, and the behavior of electroscopes near charged objects. In addition, polarization allows for microscopic-level models of everyday-life macroscopic-level phenomena. Textbooks may adequately discuss polarization, but there is little material in active learning labs and tutorials on this topic. Since polarization of materials is a microscopic phenomenon, instructors often use diagrams and figures on the classroom board to explain the process in a lecture setting. In this paper I will describe a classroom activity where the students play the role of electrons as an alternative option.

  4. Cassini ISS Observations Of The Early Stages Of The Formation Of Titan's South Polar Hood And Vortex In 2012

    Science.gov (United States)

    West, Robert A.; Del Genio, A.; Perry, J.; Ingersoll, A. P.; Turtle, E. P.; Porco, C.; Ovanessian, A.

    2012-10-01

    Northern spring equinox on Titan occurred on August 11, 2009. In March of 2012 the Imaging Science Subsystem (ISS) on the Cassini spacecraft saw the first evidence for the formation of a polar hood in the atmosphere above Titan’s south pole. Views of the limb showed an optical thickening primarily at about 360 km altitude across a few degrees of latitude centered on the pole. Images of Titan in front of Saturn provide a nearly direct measure of the line-of-sight optical depth as a function of latitude and altitude from about 250 km and higher. Two or more distinct layers are seen, both near the pole and at other latitudes. The highest of these, near 360 km altitude, hosts the embryonic polar hood. On June 27, 2012 ISS observed the pole from high latitude. These images show a distinct and unusual cloudy patch, elongated and not centered on the pole and with an elevated perimeter. The morphology and color indicate an unfamiliar (for Titan) composition and dynamical regime. The interior of the feature consists of concentrations of cloud/haze organized on spatial scales of tens of kilometers. Its morphology is reminiscent of the open cellular convection sometimes seen in the atmospheric boundary layer over Earth’s oceans under conditions of large-scale subsidence. Unlike Earth, where such convection is forced by large surface heat fluxes or the onset of drizzle, convection at 360 km on Titan is more likely to be driven from above by radiative cooling. During the 9 hours we observed Titan, this feature completed a little over one rotation around the pole, providing direct evidence for a polar vortex rotating at a rate roughly consistent with angular-momentum-conserving flow for air displaced from the equator. Part of this work was performed by the Jet Propulsion Laboratory, California Institute of Technology.

  5. Changes in aerobic performance, body composition, and physical activity in polar explorers during a year-long stay at the polar station in the Arctic

    Science.gov (United States)

    Maciejczyk, Marcin; Araźny, Andrzej; Opyrchał, Marta

    2017-04-01

    The aim of this study was to evaluate changes in physical activity, aerobic performance, and body composition in polar explorers during a 1-year stay at the polar station. The study group consisted of 10 people, including 8 men and 2 women. Aerobic performance (maximal oxygen uptake), physical activity, body mass, and composition were evaluated for the polar explores of the Polish Polar Station prior to departure, and then during their stay at the station for a period of 1 year. The measurements were performed every 3 months. Compared to the measurements taken before going to the polar station, aerobic performance significantly ( p = 0.02) increased in the first 3 months of residing at the polar station and then remained relatively stable for the following duration of the stay. In the first 3 months of the stay, we also observed the highest level of physical activity in participants. In the polar explorers, no significant ( p > 0.05) body fatness changes were noted. Nonetheless, lean body mass, body mass, and BMI significantly increased compared to the measurements taken before departure to the polar station. The greatest changes in aerobic performance, physical activity, and body composition were observed during the first 3 months after arrival to the Arctic and then, despite changing biometeorological conditions, they remained stable for the next months of the stay. We recommend the introduction of a physical preparation program before departing to the polar station to improve explorers' physical fitness, so that they can meet the physical challenges they are faced with immediately after arrival to the polar station.

  6. Dielectric and polarization behaviour of cellulose electro-active paper (EAPap)

    International Nuclear Information System (INIS)

    Yun, Gyu-Young; Kim, Joo-Hyung; Kim, Jaehwan

    2009-01-01

    Dielectric and polarization behaviour of electro-active paper (EAPap) were studied to understand the detailed material behaviour of EAPap as a novel smart material. It was revealed that the dielectric constant of EAPap was temperature and frequency dependent. The largest change in the dielectric constant was observed near 0 0 C while the highest dielectric constant was obtained at around 100 0 C, which might be related to the dipolar behaviour of the hydroxyl structure of cellulose and adsorbed or existing internal water molecules in cellulose EAPap. By thermal stimulated current measurement for polarization behaviour of cellulose EAPap, it was shown that the maximum current was observed in the temperature range 105-110 0 C. Compared with the polarization behaviour in the low temperature range, abnormal polarization was observed under an applied field mainly due to the trapped space charge in EAPap, which indicates that cellulose EAPap has a similar material behaviour to that of electret polymers. (fast track communication)

  7. Transthyretin-Binding Activity of Contaminants in Blood from Polar Bear (Ursus maritimus) Cubs

    NARCIS (Netherlands)

    Bytingsvik, J.; Simon, E.; Leonards, P.E.G.; Lamoree, M.H.; Lie, E.; Aars, J.; Derocher, A. E.; Wiig, O.; Jenssen, B.M.; Hamers, T.

    2013-01-01

    We determined the transthyretin (TTR)-binding activity of blood-accumulating contaminants in blood plasma samples of approximately 4-months-old polar bear (Ursus maritimus) cubs from Svalbard sampled in 1998 and 2008. The TTR-binding activity was measured as thyroxine (T4)-like equivalents (T4-EQ

  8. Characterisation of South African coals using instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Hart, R.J.

    1985-01-01

    This report includes the establishment of the major minor and trace element compositions of South African coals with the aim of characterising the different coal seams within a basin, defining regions of similar compositions and obtaining an overall view of the geochemistry of coals in this country. The results of 40 coal samples analysed by neutron activation analysis

  9. Physical oceanographic activities in South Africa: 1995-1998

    CSIR Research Space (South Africa)

    Grundlingh, ML

    1999-06-01

    Full Text Available This is an overview of research activities in the South African marine and coastal environment during the period 1995-1998.The report is being submitted to IAPSO( International Association for the Physical Sciences of the Ocean) in preparation...

  10. Diviner lunar radiometer observations of cold traps in the moon's south polar region

    Science.gov (United States)

    Paige, D.A.; Siegler, M.A.; Zhang, J.A.; Hayne, P.O.; Foote, E.J.; Bennett, K.A.; Vasavada, A.R.; Greenhagen, B.T.; Schofield, J.T.; McCleese, D.J.; Foote, M.C.; DeJong, E.; Bills, B.G.; Hartford, W.; Murray, B.C.; Allen, C.C.; Snook, K.; Soderblom, L.A.; Calcutt, S.; Taylor, F.W.; Bowles, N.E.; Bandfield, J.L.; Elphic, R.; Ghent, R.; Glotch, T.D.; Wyatt, M.B.; Lucey, P.G.

    2010-01-01

    Diviner Lunar Radiometer Experiment surface-temperature maps reveal the existence of widespread surface and near-surface cryogenic regions that extend beyond the boundaries of persistent shadow. The Lunar Crater Observation and Sensing Satellite (LCROSS) struck one of the coldest of these regions, where subsurface temperatures are estimated to be 38 kelvin. Large areas of the lunar polar regions are currently cold enough to cold-trap water ice as well as a range of both more volatile and less volatile species. The diverse mixture of water and high-volatility compounds detected in the LCROSS ejecta plume is strong evidence for the impact delivery and cold-trapping of volatiles derived from primitive outer solar system bodies.

  11. North–south polarization of European electricity consumption under future warming

    Science.gov (United States)

    Wenz, Leonie; Levermann, Anders; Auffhammer, Maximilian

    2017-01-01

    There is growing empirical evidence that anthropogenic climate change will substantially affect the electric sector. Impacts will stem both from the supply side—through the mitigation of greenhouse gases—and from the demand side—through adaptive responses to a changing environment. Here we provide evidence of a polarization of both peak load and overall electricity consumption under future warming for the world’s third-largest electricity market—the 35 countries of Europe. We statistically estimate country-level dose–response functions between daily peak/total electricity load and ambient temperature for the period 2006–2012. After removing the impact of nontemperature confounders and normalizing the residual load data for each country, we estimate a common dose–response function, which we use to compute national electricity loads for temperatures that lie outside each country’s currently observed temperature range. To this end, we impose end-of-century climate on today’s European economies following three different greenhouse-gas concentration trajectories, ranging from ambitious climate-change mitigation—in line with the Paris agreement—to unabated climate change. We find significant increases in average daily peak load and overall electricity consumption in southern and western Europe (∼3 to ∼7% for Portugal and Spain) and significant decreases in northern Europe (∼−6 to ∼−2% for Sweden and Norway). While the projected effect on European total consumption is nearly zero, the significant polarization and seasonal shifts in peak demand and consumption have important ramifications for the location of costly peak-generating capacity, transmission infrastructure, and the design of energy-efficiency policy and storage capacity. PMID:28847939

  12. North-south polarization of European electricity consumption under future warming.

    Science.gov (United States)

    Wenz, Leonie; Levermann, Anders; Auffhammer, Maximilian

    2017-09-19

    There is growing empirical evidence that anthropogenic climate change will substantially affect the electric sector. Impacts will stem both from the supply side-through the mitigation of greenhouse gases-and from the demand side-through adaptive responses to a changing environment. Here we provide evidence of a polarization of both peak load and overall electricity consumption under future warming for the world's third-largest electricity market-the 35 countries of Europe. We statistically estimate country-level dose-response functions between daily peak/total electricity load and ambient temperature for the period 2006-2012. After removing the impact of nontemperature confounders and normalizing the residual load data for each country, we estimate a common dose-response function, which we use to compute national electricity loads for temperatures that lie outside each country's currently observed temperature range. To this end, we impose end-of-century climate on today's European economies following three different greenhouse-gas concentration trajectories, ranging from ambitious climate-change mitigation-in line with the Paris agreement-to unabated climate change. We find significant increases in average daily peak load and overall electricity consumption in southern and western Europe (∼3 to ∼7% for Portugal and Spain) and significant decreases in northern Europe (∼-6 to ∼-2% for Sweden and Norway). While the projected effect on European total consumption is nearly zero, the significant polarization and seasonal shifts in peak demand and consumption have important ramifications for the location of costly peak-generating capacity, transmission infrastructure, and the design of energy-efficiency policy and storage capacity.

  13. Correlates of lifestyle: physical activity among South Asian Indian immigrants.

    Science.gov (United States)

    Daniel, Manju; Wilbur, JoEllen; Fogg, Louis F; Miller, Arlene Michaels

    2013-01-01

    South Asian immigrants are at increased risk for cardiovascular disease and diabetes, but little is known about their physical activity patterns. In this cross-sectional study, 110 participants were recruited to describe lifestyle physical activity behavior of this at-risk population. Education (p = .042), global health (p = .045), and self-efficacy (p = .000) had significant positive independent effects on leisure-time physical activity. Depression (p = .035) and waist circumference (p = .012) had significant negative independent effects, and frequency of experiencing discrimination a significant positive independent effect (p = .007) on daily step counts. Culture-sensitive physical activity interventions need to target South Asian Indian immigrants who are less educated, in poor health, concerned about racial discrimination, and have low self-efficacy.

  14. Polarization reversal during the solar noise storm activity of August 1971

    International Nuclear Information System (INIS)

    Kurihara, Masahiro

    1975-01-01

    Reversals of the sense of circular polarization of solar radio emission were observed for active type I storms in August 1971. Observations with a 160-MHz interferometer revealed that the reversals were caused by sudden growth and decay of a secondary storm source whose sense of polarization was opposite to that of the long-lasting main source. The time variations of both the associated S-component sources and sunspots are compared with that of the storm sources. The role of the magnetic field, which presumably connects the storm sources, the S-component sources, and the sunspots, is discussed in relation to the origin of the storm activity. (author)

  15. Enhanced Photocatalytic Activity of TiO2 Nanoparticles Supported on Electrically Polarized Hydroxyapatite.

    Science.gov (United States)

    Zhang, Xuefei; Yates, Matthew Z

    2018-05-23

    Fast recombination of photogenerated charge carriers in titanium dioxide (TiO 2 ) remains a challenging issue, limiting the photocatalytic activity. This study demonstrates increased photocatalytic performance of TiO 2 nanoparticles supported on electrically polarized hydroxyapatite (HA) films. Dense and thermally stable yttrium and fluorine co-doped HA films with giant internal polarization were synthesized as photocatalyst supports. TiO 2 nanoparticles deposited on the support were then used to catalyze the photochemical reduction of aqueous silver ions to produce silver nanoparticles. It was found that significantly more silver nanoparticles were produced on polarized HA supports than on depolarized HA supports. In addition, the photodegradation of methyl orange with TiO 2 nanoparticles on polarized HA supports was found to be much faster than with TiO 2 nanoparticles on depolarized HA supports. It is proposed that separation of photogenerated electrons and holes in TiO nanoparticles is promoted by the internal polarization of the HA support, and consequently, the recombination of charge carriers is mitigated. The results imply that materials with large internal polarization can be used in strategies for enhancing quantum efficiency of photocatalysts.

  16. THE SUBARCSECOND MID-INFRARED VIEW OF LOCAL ACTIVE GALACTIC NUCLEI. III. POLAR DUST EMISSION

    International Nuclear Information System (INIS)

    Asmus, D.; Hönig, S. F.; Gandhi, P.

    2016-01-01

    Recent mid-infrared (MIR) interferometric observations have shown that in a few active galactic nuclei (AGNs) the bulk of the infrared emission originates from the polar region above the putative torus, where only a little dust should be present. Here, we investigate whether such strong polar dust emission is common in AGNs. Out of 149 Seyferts in the MIR atlas of local AGNs, 21 show extended MIR emission on single-dish images. In 18 objects, the extended MIR emission aligns with the position angle (PA) of the system axis, established by [O iii], radio, polarization, and maser-based PA measurements. The relative amount of resolved MIR emission is at least 40% and scales with the [O iv] fluxes, implying a strong connection between the extended continuum and [O iv] emitters. These results together with the radio-quiet nature of the Seyferts support the scenario that the bulk of MIR emission is emitted by dust in the polar region and not by the torus, which would demand a new paradigm for the infrared emission structure in AGNs. The current low detection rate of polar dust in the AGNs of the MIR atlas is explained by the lack of sufficient high-quality MIR data and the requirements on the orientation, strength of narrow-line region, and distance of the AGNs. The James Webb Space Telescope will enable much deeper nuclear MIR studies with comparable angular resolution, allowing us to resolve the polar emission and surroundings in most of the nearby AGNs.

  17. COMPARISON OF CHAOTIC AND FRACTAL PROPERTIES OF POLAR FACULAE WITH SUNSPOT ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Deng, L. H.; Xiang, Y. Y.; Dun, G. T. [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650216 (China); Li, B., E-mail: wooden@escience.cn [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, School of Space Science and Physics, Shandong University at Weihai, Weihai 264209 (China)

    2016-01-15

    The solar magnetic activity is governed by a complex dynamo mechanism and exhibits a nonlinear dissipation behavior in nature. The chaotic and fractal properties of solar time series are of great importance to understanding the solar dynamo actions, especially with regard to the nonlinear dynamo theories. In the present work, several nonlinear analysis approaches are proposed to investigate the nonlinear dynamical behavior of the polar faculae and sunspot activity for the time interval from 1951 August to 1998 December. The following prominent results are found: (1) both the high- and the low-latitude solar activity are governed by a three-dimensional chaotic attractor, and the chaotic behavior of polar faculae is the most complex, followed by that of the sunspot areas, and then the sunspot numbers; (2) both the high- and low-latitude solar activity exhibit a high degree of persistent behavior, and their fractal nature is due to such long-range correlation; (3) the solar magnetic activity cycle is predictable in nature, but the high-accuracy prediction should only be done for short- to mid-term due to its intrinsically dynamical complexity. With the help of the Babcock–Leighton dynamo model, we suggest that the nonlinear coupling of the polar magnetic fields with strong active-region fields exhibits a complex manner, causing the statistical similarities and differences between the polar faculae and the sunspot-related indicators.

  18. Toward an effective adsorbent for polar pollutants: Formaldehyde adsorption by activated carbon

    International Nuclear Information System (INIS)

    Lee, Kyung Jin; Miyawaki, Jin; Shiratori, Nanako; Yoon, Seong-Ho; Jang, Jyongsik

    2013-01-01

    Highlights: • Activated carbon fiber with mild activation condition is useful as adsorbent for polar pollutants. • Diverse variations are investigated for developing an effective adsorbent. • Surface functional group is the most important factor for capacity as a adsorbent. • Surface functional groups on ACFs are investigated using micro-ATR FTIR. -- Abstract: Due to increasing concerns about environmental pollutants, the development of an effective adsorbent or sensitive sensor has been pursued in recent years. Diverse porous materials have been selected as promising candidates for detecting and removing harmful materials, but the most appropriate pore structure and surface functional groups, both important factors for effective adsorbency, have not yet been fully elucidated. In particular, there is limited information relating to the use of activated carbon materials for effective adsorbent of specific pollutants. Here, the pore structure and surface functionality of polyacrylonitrile-based activated carbon fibers were investigated to develop an efficient adsorbent for polar pollutants. The effect of pore structure and surface functional groups on removal capability was investigated. The activated carbons with higher nitrogen content show a great ability to absorb formaldehyde because of their increased affinity with polar pollutants. In particular, nitrogen functional groups that neighbor oxygen atoms play an important role in maximizing adsorption capability. However, because there is also a similar increase in water affinity in adsorbents with polar functional groups, there is a considerable decrease in adsorption ability under humid conditions because of preferential adsorption of water to adsorbents. Therefore, it can be concluded that pore structures, surface functional groups and the water affinity of any adsorbent should be considered together to develop an effective and practical adsorbent for polar pollutants. These studies can provide vital

  19. Optically active Babinet planar metamaterial film for terahertz polarization manipulation

    DEFF Research Database (Denmark)

    Zalkovskij, Maksim; Malureanu, Radu; Kremers, C.

    2013-01-01

    A planar Babinet-inverted dimer metamaterial possessing strong optical activity is proposed and characterized. An original fabrication method to produce large area (up to several cm2) freely suspended flexible metallic membranes is implemented to fabricate the metamaterial. Its optical properties...

  20. Temperature thresholds for chlorine activation and ozone loss in the polar stratosphere

    Energy Technology Data Exchange (ETDEWEB)

    Drdla, K. [NASA Ames Research Center, Moffett Field, CA (United States); Mueller, R. [Forschungszentrum Juelich (DE). Inst. of Energy and Climate Research (IEK-7)

    2012-07-01

    Low stratospheric temperatures are known to be responsible for heterogeneous chlorine activation that leads to polar ozone depletion. Here, we discuss the temperature threshold below which substantial chlorine activation occurs. We suggest that the onset of chlorine activation is dominated by reactions on cold binary aerosol particles, without the formation of polar stratospheric clouds (PSCs), i.e. without any significant uptake of HNO{sub 3} from the gas phase. Using reaction rates on cold binary aerosol in a model of stratospheric chemistry, a chlorine activation threshold temperature, T{sub ACL}, is derived. At typical stratospheric conditions, T{sub ACL} is similar in value to T{sub NAT} (within 1-2 K), the highest temperature at which nitric acid trihydrate (NAT) can exist. T{sub NAT} is still in use to parameterise the threshold temperature for the onset of chlorine activation. However, perturbations can cause T{sub ACL} to differ from T{sub NAT}: T{sub ACL} is dependent upon H{sub 2} O and potential temperature, but unlike T{sub NAT} is not dependent upon HNO3. Furthermore, in contrast to T{sub NAT}, T{sub ACL} is dependent upon the stratospheric sulfate aerosol loading and thus provides a means to estimate the impact on polar ozone of strong volcanic eruptions and some geo-engineering options, which are discussed. A parameterisation of T{sub ACL} is provided here, allowing it to be calculated for low solar elevation (or high solar zenith angle) over a comprehensive range of stratospheric conditions. Considering T{sub ACL} as a proxy for chlorine activation cannot replace a detailed model calculation, and polar ozone loss is influenced by other factors apart from the initial chlorine activation. However, T{sub ACL} provides a more accurate description of the temperature conditions necessary for chlorine activation and ozone loss in the polar stratosphere than T{sub NAT}. (orig.)

  1. Circularly polarized infrared and visible sum-frequency-generation spectroscopy: Vibrational optical activity measurement

    International Nuclear Information System (INIS)

    Cheon, Sangheon; Cho, Minhaeng

    2005-01-01

    Vibrational optical activity spectroscopies utilizing either circularly polarized ir or circularly polarized visible beams were theoretically investigated by considering the infrared and visible sum-frequency-generation (IV-SFG) schemes. In addition to the purely electric dipole-allowed chiral component of the IV-SFG susceptibility, the polarizability-electric quadrupole hyperpolarizability term also contributes to the vibrationally resonant IV-SFG susceptibility. The circular-intensity-difference signal is shown to be determined by the interferences between the all-electric dipole-allowed chiral component and the polarizability-electric-dipole or electric-dipole-electric-quadrupole Raman optical activity tensor components. The circularly polarized SFG methods are shown to be potentially useful coherent spectroscopic tools for determining absolute configurations of chiral molecules in condensed phases

  2. Polarization ray tracing in anisotropic optically active media. II. Theory and physics

    International Nuclear Information System (INIS)

    McClain, S.C.; Hillman, L.W.; Chipman, R.A.

    1993-01-01

    Refraction, reflection, and amplitude relations are derived that apply to polarization ray tracing in anisotropic, optically active media such as quartz. The constitutive relations for quartz are discussed. The refractive indices and polarization states associated with the two modes of propagation are derived as a function of wave direction. A procedure for refracting at any uniaxial or optically active interface is derived that computes both the ray direction and the wave direction. A method for computing the optical path length is given, and Fresnel transmission and ref lection equations are derived from boundary conditions on the electromagnetic fields. These ray-tracing formulas apply to uniaxial, optically active media and therefore encompass uniaxial, non-optically active materials and isotropic, optically active materials

  3. AKTIVITAS ANTIOKSIDAN DAN ANTIBAKTERI EKSTRAK POLAR DAN NON POLAR BIJI SELASIH (Ocimum sanctum Linn [Antioxidant and Antibacterial Activities from Polar and Non Polar Basil (Ocimum sanctum Linn Seed Extracts

    Directory of Open Access Journals (Sweden)

    Agustina D. R. Nurcahyanti1*

    2011-06-01

    Full Text Available The aims of this study were to determine total phenolic content, antioxidant activity and antibacterial activity of polar and nonpolar extracts of basil (O. sanctum L. seed. Seeds of basil (O. sanctum L. were extracted using a soxhlet extractor using four types organic solvent, i.e. chloroform, ethyl acetate, acetone, and methanol for eight hours each. The total phenolic content was determined using Folin Ciocalteu method, antioxidant activity was determined using reducing power and DPPH (1,1-diphenyl,2-picrylhydrazyl scavenging activity methods, while antibacterial activity was tested using agar diffusion method. The result showed that the highest total phenolic content and antioxidant activity was obtained in methanol extract with 3.63 ± 0.21 mgGAE/g phenolic total, 58.39 ± 3.81 ek/g using reducing power method and 85.73 ± 0.86% free radical scavenging activity. Furthermore the result of antibacterial activity testing showed that the highest diameter of inhibition zone was observed in ethyl acetate extract inhibition on E.coli, P.aeruginosa, B.subtilis, and S.aureus where its inhibition zone were 13.53 ± 0.63; 10.67 ± 1.05; 14.93 ± 0.80, and 13.46 ± 0.79 mm, respectively. This result suggests that both polar and nonpolar basil seed extracts possess specific biological activity. This data provide valuable and strong database for exploration of natural antibacterial agents and antioxidant for food and health industry application.

  4. Mapping Vesta Mid-Latitude Quadrangle V-12EW: Mapping the Edge of the South Polar Structure

    Science.gov (United States)

    Hoogenboom, T.; Schenk, P.; Williams, D. A.; Hiesinger, H.; Garry, W. B.; Yingst, R.; Buczkowski, D.; McCord, T. B.; Jaumann, R.; Pieters, C. M.; Gaskell, R. W.; Neukum, G.; Schmedemann, N.; Marchi, S.; Nathues, A.; Le Corre, L.; Roatsch, T.; Preusker, F.; White, O. L.; DeSanctis, C.; Filacchione, G.; Raymond, C. A.; Russell, C. T.

    2011-12-01

    NASA's Dawn spacecraft arrived at the asteroid 4Vesta on July 15, 2011, and is now collecting imaging, spectroscopic, and elemental abundance data during its one-year orbital mission. As part of the geological analysis of the surface, a series of 15 quadrangle maps are being produced based on Framing Camera images (FC: spatial resolution: ~65 m/pixel) along with Visible & Infrared Spectrometer data (VIR: spatial resolution: ~180 m/pixel) obtained during the High-Altitude Mapping Orbit (HAMO). This poster presentation concentrates on our geologic analysis and mapping of quadrangle V-12EW. This quadrangle is dominated by the arcuate edge of the large 460+ km diameter south polar topographic feature first observed by HST (Thomas et al., 1997). Sparsely cratered, the portion of this feature covered in V-12EW is characterized by arcuate ridges and troughs forming a generalized arcuate pattern. Mapping of this terrain and the transition to areas to the north will be used to test whether this feature has an impact or other (e.g., internal) origin. We are also using FC stereo and VIR images to assess whether their are any compositional differences between this terrain and areas further to the north, and image data to evaluate the distribution and age of young impact craters within the map area. The authors acknowledge the support of the Dawn Science, Instrument and Operations Teams.

  5. Paleomagnetism of the Santa Fé Group, central Brazil: Implications for the late Paleozoic apparent polar wander path for South America

    Science.gov (United States)

    Brandt, Daniele; Ernesto, Marcia; Rocha-Campos, Antonio Carlos; Dos Santos, Paulo Roberto

    2009-02-01

    Paleomagnetic and rockmagnetic data are reported for the Floresta Formation (Santa Fé Group) of the Sanfranciscana Basin, central Brazil. This formation represents the Permo-Carboniferous glacial record of the basin and comprises the Brocotó (diamictites and flow diamictites), Brejo do Arroz (red sandstones and shales with dropstones and invertebrate trails), and Lavado (red sandstones) members, which crop out near the cities of Santa Fé de Minas and Canabrava, Minas Gerais State. Both Brejo do Arroz and Lavado members were sampled in the vicinities of the two localities. Alternating field and thermal demagnetizations of 268 samples from 76 sites revealed reversed components of magnetization in all samples in accordance with the Permo-Carboniferous Reversed Superchron. The magnetic carriers are magnetite and hematite with both minerals exhibiting the same magnetization component, suggesting a primary origin for the remanence. We use the high-quality paleomagnetic pole for the Santa Fé Group (330.9°E 65.7°S; N = 60; α95 = 4.1°; k = 21) in a revised late Carboniferous to early Triassic apparent polar wander path for South America. On the basis of this result it is shown that an early Permian Pangea A-type fit is possible if better determined paleomagnetic poles become available.

  6. Study of the Effect of Active Regions on the Scattering Polarization in the Solar Corona

    Science.gov (United States)

    Derouich, M.; Badruddin

    2018-03-01

    The solar photospheric/chromospheric light exciting atoms/ions is not homogeneous because of the presence of active regions (ARs). The effect of ARs on the scattering polarization at the coronal level is an important ingredient for a realistic determination of the magnetic field. This effect is usually disregarded or mixed with other effects in the sense that the degree of its importance is not well known. The aim of this paper is to study the effect of atmospheric inhomogeneities on the coronal scattering polarization. We determined quantitatively the importance of the atmospheric inhomogeneities by using given geometries of solar ARs (plages and sunspots).

  7. Proliferative effects of apical, but not basal, matrix metalloproteinase-7 activity in polarized MDCK cells

    International Nuclear Information System (INIS)

    Harrell, Permila C.; McCawley, Lisa J.; Fingleton, Barbara; McIntyre, J. Oliver; Matrisian, Lynn M.

    2005-01-01

    Matrix metalloproteinase-7 (MMP-7) is primarily expressed in glandular epithelium. Therefore, its mechanism of action may be influenced by its regulated vectorial release to either the apical and/or basolateral compartments, where it would act on its various substrates. To gain a better understanding of where MMP-7 is released in polarized epithelium, we have analyzed its pattern of secretion in polarized MDCK cells expressing stably transfected human MMP-7 (MDCK-MMP-7), and HCA-7 and Caco2 human colon cancer cell lines. In all cell lines, latent MMP-7 was secreted to both cellular compartments, but was 1.5- to 3-fold more abundant in the basolateral compartment as compared to the apical. However, studies in the MDCK system demonstrated that MMP-7 activity was 2-fold greater in the apical compartment of MDCK-MMP-7 HIGH -polarized monolayers, which suggests the apical co-release of an MMP-7 activator. In functional assays, MMP-7 over-expression increased cell saturation density as a result of increased cell proliferation with no effect on apoptosis. Apical MMP-7 activity was shown to be responsible for the proliferative effect, which occurred, as demonstrated by media transfer experiments, through cleavage of an apical substrate and not through the generation of a soluble factor. Taken together, our findings demonstrate the importance of MMP-7 secretion in relation to its mechanism of action when expressed in a polarized epithelium

  8. ACTIVITY OF LICHENS UNDER THE INFLUENCE OF SNOW AND ICE (18th Symposium on Polar Biology)

    OpenAIRE

    Ludger, KAPPEN; Burkhard, SCHROETER

    1997-01-01

    A major aim of our investigations is to explain the adaptation of vegetation to the peculiar environmental conditions in polar regions. Our concept describes the main limiting and favorable factors influencing photosynthetic production of cryptogams, mainly lichens. Snow and ice-usually stress factors to the activity of plants-can be effectively used by lichens because of their poikilohydrous nature. Light, the basic driving force for photosynthetic activity, may be deleterious under certain ...

  9. Polarization of migrating monocytic cells is independent of PI 3-kinase activity.

    Directory of Open Access Journals (Sweden)

    Silvia Volpe

    Full Text Available BACKGROUND: Migration of mammalian cells is a complex cell type and environment specific process. Migrating hematopoietic cells assume a rapid amoeboid like movement when exposed to gradients of chemoattractants. The underlying signaling mechanisms remain controversial with respect to localization and distribution of chemotactic receptors within the plasma membrane and the role of PI 3-kinase activity in cell polarization. METHODOLOGY/PRINCIPAL FINDINGS: We present a novel model for the investigation of human leukocyte migration. Monocytic THP-1 cells transfected with the alpha(2A-adrenoceptor (alpha(2AAR display comparable signal transduction responses, such as calcium mobilization, MAP-kinase activation and chemotaxis, to the noradrenaline homologue UK 14'304 as when stimulated with CCL2, which binds to the endogenous chemokine receptor CCR2. Time-lapse video microscopy reveals that chemotactic receptors remain evenly distributed over the plasma membrane and that their internalization is not required for migration. Measurements of intramolecular fluorescence resonance energy transfer (FRET of alpha(2AAR-YFP/CFP suggest a uniform activation of the receptors over the entire plasma membrane. Nevertheless, PI 3-kinase activation is confined to the leading edge. When reverting the gradient of chemoattractant by moving the dispensing micropipette, polarized monocytes--in contrast to neutrophils--rapidly flip their polarization axis by developing a new leading edge at the previous posterior side. Flipping of the polarization axis is accompanied by re-localization of PI-3-kinase activity to the new leading edge. However, reversal of the polarization axis occurs in the absence of PI 3-kinase activation. CONCLUSIONS/SIGNIFICANCE: Accumulation and internalization of chemotactic receptors at the leading edge is dispensable for cell migration. Furthermore, uniformly distributed receptors allow the cells to rapidly reorient and adapt to changes in the

  10. 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.

  11. Case studies: Mining and milling activities - South African facilities

    International Nuclear Information System (INIS)

    Metcalf, P.E.; Woude, S. van der

    2000-01-01

    The mining and milling of minerals is a very important industry in South Africa that employs more than 300,000 people. South Africa extracts minerals with naturally occurring radionuclides, amongst which uranium, monazite and zircon. Two case studies involving environmental restoration activities that are typically associated with mining and minerals processing are discussed. The first case study, Katdoringbos, describes the restoration of a contaminated site where scrap material originating from the mining and minerals processing facilities had been recycled. The other case study, Crown 4, deals with the restoration of a contaminated site where a mine tailings dam had been removed and the owner of the land wished to develop it for commercial exploitation. (author)

  12. Relative influences of climate change and human activity on the onshore distribution of polar bears

    Science.gov (United States)

    Wilson, Ryan R.; Regehr, Eric V.; St. Martin, Michelle; Atwood, Todd C.; Peacock, Elizabeth; Miller, Susanne; Divoky, George J.

    2017-01-01

    Climate change is altering habitat for many species, leading to shifts in distributions that can increase levels of human-wildlife conflict. To develop effective strategies for minimizing human-wildlife conflict, we must understand the relative influences that climate change and other factors have on wildlife distributions. Polar bears (Ursus maritimus) are increasingly using land during summer and autumn due to sea ice loss, leading to higher incidents of conflict and concerns for human safety. We sought to understand the relative influence of sea ice conditions, onshore habitat characteristics, and human-provisioned food attractants on the distribution and abundance of polar bears while on shore. We also wanted to determine how mitigation measures might reduce human-polar bear conflict associated with an anthropogenic food source. We built a Bayesian hierarchical model based on 14 years of aerial survey data to estimate the weekly number and distribution of polar bears on the coast of northern Alaska in autumn. We then used the model to predict how effective two management options for handling subsistence-harvested whale remains in the community of Kaktovik, Alaska might be. The distribution of bears on shore was most strongly influenced by the presence of whale carcasses and to a lesser extent sea ice and onshore habitat conditions. The numbers of bears on shore were related to sea ice conditions. The two management strategies for handling the whale carcasses reduced the estimated number of bears near Kaktovik by > 75%. By considering multiple factors associated with the onshore distribution and abundance of polar bears we discerned what role human activities played in where bears occur and how successful efforts to manage the whale carcasses might be for reducing human-polar bear conflict.

  13. Parsec-scale Faraday rotation and polarization of 20 active galactic nuclei jets

    Science.gov (United States)

    Kravchenko, E. V.; Kovalev, Y. Y.; Sokolovsky, K. V.

    2017-05-01

    We perform polarimetry analysis of 20 active galactic nuclei jets using the very long baseline array at 1.4, 1.6, 2.2, 2.4, 4.6, 5.0, 8.1, 8.4 and 15.4 GHz. The study allowed us to investigate linearly polarized properties of the jets at parsec scales: distribution of the Faraday rotation measure (RM) and fractional polarization along the jets, Faraday effects and structure of Faraday-corrected polarization images. Wavelength dependence of the fractional polarization and polarization angle is consistent with external Faraday rotation, while some sources show internal rotation. The RM changes along the jets, systematically increasing its value towards synchrotron self-absorbed cores at shorter wavelengths. The highest core RM reaches 16 900 rad m-2 in the source rest frame for the quasar 0952+179, suggesting the presence of highly magnetized, dense media in these regions. The typical RM of transparent jet regions has values of an order of a hundred rad m-2. Significant transverse RM gradients are observed in seven sources. The magnetic field in the Faraday screen has no preferred orientation, and is observed to be random or regular from source to source. Half of the sources show evidence for the helical magnetic fields in their rotating magneto-ionic media. At the same time jets themselves contain large-scale, ordered magnetic fields and tend to align its direction with the jet flow. The observed variety of polarized signatures can be explained by a model of spine-sheath jet structure.

  14. Non-polar organic compounds in marine aerosols over the northern South China Sea: Influence of continental outflow.

    Science.gov (United States)

    Zhao, Yan; Zhang, Yingyi; Fu, Pingqing; Ho, Steven Sai Hang; Ho, Kin Fai; Liu, Fobang; Zou, Shichun; Wang, Shan; Lai, Senchao

    2016-06-01

    Filter samples of total suspended particle (TSP) collected during a cruise campaign over the northern South China Sea (SCS) from September to October 2013 were analyzed for non-polar organic compounds (NPOCs) as well as organic carbon (OC), elemental carbon (EC) and water-soluble ions. A total of 115 NPOCs species in groups of n-alkanes, polycyclic aromatic hydrocarbons (PAHs), iso-/antiso-alkanes, hopanes, steranes, methylalkanes, branched alkanes, cycloalkanes, alkenes and phthalates were detected. The characteristics of NPOCs in marine TSP samples were investigated to understand the sources from the Asian continent and other regions. The concentrations of total NPOCs ranged from 19.8 to 288.2 ng/m(3) with an average of 87.9 ng/m(3), which accounted for 0.8-1.7% (average 1.0%) of organic matter (OM). n-Alkanes was the predominant group, accounting for 43.1-79.5%, followed by PAHs (5.5-44.4%) and hopanes (1.6-11.4%). We found that primary combustion (biomass burning/fossil fuel combustion) was the dominant source for the majority of NPOCs (89.1%). Biomass burning in southern/southeastern China via long-range transport was proposed to be a major contributor of NPOCs in marine aerosols over the northern SCS, suggested by the significant correlations between nss-K(+) and NPOCs groups as well as the analysis of air mass back-trajectory and fire spots. For the samples with strong continental influence, the strong enhancement in concentrations of n-alkanes, PAHs, hopanes and steranes were attributed to fossil fuel (coal/petroleum) combustion. In addition, terrestrial plants waxes were another contributor to NPOCs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Transcriptomic analysis of human polarized macrophages: more than one role of alternative activation?

    Directory of Open Access Journals (Sweden)

    Eleonora Derlindati

    Full Text Available Macrophages are a heterogeneous cell population which in response to the cytokine milieu polarize in either classically activated macrophages (M1 or alternatively activated macrophages (M2. This plasticity makes macrophages essential in regulating inflammation, immune response and tissue remodeling and a novel therapeutic target in inflammatory diseases such as atherosclerosis. The aim of the study was to describe the transcriptomic profiles of differently polarized human macrophages to generate new hypotheses on the biological function of the different macrophage subtypes.Polarization of circulating monocytes/macrophages of blood donors was induced in vitro by IFN-γ and LPS (M1, by IL-4 (M2a, and by IL-10 (M2c. Unstimulated cells (RM served as time controls. Gene expression profile of M1, M2a, M2c and RM was assessed at 6, 12 and 24h after polarization with Whole Human Genome Agilent Microarray technique. When compared to RM, M1 significantly upregulated pathways involved in immunity and inflammation, whereas M2a did the opposite. Conversely, decreased and increased expression of mitochondrial metabolism, consistent with insulin resistant and insulin sensitive patterns, was seen in M1 and M2a, respectively. The time sequence in the expression of some pathways appeared to have some specific bearing on M1 function. Finally, canonical and non-canonical Wnt genes and gene groups, promoting inflammation and tissue remodeling, were upregulated in M2a compared to RM.Our data in in vitro polarized human macrophages: 1. confirm and extend known inflammatory and anti-inflammatory gene expression patterns; 2. demonstrate changes in mitochondrial metabolism associated to insulin resistance and insulin sensitivity in M1 and M2a, respectively; 3. highlight the potential relevance of gene expression timing in M1 function; 4. unveil enhanced expression of Wnt pathways in M2a suggesting a potential dual (pro-inflammatory and anti-inflammatory role of M2a in

  16. [DNA hydroxymethylase 10-11 translocation 2 (TET2) inhibits mouse macrophage activation and polarization].

    Science.gov (United States)

    Li, Bingyi; Huo, Yi; Lin, Zhifeng; Wang, Tao

    2017-09-01

    Objective To study the role of DNA hydroxymethylase 10-11 translocation 2 (TET2) in macrophage activation and polarization. Methods RAW264.7 macrophages were cultured in vitro and stimulated with 100 ng/mL LPS for 0, 1, 2, 4, 6 hours. Real-time quantitative PCR was used to detect TET2 mRNA expression. TET2 expression was knocked down with siRNA and the knock-down efficiency was evaluated by real-time quantitative PCR and Western blotting. Following siRNA transfection for 48 hours, RAW264.7 cells were stimulated by LPS for 4 hours, and then real-time quantitative PCR and ELISA were performed to detect the expressions of interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) and IL-12. The M1 polarizing markers TNF-α, inducible nitric oxide synthase (iNOS) and IL-12, and M2 polarizing markers mannose receptor (MR), arginase 1 (Arg-1) and chitinase 3-like molecule 1 (Ym1) were tested after M1 or M2 induction by LPS/IFN-γ or IL-4. Results TET2 expression increased after LPS treatment in RAW264.7 cells and reached the peak at 2 hours later. The siRNA effectively reduced the expression of TET2. The expressions of IL-6, TNF-α and IL-12 mRNAs increased after TET2 knock-down and LPS stimulation. The expressions of M1 polarization markers and M2 markers were up-regulated by the corresponding stimulations after TET2 knock-down. Conclusion TET2 has the effect of inhibiting LPS-induced macrophage activation and plays an inhibitory role in macrophage M1 and M2 polarization.

  17. Assessing Challenges and Opportunities for Education and Communication Activities for International Polar Year 2007-2008

    Science.gov (United States)

    McCaffrey, M. S.

    2005-05-01

    Considerable planning has gone into identifying ways to maximize International Polar Year 2007-2008 (IPY) as a global event that will facilitate the integration of research and education inherent in IPY, and draw the interest and involvement of people around the world. Documents developed through the IPY planning process, including NRC Reports (2004), and drafts reports on education and outreach from the ICSU IPY Planning Group in the Fall of 2004, and the Bridging the Poles workshop of June, 2004, articulate the tremendous potential for IPY beyond the formal research agenda and goals. With less that two years before the start of IPY and fewer than fours years before the activities are completed, these and emerging opportunities face a number of challenges. In addition to the limited time frame remaining to prepare for these activities, participants involved with IPY education and outreach will also need to consider factors such as: uncertain funding for such activities; the lack of established international networks for geoscience education; the need for high level coordination of IPY education and communication; and the creative and intellectual challenge of making the polar regions relevant to people around the world. The planning process has identified six constituencies as key audiences of IPY communication efforts: i) the scientific/research community, ii) young and potentially new polar researchers, iii) the pre-university education community, iv) arctic communities, iv) the general public, and v) decision-makers. Understanding and meeting these audiences' expectations through on-going evaluation and engagement will be key to successful IPY education and outreach efforts. A number of distinct education and outreach projects have been proposed to the ICSU-WMO IPY planning process, such as courses and workshops on specific aspects of IPY, including efforts to address the social and cultural dimension of Arctic peoples. To help meet the challenges, achieve the

  18. Energy and polarization of the telluric field in correlation with seismic activity in Greece

    Energy Technology Data Exchange (ETDEWEB)

    Vargemezis, G.; Tsokas, G. N. [Geophysical Laboratory of Thessaloniki, Thessaloniki (Greece); Zlotnicki, J. [Observatoire de Physique du Globe de Clermont-Ferrand, Clermont-Ferrand (France)

    2001-04-01

    Many attempts have been made to disclose anomalous changes of the electromagnetic field in relation with tectonic earthquakes. It was tentatively developed a new approach based on the energy and polarity of the electric field, and apply this method to the seismicity in Greece. The study of the parameters of the horizontal electric field is realized in a time interval of five years. The data allows the study of long-term variations of the field. Further, it was examined the possible relation of the geoelectric activity with long distance seismicity (up to 500 km). The energy of the electric signal was estimated and correlated with the logarithm of the seismic moment (M{sub 0}). The values of the seismic moment estimated for each earthquake were summed for daily intervals, and the logarithm of the sum was computed. The same process was applied to the energy of the geoelectric field. Then, a correlation was attempted between the energy of the geoelectric field and the seismic moment referring to daily intervals. In two cases, changes in the energy of the horizontal geoelectric field were observed before the burst of the seismic activity. The energy of the telluric field increased several months before the burst of seismic activity and recovered right after the occurrence of the mainshocks. The hodograms of the horizontal geoelectric field show polarization changes regardless of the magnetic field. This is possibly attributed to the process of generation of electric currents before major earthquakes. Due to high and continuous regional seismicity in Greece, it was impossible to attribute the response of the polarization to the activation of specific seismic areas. It seems that the long-term energy variations of the horizontal geoelectric field as well as the polarization could be used in tandem with other possible precursors in order to contribute to earthquake prediction studies.

  19. Relationships between the solar wind and the polar cap magnetic activity

    International Nuclear Information System (INIS)

    Berthelier, A.

    1981-01-01

    The influence of solar wind conditions on magnetic activity is described in order to delineate the differences in the response of the magnetic activity to the arrival on the magnetopause of different typical solar wind variations. By determining a new index of local magnetic activity free from seasonal and diurnal effects we put in evidence the dependence of the various effects upon the invariant latitude. Most important results are: (1) the main increase of the magnetic activity does not occur at the same invariant latitude for different interplanetary variations, e.g. peaks of Bz tend to increase magnetic activity mainly in the auroral zones while peaks of B correspond to a uniform increase in magnetic activity over the polar cap and auroral zone; (2) there is a two steps response of magnetic activity to the high speed plasma streams; (3) an increase of magnetic activity is observed for large and northward Bz, which probably indicates that the solar wind-magnetosphere coupling is efficient under these circumstances. The specific influences of the IMF polarity are also briefly reviewed. (orig.)

  20. FISHING ACTIVITIES AND FISHERMEN INCOME IN RANAU LAKE, SOUTH SUMATRA

    Directory of Open Access Journals (Sweden)

    Dina Muthmainah

    2015-06-01

    Full Text Available Fish resources contribute to the socio-economic development for people who live surrounding the waters. The fishermen of Ranau Lake, South Ogan Komering Ulu Regency, South Sumatra Province and West Lampung Regency, Lampung Province are the prime stakeholder and direct interest in fish resources, because they depend on it for their livelihoods or they are directly involved in its exploitation in some ways. However, to well manage these resources, it needs data and information about fish utilization and fishing activity. The objectives of this work are to assess fishing activities such as the fishing craft and gears, catch composition, fish yield, catch per unit of effort (CPUE and to estimate the fihermen income with economical parameter such as cost and price. Field surveys were conducted from February to November 2014. Fishing activities data were collected from field survey and interview. The results showed that fish resources utilization in Ranau Lake was categorized as traditional and small scale fisheries using different selective fishing gears such gillnet, harpoon, net trap and basket trap with the fish catch in average of 696.66 g/day; 205.03 g/day; 1.584.06 g/day and 123.67 g/day, respectively. Fisherman income (IDR 2,163,300 means the fishermen in Ranau Lake reach standard Indonesian welfare.

  1. Protecting polar wilderness : Just a western philosophical idea or a useful concept for regulating human activities in the polar regions?

    NARCIS (Netherlands)

    Bastmeijer, Kees; Leary, D.; Koivurova, T.; Alfredsson, G.

    2009-01-01

    Governments involved in Arctic and Antarctic governance have been well aware of the increasing human pressure on the Polar Regions and particularly the last two decades many initiatives have been taken to protect the Arctic and Antarctic environment. But what values are to be protected? This paper

  2. Environmental contaminants activate human and polar bear (Ursus maritimus) pregnane X receptors (PXR, NR1I2) differently

    Energy Technology Data Exchange (ETDEWEB)

    Lille-Langøy, Roger, E-mail: Roger.lille-langoy@bio.uib.no [University of Bergen, Department of Biology, P.O. Box 7803, N-5020 Bergen (Norway); Goldstone, Jared V. [Woods Hole Oceanographic Institution, 266 Woods Hole Road, 02543-1050 Woods Hole, MA (United States); Rusten, Marte [University of Bergen, Department of Molecular Biology, P.O. Box 7803, N-5020 Bergen (Norway); Milnes, Matthew R. [Mars Hill University, 100 Athletic Street, Box 6671, Mars Hill, 28754 NC (United States); Male, Rune [University of Bergen, Department of Molecular Biology, P.O. Box 7803, N-5020 Bergen (Norway); Stegeman, John J. [Woods Hole Oceanographic Institution, 266 Woods Hole Road, 02543-1050 Woods Hole, MA (United States); Blumberg, Bruce [University of California, Irvine, 92697 CA (United States); Goksøyr, Anders [University of Bergen, Department of Biology, P.O. Box 7803, N-5020 Bergen (Norway)

    2015-04-01

    Background: Many persistent organic pollutants (POPs) accumulate readily in polar bears because of their position as apex predators in Arctic food webs. The pregnane X receptor (PXR, formally NR1I2, here proposed to be named promiscuous xenobiotic receptor) is a xenobiotic sensor that is directly involved in metabolizing pathways of a wide range of environmental contaminants. Objectives: In the present study, we comparably assess the ability of 51 selected pharmaceuticals, pesticides and emerging contaminants to activate PXRs from polar bears and humans using an in vitro luciferase reporter gene assay. Results: We found that polar bear PXR is activated by a wide range of our test compounds (68%) but has a slightly more narrow ligand specificity than human PXR that was activated by 86% of the 51 test compounds. The majority of the agonists identified (70%) produces a stronger induction of the reporter gene via human PXR than via polar bear PXR, however with some notable and environmentally relevant exceptions. Conclusions: Due to the observed differences in activation of polar bear and human PXRs, exposure of each species to environmental agents is likely to induce biotransformation differently in the two species. Bioinformatics analyses and structural modeling studies suggest that amino acids that are not part of the ligand-binding domain and do not interact with the ligand can modulate receptor activation. - Highlights: • Comparative study of ligand activation of human and polar bear PXRs. • Polar bear PXR is a promiscuous ligand-activated nuclear receptor but less so than human PXR. • Environmental contaminants activate human and polar bear PXRs differently. • Expression and ligand promiscuity indicate that PXR is a xenosensor in polar bears.

  3. Environmental contaminants activate human and polar bear (Ursus maritimus) pregnane X receptors (PXR, NR1I2) differently

    International Nuclear Information System (INIS)

    Lille-Langøy, Roger; Goldstone, Jared V.; Rusten, Marte; Milnes, Matthew R.; Male, Rune; Stegeman, John J.; Blumberg, Bruce; Goksøyr, Anders

    2015-01-01

    Background: Many persistent organic pollutants (POPs) accumulate readily in polar bears because of their position as apex predators in Arctic food webs. The pregnane X receptor (PXR, formally NR1I2, here proposed to be named promiscuous xenobiotic receptor) is a xenobiotic sensor that is directly involved in metabolizing pathways of a wide range of environmental contaminants. Objectives: In the present study, we comparably assess the ability of 51 selected pharmaceuticals, pesticides and emerging contaminants to activate PXRs from polar bears and humans using an in vitro luciferase reporter gene assay. Results: We found that polar bear PXR is activated by a wide range of our test compounds (68%) but has a slightly more narrow ligand specificity than human PXR that was activated by 86% of the 51 test compounds. The majority of the agonists identified (70%) produces a stronger induction of the reporter gene via human PXR than via polar bear PXR, however with some notable and environmentally relevant exceptions. Conclusions: Due to the observed differences in activation of polar bear and human PXRs, exposure of each species to environmental agents is likely to induce biotransformation differently in the two species. Bioinformatics analyses and structural modeling studies suggest that amino acids that are not part of the ligand-binding domain and do not interact with the ligand can modulate receptor activation. - Highlights: • Comparative study of ligand activation of human and polar bear PXRs. • Polar bear PXR is a promiscuous ligand-activated nuclear receptor but less so than human PXR. • Environmental contaminants activate human and polar bear PXRs differently. • Expression and ligand promiscuity indicate that PXR is a xenosensor in polar bears

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

    Science.gov (United States)

    Whiteman, J.P.; Harlow, H.J.; Durner, George M.; Anderson-Sprecher, R.; Albeke, Shannon E.; Regehr, Eric V.; Amstrup, Steven C.; Ben-David, M.

    2015-01-01

    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.

  5. 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.

  6. Dengue antiviral activity of polar extract from Melochia umbellata (Houtt) Stapf var. Visenia

    Science.gov (United States)

    Hariani Soekamto, Nunuk; Liong, S.; Fauziah, S.; Wahid, I.; Firdaus; Taba, P.; Ahmad, F.

    2018-03-01

    A research on the dengue antiviral activity test on the polar bark extract of M. umbelatta (Houtt.) Stapf var. Vicenia have been done to determine the relation to its activity againts brine shrimp Artemia salina. The bark was extracted by maceration with n-hexane, chloroform, and ethylacetate. The activity of the ethyl acetate extract was then tested against A. salina and dengue virus. It was found that the ethyl acetate extract was active to A. salina with the LC50 value of 101.66 μg/mL and also very active to dengue virus with the IC50 value of 1.67μg/mL. It is clear that the toxicity to brine shrimp A. salina has a positive correlation with the dengue anti virus.

  7. 78 FR 16247 - Foreign-Trade Zone 38-Spartanburg County, South Carolina; Authorization of Production Activity...

    Science.gov (United States)

    2013-03-14

    ... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-86-2012] Foreign-Trade Zone 38--Spartanburg County, South Carolina; Authorization of Production Activity; ZF Transmissions Gray Court, LLC (Automatic Transmissions); Gray Court, South Carolina On November 8, 2012, the South Carolina State Ports Authority...

  8. Assessment of relative active tectonics, south central Alborz (north Iran)

    Science.gov (United States)

    Khavari, R.; Ghorashi, M.; Arian, M.

    2009-04-01

    The paper present a method for evaluating relative active tectonics based on geomorphic indices useful in evaluating morphology and topography. Indices used include: stream length-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), ratio of valley-floor width to valley height (Vf), index of drainage basin shape (Bs), and index of mountain front sinuosity (Smf). Results from the analysis are accumulated and expressed as an index of relative active tectonics (Iat), which we divide into four classes from relatively low to highest tectonic activity. The study area along the south flank of the central Alborz mountain range in north Iran is an ideal location to test the concept of an index to predict relative tectonic activity on a basis of area rather than a single valley or mountain front. The recent investigations show that neotectonism has played a key role in the geomorphic evolution of this part of the Alborz mountain range. Geomorphic indices indicate the presence of differential uplifting in the geological past. The area surrounding the Amirkabir lake shows very high relative tectonic activity.

  9. Dune-slope activity due to frost and wind throughout the north polar erg, Mars.

    Science.gov (United States)

    Diniega, Serina; Hansen, Candice J; Allen, Amanda; Grigsby, Nathan; Li, Zheyu; Perez, Tyler; Chojnacki, Matthew

    2017-01-01

    Repeat, high-resolution imaging of dunes within the Martian north polar erg have shown that these dune slopes are very active, with alcoves forming along the dune brink each Mars year. In some areas, a few hundred cubic metres of downslope sand movement have been observed, sometimes moving the dune brink 'backwards'. Based on morphological and activity-timing similarities of these north polar features to southern dune gullies, identifying the processes forming these features is likely to have relevance for understanding the general evolution/modification of dune gullies. To determine alcove-formation model constraints, we have surveyed seven dune fields, each over 1-4 Mars winters. Consistent with earlier reports, we found that alcove-formation activity occurs during the autumn-winter seasons, before or while the stable seasonal frost layer is deposited. We propose a new model in which alcove formation occurs during the autumn, and springtime sublimation activity then enhances the feature. Summertime winds blow sand into the new alcoves, erasing small alcoves over a few Mars years. Based on the observed rate of alcove erasure, we estimated the effective aeolian sand transport flux. From this, we proposed that alcove formation may account for 2-20% of the total sand movement within these dune fields.

  10. The Transcription Factor STAT6 Mediates Direct Repression of Inflammatory Enhancers and Limits Activation of Alternatively Polarized Macrophages

    OpenAIRE

    Czimmerer, Zsolt; Daniel, Bence; Horvath, Attila; Rückerl, Dominik; Nagy, Gergely; Kiss, Mate; Peloquin, Matthew; Budai, Marietta M.; Cuaranta-Monroy, Ixchelt; Simandi, Zoltan; Steiner, Laszlo; Nagy, Bela; Poliska, Szilard; Banko, Csaba; Bacso, Zsolt

    2018-01-01

    Summary The molecular basis of signal-dependent transcriptional activation has been extensively studied in macrophage polarization, but our understanding remains limited regarding the molecular determinants of repression. Here we show that IL-4-activated STAT6 transcription factor is required for the direct transcriptional repression of a large number of genes during in vitro and in vivo alternative macrophage polarization. Repression results in decreased lineage-determining transcription fac...

  11. Explanation of changes of stellar radiation polarization by means of an ''active longitudes'' hypothesis with U Mon as an example

    International Nuclear Information System (INIS)

    Polyakova, T.A.

    1980-01-01

    The hypothesis explaining the variability of some stars with U Mon as an example resulting from antipodal active regions on their surface is discussed qualitatively. The plane of polarization is determined by average magnetic field of the bipolar active region. The changes of polarization and brightness are assumed to be connected with the star rotation. The rotation period is taken to be twice as much as the period doubling of spectral lines

  12. Research Activity and Infrastructure of Korea Polar Research Institute: Current and Future Perspectives

    Science.gov (United States)

    Jin, D.; Kim, S.; Lee, H.

    2011-12-01

    The Korea Polar Research Institute (KOPRI) opened the Antarctic King Sejong research station in 1988 at the King George Island off the Antarctic Peninsula and started the polar research mainly in the fields of biology and geology with some atmosphere observations. To extend the view of polar research, the KOPRI opened the Arctic Dasan research station at Ny-Alesund, Spitsbergen Island in 2002 and has studied the rapid climate change diagnostics and some microbiological observation. The KOPRI is now expanding the Arctic research into Alaska and Canada under the international collaboration, and planning to outreach to Russia to monitor the change in permafrost and to understand its impact on global warming. To deepen the views of polar research including the ice covered oceans in both poles, the ice-breaking vessel, the ARAON of about 7000 ton, was launched recently and successfully finished the Arctic and Antarctic cruises for research activity on all perspectives of ocean sciences and support for the King Sejong station. The KOPRI is now building another Antarctic research station, called Jangbogo, at the Terra Nova Bay off the Ross Sea and plan to open the station at the March of 2014. By building the second Antarctic station together with the ARAON, the KOPRI will focus its research on understanding the rapid climate change in west Antarctica such as to monitor the calving of the Larsen Ice shelf, rapid melting of Pine Island Glacier, and upper atmosphere, to study the sea ice and ecosystem change in the Amundsen Sea and the role of the southern annular mode in the west Antarctic warming, upper atmosphere and climate change, to reconstruct paleoclimate records from ice and sediment cores.

  13. New Sulphated Flavonoids from Tamarix africana and Biological Activities of Its Polar Extract.

    Science.gov (United States)

    Karker, Manel; De Tommasi, Nunziatina; Smaoui, Abderrazak; Abdelly, Chedly; Ksouri, Riadh; Braca, Alessandra

    2016-10-01

    The phytochemical investigation of Tamarix africana Poir. (Tamaricaceae) shoot polar extract afforded three new sulphated flavonoids, (2 S ,4 R )-5,7,4'-trihydroxyflavan-4-ol 5,7-disulphate ( 1 ), (2 S )-5,7,4'-trihydroxyflavan 7- O -sulphate ( 2 ), and (2 S )-naringenin 4'- O -sulphate ( 3 ), together with ten known compounds. Their structures were determined by spectroscopic methods including 1D and 2D NMR analysis and HRMS. Biological activities of the polar extract of T. africana shoots related to its phenolic content were also investigated. A high total phenolic content (151.1 mg GAE/g) was found in the methanol shoot extract, which exhibits strong antioxidant activities using the oxygen radical absorbance capacity method and a skin cell-based assay. Moreover, the shoot extract showed significant anti-inflammatory activity, reducing nitric oxide release by 53.5 % at 160 µg/mL in lipopolysaccharide-stimulated RAW 264.7 macrophages. Finally, T. africana shoot extract inhibited the growth of A-549 lung carcinoma cells, with an IC 50 value of 34 µg/mL. Georg Thieme Verlag KG Stuttgart · New York.

  14. Near equilibrium dynamics and one-dimensional spatial—temporal structures of polar active liquid crystals

    International Nuclear Information System (INIS)

    Yang Xiao-Gang; Wang Qi; Forest, M. Gregory

    2014-01-01

    We systematically explore near equilibrium, flow-driven, and flow-activity coupled dynamics of polar active liquid crystals using a continuum model. Firstly, we re-derive the hydrodynamic model to ensure the thermodynamic laws are obeyed and elastic stresses and forces are consistently accounted. We then carry out a linear stability analysis about constant steady states to study near equilibrium dynamics around the steady states, revealing long-wave instability inherent in this model system and how active parameters in the model affect the instability. We then study model predictions for one-dimensional (1D) spatial—temporal structures of active liquid crystals in a channel subject to physical boundary conditions. We discuss the model prediction in two selected regimes, one is the viscous stress dominated regime, also known as the flow-driven regime, while the other is the full regime, in which all active mechanisms are included. In the viscous stress dominated regime, the polarity vector is driven by the prescribed flow field. Dynamics depend sensitively on the physical boundary condition and the type of the driven flow field. Bulk-dominated temporal periodic states and spatially homogeneous states are possible under weak anchoring conditions while spatially inhomogeneous states exist under strong anchoring conditions. In the full model, flow-orientation interaction generates a host of planar as well as out-of-plane spatial—temporal structures related to the spontaneous flows due to the molecular self-propelled motion. These results provide contact with the recent literature on active nematic suspensions. In addition, symmetry breaking patterns emerge as the additional active viscous stress due to the polarity vector is included in the force balance. The inertia effect is found to limit the long-time survival of spatial structures to those with small wave numbers, i.e., an asymptotic coarsening to long wave structures. A rich set of mechanisms for generating

  15. LOW-FREQUENCY OBSERVATIONS OF LINEARLY POLARIZED STRUCTURES IN THE INTERSTELLAR MEDIUM NEAR THE SOUTH GALACTIC POLE

    Energy Technology Data Exchange (ETDEWEB)

    Lenc, E.; Gaensler, B. M.; Sun, X. H.; Sadler, E. M.; Callingham, J. R. [Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW 2006 (Australia); Willis, A. G. [National Research Council of Canada, Herzberg Astronomy and Astrophysics, P.O. Box 248, Penticton, BC (Canada); Barry, N.; Beardsley, A. P.; Carroll, P. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Bell, M. E.; Briggs, F. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Bernardi, G. [Department of Physics and Electronics, Rhodes University, P.O. Box 94, Grahamstown 6140 (South Africa); Bowman, J. D. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Cappallo, R. J.; Corey, B. E. [MIT Haystack Observatory, Westford, MA 01886 (United States); Oliveira-Costa, A. de; Dillon, J. S. [MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Deshpande, A. A.; Dwarkanath, K. S. [Raman Research Institute, Bangalore 560080 (India); Emrich, D. [International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102 (Australia); and others

    2016-10-10

    We present deep polarimetric observations at 154 MHz with the Murchison Widefield Array (MWA), covering 625 deg{sup 2} centered on α = 0{sup h}and δ = −27°. The sensitivity available in our deep observations allows an in-band, frequency-dependent analysis of polarized structure for the first time at long wavelengths. Our analysis suggests that the polarized structures are dominated by intrinsic emission but may also have a foreground Faraday screen component. At these wavelengths, the compactness of the MWA baseline distribution provides excellent snapshot sensitivity to large-scale structure. The observations are sensitive to diffuse polarized emission at ∼54′ resolution with a sensitivity of 5.9 mJy beam{sup −1} and compact polarized sources at ∼2.′4 resolution with a sensitivity of 2.3 mJy beam{sup −1} for a subset (400 deg{sup 2}) of this field. The sensitivity allows the effect of ionospheric Faraday rotation to be spatially and temporally measured directly from the diffuse polarized background. Our observations reveal large-scale structures (∼1°–8° in extent) in linear polarization clearly detectable in ∼2 minute snapshots, which would remain undetectable by interferometers with minimum baseline lengths of >110 m at 154 MHz. The brightness temperature of these structures is on average 4 K in polarized intensity, peaking at 11 K. Rotation measure synthesis reveals that the structures have Faraday depths ranging from −2 to 10 rad m{sup −2} with a large fraction peaking at approximately +1 rad m{sup −2}. We estimate a distance of 51 ± 20 pc to the polarized emission based on measurements of the in-field pulsar J2330–2005. We detect four extragalactic linearly polarized point sources within the field in our compact source survey. Based on the known polarized source population at 1.4 GHz and non-detections at 154 MHz, we estimate an upper limit on the depolarization ratio of 0.08 from 1.4 GHz to 154 MHz.

  16. Antiviral activity of some South American medicinal plants.

    Science.gov (United States)

    Abad, M J; Bermejo, P; Sanchez Palomino, S; Chiriboga, X; Carrasco, L

    1999-03-01

    Folk medicinal plants are potential sources of useful therapeutic compounds including some with antiviral activities. Extracts prepared from 10 South American medicinal plants (Baccharis trinervis, Baccharis teindalensis, Eupatorium articulatum, Eupatorium glutinosum, Tagetes pusilla, Neurolaena lobata, Conyza floribunda, Phytolacca bogotensis, Phytolacca rivinoides and Heisteria acuminata) were screened for in vitro antiviral activity against herpes simplex type I (HSV-1), vesicular stomatitis virus (VSV) and poliovirus type 1. The most potent inhibition was observed with an aqueous extract of B. trinervis, which inhibited HSV-1 replication by 100% at 50-200 micrograms/mL, without showing cytotoxic effects. Good activities were also found with the ethanol extract of H. acuminata and the aqueous extract of E. articulatum, which exhibited antiviral effects against both DNA and RNA viruses (HSV-1 and VSV, respectively) at 125-250 micrograms/mL. The aqueous extracts of T. pusilla (100-250 micrograms/mL), B. teindalensis (50-125 micrograms/mL) and E. glutinosum (50-125 micrograms/mL) also inhibited the replication of VSV, but none of the extracts tested had any effect on poliovirus replication.

  17. Transthyretin-binding activity of contaminants in blood from polar bear (Ursus maritimus) cubs.

    Science.gov (United States)

    Bytingsvik, Jenny; Simon, Eszter; Leonards, Pim E G; Lamoree, Marja; Lie, Elisabeth; Aars, Jon; Derocher, Andrew E; Wiig, Oystein; Jenssen, Bjørn M; Hamers, Timo

    2013-05-07

    We determined the transthyretin (TTR)-binding activity of blood-accumulating contaminants in blood plasma samples of approximately 4-months-old polar bear (Ursus maritimus) cubs from Svalbard sampled in 1998 and 2008. The TTR-binding activity was measured as thyroxine (T4)-like equivalents (T4-EQMeas). Our findings show that the TTR-binding activity related to contaminant levels was significantly lower (45%) in 2008 than in 1998 (mean ± standard error of mean: 1998, 2265 ± 231 nM; 2008, 1258 ± 170 nM). Although we cannot exclude a potential influence of between-year differences in capture location and cub body mass, our findings most likely reflect reductions of TTR-binding contaminants or their precursors in the arctic environment (e.g., polychlorinated biphenyls [PCBs]). The measured TTR-binding activity correlated positively with the cubs' plasma levels of hydroxylated PCBs (OH-PCBs). No such association was found between TTR-binding activity and the plasma levels of perfluoroalkyl substances (PFASs). The OH-PCBs explained 60 ± 7% and 54 ± 4% of the TTR-binding activity in 1998 and 2008, respectively, and PFASs explained ≤1.2% both years. Still, almost half the TTR-binding activity could not be explained by the contaminants we examined. The considerable levels of TTR-binding contaminants warrant further effect directed analysis (EDA) to identify the contaminants responsible for the unexplained part of the observed TTR-binding activity.

  18. Anomalous high-frequency wave activity flux preceding anomalous changes in the Northern polar jet

    Science.gov (United States)

    Nakamura, Mototaka; Kadota, Minoru; Yamane, Shozo

    2010-05-01

    show anomalous acceleration or deceleration of U in the polar region, accompanied by anomalies of the opposite sign in the subtropics throughout the troposphere and stratosphere. The anomalies are conspicuously large in the polar stratosphere. The composited anomalous Z and U in the preceding and following months indicate that these large anomalies in dZ and dU occur when the polar troposphere and stratosphere are relaxing back toward the climatology from strongly anomalous states that closely resemble the positive and negative phases of the NAM. In this process of relaxation, the atmosphere actually overshoots the climatology and develops anomalies of the sign opposite to those existed initially. The anomalous wave activity flux exhibit strong signals of anomalous upward (downward) propagation of high-frequency waves in the North Atlantic storm track from the bottom of the atmosphere, penetrating up to the stratosphere, when the polar jet is anomalously strong (weak) in the preceding month. The anomalous horizontal wave activity flux shows anomalous eastward (westward) flux emanating from the North Atlantic storm track when the polar jet is anomalously strong (weak) in the preceding month. These patterns suggest that anomalous high-frequency waves originating from the North Atlantic storm track in the lower troposphere contribute to the destruction of both phases of the NAM. However, the anomalous flux divergence is very noisy everywhere due to the noisiness of the advective horizontal flux, making it difficult to ascertain the role of the high-frequency transients in the destruction of the NAM.

  19. Active overbank deposition during the last century, South River, Virginia

    Science.gov (United States)

    Pizzuto, Jim; Skalak, Katherine; Pearson, Adam; Benthem, Adam

    2016-03-01

    We quantify rates of overbank deposition over decadal to centennial timescales along the South River in Virginia using four independent methods. Detailed mercury profiles sampled adjacent to the stream channel preserve the peak historic mercury concentration on suspended sediment dating from 1955 to 1961 and suggest sedimentation rates of 8 to 50 cm/100 years. Sediment accumulation over the roots of trees suggest rates of 0 to 100 cm/100 years, with significantly higher values on levees and lower values on floodplains farther from the channel. Profiles of 137Cs and 210Pb from two eroding streambanks are fit with an advection-diffusion model calibrated at an upland reference site; these methods suggest sedimentation rates of 44 to 73 cm/100 years. Mercury inventories from 107 floodplain cores, combined with a previously published reconstruction of the history of mercury concentration on suspended sediment, provide spatially comprehensive estimates of floodplain sedimentation: median sedimentation rates are 3.8 cm/100 years for the HEC-RAS) modeling demonstrates that the floodplain of the South River remains hydraulically connected to the channel: 56% of the 100-year floodplain is inundated every two years, and 83% of the floodplain is inundated every five years. These results, combined with previously published data, provide the basis for a regional synthesis of floodplain deposition rates since European settlement. Floodplain sedimentation rates were high following European settlement, with published estimates ranging from 50 to 200 cm/100 years. Sedimentation rates decreased by 1 to 2 orders of magnitude during the twentieth and twenty-first centuries; but despite these lower sedimentation rates, floodplains continue to store a significant fraction of total suspended sediment load. Many floodplains of the mid-Atlantic region are active landforms fully connected to the rivers that flow within them and should not be considered terraces isolated from contemporary

  20. Passive bookshelf faulting driven by gravitational spreading as the cause of the tiger-stripe-fracture formation and development in the South Polar Terrain of Enceladus

    Science.gov (United States)

    Yin, A.; Pappalardo, R. T.

    2013-12-01

    Detailed photogeologic mapping of the tiger-stripe fractures in the South Polar Terrain (SPT) of Enceladus indicates that these structures are left-slip faults and terminate at hook-shaped fold-thrust zones and/or Y-shaped horsetail splay-fault zones. The semi-square-shaped tectonic domain that hosts the tiger-stripe faults is bounded by right-slip and left-slip faults on the north and south edges and fold-thrust and extensional zones on the western and eastern edges. We explain the above observations by a passive bookshelf-faulting model in which individual tiger-stripe faults are bounded by deformable wall rocks accommodating distributed deformation. Based on topographic data, we suggest that gravitational spreading had caused the SPT to spread unevenly from west to east. This process was accommodated by right-slip and left-slip faulting on the north and south sides and thrusting and extension along the eastern and southern margins of the tiger-stripe tectonic domain. The uneven spreading, expressed by a gradual northward increase in the number of extensional faults and thrusts/folds along the western and eastern margins, was accommodated by distributed right-slip simple shear across the whole tiger-stripe tectonic domain. This mode of deformation in turn resulted in the development of a passive bookshelf-fault system characterized by left-slip faulting on individual tiger-stripe fractures.

  1. “Be active!” Revisiting the South African food-based dietary ...

    African Journals Online (AJOL)

    2013-04-08

    Apr 8, 2013 ... Keywords: food-based dietary guidelines, FBDGs, physical activity participation, ... activity, obesity or NCDs have been reported in South Africa. Recent ...... Von Reusten A, Wiekert C, Fietze I, Boeing H. Association of sleep.

  2. Comparing lightning polarity and cloud microphysical properties over regions of high ground flash density in South Africa

    CSIR Research Space (South Africa)

    Simpson, LA

    2011-09-01

    Full Text Available This study aims to find a correlation between lightning polarity and microphysical properties of a storm cloud, for events where large amounts of lightning damage have occured and/or there has been a reported lightning-related fatality....

  3. Environmental contaminants activate human and polar bear (Ursus maritimus) pregnane X receptors (PXR, NR1I2) differently.

    Science.gov (United States)

    Lille-Langøy, Roger; Goldstone, Jared V; Rusten, Marte; Milnes, Matthew R; Male, Rune; Stegeman, John J; Blumberg, Bruce; Goksøyr, Anders

    2015-04-01

    Many persistent organic pollutants (POPs) accumulate readily in polar bears because of their position as apex predators in Arctic food webs. The pregnane X receptor (PXR, formally NR1I2, here proposed to be named promiscuous xenobiotic receptor) is a xenobiotic sensor that is directly involved in metabolizing pathways of a wide range of environmental contaminants. In the present study, we comparably assess the ability of 51 selected pharmaceuticals, pesticides and emerging contaminants to activate PXRs from polar bears and humans using an in vitro luciferase reporter gene assay. We found that polar bear PXR is activated by a wide range of our test compounds (68%) but has a slightly more narrow ligand specificity than human PXR that was activated by 86% of the 51 test compounds. The majority of the agonists identified (70%) produces a stronger induction of the reporter gene via human PXR than via polar bear PXR, however with some notable and environmentally relevant exceptions. Due to the observed differences in activation of polar bear and human PXRs, exposure of each species to environmental agents is likely to induce biotransformation differently in the two species. Bioinformatics analyses and structural modeling studies suggest that amino acids that are not part of the ligand-binding domain and do not interact with the ligand can modulate receptor activation. Copyright © 2015. Published by Elsevier Inc.

  4. Enhanced polarization, magnetic response and pronounced antibacterial activity of bismuth ferrite nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Kunal [Department of Biotechnology, Maulana Abul Kalam Azad University of Technology, West Bengal, Kolkata-64 (India); De, Debashis, E-mail: dr.debashis.de@ieee.org [Department of Computer Science and Engineering, Maulana Abul Kalam Azad University of Technology, West Bengal, Kolkata-64 (India); Bandyopadhyay, Jaya [Department of Biotechnology, Maulana Abul Kalam Azad University of Technology, West Bengal, Kolkata-64 (India); Dutta, Nabanita; Rana, Subhasis; Sen, Pintu [Variable Energy Cyclotron Centre, 1/AF, Bidhan Nagar, Kolkata, 700 064 (India); Bandyopadhyay, Sujit Kumar, E-mail: drsujitkumar@gmail.com [Meghnad Saha Institute of Technology, Nazirabad Rd, Uchhepota, Kolkata, West Bengal, 700150 (India); Chakraborty, P.K. [Department of Physics, Burdwan University, Burdwan, 713104 (India)

    2017-07-01

    The present work reports on the physical and biophysical characterization of bismuth ferrite (BFO) nanorods fabricated on porous anodized alumina (AAO) templates. The diameter of the nanorods was quite large, which vary in the range of 20–100 nm. The BFO nanorods exhibited enhanced polarization and significant magnetic susceptibility. Moreover, an enhanced magnetoelectric coupling was evident from magnetocapacitance measurements, which exhibited a power law. Upon analyzing through optical, petri-plate and electron microscopy imaging, we observed that, the asymmetric structure of the nanorods gave rise to augmented antibacterial response against the chosen bacteria (Staphylococcus aureus). The x-ray photoelectron spectra (XPS) data have exhibited significant peak shifts upon interaction with bacterial cells owing to a change of Bi oxidation state from one to another. Thus potential redox reaction, which might take place at the material-bio interface, is ascertained for bacterial death. Apart from physical insights, understanding the interaction between the bacteria and the nanorods of BFO could pave the way in exploring the antibacterial potentiality of such anisotropic nanoscale systems. - Highlights: • AAO supported BiFeO3 (BFO) nanorods have been investigated. • The polarization of BFO nanorods was observed to be remarkably high (∼0.04 μC/cm{sup 2}). • Strong antibacterial activity of nanorods was witnessed against Staphylococcus aureus. • The deskinned area on cytoskeletal parts as revealed through TEM imaging, suggest strong cidal activity of the nanorods. • XPS data justifies shifting of the peak due to biophysical interaction at the interface releasing reactive oxygen species.

  5. Enhanced polarization, magnetic response and pronounced antibacterial activity of bismuth ferrite nanorods

    International Nuclear Information System (INIS)

    Biswas, Kunal; De, Debashis; Bandyopadhyay, Jaya; Dutta, Nabanita; Rana, Subhasis; Sen, Pintu; Bandyopadhyay, Sujit Kumar; Chakraborty, P.K.

    2017-01-01

    The present work reports on the physical and biophysical characterization of bismuth ferrite (BFO) nanorods fabricated on porous anodized alumina (AAO) templates. The diameter of the nanorods was quite large, which vary in the range of 20–100 nm. The BFO nanorods exhibited enhanced polarization and significant magnetic susceptibility. Moreover, an enhanced magnetoelectric coupling was evident from magnetocapacitance measurements, which exhibited a power law. Upon analyzing through optical, petri-plate and electron microscopy imaging, we observed that, the asymmetric structure of the nanorods gave rise to augmented antibacterial response against the chosen bacteria (Staphylococcus aureus). The x-ray photoelectron spectra (XPS) data have exhibited significant peak shifts upon interaction with bacterial cells owing to a change of Bi oxidation state from one to another. Thus potential redox reaction, which might take place at the material-bio interface, is ascertained for bacterial death. Apart from physical insights, understanding the interaction between the bacteria and the nanorods of BFO could pave the way in exploring the antibacterial potentiality of such anisotropic nanoscale systems. - Highlights: • AAO supported BiFeO3 (BFO) nanorods have been investigated. • The polarization of BFO nanorods was observed to be remarkably high (∼0.04 μC/cm 2 ). • Strong antibacterial activity of nanorods was witnessed against Staphylococcus aureus. • The deskinned area on cytoskeletal parts as revealed through TEM imaging, suggest strong cidal activity of the nanorods. • XPS data justifies shifting of the peak due to biophysical interaction at the interface releasing reactive oxygen species.

  6. Composition of the non-polar extracts and antimicrobial activity of Chorisia insignis HBK. leaves

    Directory of Open Access Journals (Sweden)

    Salma Ahmed Mahmoud El Sawi

    2014-12-01

    Full Text Available Objective: To investigate the chemical constituents of the petroleum ether extract and the ether fraction of the 70% ethanol extract of Chorisia insignis HBK. leaves, as well as screen its antimicrobial activity. Methods: Different chromatographic methods were applied to investigate the non-polar extracts and the diffusion assay method was applied to study the antimicrobial activity. Results: A total of 50 compounds from the unsaponifiable matter and 20 fatty acid methyl esters were identified from the petroleum ether extract by GC/MS analysis. n-Hentriacontane, n-tritriacontane, stigmastanol, 3-methoxy-5, 6-dihydrostigmasterol, 7,8-dihydroergosterol, 4-methylcholesterol, cholestanol, multiflorenol, cholest-5-en-3-one, cholest-6-one, 5,6- dihydroergosterol, stigmasterol, dihydroalbigenin and 11-methyl-Δ5,7,9,15,17,23-triacont-hex-ene were isolated from the petroleum ether extract. Methyl heptacosanoate and quinic acid ester of rhamnose were isolated from the ether fraction of the 70% ethanol extract. Antimicrobial activity of the total alcohol extract and the successive fractions showed that the ether and the ethyl acetate fractions have potent antibacterial activity against Bacillus subtilis and Bacillus cereus. Conclusions: The ether and the ethyl acetate fractions could be used in pharmaceutical formulations as antibacterial agents against Bacillus subtilis and Bacillus cereus, and further clinical trials should be performed in order to support the above investigations.

  7. Activation of Wnt Planar Cell Polarity (PCP) signaling promotes growth plate column formation in vitro.

    Science.gov (United States)

    Randall, Rachel M; Shao, Yvonne Y; Wang, Lai; Ballock, R Tracy

    2012-12-01

    Disrupting the Wnt Planar Cell Polarity (PCP) signaling pathway in vivo results in loss of columnar growth plate architecture, but it is unknown whether activation of this pathway in vitro is sufficient to promote column formation. We hypothesized that activation of the Wnt PCP pathway in growth plate chondrocyte cell pellets would promote columnar organization in these cells that are normally oriented randomly in culture. Rat growth plate chondrocytes were transfected with plasmids encoding the Fzd7 cell-surface Wnt receptor, a Fzd7 deletion mutant lacking the Wnt-binding domain, or Wnt receptor-associated proteins Ror2 or Vangl2, and then cultured as three-dimensional cell pellets in the presence of recombinant Wnt5a or Wnt5b for 21 days. Cellular morphology was evaluated using histomorphometric measurements. Activation of Wnt PCP signaling components promoted the initiation of columnar morphogenesis in the chondrocyte pellet culture model, as measured by histomorphometric analysis of the column index (ANOVA p = 0.01). Activation of noncanonical Wnt signaling through overexpression of both the cell-surface Wnt receptor Fzd7 and receptor-associated protein Ror2 with addition of recombinant Wnt5a promotes the initiation of columnar architecture of growth plate chondrocytes in vitro, representing an important step toward growth plate regeneration. Copyright © 2012 Orthopaedic Research Society.

  8. Review of the strategic wind energy activities in South Africa

    CSIR Research Space (South Africa)

    Szewczuk, S

    2012-08-01

    Full Text Available Via its Integrated Resource Plan (IRP) for Electricity, the South African Government has set targets to generate electricity from a range of technologies including wind energy technology. This paper provides a strategic review of wind energy...

  9. Integrating multiscale polar active contours and region growing for microcalcifications segmentation in mammography

    International Nuclear Information System (INIS)

    Arikidis, N S; Karahaliou, A; Skiadopoulos, S; Panagiotakis, G; Costaridou, L; Likaki, E

    2009-01-01

    Morphology of individual microcalcifications is an important clinical factor in microcalcification clusters diagnosis. Accurate segmentation remains a difficult task due to microcalcifications small size, low contrast, fuzzy nature and low distinguishability from surrounding tissue. A novel application of active rays (polar transformed active contours) on B-spline wavelet representation is employed, to provide initial estimates of microcalcification boundary. Then, a region growing method is used with pixel aggregation constrained by the microcalcification boundary estimates, to obtain the final microcalcification boundary. The method was tested on dataset of 49 microcalcification clusters (30 benign, 19 malignant), originating from the DDSM database. An observer study was conducted to evaluate segmentation accuracy of the proposed method, on a 5-point rating scale (from 5:excellent to 1:very poor). The average accuracy rating was 3.98±0.81 when multiscale active rays were combined to region growing and 2.93±0.92 when combined to linear polynomial fitting, while the difference in rating of segmentation accuracy was statistically significant (p < 0.05).

  10. Current activities and plans for polarized neutron instruments of the JSNS/J-PARC project

    International Nuclear Information System (INIS)

    Furusaka, M.

    2005-01-01

    Neutron polarization is one of the key technologies for the next generation megawatt-class pulsed spallation neutron sources, such as SNS in the US and the JSNS in Japan. To polarize or analyze neutron spin, several techniques are under development in Japan: a small d-spacing magnetic multilayer mirror, spin exchange type He-3 filter and a dynamical proton polarizer. Several application techniques related to polarized neutrons are also under development, such as, a microwave-induced optical nuclear polarization technique, which allows us to polarize protons in naphtalene doped with pentacene at 77 K; neutron focusing-SANS instrument utilizing a focusing magnet; a Drabkin spin-filter instrument that has two filters in series for neutron-pulse shaping

  11. The response of ionospheric convection in the polar cap to substorm activity

    Directory of Open Access Journals (Sweden)

    M. Lester

    Full Text Available We report multi-instrument observations during an isolated substorm on 17 October 1989. The EISCAT radar operated in the SP-UK-POLI mode measuring ionospheric convection at latitudes 71°λ-78°λ. SAMNET and the EISCAT Magnetometer Cross provide information on the timing of substorm expansion phase onset and subsequent intensifications, as well as the location of the field aligned and ionospheric currents associated with the substorm current wedge. IMP-8 magnetic field data are also included. Evidence of a substorm growth phase is provided by the equatorward motion of a flow reversal boundary across the EISCAT radar field of view at 2130 MLT, following a southward turning of the interplanetary magnetic field (IMF. We infer that the polar cap expanded as a result of the addition of open magnetic flux to the tail lobes during this interval. The flow reversal boundary, which is a lower limit to the polar cap boundary, reached an invariant latitude equatorward of 71°λ by the time of the expansion phase onset. A westward electrojet, centred at 65.4°λ, occurred at the onset of the expansion phase. This electrojet subsequently moved poleward to a maximum of 68.1°λ at 2000 UT and also widened. During the expansion phase, there is evidence of bursts of plasma flow which are spatially localised at longitudes within the substorm current wedge and which occurred well poleward of the westward electrojet. We conclude that the substorm onset region in the ionosphere, defined by the westward electrojet, mapped to a part of the tail radially earthward of the boundary between open and closed magnetic flux, the "distant" neutral line. Thus the substorm was not initiated at the distant neutral line, although there is evidence that it remained active during the expansion phase. It is not obvious whether the electrojet mapped to a near-Earth neutral line, but at its most poleward, the expanded electrojet does not reach the estimated latitude of the polar cap

  12. Polar Polygons

    Science.gov (United States)

    2005-01-01

    18 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark-outlined polygons on a frost-covered surface in the south polar region of Mars. In summer, this surface would not be bright and the polygons would not have dark outlines--these are a product of the presence of seasonal frost. Location near: 77.2oS, 204.8oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  13. Cathodoluminescence study of Mg activation in non-polar and semi-polar faces of undoped/Mg-doped GaN core-shell nanorods

    Science.gov (United States)

    Hortelano, V.; Martínez, O.; Cuscó, R.; Artús, L.; Jiménez, J.

    2016-03-01

    Spectrally and spatially resolved cathodoluminescence (CL) measurements were carried out at 80 K on undoped/Mg-doped GaN core-shell nanorods grown by selective area growth metalorganic vapor phase epitaxy in order to investigate locally the optical activity of the Mg dopants. A study of the luminescence emission distribution over the different regions of the nanorods is presented. We have investigated the CL fingerprints of the Mg incorporation into the non-polar lateral prismatic facets and the semi-polar facets of the pyramidal tips. The amount of Mg incorporation/activation was varied by using several Mg/Ga flow ratios and post-growth annealing treatment. For lower Mg/Ga flow ratios, the annealed nanorods clearly display a donor-acceptor pair band emission peaking at 3.26-3.27 eV and up to 4 LO phonon replicas, which can be considered as a reliable indicator of effective p-type Mg doping in the nanorod shell. For higher Mg/Ga flow ratios, a substantial enhancement of the yellow luminescence emission as well as several emission subbands are observed, which suggests an increase of disorder and the presence of defects as a consequence of the excess Mg doping.

  14. Rearrangement of a polar core provides a conserved mechanism for constitutive activation of class B G protein-coupled receptors

    Science.gov (United States)

    Yin, Yanting; de Waal, Parker W.; He, Yuanzheng; Zhao, Li-Hua; Yang, Dehua; Cai, Xiaoqing; Jiang, Yi; Melcher, Karsten; Wang, Ming-Wei; Xu, H. Eric

    2017-01-01

    The glucagon receptor (GCGR) belongs to the secretin-like (class B) family of G protein-coupled receptors (GPCRs) and is activated by the peptide hormone glucagon. The structures of an activated class B GPCR have remained unsolved, preventing a mechanistic understanding of how these receptors are activated. Using a combination of structural modeling and mutagenesis studies, we present here two modes of ligand-independent activation of GCGR. First, we identified a GCGR-specific hydrophobic lock comprising Met-338 and Phe-345 within the IC3 loop and transmembrane helix 6 (TM6) and found that this lock stabilizes the TM6 helix in the inactive conformation. Disruption of this hydrophobic lock led to constitutive G protein and arrestin signaling. Second, we discovered a polar core comprising conserved residues in TM2, TM3, TM6, and TM7, and mutations that disrupt this polar core led to constitutive GCGR activity. On the basis of these results, we propose a mechanistic model of GCGR activation in which TM6 is held in an inactive conformation by the conserved polar core and the hydrophobic lock. Mutations that disrupt these inhibitory elements allow TM6 to swing outward to adopt an active TM6 conformation similar to that of the canonical β2-adrenergic receptor complexed with G protein and to that of rhodopsin complexed with arrestin. Importantly, mutations in the corresponding polar core of several other members of class B GPCRs, including PTH1R, PAC1R, VIP1R, and CRFR1, also induce constitutive G protein signaling, suggesting that the rearrangement of the polar core is a conserved mechanism for class B GPCR activation. PMID:28356352

  15. Rearrangement of a polar core provides a conserved mechanism for constitutive activation of class B G protein-coupled receptors.

    Science.gov (United States)

    Yin, Yanting; de Waal, Parker W; He, Yuanzheng; Zhao, Li-Hua; Yang, Dehua; Cai, Xiaoqing; Jiang, Yi; Melcher, Karsten; Wang, Ming-Wei; Xu, H Eric

    2017-06-16

    The glucagon receptor (GCGR) belongs to the secretin-like (class B) family of G protein-coupled receptors (GPCRs) and is activated by the peptide hormone glucagon. The structures of an activated class B GPCR have remained unsolved, preventing a mechanistic understanding of how these receptors are activated. Using a combination of structural modeling and mutagenesis studies, we present here two modes of ligand-independent activation of GCGR. First, we identified a GCGR-specific hydrophobic lock comprising Met-338 and Phe-345 within the IC3 loop and transmembrane helix 6 (TM6) and found that this lock stabilizes the TM6 helix in the inactive conformation. Disruption of this hydrophobic lock led to constitutive G protein and arrestin signaling. Second, we discovered a polar core comprising conserved residues in TM2, TM3, TM6, and TM7, and mutations that disrupt this polar core led to constitutive GCGR activity. On the basis of these results, we propose a mechanistic model of GCGR activation in which TM6 is held in an inactive conformation by the conserved polar core and the hydrophobic lock. Mutations that disrupt these inhibitory elements allow TM6 to swing outward to adopt an active TM6 conformation similar to that of the canonical β 2 -adrenergic receptor complexed with G protein and to that of rhodopsin complexed with arrestin. Importantly, mutations in the corresponding polar core of several other members of class B GPCRs, including PTH1R, PAC1R, VIP1R, and CRFR1, also induce constitutive G protein signaling, suggesting that the rearrangement of the polar core is a conserved mechanism for class B GPCR activation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Correlation of Ice-Rafted Detritus in South Atlantic Sediments with Climate Proxies in Polar Ice over the Last Glacial Period

    Directory of Open Access Journals (Sweden)

    Sharon L. Kanfoush

    2013-03-01

    Full Text Available Previous study identified 6–7 millennial-scale episodes of South Atlantic ice-rafted sediment deposition (SA events during the glaciation. Questions remain, however, regarding their origin, significance for sea-ice and/or Antarctic ice-sheet dynamics, and relationship to climate. Here I correlate sediment core (TTN057–21 SA events to Greenland and Antarctic ice using two independent methods, stable isotopes and geomagnetic paleointensity, placing SA events in the context of polar climate change in both hemispheres. Marine isotopic stage (MIS 3 SA events generally coincided with Greenland interstadials and with cooling following Antarctic warm events (A1-A4. This anti-phase behavior is best illustrated when SA0 coincided with both the Antarctic Cold Reversal and Bolling-Allerod warming in Greenland. Moreover, SA events coincide with sea-level rises during the deglaciation (mwp1A and MIS 3 (30.4, 38.3, 43.7, 51.5 ka, implying unpinning of grounded Weddell Sea region ice masses discharged debris-laden bergs that had a chilling effect on South Atlantic surface temperatures.

  17. Molecular mechanism of carbon nanotube to activate Subtilisin Carlsberg in polar and non-polar organic media

    Science.gov (United States)

    Zhang, Liyun; Li, Yuzhi; Yuan, Yuan; Jiang, Yuanyuan; Guo, Yanzhi; Li, Menglong; Pu, Xuemei

    2016-11-01

    In the work, we mainly used molecular dynamics (MD) simulation and protein structure network (PSN) to study subtilisin Carlsberg (SC) immobilized onto carbon nanotube (CNT) in water, acetonitrile and heptane solvents, in order to explore activation mechanism of enzymes in non-aqueous media. The result indicates that the affinity of SC with CNT follows the decreasing order of water > acetonitrile > heptane. The overall structure of SC and the catalytic triad display strong robustness to the change of environments, responsible for the activity retaining. However, the distances between two β-strands of substrate-binding pocket are significantly expanded by the immobilization in the increasing order of water communication paths to the substrate-binding pocket, leading to its larger change than the free-enzymes. Interestingly, the increase in the number of the pathways upon immobilization is not dependent on the absorbed extent but the desorbed one, indicating significant role of shifting process of experimental operations in influencing the functional region. In addition, some conserved and important hot-residues in the paths are identified, providing molecular information for functional modification.

  18. Axi-symmetric patterns of active polar filaments on spherical and composite surfaces

    Science.gov (United States)

    Srivastava, Pragya; Rao, Madan

    2014-03-01

    Experiments performed on Fission Yeast cells of cylindrical and spherical shapes, rod-shaped bacteria and reconstituted cylindrical liposomes suggest the influence of cell geometry on patterning of cortical actin. A theoretical model based on active hydrodynamic description of cortical actin that includes curvature-orientation coupling predicts spontaneous formation of acto-myosin rings, cables and nodes on cylindrical and spherical geometries [P. Srivastava et al, PRL 110, 168104(2013)]. Stability and dynamics of these patterns is also affected by the cellular shape and has been observed in experiments performed on Fission Yeast cells of spherical shape. Motivated by this, we study the stability and dynamics of axi-symmetric patterns of active polar filaments on the surfaces of spherical, saddle shaped and conical geometry and classify the stable steady state patterns on these surfaces. Based on the analysis of the fluorescence images of Myosin-II during ring slippage we propose a simple mechanical model for ring-sliding based on force balance and make quantitative comparison with the experiments performed on Fission Yeast cells. NSF Grant DMR-1004789 and Syracuse Soft Matter Program.

  19. Seasonal Evolution of the North and South Polar Vortex on Titan From 2004 to 2017 as Seen by Cassini/VIMS

    Science.gov (United States)

    Le Mouelic, S.; Robidel, R.; Rousseau, B.; Rodriguez, S.; Cornet, T.; Sotin, C.; Barnes, J. W.; Brown, R. H.; Buratti, B. J.; Baines, K. H.; Clark, R. N.; Nicholson, P. D.

    2017-12-01

    Cassini entered in Saturn's orbit in July 2004. In thirteen years, 127 targeted flybys of Titan have been performed. We focus our study on the analysis of the complete Visual and Infrared Mapping Spectrometer data set, with a particular emphasis on the evolving features on both poles. We have computed individual global maps of the north and south poles for each of the 127 targeted flybys, using VIMS wavelengths sensitive both to clouds and surface features. First evidences for a vast ethane cloud covering the North Pole is seen as soon as the first and second targeted flyby in October 2004 and December 2005 [1]. The first detailed imaging of this north polar feature with VIMS was obtained in December 2006, thanks to a change in inclination of the spacecraft orbit [2]. At this time, the northern lakes and seas of Titan were totally masked to the optical instruments by the haze and clouds, whereas the southern pole was well illuminated and mostly clear of haze and vast clouds. The vast north polar feature progressively vanished around the equinox in 2009 [2,3,4], in agreement with the predictions of Global Circulation Models [5]. It revealed progressively the underlying lakes to the ISS and VIMS instruments, which show up very nicely in VIMS in a series of flybys between T90 and T100. First evidences of an atmospheric vortex growing over the south pole occurred in May 2012 (T82), with a high altitude feature being detected consistently at each flyby up to the last T126 targeted flyby, and also appearing in more distant observations up to the end of the Cassini mission. Cassini has covered almost half a titanian year, corresponding to two seasons. The situation observed at the South Pole in the last images may correspond to what was observed in the north as Cassini just arrived. [1] Griffith et al., Science, 2006. [2] Le Mouélic et al., PSS, 2012. [3] Rodriguez et al., Nature, 2009. [4] Rodriguez et al., Icarus 2011. [4] Hirtzig et al., Icarus, 2013. [5] Rannou et al

  20. A Classroom Activity for Teaching Electric Polarization of Insulators and Conductors

    Science.gov (United States)

    Deligkaris, Christos

    2018-01-01

    The phenomenon of electric polarization is crucial to student understanding of forces exerted between charged objects and insulators or conductors, the process of charging by induction, and the behavior of electroscopes near charged objects. In addition, polarization allows for microscopic-level models of everyday-life macroscopic-level phenomena.…

  1. Spatial variation in soil active-layer geochemistry across hydrologic margins in polar desert ecosystems

    Directory of Open Access Journals (Sweden)

    J. E. Barrett

    2009-12-01

    Full Text Available Polar deserts are characterized by severe spatial-temporal limitations of liquid water. In soil active layers of the Antarctic Dry Valleys, liquid water is infrequently available over most of the arid terrestrial landscape. However, soils on the margins of glacial melt-water streams and lakes are visibly wet during the brief Austral summer when temperatures permit the existence of liquid water. We examined the role of these hydrologic margins as preferential zones for the transformation and transport of nutrient elements and solutes in an environment where geochemical weathering and biological activity is strictly limited by the dearth of liquid water. We report on hydropedological investigations of aquatic-terrestrial transition zones adjacent to 11 stream and lake systems in the Antarctic Dry Valleys. Our results show that wetted zones extended 1–11 m from the edges of lotic and lentic systems. While capillary demand and surface evaporation drive a one-way flux of water through these zones, the scale of these transition zones is determined by the topography and physical characteristics of the surrounding soils. Nutrient concentrations and fluxes appear to be influenced by both the hydrology and microbial-mediated biogeochemical processes. Salt concentrations are enriched near the distal boundary of the wetted fronts due to evapo-concentration of pore water in lake margin soils, while organic matter, ammonium and phosphate concentrations are highest in stream channel sediments where potential for biological activity is greatest. Thus, in the Antarctic Dry Valleys, intermittently wet soils on the margins of streams and lakes are important zones of both geochemical cycling and biological activity.

  2. Polar stratospheric cloud evolution and chlorine activation measured by CALIPSO and MLS, and modeled by ATLAS

    Directory of Open Access Journals (Sweden)

    H. Nakajima

    2016-03-01

    Full Text Available We examined observations of polar stratospheric clouds (PSCs by CALIPSO, and of HCl and ClO by MLS along air mass trajectories, to investigate the dependence of the inferred PSC composition on the temperature history of the air parcels and the dependence of the level of chlorine activation on PSC composition. Several case studies based on individual trajectories from the Arctic winter 2009/2010 were conducted, with the trajectories chosen such that the first processing of the air mass by PSCs in this winter occurred on the trajectory. Transitions of PSC composition classes were observed to be highly dependent on the temperature history. In cases of a gradual temperature decrease, nitric acid trihydrate (NAT and super-cooled ternary solution (STS mixture clouds were observed. In cases of rapid temperature decrease, STS clouds were first observed, followed by NAT/STS mixture clouds. When temperatures dropped below the frost point, ice clouds formed and then transformed into NAT/STS mixture clouds when temperature increased above the frost point. The threshold temperature for rapid chlorine activation on PSCs is approximately 4 K below the NAT existence temperature, TNAT. Furthermore, simulations of the ATLAS chemistry and transport box model along the trajectories were used to corroborate the measurements and show good agreement with the observations. Rapid chlorine activation was observed when an air mass encountered PSCs. Usually, chlorine activation was limited by the amount of available ClONO2. Where ClONO2 was not the limiting factor, a large dependence on temperature was evident.

  3. In vitro biomonitoring in polar extracts of solid phase matrices reveals the presence of unknown compounds with estrogenic activity

    NARCIS (Netherlands)

    Legler, J.; Leonards, P.E.G.; Spenkelink, A.; Murk, A.J.

    2003-01-01

    Determination of estrogenic activity has so far mainly concentrated on the assessment of compounds in surface water and effluent. This study is one of the first to biomonitor (xeno-)estrogens in sediment, suspended particulate matter and aquatic organisms. The relatively polar acetone extracts from

  4. A note on the perverse effects of actively open-minded thinking on climate-change polarization

    Directory of Open Access Journals (Sweden)

    Dan M. Kahan

    2016-11-01

    Full Text Available This research note presents evidence that political polarization over the reality of human-caused climate change increases in tandem with individuals’ scores on a standard measure of actively open-minded thinking. This finding is at odds with the position that attributes political conflict over facts to a personality trait of closed-mindedness associated with political conservatism.

  5. Comparative Activity and Functional Ecology of Permafrost Soils and Lithic Niches in a Hyper-Arid Polar Desert

    Science.gov (United States)

    Goordial, J.; Davila, A.; Greer, C. W.; Cannam, R.; DiRuggiero, J.; McKay, C. P.; Whyte, L. G.

    2016-01-01

    This study represents the first metagenomic interrogation of Antarctic permafrost and polar cryptoendolithic microbial communities. The results underlie two different habitability conditions in the same location under extreme cold and dryness: the permafrost habitat where viable microbial life and activity is questionable, and the cryptoendolithic habitat which contains organisms capable of growth under the extreme conditions of the Antarctic Dry Valleys.

  6. Seasonal, interannual, and long-term variabilities in biomass burning activity over South Asia.

    Science.gov (United States)

    Bhardwaj, P; Naja, M; Kumar, R; Chandola, H C

    2016-03-01

    The seasonal, interannual, and long-term variations in biomass burning activity and related emissions are not well studied over South Asia. In this regard, active fire location retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), the retrievals of aerosol optical depth (AOD) from MODIS Terra, and tropospheric column NO2 from Ozone Monitoring Instrument (OMI) are used to understand the effects of biomass burning on the tropospheric pollution loadings over South Asia during 2003-2013. Biomass burning emission estimates from Global Fire Emission Database (GFED) and Global Fire Assimilation System (GFAS) are also used to quantify uncertainties and regional discrepancies in the emissions of carbon monoxide (CO), nitrogen oxide (NOx), and black carbon (BC) due to biomass burning in South Asia. In the Asian continent, the frequency of fire activity is highest over Southeast Asia, followed by South Asia and East Asia. The biomass burning activity in South Asia shows a distinct seasonal cycle that peaks during February-May with some differences among four (north, central, northeast, and south) regions in India. The annual biomass burning activity in north, central, and south regions shows an increasing tendency, particularly after 2008, while a decrease is seen in northeast region during 2003-2013. The increase in fire counts over the north and central regions contributes 24 % of the net enhancement in fire counts over South Asia. MODIS AOD and OMI tropospheric column NO2 retrievals are classified into high and low fire activity periods and show that biomass burning leads to significant enhancement in tropospheric pollution loading over both the cropland and forest regions. The enhancement is much higher (110-176 %) over the forest region compared to the cropland (34-62 %) region. Further efforts are required to understand the implications of biomass burning on the regional air quality and climate of South Asia.

  7. Antifungal activity from polar and non-polar extracts of some Chenopodiaceae wild species growing in Tunisia.

    Science.gov (United States)

    Boughalleb, N; Trabelsi, L; Harzallah-Skhiri, F

    2009-01-01

    Nine plants belonging to Chenopodiaceae family were collected around salt marshes near Monastir, located in the east Mediterranean coast of Tunisia. They were tested for their antifungal activities against six plant pathogenic fungi: Botrytis cinerea, Fusarium oxysporum f. sp. niveum, F. solani f. sp. cucurbitae, Phytophthora cactorum, Rhizoctonia solani and Nattrassia mangiferae. Data of this study showed that the highest inhibition of Botrytis cinerea growth was observed with the petroleum ether extract of Atriplex inflata fruits (F) (24.5 mm). The in vitro growth of F. oxysporum f. sp. niveum was reduced only with A. inflata whole plant (WP) petroleum ether extract (32.3 mm). The most important inhibition zones were obtained against F. solani f. sp. cucurbitae with Atriplex semibaccata methanol and acetone extracts (34.7 and 31.0 mm, respectively). This work revealed that fungitoxic compounds were probably present in the petroleum ether extract obtained from A. portulacoides (WP), since it has suppressed the growth of F. s. cucurbitae. Our investigation proved that many Chenopodiaceae species adapted to saline soils may contain phytochemical compounds with fungicidal properties.

  8. Activity of the 7Be isotope in plants from south-west Finland

    International Nuclear Information System (INIS)

    Loennroth, T.; Kaellman, K.M.; Agren, D.; Lill, J.O.

    2007-01-01

    We report the measurements of 7 Be activity in nine vegetable species through the detection of its 477.6 keV γ-ray of 7 Li. The plants were grown 10 km south of the city of Turku in south-west Finland, located at approximately about 23E, 62N. The results show that nettle, salad and cucumber have activities that exceed the detection limit. (author)

  9. Possible Mafic Patches in Scott Crater Highlight the Need for Resource Exploration on the Lunar South Polar Region

    Science.gov (United States)

    Cooper, Bonnie L.

    2007-01-01

    Possible areas of mafic material on the rim and floor of Scott crater (82.1 deg S, 48.5 deg E) are suggested by analysis of shadow-masked Clementine false-color-ratio images. Mafic materials common in mare and pyroclastic materials can produce more oxygen than can highlands materials, and mafic materials close to the south pole may be important for propellant production for a future lunar mission. If the dark patches are confirmed as mafic materials, this finding would suggest that other mafic patches may exist, even closer to the poles, which were originally mapped as purely anorthositic.

  10. Dual protection in sexually active women | Kleinschmidt | South ...

    African Journals Online (AJOL)

    Objective. To determine the prevalence and co-factors associated with the practice of dual protection against sexually transmitted infections (STis) and unwanted pregnancy in a cross-sectional sample of South African women. Design. Secondary analysis of cross-sectional household survey data. Methods. Statistical ...

  11. Review of the wind energy activities in South Africa

    CSIR Research Space (South Africa)

    Szewczuk, S

    2014-03-01

    Full Text Available as well as to indicate the collaboration and partnerships between the various stakeholders form country-level to project-level. The South African government has established the necessary and robust framework for the establishment of a wind energy industry...

  12. Invited Article: An active terahertz polarization converter employing vanadium dioxide and a metal wire grating in total internal reflection geometry

    Science.gov (United States)

    Liu, Xudong; Chen, Xuequan; Parrott, Edward P. J.; Han, Chunrui; Humbert, Georges; Crunteanu, Aurelian; Pickwell-MacPherson, Emma

    2018-05-01

    Active broadband terahertz (THz) polarization manipulation devices are challenging to realize, but also of great demand in broadband terahertz systems. Vanadium dioxide (VO2) shows a promising phase transition for active control of THz waves and provides broadband polarization characteristics when integrated within grating-type structures. We creatively combine a VO2-based grating structure with a total internal reflection (TIR) geometry providing a novel interaction mechanism between the electromagnetic waves and the device, to realize a powerful active broadband THz polarization-controlling device. The device is based on a Si-substrate coated with a VO2 layer and a metal grating structure on top, attached to a prism for generating the TIR condition on the Si-VO2-grating interface. The grating is connected to electrodes for electrically switching the VO2 between its insulating and conducting phases. By properly selecting the incident angle of the THz waves, the grating direction, and the incident polarization state, we first achieved a broadband intensity modulator under a fused silica prism with an average modulation depth of 99.75% in the 0.2-1.1 THz region. Additionally, we realized an active ultra-broadband quarter-wave converter under a Si prism that can be switched between a 45° linear rotator and a quarter wave converter in the 0.8-1.5 THz region. This is the first demonstration of an active quarter-wave converter with ultra-broad bandwidth performance. Our work shows a highly flexible and multifunctional polarization-controlling device for broadband THz applications.

  13. The Effects of GABAergic Polarity Changes on Episodic Neural Network Activity in Developing Neural Systems

    Directory of Open Access Journals (Sweden)

    Wilfredo Blanco

    2017-09-01

    Full Text Available Early in development, neural systems have primarily excitatory coupling, where even GABAergic synapses are excitatory. Many of these systems exhibit spontaneous episodes of activity that have been characterized through both experimental and computational studies. As development progress the neural system goes through many changes, including synaptic remodeling, intrinsic plasticity in the ion channel expression, and a transformation of GABAergic synapses from excitatory to inhibitory. What effect each of these, and other, changes have on the network behavior is hard to know from experimental studies since they all happen in parallel. One advantage of a computational approach is that one has the ability to study developmental changes in isolation. Here, we examine the effects of GABAergic synapse polarity change on the spontaneous activity of both a mean field and a neural network model that has both glutamatergic and GABAergic coupling, representative of a developing neural network. We find some intuitive behavioral changes as the GABAergic neurons go from excitatory to inhibitory, shared by both models, such as a decrease in the duration of episodes. We also find some paradoxical changes in the activity that are only present in the neural network model. In particular, we find that during early development the inter-episode durations become longer on average, while later in development they become shorter. In addressing this unexpected finding, we uncover a priming effect that is particularly important for a small subset of neurons, called the “intermediate neurons.” We characterize these neurons and demonstrate why they are crucial to episode initiation, and why the paradoxical behavioral change result from priming of these neurons. The study illustrates how even arguably the simplest of developmental changes that occurs in neural systems can present non-intuitive behaviors. It also makes predictions about neural network behavioral changes

  14. Polarized Light Corridor Demonstrations.

    Science.gov (United States)

    Davies, G. R.

    1990-01-01

    Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

  15. Establishing a definition of polar bear (Ursus maritimus) health: A guide to research and management activities

    Science.gov (United States)

    Patyk, Kelly A.; Duncan, Colleen G.; Nol, Pauline; Sonne, C.; Laidre, Kristin L.; Obbard, Martyn E.; Wiig, Øystein; Aars, Jon; Regehr, Eric V.; Gustafson, L.; Atwood, Todd C.

    2015-01-01

    The meaning of health for wildlife and perspectives on how to assess and measure health, are not well characterized. For wildlife at risk, such as some polar bear (Ursus maritimus) subpopulations, establishing comprehensive monitoring programs that include health status is an emerging need. Environmental changes, especially loss of sea ice habitat, have raised concern about polar bear health. Effective and consistent monitoring of polar bear health requires an unambiguous definition of health. We used the Delphi method of soliciting and interpreting expert knowledge to propose a working definition of polar bear health and to identify current concerns regarding health, challenges in measuring health, and important metrics for monitoring health. The expert opinion elicited through the exercise agreed that polar bear health is defined by characteristics and knowledge at the individual, population, and ecosystem level. The most important threats identified were in decreasing order: climate change, increased nutritional stress, chronic physiological stress, harvest management, increased exposure to contaminants, increased frequency of human interaction, diseases and parasites, and increased exposure to competitors. Fifteen metrics were identified to monitor polar bear health. Of these, indicators of body condition, disease and parasite exposure, contaminant exposure, and reproductive success were ranked as most important. We suggest that a cumulative effects approach to research and monitoring will improve the ability to assess the biological, ecological, and social determinants of polar bear health and provide measurable objectives for conservation goals and priorities and to evaluate progress.

  16. Induced polarization and self-potential geophysical signature of bacterial activity in porous media (Invited)

    Science.gov (United States)

    Revil, A.

    2013-12-01

    The first part of the presentation will be dedicated to the spectral induced polarization signature of bacteria in porous media. We developed a quantitative model to investigate frequency-domain induced polarization response of suspensions of bacteria and bacteria growth in porous media. Induced polarization of bacteria (alpha-polarization) is related to the properties of the electrical double layer of the bacteria. Surface conductivity and alpha-polarization are due to the Stern layer of counterions occurring in a brush of polymers coating the surface of the bacteria. These phenomena can be related to the cation exchange capacity of the bacteria. The mobility of the counterions in this Stern layer is found to be very small (4.7×10-10 m2s-1 V-1 at 25°C). This implies a very low relaxation frequency for the alpha-polarization of the bacteria cells (typically around 0.1 to 5 Hertz) in agreement with experimental observations. This new model can be coupled to reactive transport modeling codes in which the evolution of bacterial populations are usually described by Monod kinetics. We show that the growth rate and endogenous decay coefficients of bacteria in a porous sand can be inferred non-intrusively from time lapse frequency-domain induced polarization data. The second part of the presentation will concern the biogeobattery mechanism showing new data, the concept of transient biogeobattery and the influence of the concentration of the electron acceptors in the process.

  17. Establishing a definition of polar bear (Ursus maritimus) health: a guide to research and management activities.

    Science.gov (United States)

    Patyk, Kelly A; Duncan, Colleen; Nol, Pauline; Sonne, Christian; Laidre, Kristin; Obbard, Martyn; Wiig, Øystein; Aars, Jon; Regehr, Eric; Gustafson, Lori L; Atwood, Todd

    2015-05-01

    The meaning of health for wildlife and perspectives on how to assess and measure health, are not well characterized. For wildlife at risk, such as some polar bear (Ursus maritimus) subpopulations, establishing comprehensive monitoring programs that include health status is an emerging need. Environmental changes, especially loss of sea ice habitat, have raised concern about polar bear health. Effective and consistent monitoring of polar bear health requires an unambiguous definition of health. We used the Delphi method of soliciting and interpreting expert knowledge to propose a working definition of polar bear health and to identify current concerns regarding health, challenges in measuring health, and important metrics for monitoring health. The expert opinion elicited through the exercise agreed that polar bear health is defined by characteristics and knowledge at the individual, population, and ecosystem level. The most important threats identified were in decreasing order: climate change, increased nutritional stress, chronic physiological stress, harvest management, increased exposure to contaminants, increased frequency of human interaction, diseases and parasites, and increased exposure to competitors. Fifteen metrics were identified to monitor polar bear health. Of these, indicators of body condition, disease and parasite exposure, contaminant exposure, and reproductive success were ranked as most important. We suggest that a cumulative effects approach to research and monitoring will improve the ability to assess the biological, ecological, and social determinants of polar bear health and provide measurable objectives for conservation goals and priorities and to evaluate progress. Published by Elsevier B.V.

  18. PHENOLIC DERIVATIVES AND ANTIOXIDANT ACTIVITY OF POLAR EXTRACTS FROM Bauhinia pulchella

    Directory of Open Access Journals (Sweden)

    Adonias Almeida Carvalho

    Full Text Available A tea made with the leaves or stem bark of Bauhinia pulchella Benth (Fabaceae is used in the treatment of diabetes. Ethanol (EEF and aqueous (EAF extracts were obtained from the leaves and the antioxidant and citotoxic activities were tested, as well as quantify the content of flavonoids and phenolic compounds (TPC. EEF and EAF showed similar profiles by HPLC, with the presence of three compounds. Column chromatography reverse phase (C18 and Sephadex LH-20, followed by semi preparative HPLC-C18 of EAF resulted in three flavonoids. Their structures were identified by 1H and 13C NMR as myricitrin (1, quercitrin (2 and afzelin (3. In assay of determination of reactive substances to thiobarbituric acid (TBARS, with DPPH, ABTS and nitric oxide (NO• free radicals, EAF showed antioxidant potential higher than the EEF. This is the first report of the occurrence of the flavonoids 1-3, in the species B. pulchella. EEF and EAF were inactive in the cytotoxicity assays. In short, the polar extracts from the leaves of B. pulchella proved to be promising sources of biomolecules phenolic, with antioxidant potential, which may, in the future, be used as chemical markers for species and validation of therapeutic use.

  19. In vivo antileishmanial activity and chemical profile of polar extract from Selaginella sellowii

    Directory of Open Access Journals (Sweden)

    Dayane Priscilla de Souza Queiroz

    2016-01-01

    Full Text Available The polar hydroethanolic extract from Selaginella sellowii(SSPHE has been previously proven active on intracellular amastigotes (in vitro test and now was tested on hamsters infected with Leishmania (Leishmania amazonensis (in vivo test. SSPHE suppressed a 100% of the parasite load in the infection site and draining lymph nodes at an intralesional dose of 50 mg/kg/day × 5, which was similar to the results observed in hamsters treated with N-methylglucamine antimonate (Sb (28 mg/Kg/day × 5. When orally administered, SSPHE (50 mg/kg/day × 20 suppressed 99.2% of the parasite load in infected footpads, while Sb suppressed 98.5%. SSPHE also enhanced the release of nitric oxide through the intralesional route in comparison to Sb. The chemical fingerprint of SSPHE by high-performance liquid chromatography with diode-array detection and tandem mass spectrometry showed the presence of biflavonoids and high molecular weight phenylpropanoid glycosides. These compounds may have a synergistic action in vivo. Histopathological study revealed that the intralesional treatment with SSPHE induced an intense inflammatory infiltrate, composed mainly of mononuclear cells. The present findings reinforce the potential of this natural product as a source of future drug candidates for American cutaneous leishmaniasis.

  20. Lactobacilli activate human dendritic cells that skew T cells toward T helper 1 polarization.

    Science.gov (United States)

    Mohamadzadeh, Mansour; Olson, Scott; Kalina, Warren V; Ruthel, Gordon; Demmin, Gretchen L; Warfield, Kelly L; Bavari, Sina; Klaenhammer, Todd R

    2005-02-22

    Professional antigen-presenting dendritic cells (DCs) are critical in regulating T cell immune responses at both systemic and mucosal sites. Many Lactobacillus species are normal members of the human gut microflora and most are regarded as safe when administered as probiotics. Because DCs can naturally or therapeutically encounter lactobacilli, we investigated the effects of several well defined strains, representing three species of Lactobacillus on human myeloid DCs (MDCs) and found that they modulated the phenotype and functions of human MDCs. Lactobacillus-exposed MDCs up-regulated HLA-DR, CD83, CD40, CD80, and CD86 and secreted high levels of IL-12 and IL-18, but not IL-10. IL-12 was sustained in MDCs exposed to all three Lactobacillus species in the presence of LPS from Escherichia coli, whereas LPS-induced IL-10 was greatly inhibited. MDCs activated with lactobacilli clearly skewed CD4(+) and CD8(+) T cells to T helper 1 and Tc1 polarization, as evidenced by secretion of IFN-gamma, but not IL-4 or IL-13. These results emphasize a potentially important role for lactobacilli in modulating immunological functions of DCs and suggest that certain strains could be particularly advantageous as vaccine adjuvants, by promoting DCs to regulate T cell responses toward T helper 1 and Tc1 pathways.

  1. Barriers and Facilitators of Physical Activity in Children of a South Asian Ethnicity

    Directory of Open Access Journals (Sweden)

    Lee Smith

    2018-03-01

    Full Text Available Children of South Asian ethnicity residing in England have low levels of physical activity. Limited literature exists on correlates, barriers, and facilitators to activity in South Asian children. The aim of this study was to fill this gap in the literature. Interviews were conducted with 10 parents of South Asian ethnicity residing in the UK. Interviews covered a description of the family setup, participants’ opinions of physical activity including barriers and facilitators and their children’s participation, as well as approaches to general parenting, and how children spend their free time. Data were analysed using thematic analysis. Key themes identified included (i restraints on parents’ and children’s time to be physically active; (ii the role of the family in children’s physical activity participation; (iii situational barriers to physical activity; (iv physical activity not a priority; (v opportunities to be active; and (vi perception of activity level and health. A number of key barriers to South Asian children’s participation in physical activity were identified, including (i restraints on parents and children’s time; (ii parents providing limited support for physical activity; and (iii physical activity having a low priority. A number of facilitators were also identified (i play; (ii school-time; and (iii extra-curricular clubs. In this sample of South Asian parents residing in the UK several socio-cultural barriers and facilitators of their children’s physical activity have been identified. The study provides preliminary data for a larger study to ascertain if such barriers and facilitators are representative of the wider South Asian community, so that recommendations for intervention and policies can be made.

  2. Daily and seasonal activity patterns of free range South-American rattlesnake (Crotalus durissus

    Directory of Open Access Journals (Sweden)

    ALEXANDRO M. TOZETTI

    2013-09-01

    Full Text Available This study aimed at describing daily and seasonal variation in the activity of a population of South-American rattlesnakes (Crotalus durissus in a savanna like habitat (Cerrado in Southeastern Brazil. Seasonal and daily activities of snakes were evaluated by the number of captures of snakes during road surveys, accidental encounters, and relocations by radio-tracking. Our results show that climatic variables such as air temperature and rainfall have little influence on the activity pattern of rattlesnakes. Our findings indicate that rattlesnakes spend most of the day resting and most of the night in ambush posture. The South-American rattlesnake is active throughout the year with a discrete peak in activity of males during the matting season. The possibility of maintaining activity levels even during the coldest and driest season can facilitate the colonization of several habitats in South America. This possibility currently facilitates the colonization of deforested areas by rattlesnakes.

  3. Daily and seasonal activity patterns of free range South-American rattlesnake (Crotalus durissus).

    Science.gov (United States)

    Tozetti, Alexandro M; Martins, Marcio

    2013-09-01

    This study aimed at describing daily and seasonal variation in the activity of a population of South-American rattlesnakes (Crotalus durissus) in a savanna like habitat (Cerrado) in Southeastern Brazil. Seasonal and daily activities of snakes were evaluated by the number of captures of snakes during road surveys, accidental encounters, and relocations by radio-tracking. Our results show that climatic variables such as air temperature and rainfall have little influence on the activity pattern of rattlesnakes. Our findings indicate that rattlesnakes spend most of the day resting and most of the night in ambush posture. The South-American rattlesnake is active throughout the year with a discrete peak in activity of males during the matting season. The possibility of maintaining activity levels even during the coldest and driest season can facilitate the colonization of several habitats in South America. This possibility currently facilitates the colonization of deforested areas by rattlesnakes.

  4. A concentration-independent micro/nanofluidic active diode using an asymmetric ion concentration polarization layer.

    Science.gov (United States)

    Lee, Hyekyung; Kim, Junsuk; Kim, Hyeonsoo; Kim, Ho-Young; Lee, Hyomin; Kim, Sung Jae

    2017-08-24

    Over the past decade, nanofluidic diodes that rectify ionic currents (i.e. greater current in one direction than in the opposite direction) have drawn significant attention in biomolecular sensing, switching and energy harvesting devices. To obtain current rectification, conventional nanofluidic diodes have utilized complex nanoscale asymmetry such as nanochannel geometry, surface charge density, and reservoir concentration. Avoiding the use of sophisticated nano-asymmetry, micro/nanofluidic diodes using microscale asymmetry have been recently introduced; however, their diodic performance is still impeded by (i) low (even absent) rectification effects at physiological concentrations over 100 mM and strong dependency on the bulk concentration, and (ii) the fact that they possess only passive predefined rectification factors. Here, we demonstrated a new class of micro/nanofluidic diode with an ideal perm-selective nanoporous membrane based on ion concentration polarization (ICP) phenomenon. Thin side-microchannels installed near a nanojunction served as mitigators of the amplified electrokinetic flows generated by ICP and induced convective salt transfer to the nanoporous membrane, leading to actively controlled micro-scale asymmetry. Using this device, current rectifications were successfully demonstrated in a wide range of electrolytic concentrations (10 -5 M to 3 M) as a function of the fluidic resistance of the side-microchannels. Noteworthily, it was confirmed that the rectification factors were independent from the bulk concentration due to the ideal perm-selectivity. Moreover, the rectification of the presenting diode was actively controlled by adjusting the external convective flows, while that of the previous diode was passively determined by invariant nanoscale asymmetry.

  5. Web-based Tools for Educators: Outreach Activities of the Polar Radar for Ice Sheet Measurements (PRISM) Project

    Science.gov (United States)

    Braaten, D. A.; Holvoet, J. F.; Gogineni, S.

    2003-12-01

    The Radar Systems and Remote Sensing Laboratory at the University of Kansas (KU) has implemented extensive outreach activities focusing on Polar Regions as part of the Polar Radar for Ice Sheet Measurements (PRISM) project. The PRISM project is developing advanced intelligent remote sensing technology that involves radar systems, an autonomous rover, and communications systems to measure detailed ice sheet characteristics, and to determine bed conditions (frozen or wet) below active ice sheets in both Greenland and Antarctica. These measurements will provide a better understanding of the response of polar ice sheets to global climate change and the resulting impact the ice sheets will have on sea level rise. Many of the research and technological development aspects of the PRISM project, such as robotics, radar systems, climate change and exploration of harsh environments, can kindle an excitement and interest in students about science and technology. These topics form the core of our K-12 education and training outreach initiatives, which are designed to capture the imagination of young students, and prompt them to consider an educational path that will lead them to scientific or engineering careers. The K-12 PRISM outreach initiatives are being developed and implemented in a collaboration with the Advanced Learning Technology Program (ALTec) of the High Plains Regional Technology in Education Consortium (HPR*TEC). ALTec is associated with the KU School of Education, and is a well-established educational research center that develops and hosts web tools to enable teachers nationwide to network, collaborate, and share resources with other teachers. An example of an innovative and successful web interface developed by ALTec is called TrackStar. Teachers can use TrackStar over the Web to develop interactive, resource-based lessons (called tracks) on-line for their students. Once developed, tracks are added to the TrackStar database and can be accessed and modified

  6. Electrochemical Cathodic Polarization, a Simplified Method That Can Modified and Increase the Biological Activity of Titanium Surfaces: A Systematic Review.

    Directory of Open Access Journals (Sweden)

    Jose Carlos Bernedo Alcazar

    Full Text Available The cathodic polarization seems to be an electrochemical method capable of modifying and coat biomolecules on titanium surfaces, improving the surface activity and promoting better biological responses.The aim of the systematic review is to assess the scientific literature to evaluate the cellular response produced by treatment of titanium surfaces by applying the cathodic polarization technique.The literature search was performed in several databases including PubMed, Web of Science, Scopus, Science Direct, Scielo and EBSCO Host, until June 2016, with no limits used. Eligibility criteria were used and quality assessment was performed following slightly modified ARRIVE and SYRCLE guidelines for cellular studies and animal research.Thirteen studies accomplished the inclusion criteria and were considered in the review. The quality of reporting studies in animal models was low and for the in vitro studies it was high. The in vitro and in vivo results reported that the use of cathodic polarization promoted hydride surfaces, effective deposition, and adhesion of the coated biomolecules. In the experimental groups that used the electrochemical method, cellular viability, proliferation, adhesion, differentiation, or bone growth were better or comparable with the control groups.The use of the cathodic polarization method to modify titanium surfaces seems to be an interesting method that could produce active layers and consequently enhance cellular response, in vitro and in vivo animal model studies.

  7. Interannual and seasonal changes in the south seasonal polar cap of Mars: Observations from MY 28-31 using MARCI

    Science.gov (United States)

    Calvin, W. M.; Cantor, B. A.; James, P. B.

    2017-08-01

    The Mars Color Imager (MARCI) camera on the Mars Reconnaissance Orbiter provides daily synoptic coverage that allows monitoring of seasonal cap retreat and interannual changes that occur between Mars Years (MY) and over the southern summer. We present the first analysis of this data for the southern seasonal cap evolution observed in MY 28, 29, 30 and 31 (2/2007 to 07/2013). Observation over multiple Mars years allows us to compare changes between years as well as longer-term evolution of the high albedo deposits at the poles. Seasonal cap retreat is similar in all years and to retreats observed in other years by both optical and thermal instruments. The cryptic terrain has a fairly consistent boundary in each year, but numerous small-scale variations occur in each MY observed. Additionally, numerous small dark deposits are identified outside the classically identified cyptic region, including Inca City and other locations not previously noted. The large water ice outlier is observed to retain seasonal frost the longest (outside the polar dome) and is also highly variable in each MY. The development of the cryptic/anti-cryptic hemispheres is inferred to occur due to albedo variations that develop after dust venting starts and may be caused by recondensation of CO2 ice on the brightest and coldest regions controlled by topographic winds. Ground ice may play a role in which regions develop cryptic terrain, as there is no elevation control on either cryptic terrain or the late season brightest deposits.

  8. Additions and corrections to the absorption coefficients of CO2 ice: Applications to the Martian south polar cap

    International Nuclear Information System (INIS)

    Calvin, W.M.

    1990-01-01

    Reflectance spectra of carbon dioxide frosts were calculated using the optical constants provided by Warren (1986) for the wavelength region 2-6 μm. In comparing these calculated spectra to spectra of frosts observed in the laboratory and on the surface of Mars, problems in the optical constants presented by Warren (1986) became apparent. Absorption coefficients for CO 2 ice have been derived using laboratory reflectance measurements and the Hapke (1981) model for calculating diffuse reflectance. This provides approximate values in regions where no data were previously available and indicates where corrections to the compilation by Warren (1986) are required. Using these coefficients to calculate the reflectance of CO 2 ice at varying grain sizes indicates that a typical Mariner polar cap spectrum is dominated by absorptions due to CO 2 frost or ice at grain sizes that are quite large, probably of the order of millimeters to centimeters. There are indications of contamination of water frost or dust, but confirmation will require more precise absorption coefficients for solid CO 2 than can be obtained from the method used here

  9. Active Upper-atmosphere Chemistry and Dynamics from Polar Circulation Reversal on Titan

    Science.gov (United States)

    Teanby, Nicholas A.; Irwin, Patrick Gerard Joseph; Nixon, Conor A.; DeKok, Remco; Vinatier, Sandrine; Coustenis, Athena; Sefton-Nash, Elliot; Calcutt, Simon B.; Flasar, Michael F.

    2012-01-01

    Saturn's moon Titan has a nitrogen atmosphere comparable to Earth's, with a surface pressure of 1.4 bar. Numerical models reproduce the tropospheric conditions very well but have trouble explaining the observed middle-atmosphere temperatures, composition and winds. The top of the middle-atmosphere circulation has been thought to lie at an altitude of 450 to 500 kilometres, where there is a layer of haze that appears to be separated from the main haze deck. This 'detached' haze was previously explained as being due to the colocation of peak haze production and the limit of dynamical transport by the circulation's upper branch. Herewe report a build-up of trace gases over the south pole approximately two years after observing the 2009 post-equinox circulation reversal, from which we conclude that middle-atmosphere circulation must extend to an altitude of at least 600 kilometres. The primary drivers of this circulation are summer-hemisphere heating of haze by absorption of solar radiation and winter-hemisphere cooling due to infrared emission by haze and trace gases; our results therefore imply that these effects are important well into the thermosphere (altitudes higher than 500 kilometres). This requires both active upper-atmosphere chemistry, consistent with the detection of high-complexity molecules and ions at altitudes greater than 950 kilometres, and an alternative explanation for the detached haze, such as a transition in haze particle growth from monomers to fractal structures.

  10. 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.)

  11. Physical activity among South Asian women: a systematic, mixed-methods review

    OpenAIRE

    Babakus, Whitney S; Thompson, Janice L

    2012-01-01

    Abstract Introduction The objective of this systematic mixed-methods review is to assess what is currently known about the levels of physical activity (PA) and sedentary time (ST) and to contextualize these behaviors among South Asian women with an immigrant background. Methods A systematic search of the literature was conducted using combinations of the key words PA, ST, South Asian, and immigrant. A mixed-methods approach was used to analyze and synthesize all evidence, both quantitative an...

  12. Monitoring microbial growth and activity using spectral induced polarization and low-field nuclear magnetic resonance

    Science.gov (United States)

    Zhang, Chi; Keating, Kristina; Revil, Andre

    2015-04-01

    Microbes and microbial activities in the Earth's subsurface play a significant role in shaping subsurface environments and are involved in environmental applications such as remediation of contaminants in groundwater and oil fields biodegradation. Stimulated microbial growth in such applications could cause wide variety of changes of physical/chemical properties in the subsurface. It is critical to monitor and determine the fate and transportation of microorganisms in the subsurface during such applications. Recent geophysical studies demonstrate the potential of two innovative techniques, spectral induced polarization (SIP) and low-field nuclear magnetic resonance (NMR), for monitoring microbial growth and activities in porous media. The SIP measures complex dielectric properties of porous media at low frequencies of exciting electric field, and NMR studies the porous structure of geologic media and characterizes fluids subsurface. In this laboratory study, we examined both SIP and NMR responses from bacterial growth suspension as well as suspension mixed with silica sands. We focus on the direct contribution of microbes to the SIP and NMR signals in the absence of biofilm formation or biomineralization. We used Zymomonas mobilis and Shewanella oneidensis (MR-1) for SIP and NMR measurements, respectively. The SIP measurements were collected over the frequency range of 0.1 - 1 kHz on Z. mobilis growth suspension and suspension saturated sands at different cell densities. SIP data show two distinct peaks in imaginary conductivity spectra, and both imaginary and real conductivities increased as microbial density increased. NMR data were collected using both CPMG pulse sequence and D-T2 mapping to determine the T2-distribution and diffusion properties on S. oneidensis suspension, pellets (live and dead), and suspension mixed with silica sands. NMR data show a decrease in the T2-distribution in S. oneidensis suspension saturated sands as microbial density increase. A

  13. 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.

  14. Radio polarization properties of quasars and active galaxies at high redshifts

    Science.gov (United States)

    Vernstrom, T.; Gaensler, B. M.; Vacca, V.; Farnes, J. S.; Haverkorn, M.; O'Sullivan, S. P.

    2018-04-01

    We present the largest ever sample of radio polarization properties for z > 4 sources, with 14 sources having significant polarization detections. Using wide-band data from the Karl G. Jansky Very Large Array, we obtained the rest-frame total intensity and polarization properties of 37 radio sources, nine of which have spectroscopic redshifts in the range 1 ≤ z ≤ 1.4, with the other 28 having spectroscopic redshifts in the range 3.5 ≤ z ≤ 6.21. Fits are performed for the Stokes I and fractional polarization spectra, and Faraday rotation measures are derived using rotation measure synthesis and QU fitting. Using archival data of 476 polarized sources, we compare high-redshift (z > 3) source properties to a 15 GHz rest-frame luminosity matched sample of low-redshift (z 3 sources and 57 ± 4 rad m-2 for z < 3. Although there is some indication of lower intrinsic rotation measures at high-z possibly due to higher depolarization from the high-density environments, using several statistical tests we detect no significant difference between low- and high-redshift sources. Larger samples are necessary to determine any true physical difference.

  15. Lifestyles and routine activities of South African teenagers at risk of being trafficked for involuntary prostitution.

    Science.gov (United States)

    Lutya, Thozama Mandisa

    2010-12-01

    The United Nations estimates that 79% of teenage girls trafficked globally every year are forced into involuntary prostitution. About 247 000 South African children work in exploitative conditions; about 40 000 South African female teenagers work as prostitutes. This paper investigates lifestyles and routine activities of teenagers at risk of being trafficked for involuntary prostitution. The key concepts involuntary prostitution, intergenerational sex and exploitative conditions are defined in relation to the lifestyles and routine activities of South African female teenagers. Human trafficking for involuntary prostitution is described, based on a literature review. Lifestyle exposure and routine activities theories help to explain the potential victimisation of these teenagers in human trafficking for involuntary prostitution. Actual lifestyle and routine activities of South African teenagers and risky behaviours (substance abuse, intergenerational sex and child prostitution) are discussed as factors that make teens vulnerable to such trafficking. This paper recommends that human trafficking prevention efforts (awareness programmes and information campaigns) be directed at places frequented by human traffickers and teenagers in the absence of a capable guardian to reduce victimisation, as traffickers analyse the lifestyles and routine activities of their targets. South Africa should also interrogate entrenched practices such as intergenerational sex.

  16. Xenoestrogenic and dioxin-like activity in blood of East Greenland polar bears (Ursus maritimus)

    DEFF Research Database (Denmark)

    Erdmann, Simon Erik; Dietz, Rune; Sonne, Christian

    2013-01-01

    The aims of the project were to (i) extract the lipophilic persistent organic pollutants (POPs) from the blood of 99 East Greenland polar bears and assess the combined mixture effect on the estrogen receptor (ER) and the aryl hydrocarbon receptor (AhR) mediated transactivity; (ii) To evaluate...... whether the receptor transactivities were associated with selected POP markers, and (iii) compare the receptor transactivities in polar bears with earlier studies on Greenlandic Inuit. Lipophilic POPs were extracted using a combination of solid-phase extraction (SPE) and high performance liquid...... induced ER response. Positive correlations were found in subadult bears between XER and several POP biomarkers. XER and XERcomp correlated positively to each other. A total of 91% of the polar bear blood extracts elicited agonistic AhR transactivity. The AhR-TCDD equivalent (AhR-TEQ) median levels were...

  17. Centralising Space: The Physical Education and Physical Activity Experiences of South Asian, Muslim Girls

    Science.gov (United States)

    Stride, Annette

    2016-01-01

    This paper explores the physical education (PE) and physical activity experiences of a group of South Asian, Muslim girls, a group typically marginalised in PE and physical activity research. The study responds to ongoing calls for research to explore across different spaces in young people's lives. Specifically, I draw on a…

  18. Periodic Variation of the North-South Asymmetry of Solar Activity ...

    Indian Academy of Sciences (India)

    Abstract. We report here a study of various solar activity phenomena occurring in both north and south hemispheres of the Sun during solar cycles 8-23. In the study we have used sunspot data for the period 1832—. 1976, flare index data for the period 1936-1993, Hα flare data 1993-1998 and solar active prominences data ...

  19. Effect of habitat and foraging height on bat activity in the coastal plain of South Carolina.

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, Jennifer, M.; Menzel, Michael A.; Kilgo, John C.; Ford, W. Mark; Edwards, John W.; McCracken, Gary F.

    2005-07-01

    A comparison of bat activity levels in the Coastal Plain of South Carolina among 5 habitat types: forested riparian areas, clearcuts, young pine plantations, mature pine plantations and pine savannas, using time expansion radio-microphones and integrated detectors to simultaneously monitor bat activity at three heights in each habitat type.

  20. Noise and vibration levels in artificial polar bear dens as related to selected petroleum exploration and developmental activities

    International Nuclear Information System (INIS)

    Blix, A.S.; Lentfer, J.W.

    1992-01-01

    Petroleum exploration and development are occurring in various locations in the Arctic, where there are important denning sites for polar bears. Petroleum activities usually coincide with winter denning activities by bears, who may abandon dens if subject to prolonged annoyance. A study was carried out to measure noise and vibration levels in artificial polar bear dens at Prudhoe's Bar, Alaska, resulting from seismic testing, drilling and transport. A microphone and an accelerometer were frozen to the floor of the dens, with leads passed through a consolidated snow filled entrance to a truck, tent or helicopter. Tests were carried out on land, sea ice, and next to a drilling tower on an artificial island, which was also used to measure noise levels resulting from a helicopter taking off. It was concluded that the dry and wind-beaten arctic snow muffles both sound and vibration extremely well, and it is unlikely that polar bears in their dens will be disturbed by the type of petroleum-related activities measured, provided they do not take place within 100 m of the dens. 8 refs., 7 figs., 1 tab

  1. Polarization signatures of strong gravity in active galactic nuclei accretion discs

    Czech Academy of Sciences Publication Activity Database

    Dovčiak, Michal; Karas, Vladimír; Matt, G.

    2004-01-01

    Roč. 355, č. 3 (2004), s. 1005-1009 ISSN 0035-8711 R&D Projects: GA ČR GA202/02/0735; GA ČR GA205/03/0902 Institutional research plan: CEZ:AV0Z1003909 Keywords : relativity * polarization * galaxies Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.238, year: 2004

  2. Off-axis irradiation and the polarization of broad emission lines in active galactic nuclei

    Czech Academy of Sciences Publication Activity Database

    Goosmann, R. W.; Gaskell, C.M.; Marin, Frederic

    2014-01-01

    Roč. 54, č. 7 (2014), s. 1341-1346 ISSN 0273-1177 Institutional support: RVO:67985815 Keywords : polarization * radiative transfer * R line profiles Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 1.358, year: 2014

  3. Analysis of late Jurassic-recent paleomagnetic data from active plate margins of South America

    Science.gov (United States)

    Beck, Myrl E.

    Paleomagnetic results for rocks of late Mesozoic and Cenozoic age from South America are analyzed and interpreted. Emphasis is placed on the active margins of the continent. Some important conclusions are reached, with varying degrees of certainty: (1) The reference APW path for stable South America is fairly well defined for the Late Jurassic and Cretaceous, and is not much different from the present rotation axis. (2) The so-called "Bolivian orocline" involved counterclockwise rotations in Peru and northernmost Chile and clockwise rotations in Chile south of about latitude 18.5S. These rotations probably are a result of in situ small-block rotations in response to shear, not actual oroclinal bending. (3) The Bonaire block of northern Venezuela and Colombia has been rotated clockwise relative to the stable interior of South America by about 90°. It also seems to have drifted northward relative to the craton by as much as 1600 km. It probably represents a true accreted terrane, one of very few recognized in South America so far. (4) The "Magellanes orocline" at the southern tip of South America apparently involves some counterclockwise rotation of paleomagnetic vectors, but this too is probably the result of distributed shear. (5) Tectonic processes have very thoroughly "rearranged" the rocks making up the active margins of South America. "Rearrange" here denotes displacement of crustal blocks relative to their surroundings, without significant internal deformation By analogy with North America "rearrangement" might entail in situ block rotation, translation of crustal blocks along the continental margin, and accretion of exotic "tectonostratigraphic terranes". However, in western South America "rearrangement" seems to have consisted dominantly of block rotations that were essentially in situ. For the parts of the Andes investigated so far, late Mesozoic and Cenozoic accretion of exotic terranes and large-scale translation of crustal slivers, as found in western

  4. The Flavonoid Quercetin Ameliorates Liver Inflammation and Fibrosis by Regulating Hepatic Macrophages Activation and Polarization in Mice

    Directory of Open Access Journals (Sweden)

    Xi Li

    2018-02-01

    Full Text Available At present, there are no effective antifibrotic drugs for patients with chronic liver disease; hence, the development of antifibrotic therapies is urgently needed. Here, we performed an experimental and translational study to investigate the potential and underlying mechanism of quercetin treatment in liver fibrosis, mainly focusing on the impact of quercetin on macrophages activation and polarization. BALB/c mice were induced liver fibrosis by carbon tetrachloride (CCl4 for 8 weeks and concomitantly treated with quercetin (50 mg/kg or vehicle by daily gavage. Liver inflammation, fibrosis, and hepatic stellate cells (HSCs activation were examined. Moreover, massive macrophages accumulation, M1 macrophages and their related markers, such as tumor necrosis factor (TNF-α, interleukin (IL-1β, IL-6, and monocyte chemotactic protein-1 (MCP-1 in livers were analyzed. In vitro, we used Raw 264.7 cells to examine the effect of quercetin on M1-polarized macrophages activation. Our results showed that quercetin dramatically ameliorated liver inflammation, fibrosis, and inhibited HSCs activation. These results were attributed to the reductive recruitment of macrophages (F4/80+ and CD68+ into the liver in quercetin-treated fibrotic mice confirmed by immunostaining and expression levels of marker molecules. Importantly, quercetin strongly inhibited M1 polarization and M1-related inflammatory cytokines in fibrotic livers when compared with vehicle-treated mice. In vitro, studies further revealed that quercetin efficiently inhibited macrophages activation and M1 polarization, as well as decreased the mRNA expression of M1 macrophage markers such as TNF-α, IL-1β, IL-6, and nitric oxide synthase 2. Mechanistically, the inhibition of M1 macrophages by quercetin was associated with the decreased levels of Notch1 expression on macrophages both in vivo and in vitro. Taken together, our data indicated that quercetin attenuated CCl4-induced liver inflammation and

  5. Tautomerism and isomerism in some antitrichinellosis active benzimidazoles: Morphological study in polarized light, quantum chemical computations

    Science.gov (United States)

    Anichina, Kameliya; Mavrova, Anelia; Yancheva, Denitsa; Tsenov, Jordan; Dimitrov, Rasho

    2017-12-01

    The morphology of the crystal structure of some antitrichinellosis active benzimidazole derivatives including (1H-benzimidazol-2-ylthio)acetic acids, [1,3]thiazolo[3,2-a]benzimidazol-3(2H)-ones, 1H-benzimidazol-2-ylthioacetylpiperazines and starting 2-mercapto benzimidazoles, was studied by the use of Polarized Light Microscopy (PLM). Characterization of the crystal phase was complimented by Differential scanning calorimetry analysis (DSC) and spectroscopic data. DFT computations were performed in order to investigate the prototropic tautomerism and the geometry of the molecule of the synthesized compounds. One distinct type of crystal structure for each one of 5 or 6-methyl-(1H-benzimidazol-2-ylthio)acetic acid 6 was observed by PLM - dendritic and needle-shaped formations. Compound 14, containing a methyl substituent in the benzimidazole ring crystallized also into two phases; while for the unsubstituted compound 13 a separation of phases does not take place. The influence of the both solvents - chloroform and ethanol on the phase separation and the formation of the crystalline structure of compound 14 was investigated. The morphological study showed that the cyclization of 6 in the presence of acetic anhydride in pyridine medium led to a mixture of 6-methyl-[1,3]tiazolo[3,2-a]benzimidazol-3(2H)-one (10a) and 7-methyl-[1,3]thiazolo[3,2-a]-benzimidazole-3(2H)-one (10b), which crystallized in the form of fibrils and spherulites respectively. It was found that a difference in the crystal structures of substituted and unsubstituted benzimidazol-2-thiones, respectively benzimidazol-2-thiol derivatives exists, which may be due not only to the thiol-thione tautomerism but to the prototropic properties of the hydrogen atom in first position of the ring. The calculation results indicated that the thione form is more stable than the thiol tautomer by 51-55 kJ mol-1. But at the same time ΔG for the two thiol tautomers is below 0.5 kJ mol-1. In solid phase the 5

  6. Tonian paleomagnetism of the red beds of Madiyi Formation, lower Banxi Group in South China: implications for pre-Sturtian climate, Rodinia reconstruction and true polar wander

    Science.gov (United States)

    Hanbiao, X.; Zhang, S.; Xiao, Q.; Li, H.; Chang, L.; Fu, H.; Liu, R.

    2017-12-01

    We present a new Tonian paleomagnetic pole from the red beds of ca. 810 Ma Madiyi Formation, lower Banxi Group in the central South China Block (SCB). Detailed thermal demagnetization reveals two distinct magnetic components among the samples. A low temperature component (LTC), removed from almost all the samples below 580°C, yielded a paleopole at 68.0°N, 211.7°E (A95=1.9) that is close to the pole of late Jurassic. The high temperature component (HTC), isolated between 580-690°C, gave a mean direction of D=310.0°, I=57.4°, α95=3.7 (108 samples of 13 sites) after bedding correction, corresponding to a paleomagnetic pole at 47.6°N, 46.7°E (A95=5.6°). The HTC passed a reversal test on 95% and 99% confidence level. Directional distribution of the HTC show significant elongation which may indicate inclination shallowing, and the inclination was corrected to 75.1° using E/I technique, corresponding to a paleolatitude at 60.8±3.4° of research area. The paleopole calculated from the E/I-corrected HTC is at 44.8°N, 80.2°E (A95=3.4°), being significantly distinct from any younger poles of the SCB. This new pole plus existing high quality paleomagnetic poles from the SCB demonstrate that the SCB experienced a polar-equatorial region drifting tendency from 825 Ma to Cambrian. The high-paleolatitude red beds rather than glacial sediments deposited in the SCB, combined with coeval widespread evaporative in other continents, possibly suggest pre-Cryogenian global greenhouse climate. In our reconstruction at 800 Ma, the SCB was placed on the northwest periphery of Rodinia, with its western margin adjacent to the northern India, rather than occupying a central position of Rodinia. The distribution of 825-750 Ma poles of the SCB, East Svalbard, Australia, Laurentia, India along a great arc may be associated with true polar wander around 800 Ma.

  7. Direct current (DC) resistivity and Induced Polarization (IP) monitoring of active layer dynamics at high temporal resolution

    DEFF Research Database (Denmark)

    Doetsch, J.; Fiandaca, G.; Ingeman-Nielsen, Thomas

    2015-01-01

    With permafrost thawing and changes in active layer dynamics induced by climate change, interactions between biogeochemical and thermal processes in the ground are of great importance. Here, active layer dynamics have been monitored using direct current (DC) resistivity and induced polarization (IP...... the soil freezing as a strong increase in resistivity. While the freezing horizon generally moves deeper with time, some variations in the freezing depth are observed along the profile. Comparison with depth-specific soil temperature indicates an exponential relationship between resistivity and below...

  8. Direct current (DC) resistivity and induced polarization (IP) monitoring of active layer dynamics at high temporal resolution

    DEFF Research Database (Denmark)

    Doetsch, Joseph; Ingeman-Nielsen, Thomas; Christiansen, Anders V.

    2015-01-01

    With permafrost thawing and changes in active layer dynamics induced by climate change, interactions between biogeochemical and thermal processes in the ground are of great importance. Here, active layer dynamics have been monitored using direct current (DC) resistivity and induced polarization (IP...... in resistivity. While the freezing horizon generally moves deeper with time, some variations in the freezing depth are observed along the profile. Comparison with depth-specific soil temperature indicates an exponential relationship between resistivity and below-freezing temperature. Time-lapse inversions...

  9. Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from USCGC POLAR SEA in the South Pacific Ocean and Southern Oceans from 1994-02-04 to 1994-02-10 (NODC Accession 0116062)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0116062 includes chemical, discrete sample, physical and profile data collected from USCGC POLAR SEA in the South Pacific Ocean and Southern Oceans...

  10. Long-term north-south asymmetry in solar wind speed inferred from geomagnetic activity: A new type of century-scale solar oscillation?

    DEFF Research Database (Denmark)

    Mursula, K.; Zieger, B.

    2001-01-01

    A significant and very similar annual variation in solar wind speed and in geomagnetic activity was recently found around all the four solar cycle minima covered by direct SW observations since mid-1960's. We have shown that the phase of this annual variation reverses with the Sun's polarity...... reversal, depicting a new form of 22-year periodicity. The annual variation results from a small north-south asymmetry in SW speed distribution where the minimum speed region is shifted toward the northern magnetic hemisphere. Here we study the very long-term evolution of the annual variation using early...... registrations of geomagnetic activity. We find a significant annual variation during the high-activity solar cycles in mid-19th century and since 1930's. Most interestingly, the SW speed asymmetry in mid-19th century was opposite to the present asymmetry, i.e., the minimum speed region was then shifted toward...

  11. Active learning in physiology practical work | Allers | South African ...

    African Journals Online (AJOL)

    A statistical analysis of the results indicates that when students are actively involved in the teaching-learning process, they enhance their ability to use cognitive skills such as interpretation, judgement and problem-solving skills. The results also underline the importance of an active approach towards practical work and ...

  12. South African Helichrysum species: a review of the traditional uses, biological activity and phytochemistry.

    Science.gov (United States)

    Lourens, A C U; Viljoen, A M; van Heerden, F R

    2008-10-28

    In South Africa, the genus Helichrysum is widely used in traditional medicine. The uses are well documented although renaming of species and the resulting confusing taxonomic nomenclature may cause uncertainty as to which specific species was referred to in some reports. The aim of this paper is to present a collated and coherent overview of the documented traditional uses of Helichrysum species and to update the botanical identity of previously studied species. Databases (Scifinder, ISI Web of Knowledge) and several books were used to collect in information on South African Helichrysum species. The traditional uses, chemistry and biological activity of Helichrysum species have been summarized. It was attempted to give clarity as to exactly which species is refer to in the ethnobotanical literature. Although a large number of ethnopharmacological uses have been documented and the chemistry of the genus has been studied extensively, only a few South African species have been investigated for their biological activity.

  13. Physical activity among South Asian women: a systematic, mixed-methods review.

    Science.gov (United States)

    Babakus, Whitney S; Thompson, Janice L

    2012-12-20

    The objective of this systematic mixed-methods review is to assess what is currently known about the levels of physical activity (PA) and sedentary time (ST) and to contextualize these behaviors among South Asian women with an immigrant background. A systematic search of the literature was conducted using combinations of the key words PA, ST, South Asian, and immigrant. A mixed-methods approach was used to analyze and synthesize all evidence, both quantitative and qualitative. Twenty-six quantitative and twelve qualitative studies were identified as meeting the inclusion criteria. Studies quantifying PA and ST among South Asian women showed low levels of PA compared with South Asian men and with white European comparison populations. However making valid comparisons between studies was challenging due to a lack of standardized PA measurement. The majority of studies indicated that South Asian women did not meet recommended amounts of PA for health benefits. Few studies assessed ST. Themes emerging from qualitative studies included cultural and structural barriers to PA, faith and education as facilitators, and a lack of understanding of the recommended amounts of PA and its benefits among South Asian women. Quantitative and qualitative evidence indicate that South Asian women do not perform the recommended level of PA for health benefits. Both types of studies suffer from limitations due to methods of data collection. More research should be dedicated to standardizing objective PA measurement and to understanding how to utilize the resources of the individuals and communities to increase PA levels and overall health of South Asian women.

  14. Physical activity among South Asian women: a systematic, mixed-methods review

    Directory of Open Access Journals (Sweden)

    Babakus Whitney S

    2012-12-01

    Full Text Available Abstract Introduction The objective of this systematic mixed-methods review is to assess what is currently known about the levels of physical activity (PA and sedentary time (ST and to contextualize these behaviors among South Asian women with an immigrant background. Methods A systematic search of the literature was conducted using combinations of the key words PA, ST, South Asian, and immigrant. A mixed-methods approach was used to analyze and synthesize all evidence, both quantitative and qualitative. Twenty-six quantitative and twelve qualitative studies were identified as meeting the inclusion criteria. Results Studies quantifying PA and ST among South Asian women showed low levels of PA compared with South Asian men and with white European comparison populations. However making valid comparisons between studies was challenging due to a lack of standardized PA measurement. The majority of studies indicated that South Asian women did not meet recommended amounts of PA for health benefits. Few studies assessed ST. Themes emerging from qualitative studies included cultural and structural barriers to PA, faith and education as facilitators, and a lack of understanding of the recommended amounts of PA and its benefits among South Asian women. Conclusions Quantitative and qualitative evidence indicate that South Asian women do not perform the recommended level of PA for health benefits. Both types of studies suffer from limitations due to methods of data collection. More research should be dedicated to standardizing objective PA measurement and to understanding how to utilize the resources of the individuals and communities to increase PA levels and overall health of South Asian women.

  15. X-ray polarization fluctuations induced by cloud eclipses in active galactic nuclei

    Czech Academy of Sciences Publication Activity Database

    Marin, Frederic; Dovčiak, Michal

    2015-01-01

    Roč. 573, January (2015), A60/1-A60/8 ISSN 0004-6361 R&D Projects: GA MŠk LD12010 Grant - others:EU(XE) COST action MP1104 Institutional support: RVO:67985815 Keywords : galaxies: Seyfert * polarization * radiative transfer * relativistic processes * scattering * X-rays: general Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.378, year: 2014

  16. Treeline advances and associated shifts in the ground vegetation alter fine root dynamics and mycelia production in the South and Polar Urals.

    Science.gov (United States)

    Solly, Emily F; Djukic, Ika; Moiseev, Pavel A; Andreyashkina, Nelly I; Devi, Nadezhda M; Göransson, Hans; Mazepa, Valeriy S; Shiyatov, Stepan G; Trubina, Marina R; Schweingruber, Fritz H; Wilmking, Martin; Hagedorn, Frank

    2017-02-01

    Climate warming is shifting the elevational boundary between forests and tundra upwards, but the related belowground responses are poorly understood. In the pristine South and Polar Urals with shifts of the treeline ecotone documented by historical photographs, we investigated fine root dynamics and production of extramatrical mycorrhizal mycelia (EMM) along four elevational transects reaching from the closed forest to the treeless tundra. In addition, we analysed elevational differences in climate and vegetation structure, and excavated trees to estimate related changes in the partitioning between below- and aboveground biomass. Fine root biomass of trees (<2 mm) increased by 13-79% with elevation, paralleled by a 35-72% increase in ground vegetation fine roots from the closed forest to the tundra. During the first year of decomposition, mass loss of fine root litter from different vegetation types was greater at lower elevations in the forest-tundra ecotone. The ratio between fine roots of trees and stem biomass largely increased with elevation in both regions, but these increases were not accompanied by a distinct production of EMM. Production of EMM, however, increased with the presence of ectomycorrhizal trees at the transition from the tundra to the forest. Our results imply that the recorded upward expansion of forest into former tundra in the Ural Mountains by 4-8 m per decade is decreasing the partitioning of plant biomass to fine roots. They further suggest that climate-driven forest advances will alter EMM production rates with potential feedbacks on soil carbon and nutrient cycling in these ecosystems.

  17. Following the south polar cap recession as viewed by OMEGA/MEX using automatic detection of H2O and CO2 ices.

    Science.gov (United States)

    Schmidt, F.; Doute, S.; Schmitt, B.

    In order to understand Mars' current climate it is necessary to detect, characterize and monitor CO2 and H2O at the surface (permanent and seasonal icy deposits) and in the atmosphere (vapor and clouds). Here we will focus on the South Seasonal Polar Cap (SSPC) whose recession was previously observed with different techniques : from earth in the visible range with HST [James 1996], or from MGS spacecraft with MOC images [Benson 2005], in the thermal IR range by the TES [Kieffer 2000], in the near infrared by OMEGA/MEX [Langevin submitted]. The time and space evolutions of the SSPC is a major annual climatic signal both at the global and the regional scales. In particular the measurement of the temporal and spatial distributions of CO2 constrains exchange processes between both surface and atmosphere. This exchange may involve preponderant species : H2O, CO2 and dust. In this work we will apply a new detection technique : "wavanglet" in order to follow the recession of the SSPC thanks to OMEGA/MEX observations. This method was especially developed in the goal to classify a huge dataset, such OMEGA ones. We propose to use "wavanglet" as a supervised automatic classification method that identifies spectral features and classifies the image in spectrally homogeneous units. Additionally we will evaluate quantitative detection limits of "wavanglet" based on synthetic dataset simulating OMEGA spectra in typical situation of the SSPC. This detection limit will be discussed in terms of abundance for H2O and CO2 ices in order to improve the interpretation of the classification. Finally we will present the recession of the SSPC using "wavanglet" and we will compare the results with those of earlier investigation. An interpretation of the similarities and disagreements between those maps will be done.

  18. Longitudinal fecal hormone analysis for monitoring reproductive activity in the female polar bear (Ursus maritimus).

    Science.gov (United States)

    Stoops, M A; MacKinnon, K M; Roth, T L

    2012-12-01

    The objective was to identify suitable enzyme immunoassays to monitor gonadal and placental function in the female polar bear. Immunoreactive progesterone, progesterone metabolite (PdG), estrogen, and androgen metabolite (T) concentrations were measured in fecal samples collected over 24 mo from captive female bears (N = 20). Whereas fecal extracts produced displacement curves parallel to the standard curve for each respective steroid, T and PdG more accurately reflected reproductive events. Concentrations of fecal T increased (P bears excreted higher PdG concentrations (P bears also had a PdG rise in the Fall, suggesting they experienced either pregnancy loss or a pseudopregnancy. Differentiating pregnant and pseudopregnant states was not achieved using fecal PdG alone, but when combined with fecal T, comprehensive diagnoses could be made. Nonparturient bears demonstrated elevated (P bears did not. In summary, noninvasive hormone monitoring techniques were established for the female polar bear. Although this study was directed at facilitating management and breeding efforts of captive polar bears, the methods could be applied to studies of reproductive function in wild populations. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. The Great Solar Active Region NOAA 12192: Helicity Transport, Filament Formation, and Impact on the Polar Field

    Science.gov (United States)

    Petrie, Gordon; McMaken, Tyler C.

    2017-08-01

    The solar active region (AR), NOAA 12192, appeared in 2014 October as the largest AR in 24 years. Here we examine the counterintuitive nature of two diffusion-driven processes in the region: the role of helicity buildup in the formation of a major filament, and the relationship between the effects of supergranular diffusion and meridional flow on the AR and on the polar field. Quantitatively, calculations of current helicity and magnetic twist from Helioseismic and Magnetic Imager (HMI) vector magnetograms indicate that, though AR 12192 emerged with negative helicity, positive helicity from subsequent flux emergence, consistent with the hemispheric sign-preference of helicity, increased over time within large-scale, weak-field regions such as those near the polarity inversion line (PIL). Morphologically, Atmospheric Imaging Assembly observations of filament barbs, sigmoidal patterns, and bases of Fe xii stalks initially exhibited signatures of negative helicity, and the long filament that subsequently formed had a strong positive helicity consistent with the helicity buildup along the PIL. We find from full-disk HMI magnetograms that AR 12192's leading positive flux was initially closer to the equator but, owing either to the region’s magnetic surroundings or to its asymmetric flux density distribution, was transported poleward more quickly on average than its trailing negative flux, contrary to the canonical pattern of bipole flux transport. This behavior caused the AR to have a smaller effect on the polar fields than expected and enabled the formation of the very long neutral line where the filament formed.

  20. Features of Investment Activity in Agriculture in the South of Russia and Ways of its Activation

    Directory of Open Access Journals (Sweden)

    Vladimir Ivanovich Trukhachev

    2018-03-01

    Full Text Available The relevance of this article on the topic: “Features of Investment Activity in Agriculture in the South of Russia and Ways of its Activation” is that at the present time, as a result of the systemic crisis of the Russian economy, a set of objective prerequisites for improving the financial and credit mechanisms in the agro industrial complex has been formed. The fall in the rouble exchange rate to foreign currencies made foreign agricultural products and food too expensive on the Russian market and sales fell sharply in Russia. This led to the emergence of free niches in the domestic agrarian market and increased the competitiveness of domestic agricultural products and food. In these conditions, an important task for Russian agricultural producers is to increase the volume of production and sales of agricultural products, and this requires an increase in production capacity, modernization of the material and technical base. To solve these problems, it is necessary to increase investment in the agricul-tural sector of the economy, which without improving the existing credit and financial system in the Russian agribusiness sector cannot be done. Based on the goal set by the authors, the subject of the study are factors and patterns that affect investment in agriculture. To write the article, dialectical methods of cognition of socioeconomic, natural-biological processes and phenomena were used as well as the systemic approach: analytical, economic-statistical, monographic, calculating and constructive and expert evaluations. This allowed working out effective measures to intensify investment activity by improving the lending process as the main source of external investment, and solving the problems of financing agricultural organizations, using non-traditional external sources of investment for agriculture in Stavropol Krai.

  1. Landscape scale attributes of elk centers of activity in the central Black Hills of South Dakota

    Science.gov (United States)

    Cynthia H. Stubblefield; Kerri T. Vierling; Mark A. Rumble

    2006-01-01

    We researched the environmental attributes (n = 28) associated with elk (n = 50) summer range (1 May ­30 Sep) in the central Black Hills of South Dakota, USA, during 1998-­2001. We defined high-use areas or centers of activity as landscapes underlying large concentrations of elk locations resulting from the shared fidelity of...

  2. Effectiveness of highly active antiretroviral therapy administered by general practitioners in rural South Africa

    NARCIS (Netherlands)

    Barth, R. E.; van der Meer, J. T. M.; Hoepelman, A. I. M.; Schrooders, P. A.; van de Vijver, D. A.; Geelen, S. P. M.; Tempelman, H. A.

    2008-01-01

    The purpose of this study was to assess the one-year efficacy of highly active antiretroviral therapy (HAART) administered by general practitioners in a primary care community clinic in rural South Africa. We performed an observational cohort study of 675 treatment-naive human immunodeficiency virus

  3. The Evolution of Student Activism and Its Influence on Tuition Fees in South Korean Universities

    Science.gov (United States)

    Shin, Jung Cheol; Kim, Hoon-Ho; Choi, Hong-Sam

    2014-01-01

    This article briefly overviews the student movement working for political democratisation during the authoritarian governments in South Korea. The article focuses on how student activism has changed as a reflection of political developments from the dictatorship through to the civilian democratic governments. Further, it analyses how tuition-fee…

  4. Evaluation of antioxidant activity of hydromethanolic extracts of some medicinal species from South Algeria

    Directory of Open Access Journals (Sweden)

    Tarik Mohammed Chaouche

    2014-06-01

    Conclusion: This investigation confirmed that several medicinal herbs from South Algeria possess high in vitro antioxidant potency. Overall, our results can be considered very promising in the continuing effort to utilize plant species successfully for medicinal purposes in humans, providing further justification for the hypothesis that phenolic compounds in these plants can provide substantial antioxidant activity.

  5. The antibacterial activity of Clausena anisata hook, a South African ...

    African Journals Online (AJOL)

    African Journal of Traditional, Complementary and Alternative Medicines ... Background: Clausena anisata Hook also known as Iperepesi in Xhosa language is a medicinal plant used traditionally for the treatment of various ailments and ... Key words: Clausena anisata; tuberculosis; antibacterial activity; herbal medicine.

  6. Effect of Ascorbic Acid on Lipoprotein Lipase Activity | Kotze | South ...

    African Journals Online (AJOL)

    Baboons kept on hypovitaminotic C diets, but without clinical signs of scurvy, had significantly higher heart muscle lipoprotein lipase activity than baboons on vitamin C 34 mg/kg body mass/day. When the serum vitamin C levels were above 0,35 mg/100 ml the heart muscle lipoprotein lipase was repressed. Serum vitamin C ...

  7. Polar bears experience skeletal muscle atrophy in response to food deprivation and reduced activity in winter and summer

    Science.gov (United States)

    Harlow, Henry J.; Durner, George M.; Regehr, Eric V.; Rourke, Bryan C.; Robles, Manuel; Amstrup, Steven C.; Ben-David, Merav

    2017-01-01

    Abstract When reducing activity and using stored energy during seasonal food shortages, animals risk degradation of skeletal muscles, although some species avoid or minimize the resulting atrophy while experiencing these conditions during hibernation. Polar bears may be food deprived and relatively inactive during winter (when pregnant females hibernate and hunting success declines for other demographic groups) as well as summer (when sea ice retreats from key foraging habitats). We investigated muscle atrophy in samples of biceps femoris collected from free-ranging polar bears in the Southern Beaufort Sea (SBS) throughout their annual cycle. Atrophy was most pronounced in April–May as a result of food deprivation during the previous winter, with muscles exhibiting reduced protein concentration, increased water content, and lower creatine kinase mRNA. These animals increased feeding and activity in spring (when seal prey becomes more available), initiating a period of muscle recovery. During the following ice melt of late summer, ~30% of SBS bears abandon retreating sea ice for land; in August, these ‘shore’ bears exhibited no muscle atrophy, indicating that they had fully recovered from winter food deprivation. These individuals subsequently scavenged whale carcasses deposited by humans and by October, had retained good muscle condition. In contrast, ~70% of SBS bears follow the ice north in late summer, into deep water with less prey. These ‘ice’ bears fast; by October, they exhibited muscle protein loss and rapid changes in myosin heavy-chain isoforms in response to reduced activity. These findings indicate that, unlike other bears during winter hibernation, polar bears without food in summer cannot mitigate atrophy. Consequently, prolonged summer fasting resulting from climate change-induced ice loss creates a risk of greater muscle atrophy and reduced abilities to travel and hunt. PMID:28835844

  8. Polar bears experience skeletal muscle atrophy in response to food deprivation and reduced activity in winter and summer

    Science.gov (United States)

    Whiteman, John P.; Harlow, Henry J.; Durner, George M.; Regehr, Eric V.; Rourke, Bryan C.; Robles, Manuel; Amstrup, Steven C.; Ben-David, Merav

    2017-01-01

    When reducing activity and using stored energy during seasonal food shortages, animals risk degradation of skeletal muscles, although some species avoid or minimize the resulting atrophy while experiencing these conditions during hibernation. Polar bears may be food deprived and relatively inactive during winter (when pregnant females hibernate and hunting success declines for other demographic groups) as well as summer (when sea ice retreats from key foraging habitats). We investigated muscle atrophy in samples of biceps femoris collected from free-ranging polar bears in the Southern Beaufort Sea (SBS) throughout their annual cycle. Atrophy was most pronounced in April–May as a result of food deprivation during the previous winter, with muscles exhibiting reduced protein concentration, increased water content, and lower creatine kinase mRNA. These animals increased feeding and activity in spring (when seal prey becomes more available), initiating a period of muscle recovery. During the following ice melt of late summer, ~30% of SBS bears abandon retreating sea ice for land; in August, these ‘shore’ bears exhibited no muscle atrophy, indicating that they had fully recovered from winter food deprivation. These individuals subsequently scavenged whale carcasses deposited by humans and by October, had retained good muscle condition. In contrast, ~70% of SBS bears follow the ice north in late summer, into deep water with less prey. These ‘ice’ bears fast; by October, they exhibited muscle protein loss and rapid changes in myosin heavy-chain isoforms in response to reduced activity. These findings indicate that, unlike other bears during winter hibernation, polar bears without food in summer cannot mitigate atrophy. Consequently, prolonged summer fasting resulting from climate change-induced ice loss creates a risk of greater muscle atrophy and reduced abilities to travel and hunt.

  9. Polar bears experience skeletal muscle atrophy in response to food deprivation and reduced activity in winter and summer.

    Science.gov (United States)

    Whiteman, John P; Harlow, Henry J; Durner, George M; Regehr, Eric V; Rourke, Bryan C; Robles, Manuel; Amstrup, Steven C; Ben-David, Merav

    2017-01-01

    When reducing activity and using stored energy during seasonal food shortages, animals risk degradation of skeletal muscles, although some species avoid or minimize the resulting atrophy while experiencing these conditions during hibernation. Polar bears may be food deprived and relatively inactive during winter (when pregnant females hibernate and hunting success declines for other demographic groups) as well as summer (when sea ice retreats from key foraging habitats). We investigated muscle atrophy in samples of biceps femoris collected from free-ranging polar bears in the Southern Beaufort Sea (SBS) throughout their annual cycle. Atrophy was most pronounced in April-May as a result of food deprivation during the previous winter, with muscles exhibiting reduced protein concentration, increased water content, and lower creatine kinase mRNA. These animals increased feeding and activity in spring (when seal prey becomes more available), initiating a period of muscle recovery. During the following ice melt of late summer, ~30% of SBS bears abandon retreating sea ice for land; in August, these 'shore' bears exhibited no muscle atrophy, indicating that they had fully recovered from winter food deprivation. These individuals subsequently scavenged whale carcasses deposited by humans and by October, had retained good muscle condition. In contrast, ~70% of SBS bears follow the ice north in late summer, into deep water with less prey. These 'ice' bears fast; by October, they exhibited muscle protein loss and rapid changes in myosin heavy-chain isoforms in response to reduced activity. These findings indicate that, unlike other bears during winter hibernation, polar bears without food in summer cannot mitigate atrophy. Consequently, prolonged summer fasting resulting from climate change-induced ice loss creates a risk of greater muscle atrophy and reduced abilities to travel and hunt.

  10. Xenoestrogenic and dioxin-like activity in blood of East Greenland polar bears (Ursus maritimus).

    Science.gov (United States)

    Erdmann, Simon E; Dietz, Rune; Sonne, Christian; Bechshøft, Thea Ø; Vorkamp, Katrin; Letcher, Robert J; Long, Manhai; Bonefeld-Jørgensen, Eva C

    2013-07-01

    The aims of the project were to (i) extract the lipophilic persistent organic pollutants (POPs) from the blood of 99 East Greenland polar bears and assess the combined mixture effect on the estrogen receptor (ER) and the aryl hydrocarbon receptor (AhR) mediated transactivity; (ii) To evaluate whether the receptor transactivities were associated with selected POP markers, and (iii) compare the receptor transactivities in polar bears with earlier studies on Greenlandic Inuit. Lipophilic POPs were extracted using a combination of solid-phase extraction (SPE) and high performance liquid chromatography (HPLC). ER mediated transactivity was determined using the ER luciferase reporter MVLN cell assay. The extracts were tested alone (XER) and together with 17β-estradiol (E2) as a physiological mimic (XERcomp). Dioxins and dioxin-like (DL) compounds were extracted by a combination of SPE and the Supelco Dioxin Prep System®. AhR mediated dioxin-like transactivity was determined using the AhR luciferase reporter Hepa 1.12cR cell assay. Agonistic ER transactivity was elicited by 19% of the samples, and a further increased E2 induced ER response was found for 52%, whereas 17% antagonized the E2 induced ER response. Positive correlations were found in subadult bears between XER and several POP biomarkers. XER and XERcomp correlated positively to each other. A total of 91% of the polar bear blood extracts elicited agonistic AhR transactivity. The AhR-TCDD equivalent (AhR-TEQ) median levels were higher among adult bears compared to subadult bears, but not significantly. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Circulation of the polar thermosphere during geomagnetically quiet and active times as observed by Dynamics Explorer 2

    International Nuclear Information System (INIS)

    McCormac, F.G.; Killeen, T.L.; Thayer, J.P.; Hernandez, G.; Tschan, C.R.; Ponthieu, J.J.; Spencer, N.W.

    1987-01-01

    Neutral wind measurements obtained by instruments on board the Dynamics Explorer 2 (DE 2) spacecraft have been used to study the effects of geomagnetic activity on the circulation of the high-latitude neutral thermosphere for solar maximum conditions during the periods of November 1981 through January 1982 and November 1982 through January 1983. The data have been sorted and ordered according to the two geophysical indices Kp and (auroral electrojet) AE. Simple expressions have been derived which describe (1) the maximum antisunward wind speed in the geomagnetic polar cap, (2) the maximum sunward wind speeds in the dawn and dusk sectors of the auroral oval, and (3) the latitudinal extent of the polar cap antisunward neutral wind as functions of Kp and AE. The results show a positive correlation between the geomagnetic indices and the three characteristic features of the neutral circulation described above. Averaged vector wind fields in geomagnetic coordinates for Kp ≤ 2 and Kp ≥ 4 in both northern and southern hemispheres for the 6 months have been derived from the data. In doing this, a first-order invariance of the neutral wind circulation in geomagnetic coordinates as a function of universal time (UT) was assumed. The results show a two-cell circulation pattern in the northern winter hemisphere for both quiet and active geomagnetic periods. The cell sizes increase with increasing geomagnetic activity. The dusk cell is always dominant. The southern summer hemisphere averages show only the dusk circulation cell for both quiet and active geomagnetic periods. The cell sizes increase with increasing geomagnetic activity. The dusk cell is always dominant. The southern summer hemisphere averages show only the dusk circulation cell for both quiet and active geomagnetic periods. A diminution of this cell occurs for reduced levels of geomagnetic activity

  12. Activation of PPARγ by a Natural Flavonoid Modulator, Apigenin Ameliorates Obesity-Related Inflammation Via Regulation of Macrophage Polarization

    Directory of Open Access Journals (Sweden)

    Xiujing Feng

    2016-07-01

    Full Text Available PPARγ has emerged as a master regulator of macrophage polarization and is the molecular target of the thiazolidinedione drugs. Here we show that apigenin binds and activates PPARγ by acting as a modulator. Activation of PPARγ by apigenin blocks p65 translocation into nuclei through inhibition of p65/PPARγ complex translocation into nuclei, thereby decreasing NF-κB activation and favoringM2 macrophage polarization. In HFD and ob/ob mice, apigenin significantly reverses M1 macrophage into M2 and reduces the infiltration of inflammatory cells in liver and adipose tissues, as well as decreases the levels of pro-inflammatory cytokines, thereby alleviating inflammation. Strikingly, apigenin reduces liver and muscular steatosis, decreases the levels of ALT, AST, TC and TG, improving glucose resistance obviously. Unlike rosiglitazone, apigenin does not cause significant weight gain, osteoporosis et al. Our findings identify apigenin as a modulator of PPARγ and a potential lead compound for treatment of metabolic disorders.

  13. Marine polar steroids

    International Nuclear Information System (INIS)

    Stonik, Valentin A

    2001-01-01

    Structures, taxonomic distribution and biological activities of polar steroids isolated from various marine organisms over the last 8-10 years are considered. The peculiarities of steroid biogenesis in the marine biota and their possible biological functions are discussed. Syntheses of some highly active marine polar steroids are described. The bibliography includes 254 references.

  14. Diverse deep-sea fungi from the South China Sea and their antimicrobial activity.

    Science.gov (United States)

    Zhang, Xiao-Yong; Zhang, Yun; Xu, Xin-Ya; Qi, Shu-Hua

    2013-11-01

    We investigated the diversity of fungal communities in nine different deep-sea sediment samples of the South China Sea by culture-dependent methods followed by analysis of fungal internal transcribed spacer (ITS) sequences. Although 14 out of 27 identified species were reported in a previous study, 13 species were isolated from sediments of deep-sea environments for the first report. Moreover, these ITS sequences of six isolates shared 84-92 % similarity with their closest matches in GenBank, which suggested that they might be novel phylotypes of genera Ajellomyces, Podosordaria, Torula, and Xylaria. The antimicrobial activities of these fungal isolates were explored using a double-layer technique. A relatively high proportion (56 %) of fungal isolates exhibited antimicrobial activity against at least one pathogenic bacterium or fungus among four marine pathogenic microbes (Micrococcus luteus, Pseudoaltermonas piscida, Aspergerillus versicolor, and A. sydowii). Out of these antimicrobial fungi, the genera Arthrinium, Aspergillus, and Penicillium exhibited antibacterial and antifungal activities, while genus Aureobasidium displayed only antibacterial activity, and genera Acremonium, Cladosporium, Geomyces, and Phaeosphaeriopsis displayed only antifungal activity. To our knowledge, this is the first report to investigate the diversity and antimicrobial activity of culturable deep-sea-derived fungi in the South China Sea. These results suggest that diverse deep-sea fungi from the South China Sea are a potential source for antibiotics' discovery and further increase the pool of fungi available for natural bioactive product screening.

  15. Chemical characterization by GC-MS and phytotoxic potential of non-polar and polar fractions of seeds of Dioteryx odorata (Aubl. Willd. from Venezuelan regions

    Directory of Open Access Journals (Sweden)

    Alberto de J. Oliveros-Bastidas

    2013-01-01

    Full Text Available Dipteryx odorata (Aubl. Willd. is a tall arboreal species native to Central and Northern South America. This paper describes the chemical characterization and phytotoxic potential of polar and non-polar extracts from D. odorata seeds. Structural determinations were accomplished by chemical derivatization and analyzed by GC/MS. The chemical composition of the non-polar fraction (hexane and dichloromethane presented fatty acids as major constituent. Medium polar and polar fractions (ethyl acetate and ethanol: water contained carboxylic acid and high 6,7-Dyhidroxycoumarin-β-D-glucopyranoside content, not previously reported for seeds of D. odorata. Extracts showed a significant level of phytotoxic activity, correlated to the content of coumarin derivatives, predominantly in the polar fraction.

  16. Objectively determined habitual physical activity in South African adolescents: the PAHL study

    Science.gov (United States)

    2014-01-01

    Background There is limited data on objectively determined habitual physical activity (PA) in 16-year old South African adolescents. The purpose of this study was to objectively determine the habitual PA of adolescents from the North West Province of South Africa by race and gender. Methods Adolescents (137 girls, 89 boys) from the ongoing Physical Activity and Health Longitudinal Study (PAHL study), participated in the present study. Habitual PA was objectively recorded by means of the Actiheart® over a period of 7 days. Time spent in moderate-to-vigorous intensity physical activity (MVPA) was assessed. Results Average MVPA for the study sample was 50.9 ± 40.3 minutes/day. Girls were significantly more active than boys expending more time in MVPA (61.13 ± 52.2 minutes/day; p Physical activity varies by both gender and race in adolescents from the North West Province of South Africa. Objectively determined data from our study indicates that girls habitually spend more time in MVPA per day than boys, and that white adolescents habitually engage in more MVPA than black adolescents. Seeing as the average MVPA per day for the entire study sample falls below the recommended daily average of 60minutes/day, adolescents should be the foremost targets of interventions aimed at enhancing habitual PA. PMID:24885503

  17. Protease activity of Per a 10 potentiates Th2 polarization by increasing IL-23 and OX40L.

    Science.gov (United States)

    Agrawal, Komal; Kale, Sagar L; Arora, Naveen

    2015-12-01

    Proteases are implicated in exacerbation of allergic diseases. In this study, the role of proteolytic activity of Per a 10 was evaluated on Th2 polarization. Intranasal administration of Per a 10 in mice led to allergic airway inflammation as seen by higher IgE levels, cellular infiltration, IL-17A, and Th2 cytokines, whereas, inactive (Δ)Per a 10 showed attenuated response. There was an increased OX40L expression on lung and lymph node dendritic cells in Per a 10 immunized group and on Per a 10 stimulated BMDCs. Reduction in CD40 expression without any change at transcript level in lungs of Per a 10 immunized mice suggested CD40 cleavage. BMDCs pulsed with Per a 10 showed reduced CD40 expression with lower IL-12p70 secretion as compared to heat inactivated Per a 10. IL-23, TNF-α, and IL-6 levels were significantly higher in Per a 10 stimulated BMDCs supernatant. In DC-T cell coculture studies, Per a 10 pulsed BMDCs showed higher levels of IL-4 and IL-13 that were reduced on blocking of either IL-23 or OX40L. In conclusion, the data suggests a critical role of protease activity of Per a 10 in promoting Th2 polarization by increasing IL-23 secretion and OX40L expression on dendritic cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. C-band Joint Active/Passive Dual Polarization Sea Ice Detection

    Science.gov (United States)

    Keller, M. R.; Gifford, C. M.; Winstead, N. S.; Walton, W. C.; Dietz, J. E.

    2017-12-01

    A technique for synergistically-combining high-resolution SAR returns with like-frequency passive microwave emissions to detect thin (Radar (SAR) is high resolution (5-100m) but because of cross section ambiguities automated algorithms have had difficulty separating thin ice types from water. The radiometric emissivity of thin ice versus water at microwave frequencies is generally unambiguous in the early stages of ice growth. The method, developed using RADARSAT-2 and AMSR-E data, uses higher-ordered statistics. For the SAR, the COV (coefficient of variation, ratio of standard deviation to mean) has fewer ambiguities between ice and water than cross sections, but breaking waves still produce ice-like signatures for both polarizations. For the radiometer, the PRIC (polarization ratio ice concentration) identifies areas that are unambiguously water. Applying cumulative statistics to co-located COV levels adaptively determines an ice/water threshold. Outcomes from extensive testing with Sentinel and AMSR-2 data are shown in the results. The detection algorithm was applied to the freeze-up in the Beaufort, Chukchi, Barents, and East Siberian Seas in 2015 and 2016, spanning mid-September to early November of both years. At the end of the melt, 6 GHz PRIC values are 5-10% greater than those reported by radiometric algorithms at 19 and 37 GHz. During freeze-up, COV separates grease ice (cross-pol/co-pol SAR ratio corrects for COV deficiencies. In general, the dual-sensor detection algorithm reports 10-15% higher total ice concentrations than operational scatterometer or radiometer algorithms, mostly from ice edge and coastal areas. In conclusion, the algorithm presented combines high-resolution SAR returns with passive microwave emissions for automated ice detection at SAR resolutions.

  19. Should Physical Activity Recommendations for South Asian Adults Be Ethnicity-Specific? Evidence from a Cross-Sectional Study of South Asian and White European Men and Women.

    Science.gov (United States)

    Iliodromiti, Stamatina; Ghouri, Nazim; Celis-Morales, Carlos A; Sattar, Naveed; Lumsden, Mary Ann; Gill, Jason M R

    2016-01-01

    International public health guidelines recommend that adults undertake at least 150 min.week-1 of moderate-intensity physical activity. However, the underpinning evidence has largely been obtained from studies of populations of white European descent. It is unclear whether these recommendations are appropriate for other ethnic groups, particularly South Asians, who have greater cardio-metabolic risk than white Europeans. The objective of our study was to determine the level of moderate-intensity physical activity required in South Asians adults to confer a similar cardio-metabolic risk profile to that observed in Europeans of similar age and body mass index (BMI) undertaking the currently recommended levels of 150 min.week-1. 148 South Asians and 163 white Europeans aged 18 to 70 years were recruited. Physical activity was measured objectively via vertical axis accelerations from hip-worn accelerometers. Factor analysis was used to summarize the measured risk biomarkers into a single underlying latent "factor" describing overall cardio-metabolic risk. Sex did not modify the association between physical activity and the cardio-metabolic risk factor, so data for both sexes were combined and models adjusted for age, sex, BMI and accelerometer wear time. We estimated that South Asian adults needed to undertake 232 (95% Confidence interval: 200 to 268) min.week-1 in order to obtain the same cardio-metabolic risk factor score as a white European undertaking 150 minutes of moderate-equivalent physical activity per week. The present findings suggest that South Asian men and women need to undertake ~230 minutes of moderate intensity physical activity per week. This equates to South Asians undertaking an extra 10-15 minutes of moderate intensity physical activity per day on top of existing recommendations.

  20. Should Physical Activity Recommendations for South Asian Adults Be Ethnicity-Specific? Evidence from a Cross-Sectional Study of South Asian and White European Men and Women.

    Directory of Open Access Journals (Sweden)

    Stamatina Iliodromiti

    Full Text Available International public health guidelines recommend that adults undertake at least 150 min.week-1 of moderate-intensity physical activity. However, the underpinning evidence has largely been obtained from studies of populations of white European descent. It is unclear whether these recommendations are appropriate for other ethnic groups, particularly South Asians, who have greater cardio-metabolic risk than white Europeans. The objective of our study was to determine the level of moderate-intensity physical activity required in South Asians adults to confer a similar cardio-metabolic risk profile to that observed in Europeans of similar age and body mass index (BMI undertaking the currently recommended levels of 150 min.week-1. 148 South Asians and 163 white Europeans aged 18 to 70 years were recruited. Physical activity was measured objectively via vertical axis accelerations from hip-worn accelerometers. Factor analysis was used to summarize the measured risk biomarkers into a single underlying latent "factor" describing overall cardio-metabolic risk. Sex did not modify the association between physical activity and the cardio-metabolic risk factor, so data for both sexes were combined and models adjusted for age, sex, BMI and accelerometer wear time. We estimated that South Asian adults needed to undertake 232 (95% Confidence interval: 200 to 268 min.week-1 in order to obtain the same cardio-metabolic risk factor score as a white European undertaking 150 minutes of moderate-equivalent physical activity per week. The present findings suggest that South Asian men and women need to undertake ~230 minutes of moderate intensity physical activity per week. This equates to South Asians undertaking an extra 10-15 minutes of moderate intensity physical activity per day on top of existing recommendations.

  1. Application of Polarization Modulated Infrared Reflection Absorption Spectroscopy for electrocatalytic activity studies of laccase adsorbed on modified gold electrodes

    International Nuclear Information System (INIS)

    Olejnik, Piotr; Pawłowska, Aleksandra; Pałys, Barbara

    2013-01-01

    Orientation of the enzyme macromolecule on the electrode surface is crucially important for the efficiency of the electron transport between the active site and electrode surface. The orientation can be controlled by affecting the surface charge and the pH of the buffer solution. In this contribution we study laccase physically adsorbed on gold surface modified by mercapto-ethanol, lipid and variously charged diazonium salts. Polarization Modulated Infrared Reflection Absorption Spectroscopy (PMIRRAS) enables the molecular orientation study of the protein molecule by comparison of the amide I to amide II band intensity ratios assuming that the protein secondary structure does not change. We observe significant differences in the intensity ratios depending on the kind of support and the enzyme deposition. The comparison of infrared spectra and cyclic voltammetry responses of variously prepared laccase layers reveals that the parallel orientation of beta-sheet moieties results in high enzyme activity

  2. The Great Solar Active Region NOAA 12192: Helicity Transport, Filament Formation, and Impact on the Polar Field

    Energy Technology Data Exchange (ETDEWEB)

    McMaken, Tyler C. [National Solar Observatory REU Program, 3665 Discovery Drive, 3rd Floor, Boulder, CO 80303 (United States); Petrie, Gordon J. D., E-mail: tmcmaken@gmail.com, E-mail: gpetrie@noao.edu [National Solar Observatory, 3665 Discovery Drive, 3rd Floor, Boulder, CO 80303 (United States)

    2017-05-10

    The solar active region (AR), NOAA 12192, appeared in 2014 October as the largest AR in 24 years. Here we examine the counterintuitive nature of two diffusion-driven processes in the region: the role of helicity buildup in the formation of a major filament, and the relationship between the effects of supergranular diffusion and meridional flow on the AR and on the polar field. Quantitatively, calculations of current helicity and magnetic twist from Helioseismic and Magnetic Imager (HMI) vector magnetograms indicate that, though AR 12192 emerged with negative helicity, positive helicity from subsequent flux emergence, consistent with the hemispheric sign-preference of helicity, increased over time within large-scale, weak-field regions such as those near the polarity inversion line (PIL). Morphologically, Atmospheric Imaging Assembly observations of filament barbs, sigmoidal patterns, and bases of Fe xii stalks initially exhibited signatures of negative helicity, and the long filament that subsequently formed had a strong positive helicity consistent with the helicity buildup along the PIL. We find from full-disk HMI magnetograms that AR 12192's leading positive flux was initially closer to the equator but, owing either to the region’s magnetic surroundings or to its asymmetric flux density distribution, was transported poleward more quickly on average than its trailing negative flux, contrary to the canonical pattern of bipole flux transport. This behavior caused the AR to have a smaller effect on the polar fields than expected and enabled the formation of the very long neutral line where the filament formed.

  3. DC type 2 polarization depends on both the allergic status of the individual and protease activity of Per a 10.

    Science.gov (United States)

    Goel, Chhavi; Gaur, S N; Bhati, Gaurav; Arora, Naveen

    2015-10-01

    Cockroach proteases are important risk factors for asthma development in predisposed individuals. In the present study, effect of allergic status of patients on DCs polarization in response to protease allergen Per a 10 was investigated. Cockroach-allergic, other-allergic patients and healthy individuals were selected following the guidelines of ATS/ARIA. Monocyte-derived dendritic cells (DCs) were generated from the selected individuals and stimulated with Per a 10. Flow cytometric analysis showed a significantly high expression of CD80 and CD86 on DCs from cockroach-allergic patients after Per a 10 stimulation as compared to healthy individuals or other-allergic patients (PPer a 10 induced comparable level of CD83 expression on DCs from all the 3 groups, showing it was irrespective of the allergic status. CD40 expression was significantly low (PPer a 10 induced lower CD40 expression on DCs than the heat-inactivated Per a 10 (PPer a 10 stimulated DC cultures was significantly higher than in heat-inactivated Per a 10 (PPer a 10-stimulated DCs than heat-inactivated Per a 10-stimulated DCs. Per a 10-stimulated DCs from cockroach-allergic patients secreted high levels of IL-5, IL-6, TNF-α than that from healthy individuals or other-allergic patients (PPer a 10-stimulated DCs from cockroach-allergic patients induced increased secretions of IL-4, IL-5, IL-6, TNF-α and low IL-12 by T cells as compared to those from other groups (PPer a 10 allergen, polarization of DCs shifts toward type 2 in cockroach-allergic patients but not in the healthy individuals or other-allergic patients. In conclusion, both allergic status of the individual and protease activity of Per a 10 are important parameters that participate in DCs polarization. Copyright © 2015 Elsevier GmbH. All rights reserved.

  4. Cytotoxic activity of different polarity fractions obtained from methanolic extracts of Vismia baccifera and Vismia macrophylla (Hypericaceae collected in Venezuela

    Directory of Open Access Journals (Sweden)

    Janne del C. Rojas

    2017-10-01

    Full Text Available Context: Cancer is a complex disease involving numerous changes in cell physiology and abnormal cell growth, which lead to malignant tumors. Many investigations are still carrying on in different areas including, natural products, to find a possible break point to this pathology. Aims: To evaluate the cytotoxic activity on different polar extracts from Vismia baccifera and Vismia macrophylla collected in two locations of the Venezuelan Andes. Methods: Cytotoxic activity assay was carried out following the colorimetric (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide MTT assay. Human tumor cell Lines from breast carcinoma without gene over-expression (MCF-7, breast carcinoma with overexpressed gene (SKBr3, prostate carcinoma (PC3 and cervix epithelial carcinoma (HeLa were tested with different polarity solvent extracts (hexane, dichloromethane, ethyl acetate, butanol, water from the two species under investigation. Human dermis fibroblasts were used as control cells. Mean inhibitory concentration (IC50 was calculated. Results: Extracts from V. macrophylla showed significant inhibition of cervix epithelial carcinoma with values ranging from 6.09 µg/mL to 17.51 µg/mL; breast carcinoma with an overexpressed gene with values from 12.14 µg/mL to 16.90 µg/mL and prostate carcinoma from 10.91 µg/mL to 17.70 µg/mL. V. baccifera extracts showed the strongest activity against prostate carcinoma with an IC50 value of 2.92 µg/mL. Conclusions: The present study showed evidence for the anticancer activity of Vismia baccifera and Vismia macrophylla extracts since caused growth inhibition in different cell lines at low concentrations, thus, it is considered not only an important contribution to the natural products research but bring supportive data for further investigations on cancer research.

  5. Why is North China seismically active while South China largely aseismic?

    Science.gov (United States)

    Yang, Y.; Liu, M.

    2002-12-01

    The North China block (also known as the Sino-Korean craton) is a region of strong intraplate seismicity and active crustal deformation. Many large earthquakes, including the most devastating earthquake in modern history at Tangshan in 1976 (M=7.5), occurred in this heavily populated region. The South China block (i.e., the Yangtz craton), in contrast, is largely aseismic, although its basement rocks are younger and much of the region is closer to the present plate boundaries than the North China block. We have investigated the contrasting active tectonics between the North and South China blocks using a three-dimensional finite element model. The model approximates the geometry of the two blocks and the surrounding tectonic units. The first-order variations of lithospheric rheology, both laterally and vertically, of these blocks are considered. The kinematic boundary conditions based on the GPS data are applied to the model, and the distribution of gravitational buoyancy force within the Asian continent is calculated using digital topography. Our results suggest that the particular boundary conditions surrounding the North and South China blocks may provide the basic explanation for the contrasting seismicity between these two regions. Aligned with the axis of compression from the indenting Indian plate and supported by the stable eastern Siberia, the North China block is predicted to experience strong deviatoric stresses. A weaker crust, as indicated by the widespread Late Cenozoic volcanism and rifts and high heat flow today, further explain the abundance of seismicity in the North China block. The South China block, on the other hand, sits in the "pressure shadow" of the Indo-Asian collision with little tectonic stresses transmitted from the collision zone. The east-southeastward extrusion of the Asian continent following the Indo-Asian collision allowed the South China block to move as a coherent block as shown by the GPS data, resulting in little internal

  6. Dietary and physical activity strategies to prevent type 2 diabetes in South Asian adults: protocol for a systematic review

    NARCIS (Netherlands)

    Muilwijk, Mirthe; Stronks, Karien; Qureshi, Samera Azeem; Beune, Erik; Celis-Morales, Carlos; Gill, Jason; Sheikh, Aziz; Jenum, Anne Karen; van Valkengoed, Irene G. M.

    2017-01-01

    Introduction Type 2 diabetes (T2D) is a major health concern among populations of South Asian ethnicity. Although dietary and physical activity interventions may reduce the risk of T2D, the effectiveness has been moderate among South Asians. This might (in part) be because this subgroup follows

  7. Division of volcanic activity cycles in the late mesozoic in South Jiangxi and North Guangdong

    International Nuclear Information System (INIS)

    Li Qinglong; Wu Jianhua

    1999-01-01

    Based on stratigraphical unconformity, rock association, fossil assemblage, isotope age and tectonic features, the volcanic activity in late Mesozoic in south Jiangxi and north Guandong can be divided into four cycles: Yutian volcanic activity cycle, Lianhuazhai volcanic activity cycle. Banshi volcanic activity cycle and Nanxiong volcanic activity cycle. Yutian volcanic cycle which occurs in middle Jurassic epoch is the bimodal rock association composed of rhyolite and basalt. Lianhuazhai volcanic cycle which occurs in late Jurassic epoch is unimodal rock association composed of rhyolite. Banshi volcanic cycle occurs from the late stage of early Cretaceous to the early stage of late Cretaceous epoch. There are two types of rock associations related to this cycle: unimodal rock association composed of rhyolite or basalt and bimodal rock association composed of rhyolite and basalt. Nanxiong volcanic activity cycle which occurred in late stage of late Cretaceous epoch is the unimodal rock association composed of basalt which is the interlayer of the red sedimentary series

  8. Haemophilus ducreyi infection induces activation of the NLRP3 inflammasome in nonpolarized but not in polarized human macrophages.

    Science.gov (United States)

    Li, Wei; Katz, Barry P; Bauer, Margaret E; Spinola, Stanley M

    2013-08-01

    Recognition of microbial infection by certain intracellular pattern recognition receptors leads to the formation of a multiprotein complex termed the inflammasome. Inflammasome assembly activates caspase-1 and leads to cleavage and secretion of the proinflammatory cytokines interleukin-1 beta (IL-1β) and IL-18, which help control many bacterial pathogens. However, excessive inflammation mediated by inflammasome activation can also contribute to immunopathology. Here, we investigated whether Haemophilus ducreyi, a Gram-negative bacterium that causes the genital ulcer disease chancroid, activates inflammasomes in experimentally infected human skin and in monocyte-derived macrophages (MDM). Although H. ducreyi is predominantly extracellular during human infection, several inflammasome-related components were transcriptionally upregulated in H. ducreyi-infected skin. Infection of MDM with live, but not heat-killed, H. ducreyi induced caspase-1- and caspase-5-dependent processing and secretion of IL-1β. Blockage of H. ducreyi uptake by cytochalasin D significantly reduced the amount of secreted IL-1β. Knocking down the expression of the inflammasome components NLRP3 and ASC abolished IL-1β production. Consistent with NLRP3-dependent inflammasome activation, blocking ATP signaling, K(+) efflux, cathepsin B activity, and lysosomal acidification all inhibited IL-1β secretion. However, inhibition of the production and function of reactive oxygen species did not decrease IL-1β production. Polarization of macrophages to classically activated M1 or alternatively activated M2 cells abrogated IL-1β secretion elicited by H. ducreyi. Our study data indicate that H. ducreyi induces NLRP3 inflammasome activation via multiple mechanisms and suggest that the heterogeneity of macrophages within human lesions may modulate inflammasome activation during human infection.

  9. A model for promoting physical activity among rural South African adolescent girls

    Science.gov (United States)

    Kinsman, John; Norris, Shane A.; Kahn, Kathleen; Twine, Rhian; Riggle, Kari; Edin, Kerstin; Mathebula, Jennifer; Ngobeni, Sizzy; Monareng, Nester; Micklesfield, Lisa K.

    2015-01-01

    Background In South Africa, the expanding epidemic of non-communicable diseases is partly fuelled by high levels of physical inactivity and sedentary behaviour. Women especially are at high risk, and interventions promoting physical activity are urgently needed for girls in their adolescence, as this is the time when many girls adopt unhealthy lifestyles. Objective This qualitative study aimed to identify and describe facilitating factors and barriers that are associated with physical activity among adolescent girls in rural, north-eastern South Africa and, based on these, to develop a model for promoting leisure-time physical activity within this population. Design The study was conducted in and around three secondary schools. Six focus group discussions were conducted with adolescent girls from the schools, and seven qualitative interviews were held with sports teachers and youth leaders. The data were subjected to thematic analysis. Results Seven thematic areas were identified, each of which was associated with the girls’ self-reported levels of physical activity. The thematic areas are 1) poverty, 2) body image ideals, 3) gender, 4) parents and home life, 5) demographic factors, 6) perceived health effects of physical activity, and 7) human and infrastructural resources. More barriers to physical activity were reported than facilitating factors. Conclusions Analysis of the barriers found in the different themes indicated potential remedial actions that could be taken, and these were synthesised into a model for promoting physical activity among South African adolescent girls in resource-poor environments. The model presents a series of action points, seen both from the ‘supply-side’ perspective (such as the provision of resources and training for the individuals, schools, and organisations which facilitate the activities) and from the ‘demand-side’ perspective (such as the development of empowering messages about body image for teenage girls, and

  10. A model for promoting physical activity among rural South African adolescent girls

    Directory of Open Access Journals (Sweden)

    John Kinsman

    2015-12-01

    Full Text Available Background: In South Africa, the expanding epidemic of non-communicable diseases is partly fuelled by high levels of physical inactivity and sedentary behaviour. Women especially are at high risk, and interventions promoting physical activity are urgently needed for girls in their adolescence, as this is the time when many girls adopt unhealthy lifestyles. Objective: This qualitative study aimed to identify and describe facilitating factors and barriers that are associated with physical activity among adolescent girls in rural, north-eastern South Africa and, based on these, to develop a model for promoting leisure-time physical activity within this population. Design: The study was conducted in and around three secondary schools. Six focus group discussions were conducted with adolescent girls from the schools, and seven qualitative interviews were held with sports teachers and youth leaders. The data were subjected to thematic analysis. Results: Seven thematic areas were identified, each of which was associated with the girls’ self-reported levels of physical activity. The thematic areas are 1 poverty, 2 body image ideals, 3 gender, 4 parents and home life, 5 demographic factors, 6 perceived health effects of physical activity, and 7 human and infrastructural resources. More barriers to physical activity were reported than facilitating factors. Conclusions: Analysis of the barriers found in the different themes indicated potential remedial actions that could be taken, and these were synthesised into a model for promoting physical activity among South African adolescent girls in resource-poor environments. The model presents a series of action points, seen both from the ‘supply-side’ perspective (such as the provision of resources and training for the individuals, schools, and organisations which facilitate the activities and from the ‘demand-side’ perspective (such as the development of empowering messages about body image for

  11. Sedentary behaviour and physical activity in South Asian women: time to review current recommendations?

    Science.gov (United States)

    Waidyatilaka, Indu; Lanerolle, Pulani; Wickremasinghe, Rajitha; Atukorala, Sunethra; Somasundaram, Noel; de Silva, Angela

    2013-01-01

    Our aims were to describe activity and sedentary behaviours in urban Asian women, with dysglycaemia (diagnosed at recruitment), and without dysglycaemia and examine the relative contribution of these parameters to their glycaemic status. 2800 urban women (30-45 years) were selected by random cluster sampling and screened for dysglycaemia for a final sample of 272 newly diagnosed, drug naive dysglycaemic and 345 normoglycaemic women. Physical activity and sedentary behaviours were assessed by the International Physical Activity Questionnaire (IPAQ). Demographic data, diet and anthropometry were recorded. Logistic regression analysis assessed contribution of all parameters to dysglycaemia and exposure attributable fractions were calculated. The mean energy expenditure on walking (2648.5±1023.7 MET-min/week) and on moderate and vigorous physical activity (4342.3±1768.1 MET-min/week) for normoglycemic women and dysglycaemic women (walking;1046.4±728.4 MET-min/week, moderate and vigorous physical activity; 1086.7±1184.4 MET-min/week) was above the recommended amount of physical activity per week. 94.3% of women spent >1000 MET-minutes/week on activity. Mean sitting and TV time for normoglycaemic and dysglycaemic women were 154.3±62.8, 38.4±31.9, 312.6±116.7 and 140.2±56.5 minutes per day respectively. Physical activity and sedentary behaviour contributed to dysglycaemia after adjustment for family history, diet, systolic blood pressure and Body Mass Index. Exposure attributable fractions for dysglycaemia were; lower physical activity: 78%, higher waist circumference: 94%, and TV viewing time: 85%. Urban South Asian women are at risk of dysglycaemia at lower levels of sedentary behaviour and greater physical activity than western populations, indicating the need for re-visiting current physical activity guidelines for South Asians.

  12. Sedentary behaviour and physical activity in South Asian women: time to review current recommendations?

    Directory of Open Access Journals (Sweden)

    Indu Waidyatilaka

    Full Text Available OBJECTIVE: Our aims were to describe activity and sedentary behaviours in urban Asian women, with dysglycaemia (diagnosed at recruitment, and without dysglycaemia and examine the relative contribution of these parameters to their glycaemic status. METHODS: 2800 urban women (30-45 years were selected by random cluster sampling and screened for dysglycaemia for a final sample of 272 newly diagnosed, drug naive dysglycaemic and 345 normoglycaemic women. Physical activity and sedentary behaviours were assessed by the International Physical Activity Questionnaire (IPAQ. Demographic data, diet and anthropometry were recorded. Logistic regression analysis assessed contribution of all parameters to dysglycaemia and exposure attributable fractions were calculated. RESULTS: The mean energy expenditure on walking (2648.5±1023.7 MET-min/week and on moderate and vigorous physical activity (4342.3±1768.1 MET-min/week for normoglycemic women and dysglycaemic women (walking;1046.4±728.4 MET-min/week, moderate and vigorous physical activity; 1086.7±1184.4 MET-min/week was above the recommended amount of physical activity per week. 94.3% of women spent >1000 MET-minutes/week on activity. Mean sitting and TV time for normoglycaemic and dysglycaemic women were 154.3±62.8, 38.4±31.9, 312.6±116.7 and 140.2±56.5 minutes per day respectively. Physical activity and sedentary behaviour contributed to dysglycaemia after adjustment for family history, diet, systolic blood pressure and Body Mass Index. Exposure attributable fractions for dysglycaemia were; lower physical activity: 78%, higher waist circumference: 94%, and TV viewing time: 85%. CONCLUSIONS: Urban South Asian women are at risk of dysglycaemia at lower levels of sedentary behaviour and greater physical activity than western populations, indicating the need for re-visiting current physical activity guidelines for South Asians.

  13. Simulation of the adsorption capacity of polar organic compounds and dyes from water onto activated carbons: Model development and validation

    Directory of Open Access Journals (Sweden)

    Warisa Bunmahotama

    2018-03-01

    Full Text Available A model approach is developed to simulate the adsorption isotherms of low-molecular-weight polar organic compounds (LMWPOCs, halogenated LMWPOCs, and dye molecules onto activated carbons (AC. The models were based on the Dubinin–Astakhov equation, with the limiting pore volume of adsorbent estimated from the pore size distribution data, and the adsorption affinity of the adsorbate described by the molecular connectivity index. The models were used to simulate the adsorption data of 87 LMWPOCs onto six ACs, 25 halogenated LMWPOCs onto two ACs and 22 dyes onto three ACs. The developed models follow the experimental data fairly well, with errors of 49, 33 and 43% for the tested LMWPOCs, halogenated LMWPOCs, and dyes, respectively. This study shows that the developed model approach may provide a simple means for the estimation of adsorption capacity for LMWPOCs and dyes onto ACs in water.

  14. Unusual Polar Conditions in Solar Cycle 24 and Their Implications for Cycle 25

    Science.gov (United States)

    Gopalswamy, Nat; Yashiro, Seiji; Akiyama, Sachiko

    2016-01-01

    We report on the prolonged solar-maximum conditions until late 2015 at the north-polar region of the Sun indicated by the occurrence of high-latitude prominence eruptions (PEs) and microwave brightness temperature close to the quiet-Sun level. These two aspects of solar activity indicate that the polarity reversal was completed by mid-2014 in the south and late 2015 in the north. The microwave brightness in the south-polar region has increased to a level exceeding the level of the Cycle 23/24 minimum, but just started to increase in the north. The northsouth asymmetry in the polarity reversal has switched from that in Cycle 23. These observations lead us to the hypothesis that the onset of Cycle 25 in the northern hemisphere is likely to be delayed with respect to that in the southern hemisphere. We find that the unusual condition in the north is a direct consequence of the arrival of poleward surges of opposite polarity from the active region belt. We also find that multiple rush-to-the-pole episodes were indicated by the PE locations that lined up at the boundary between opposite-polarity surges. The high-latitude PEs occurred in the boundary between the incumbent polar flux and the insurgent flux of opposite polarity.

  15. The analysis of the population economic activity and unemployment in the South Moravian region

    Directory of Open Access Journals (Sweden)

    Jaroslava Hudečková

    2005-01-01

    Full Text Available This article deals with analysis of the South Moravian region population economic activity and unemployment state and development. The analysis of the population economic activity and unemployment is a part of the demographic, social and economic population analysis. The unemployment is considered to be an unfavourable effect, but its low rate is a natural part of the market economy. The unemployment was from the general and registered unemployment rate in years 1995–2003 point of view evaluated. Some indicators of the South Moravian region were with the whole Czech Republic compared. The unemployment in the South Moravian region marked a negative development in mentioned period and in the year 2003 achieved value of 11.45%. The trend of the unemployment development was defined and also the seasonal character with the seasonal indexes was analysed. The highest unemployment was proved in winter months (January–March and least in May and June. There was proved the high dependency rate among the number of vacancies, the number of applicants for one vacancy and unemployment rate.

  16. Further studies on South African plants: Acaricidal activity of organic plant extracts against Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

    CSIR Research Space (South Africa)

    Wellington, Kevin W

    2017-01-01

    Full Text Available -1 Veterinary Parasitology, vol. 234: 10-12 Further studies on South African plants: Acaricidal activity of organic plant extracts against Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) Wellington, KW Leboho, T Sakong, BM Adenubi, OT Eloff, JN...

  17. Impact of climate and weather on the activities of the building and construction industry in South Africa

    CSIR Research Space (South Africa)

    De Villiers, GDT

    1986-01-01

    Full Text Available This study represents a quantitative survey of the impact of the climate and weather on the activities of the building and construction industry in South Africa. Seasonal productivity problems, the seasonal provision of special facilities...

  18. Time spent in sedentary activities in a pediatric population in Pretoria Central, South Africa.

    Science.gov (United States)

    Goon, Daniel T; Nsibambi, Constance A; Chebet, Milton

    2016-12-01

    Scant information exist on screen time behavior of South Africa children and whether they do not meet the recommendation of American Association of Pediatrics (AAP) concerning screen time activity for children is only speculative. Therefore, the purpose of this study was to examine the time spent in sedentary activities, especially screen time of South African children with regard to gender. This cross-sectional study involved a random sample of 1136 school children (548 boys; 588 girls) aged 9-13 years attending public schools in Central Pretoria, South Africa. Questionnaire was used to collect data on the participants' sedentary behaviors. The prevalence estimates for sedentary time activity was based on the guidelines (i.e., <2 or ≥2 hours per day) of AAP. The mean age of the children was 11.1±1.4 years. Sedentary activity data were collected from 548 boys (48.2%) and 588 (51.8%) girls. The majority of children spent more than two hours per day (exceeding the AAP recommendation for sedentary activity) watching TV (3.0%), worked or played on the computer (25.4%), read (1.0%), played music (27.9%), played board games (14.7%), washing clothes (8.0%), floor sweeping (10.5%), art work (18.2%), and spent time on other unspecified activities (28.6%). Boys spent more time (2 hours, 3-4 hours) watching TV (38.3%; P=0.001), playing computer (31.8 %; P=0.024) and board games (17.4%; P=0.012) than girls. The corresponding figures for girls were 35.7%, 19.2% and 12.5% for TV, computer and board games, respectively. However, the proportion of those who spent more time playing music was higher among girls (32.7%) than boys (22.4%) (P=0.002). Overall, the time spent exceeding AAP recommendation (≥ 2 hours) was not statistically (P=0.427) different between boys and girls. The time spent in sedentary activities, particularly in screen time activity among urban primary school children in Pretoria Central is excessively higher than the recommendation (i.e., ≥2 hours per day

  19. Physical Activity and Sedentary Behavior in an Ethnically Diverse Group of South African School Children

    Directory of Open Access Journals (Sweden)

    Joanne McVeigh, Rebecca Meiring

    2014-06-01

    Full Text Available Few studies have examined physical activity and inactivity levels in an urban South African setting across 12 years of formal schooling. This information is important for implementing strategies to curb increasing trends of physical inactivity and related negative consequences, especially in low to middle income countries facing multiple challenges on overburdened health care systems. We examined levels of physical activity and sedentary behaviour cross-sectionally over 12 school years from childhood to adolescence in Black, White and Indian boys and girls. The aim of our study was to describe gender and race related patterns of physical and sedentary activity levels in a sample of South African children and to determine whether there were associations between these variables and body mass status. Physical activity questionnaires, previously validated in a South African setting, were used to gather information about activity and sedentary behaviours among 767 Black, White and Indian children (5-18 years of age across the 12 grades of formal schooling. Body mass and height were also measured. Time spent in moderate-vigorous physical activity declined over the school years for all race groups and was consistently lower for girls than boys (p = 0.03, while time spent in sedentary activity increased with increasing grade (p 0.05 whereas time spent in sedentary activities was significantly and positively correlated with body mass across all race groups: Indian (r = 0.25, p < 0.001, White (r = 0.22, p < 0.001 and Black (r = 0.37, p = 0.001. The strength of the associations was similar for boys and girls. Black and Indian children were less physically active than their white peers (p < 0.05, and Black children also spent more time in sedentary activity (p < 0.05. Additionally, Black children had the highest proportion of overweight participants (30%, and Indian children the most number of underweight children (13%. Regardless of ethnicity, children who

  20. Esterase Active in Polar Organic Solvents from the Yeast Pseudozyma sp. NII 08165

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    Deepthy Alex

    2014-01-01

    Full Text Available Esterases/lipases active in water miscible solvents are highly desired in biocatalysis where substrate solubility is limited and also when the solvent is desired as an acyl acceptor in transesterification reactions, as with the case of biodiesel production. We have isolated an esterase from the glycolipid producing yeast-Pseudozyma sp. NII 08165 which in its crude form was alkali active, thermo stable, halo tolerant and also capable of acting in presence of high methanol concentration. The crude enzyme which maintained 90% of its original activity after being treated at 70°C was purified and the properties were characterized. The partially purified esterase preparation had temperature and pH optima of 60°C and 8.0 respectively. The enzyme retained almost complete activity in presence of 25% methanol and 80% activity in the same strength of ethanol. Conditions of enzyme production were optimized, which lead to 9 fold increase in the esterase yield. One of the isoforms of the enzyme LIP1 was purified to homogeneity and characterized. Purified LIP1 had a Km and Vmax of 0.01 and 1.12, respectively. The purified esterase lost its thermo and halo tolerance but interestingly, retained 97% activity in methanol.

  1. What does "success" in public engagement activities mean? A comparison of goals, motivations and embedded assumptions in four polar outreach activities.

    Science.gov (United States)

    Roop, H. A.; Salmon, R. A.

    2015-12-01

    Using four very different polar outreach case studies, we will discuss scientists' motivations, expectations, and institutional incentives (and dis-incentives) to engage with the public, and argue that improved training, evaluation, and academic value needs to be associated with scientist-led communication efforts - as well as clearer fora for sharing best practice in this field. We will illustrate our argument using examples from an Antarctic festival with public lectures and science cafes, outreach associated with an Antarctic expedition, the global launch of a climate change documentary that had a significant focus on Antarctica, and a series of "Polar Weeks" led by an international community of scientists and educators. While there is an excellent culture of accountability in both formal and informal science communication sectors, the same rigour is not applied to the majority of 'outreach' activities that are initiated by the science research community. Many of these activities are undertaken based on 'what feels right' and opportunism, and are proclaimed to be a success based on little or no formal evaluation. As a result, much of this work goes undocumented, is not evaluated from the perspective of the science community, and is rarely subject to peer-review and its associated benefits, including professional rewards. We therefore recommend new opportunities for publication in this field that would encourage science communication theory and practice to better inform each other, and for scientists to gain professional recognition for their efforts in this arena.

  2. 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

  3. Polar extracts from (Tunisian Acacia salicina Lindl. Study of the antimicrobial and antigenotoxic activities

    Directory of Open Access Journals (Sweden)

    Boubaker Jihed

    2012-04-01

    Full Text Available Abstract Background Methanolic, aqueous and Total Oligomer Flavonoids (TOF-enriched extracts obtained from the leaves of Acacia salicina 'Lindl.' were investigated for antibacterial, antimutagenic and antioxidant activities. Methods The antimicrobial activity was tested on the Gram positive and Gram negative reference bacterial strains. The Mutagenic and antimutagenic activities against direct acting mutagens, methylmethane sulfonate (MMS and 4-nitro-o-phenylenediamine (NOPD, and indirect acting mutagens, 2-aminoanthracene (2-AA and benzo[a]pyrene (B(aP were performed with S. typhimurium TA102 and TA98 assay systems. In addition, the enzymatic and nonenzymatic methods were employed to evaluate the anti-oxidative effects of the tested extracts. Results A significant effect against the Gram positive and Gram negative reference bacterial strains was observed with all the extracts. The mutagenic and antimutagenic studies revealed that all the extracts decreased the mutagenicity induced by B(aP (7.5 μg/plate, 2-AA (5 μg/plate, MMS (1.3 mg/plate and NOPD (10 μg/plate. Likewise, all the extracts showed an important free radical scavenging activity towards the superoxide anion generated by the xanthine/xanthine oxidase assay system, as well as high Trolox Equivalent Antioxidant Capacity (TEAC, against the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS+• radical. TOF-enriched extract exhibited the highest protective effect against free radicals, direct acting-mutagen and metabolically activated S9-dependent mutagens. Conclusions The present study indicates that the extracts from A. salicina leaves are a significant source of compounds with the antimutagenic and antioxidant activities, and this may be useful for developing potential chemopreventive substances.

  4. Electron transfer across the polarized interface between water and a hydrophobic redox-active ionic liquid

    Czech Academy of Sciences Publication Activity Database

    Langmaier, Jan; Trojánek, Antonín; Samec, Zdeněk

    2010-01-01

    Roč. 12, č. 10 (2010), s. 1333-1335 ISSN 1388-2481 R&D Projects: GA MŠk ME08098; GA ČR GAP206/10/1231 Institutional research plan: CEZ:AV0Z40400503 Keywords : redox-active ionic liquid * membrane * cyclic voltammetry Subject RIV: CG - Electrochemistry Impact factor: 4.282, year: 2010

  5. Modulation of human macrophage activity by Ascaris antigens is dependent on macrophage polarization state

    DEFF Research Database (Denmark)

    Almeida, Sara; Nejsum, Peter; Williams, Andrew R.

    2018-01-01

    Parasitic worms (helminths) are known to actively modulate host immune responses and inflammation. The aim of this study was to investigate if adult body fluid (ABF) from the helminth Ascaris suum has immunomodulatory effects on different subtypes of human monocyte-derived macrophages (Mɸ) in vitro...

  6. Chemical Characterization and Antioxidant, Antimicrobial, and Anti-Inflammatory Activities of South Brazilian Organic Propolis

    Science.gov (United States)

    Tiveron, Ana Paula; Rosalen, Pedro Luiz; Franchin, Marcelo; Lacerda, Risia Cristina Coelho; Bueno-Silva, Bruno; Benso, Bruna; Denny, Carina; Ikegaki, Masaharu; de Alencar, Severino Matias

    2016-01-01

    South Brazilian organic propolis (OP), which has never been studied before, was assessed and its chemical composition, scavenging potential of reactive oxygen species, antimicrobial and anti-inflammatory activities are herein presented. Based on the chemical profile obtained using HPLC, OP was grouped into seven variants (OP1–OP7) and all of them exhibited high scavenging activity, mainly against superoxide and hypochlorous acid species. OP1, OP2, and OP3 had the smallest minimal inhibitory concentration (MIC) against Gram-positive bacteria Streptococcus mutans, Streptococcus oralis, and Streptococcus aureus (12.5–100 μg/mL). OP1, OP2, OP3, and OP4 were more effective against Pseudomonas aeruginosa (Gram-negative), with MIC values ranging from 100 to 200 μg/mL. OP6 showed anti-inflammatory activity by decreasing NF-kB activation and TNF-α release in RAW 264.7 macrophages, and expressing the NF-κB-luciferase reporter stable gene. Therefore, south Brazilian OP can be considered an excellent source of bioactive compounds with great potential of application in the pharmaceutical and food industry. PMID:27802316

  7. Development of Reduced Activation Ferritic-Martensitic Steels in South Korea

    International Nuclear Information System (INIS)

    Chun, Y. B.; Choi, B. K.; Han, C. H.; Lee, D. W.; Cho, S.; Kim, T. K.; Jeong, Y. H.

    2012-01-01

    In the mid-1980s research programs for development of low activation materials began. This is based on the US Nuclear Regulatory Commission Guidelines (10CFR part 61) that were developed to reduce longlived radioactive isotopes, which allows nuclear reactor waste to be disposed of by shallow land burial when removed from service. Development of low activation materials is also key issue in nuclear fusion systems, as the structural components can became radioactive due to nuclear transmutation caused by exposure to high dose neutron irradiation. Reduced-activation ferritic martensitic (RAFM) steels have been developed in the leading countries in nuclear fusion technology, and are now being considered as candidate structural material for the test blanket module (TBM) in the international thermonuclear experiment reactor (ITER). South Korea joined the ITER program in 2003 and since then extensive effort has been made for developing the helium-cooled solid-breeder (HCSB) TBM which is scheduled to be tested in the ITER program. However, there has been no research activity to develop RAFM steels in South Korea, while all the participants in the ITER program have developed their own RAFM steels. It is recently that the Korea Atomic Energy Research Institute (KAERI) started the Korean RAFM steel research program, aiming at an application for the HCSB-type TBM structure in ITER. In what follows, the current status of RAFM steels and the R and D program led by KAERI to develop Korean RAFM steels are summarized

  8. Prevalence and Impact of Diabetes Mellitus Among Patients with Active Pulmonary Tuberculosis in South Korea.

    Science.gov (United States)

    Lee, Eun Hye; Lee, Jung Mo; Kang, Young Ae; Leem, Ah Young; Kim, Eun Young; Jung, Ji Ye; Park, Moo Suk; Kim, Young Sam; Kim, Se Kyu; Chang, Joon; Kim, Song Yee

    2017-04-01

    South Korea has an increasing prevalence of diabetes and a relatively high burden of tuberculosis. We aimed to determine the prevalence of diabetes in patients with active pulmonary tuberculosis (PTB) and examine the effect of diabetes on tuberculosis treatment outcomes. Data from patients ≥30 years diagnosed with and treated for PTB between January 2010 and December 2012 at Severance Hospital, a 2000-bed tertiary referral hospital in Seoul, South Korea, were analyzed and compared with data from a contemporaneous general population sample extracted from KNHANES V. Diabetes prevalence was 24.2% (252/1044) among patients with PTB and 11.6% (1700/14,655) among controls. Diabetes [odds ratios (OR) 2.56, 95% confidence interval (CI) 1.56-4.21, P Diabetes was the only factor associated with unsuccessful treatment outcomes (OR 1.67, 95% CI 1.03-2.70, P = 0.039). The prevalence of diabetes was markedly higher in patients with PTB than in a sample of the general South Korean population. Diabetes may delay sputum conversion and adversely affect treatment outcomes; detection and management of diabetes in patients with PTB is crucial.

  9. Qualitative study exploring healthy eating practices and physical activity among adolescent girls in rural South Africa.

    Science.gov (United States)

    Sedibe, Heather M; Kahn, Kathleen; Edin, Kerstin; Gitau, Tabitha; Ivarsson, Anneli; Norris, Shane A

    2014-08-26

    Dietary behaviours and physical activity are modifiable risk factors to address increasing levels of obesity among children and adolescents, and consequently to reduce later cardiovascular and metabolic disease. This paper explores perceptions, attitudes, barriers, and facilitators related to healthy eating and physical activity among adolescent girls in rural South Africa. A qualitative study was conducted in the rural Agincourt subdistrict, covered by a health and sociodemographic surveillance system, in Mpumalanga province, South Africa. Semistructured "duo-interviews" were carried out with 11 pairs of adolescent female friends aged 16 to 19 years. Thematic content analysis was used. The majority of participants considered locally grown and traditional foods, especially fruits and vegetables, to be healthy. Their consumption was limited by availability, and these foods were often sourced from family or neighbourhood gardens. Female caregivers and school meal programmes facilitated healthy eating practices. Most participants believed in the importance of breakfast, even though for the majority, limited food within the household was a barrier to eating breakfast before going to school. The majority cited limited accessibility as a major barrier to healthy eating, and noted the increasing intake of "convenient and less healthy foods". Girls were aware of the benefits of physical activity and engaged in various physical activities within the home, community, and schools, including household chores, walking long distances to school, traditional dancing, and extramural activities such as netball and soccer. The findings show widespread knowledge about healthy eating and the benefits of consuming locally grown and traditional food items in a population that is undergoing nutrition transition. Limited access and food availability are strong barriers to healthy eating practices. School meal programmes are an important facilitator of healthy eating, and breakfast

  10. DUST IN THE POLAR REGION AS A MAJOR CONTRIBUTOR TO THE INFRARED EMISSION OF ACTIVE GALACTIC NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Hoenig, S. F.; Antonucci, R. [Department of Physics, University of California in Santa Barbara, Broida Hall, Santa Barbara, CA 93109 (United States); Kishimoto, M.; Tristram, K. R. W.; Asmus, D.; Weigelt, G. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Prieto, M. A. [Instituto de Astrofisica de Canarias, E-38200 La Laguna, Tenerife (Spain); Gandhi, P. [Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Burtscher, L. [Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrae, D-85748 Garching (Germany); Duschl, W. J., E-mail: shoenig@physics.ucsb.edu [Institut fuer Theoretische Physik und Astrophysik, Christian-Albrechts-Universitaet zu Kiel, Leibnizstr. 15, D-24098, Kiel (Germany)

    2013-07-10

    Dust around active galactic nuclei (AGNs) is distributed over a wide range of spatial scales and can be observed in the infrared (IR). It is generally assumed that the distribution on parsec scales forms a geometrically and optically thick entity in the equatorial plane around the accretion disk and broad-line region-dubbed {sup d}ust torus{sup -}that emits the bulk of the subarcsecond-scale IR emission and gives rise to orientation-dependent obscuration. However, recent IR interferometry studies with unprecedented position angle (P.A.) and baseline coverage on these small scales in two obscured (type 2) AGNs have revealed that the majority of the mid-IR emission in these objects is elongated in the polar direction. These observations are difficult to reconcile with the standard interpretation that most of the parsec-scale mid-IR emission in AGNs originate from the torus and challenges the justification of using simple torus models to model the broadband IR emission. Here, we report detailed interferometry observations of the unobscured (type 1) AGN in NGC 3783 that allow us to constrain the size, elongation, and direction of the mid-IR emission with high accuracy. The mid-IR emission is characterized by a strong elongation toward position angle P.A. -52 Degree-Sign , closely aligned with the polar axis (P.A. -45 Degree-Sign ). We determine half-light radii along the major and minor axes at 12.5 {mu}m of (20.0 {+-} 3.0) mas Multiplication-Sign (6.7 {+-} 1.0) mas or (4.23 {+-} 0.63) pc Multiplication-Sign (1.42 {+-} 0.21) pc, which corresponds to intrinsically scaled sizes of (69.4 {+-} 10.8) r{sub in} Multiplication-Sign (23.3 {+-} 3.5) r{sub in} for the inner dust radius of r{sub in} = 0.061 pc as inferred from near-IR reverberation mapping. This implies an axis ratio of 3:1, with about 60%-90% of the 8-13 {mu}m emission associated with the polar-elongated component. It is quite likely that the hot-dust emission as recently resolved by near-IR interferometry is

  11. 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

  12. Optically Active CdSe-Dot/CdS-Rod Nanocrystals with Induced Chirality and Circularly Polarized Luminescence.

    Science.gov (United States)

    Cheng, Jiaji; Hao, Junjie; Liu, Haochen; Li, Jiagen; Li, Junzi; Zhu, Xi; Lin, Xiaodong; Wang, Kai; He, Tingchao

    2018-05-30

    Ligand-induced chirality in semiconductor nanocrystals (NCs) has attracted attention because of the tunable optical properties of the NCs. Induced circular dichroism (CD) has been observed in CdX (X = S, Se, Te) NCs and their hybrids, but circularly polarized luminescence (CPL) in these fluorescent nanomaterials has been seldom reported. Herein, we describe the successful preparation of l- and d-cysteine-capped CdSe-dot/CdS-rods (DRs) with tunable CD and CPL behaviors and a maximum anisotropic factor ( g lum ) of 4.66 × 10 -4 . The observed CD and CPL activities are sensitive to the relative absorption ratio of the CdS shell to the CdSe core, suggesting that the anisotropic g-factors in both CD and CPL increase to some extent for a smaller shell-to-core absorption ratio. In addition, the molar ratio of chiral cysteine to the DRs is investigated. Instead of enhancing the chiral interactions between the chiral molecules and DRs, an excess of cysteine molecules in aqueous solution inhibits both the CD and CPL activities. Such chiral and emissive NCs provide an ideal platform for the rational design of semiconductor nanomaterials with chiroptical properties.

  13. In vitro antiplasmodial activity of medicinal plants native to or naturalised in South Africa

    CSIR Research Space (South Africa)

    Clarkson, C

    2004-06-01

    Full Text Available Leucas martinicensis (L.) R.Br. BP01204 Whole plant DCM/MeOH (1:1) 0.813.3 Water 0.7 > 100 Ocimum americanum L. var. americanum BP01210 Whole plant DCM/MeOH (1:1) 0.14.2 Water 0.8 > 100 Salvia repens Burch. ex Benth. BP00998 Whole plant DCM/MeOH (1:1) 1... al., 1997) and Ocimum americanum L. var. ameri- canum (Lamiaceae) (Vieira et al., 2003), there are no reports on their antiplasmodial activity. Several representatives Table 2 Native or naturalised South African plants with high antiplasmodial...

  14. Gender and Sex Trading Among Active Methamphetamine Users in Cape Town, South Africa.

    Science.gov (United States)

    Lion, Ryan R; Watt, Melissa H; Wechsberg, Wendee M; Meade, Christina S

    2017-05-12

    South Africa has experienced a tremendous rise in methamphetamine use since the year 2000. Sex trading is a global phenomenon that has been observed in active drug users and has been associated with risks for HIV infection and violence. This paper describes and examines the correlates of sex trading among active methamphetamine users in Cape Town, South Africa. Through peer referral, 360 (201 male; 159 female) active methamphetamine users were recruited in a peri-urban township. Demographics, sex trading, drug use, trauma, and mental health were assessed by a structured clinical interview and computer survey. Logistic regression models were used to examine predictors of sex trading for men and women. In the past 3 months, 40% of men and 33% of women endorsed trading sex for methamphetamine or money. Among these, they reported trading with same sex partners (33%), high rates of inconsistent condom use (73%), and incidences of physical (23%) and sexual (27%) assault when sex trading. Increased drug use severity was correlated with sex trading. Women with experiences of violence and trauma were also more likely to trade sex. Conclusions/importance: The results stress a need for linkage to drug treatment, as addiction may be fueling sex trading. Targeted interventions geared towards safe sex practices may reduce risky sexual behaviors. Women need interventions that are attuned to their specific vulnerabilities. More research is needed to explore the experiences of men who have sex with men given their particularly high rates of sex trading behavior.

  15. Comparative studies on extracts from Hericium erinaceus by different polarity reagents to gain higher antioxidant activities.

    Science.gov (United States)

    Jiang, Shengjuan; Wang, Yuliang; Zhang, Xiaolong

    2016-07-01

    Hericium erinaceus (H. erinaceus) is a source of exogenous antioxidants that has been traditionally used in China for the prevention and treatment of oxidative stress-associated disease. In the present study, the bioactive compounds of H. erinaceus were extracted with the following eight representative reagents: n-Hexane, xylene, chloroform, anhydrous ether, ethyl acetate, acetone, anhydrous ethanol and distilled water. The in vitro antioxidant activities were also evaluated. All of the extracted compounds exhibited reducing power and scavenging activity against 1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion free radicals. In addition, the antioxidant capacities varied with the used chemical reagents and exhibited dose-dependent effects. Extracts from anhydrous ethanol, chloroform and acetone were capable of inhibiting lipid peroxidation. The anhydrous ethanol extracts were observed to have significant levels of antioxidant compounds since they had a strong reducing power, high scavenging rates against DPPH and superoxide anion-free radicals (>90%), and high inhibition rates on lipid peroxidation (>60%). The present study will provide reference data for the antioxidant applications of H. erinaceus in pharmaceutical use and disease prevention.

  16. REGULARITY OF THE NORTH–SOUTH ASYMMETRY OF SOLAR ACTIVITY: REVISITED

    International Nuclear Information System (INIS)

    Zhang, J.; Feng, W.

    2015-01-01

    Extended time series of Solar Activity Indices (ESAI) extended the Greenwich series of sunspot area from the year 1874 back to 1821. The ESAI's yearly sunspot area in the northern and southern hemispheres from 1821 to 2013 is utilized to investigate characteristics of the north–south hemispherical asymmetry of sunspot activity. Periodical behavior of about 12 solar cycles is also confirmed from the ESAI data set to exist in dominant hemispheres, linear regression lines of yearly asymmetry values, and cumulative counts of yearly sunspot areas in the hemispheres for solar cycles. The period is also inferred to appear in both the cumulative difference in the yearly sunspot areas in the hemispheres over the entire time interval and in its statistical Student's t-test. The hemispherical bias of sunspot activity should be regarded as an impossible stochastic phenomenon over a long time period

  17. Determination of 137Cs activities in soil samples from east and south Marmara region, Turkey

    International Nuclear Information System (INIS)

    Kilic, Oe.; Belivermis, M.; Cotuk, Y.; Coskun, M.; Cayir, A.; Kuecer, R.

    2006-01-01

    Activity concentrations of 1 37Cs, 4 0K and physico-chemical parameters of soil samples collected from 99 sampling stations in the east and south of Marmara Region of Turkey were determined. The study region was divided into 20 x 20 km grids and soil samples collected randomly in each square from 0-5 cm surface layer. Activities were measured by means of multichannel gamma analyser provided with high purity germanium detector. Relations among 1 37Cs concentrations and physico-chemical parameters of soils and climatic factors of the region were evaluated. Arc View GIS version 3.1 was used mapping of study area. Distribution of radionuclide concentrations in the region illustrated with contour maps using Surfer 8.0 for Windows. The range of activity concentrations of 1 37Cs and 4 0K were measured to be 0.92-153.72 and 69.24-1085.57 Bq/kg respectively

  18. Climate modulates internal wave activity in the Northern South China Sea

    Science.gov (United States)

    DeCarlo, Thomas M.; Karnauskas, Kristopher B.; Davis, Kristen A.; Wong, George T. F.

    2015-02-01

    Internal waves (IWs) generated in the Luzon Strait propagate into the Northern South China Sea (NSCS), enhancing biological productivity and affecting coral reefs by modulating nutrient concentrations and temperature. Here we use a state-of-the-art ocean data assimilation system to reconstruct water column stratification in the Luzon Strait as a proxy for IW activity in the NSCS and diagnose mechanisms for its variability. Interannual variability of stratification is driven by intrusions of the Kuroshio Current into the Luzon Strait and freshwater fluxes associated with the El Niño-Southern Oscillation. Warming in the upper 100 m of the ocean caused a trend of increasing IW activity since 1900, consistent with global climate model experiments that show stratification in the Luzon Strait increases in response to radiative forcing. IW activity is expected to increase in the NSCS through the 21st century, with implications for mitigating climate change impacts on coastal ecosystems.

  19. A brief report on the statistical study of net electric current in solar active regions with longitudinal fields of opposite polarity

    International Nuclear Information System (INIS)

    Gao Yu

    2013-01-01

    Dynamic processes occurring in solar active regions are dominated by the solar magnetic field. As of now, observations using a solar magnetograph have supplied us with the vector components of a solar photospheric magnetic field. The two transverse components of a photospheric magnetic field allow us to compute the amount of electric current. We found that the electric current in areas with positive (negative) polarity due to the longitudinal magnetic field have both positive and negative signs in an active region, however, the net current is found to be an order-of-magnitude less than the mean absolute magnitude and has a preferred sign. In particular, we have statistically found that there is a systematic net electric current from areas with negative (positive) polarity to areas with positive (negative) polarity in solar active regions in the northern (southern) hemisphere, but during the solar minimum this tendency is reversed over time at some latitudes. The result indicates that there is weak net electric current in areas of solar active regions with opposite polarity, thus providing further details about the hemispheric helicity rule found in a series of previous studies.

  20. Determination of uranium and thorium activity concentrations using activation analysis in beach sands from extreme south Bahia, Brazil

    International Nuclear Information System (INIS)

    Vasconcelos, Danilo C.; Oliveira, Arno H.; Silva, Mario R.S.; Penna, Rodrigo; Santos, Talita O.; Pereira, Claubia; Rocha, Zildete; Menezes, Maria Angela B.C.

    2009-01-01

    Levels of natural radioactivity are the major cause of external exposure to gamma radiation. Thus, the determination of activity concentration of primordial radionuclides, such as 238 U and 232 Th, in soils, sand and rock is of basic importance to estimate the radiation levels to which man is directly or indirectly exposed. In order to study the process of specific activity of 238 U and 232 Th, beaches sands samples were collected from eight different locations in extreme south of Bahia state from Brazil. The samples have been analyzed by instrumental neutron activation analyses and for determination of thorium concentrations and delayed neutrons analysis for determination of uranium. The mean specific activity for 238 U and 232 Th was higher in Cumuruxatiba than in others locations studied. Alcobaca and Caraiva also presented high values. The concentrations of these radionuclides were compared with typical world values and Cumuruxatiba have specific activity higher than the others locations, 2,984 Bq/kg maximum value for 238 U and 1,8450 Bq/kg maximum value for 232 Th and activity concentrations in Cumuruxatiba are higher in black sand than in no black sand, suggesting presence of monazite.(author)

  1. Agritourism activities in the Mopani District Municipality, Limpopo Province, South Africa: perceptions and opportunities

    Directory of Open Access Journals (Sweden)

    S L Myer

    2013-12-01

    Full Text Available Farms in South Africa have to compete in a very hostile agricultural economic environment and it has become imperative for farmers to find new ways of generating additional income. Research undertaken in the Mopani District Municipality (MDM in the Limpopo Province of South Africa identified agritourism as a potential means to this end. The main aim of this primarily qualitative study was to gain a better understanding of the perceptions and opportunities for agritourism in the study area. Data were mainly collected through interviews and questionnaires. Participants consisted of farmers and tourists, as well as owners of existing agritourism farms within the MDM. Five current active agritourism establishments were identified. Key fidnings revealed that agritourism is not being utilised to its full potential. Although perceptions of respondents towards agritourism are positive, marketing around it is insufficient and not all farmers are willing to host agritourism activities on their farms for various reasons. However, the MDM is a tourist hub with many visitors passing through various reasons. However, the MDM is a tourist hub with many visitors passing through the area en route to the Kruger National Park. Therefore, the potential already exists to host agritourism activities that will benefit farmers in various ways. By developing farm trails, scheduling daily farm activities, using information brochures, forming networks with existing tourist establishments, encouraging the use of local and fresh produce and providing good roadside signage, farmers can gain increased exposure and recognition for what they do and opportunities for growth and development may be realised.  Keywords: Agritourism, farm tourism, alternative tourism, farm activities, tourism

  2. 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

  3. Antimicrobial Activity and Chemical Composition of Essential Oils from Verbenaceae Species Growing in South America

    Directory of Open Access Journals (Sweden)

    Cristina M. Pérez Zamora

    2018-03-01

    Full Text Available The Verbenaceae family includes 2600 species grouped into 100 genera with a pantropical distribution. Many of them are important elements of the floras of warm-temperature and tropical regions of America. This family is known in folk medicine, and its species are used as digestive, carminative, antipyretic, antitussive, antiseptic, and healing agents. This review aims to collect information about the essential oils from the most reported species of the Verbenaceae family growing in South America, focusing on their chemical composition, antimicrobial activity, and synergism with commercial antimicrobials. The information gathered comprises the last twenty years of research within the South American region and is summarized taking into consideration the most representative species in terms of their essential oils. These species belong to Aloysia, Lantana, Lippia, Phyla, and Stachytarpheta genera, and the main essential oils they contain are monoterpenes and sesquiterpenes, such as β-caryophyllene, thymol, citral, 1,8-cineole, carvone, and limonene. These compounds have been found to possess antimicrobial activities. The synergism of these essential oils with antibiotics is being studied by several research groups. It constitutes a resource of interest for the potential use of combinations of essential oils and antibiotics in infection treatments.

  4. 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...

  5. Radical scavenging activity of selected medicinal plants from Limpopo province of South Africa.

    Science.gov (United States)

    Chauke, A M; Shai, L J; Mphahlele, P M; Mogale, M A

    2012-01-01

    Plants collected from Limpopo province of South Africa were investigated for their antioxidative potential using the DPPH radical scavenging assay. Acetone extracts of Flueggea virosa had the highest antioxidant activity with an IC₅₀ value of 30 µg/ml, closely matching the ascorbic acid with an IC₅₀ value of 25 µg/ml. The lowest antioxidant readings were observed with extracts of Rhynchosia venulosa (root extract) and Ficus ingens (leaf extract). Acetone extract of Bridelia virosa leaves had the highest phenolic content (156 mg GAE/g extract), while the lowest content was recorded for R. venulosa root extract and leaf extract of F. ingens (8.3 and 17.7 mg GAE/g extract, respectively). There was a linear correlation between antioxidant activity and total phenolic content. Extracts with high phenolic content had low IC₅₀ values, while extracts with low phenolic concentrations had high IC₅₀ values.

  6. Behavioral and electroencephalographic evaluation of the anticonvulsive activity of Moringa oleifera leaf non-polar extracts and one metabolite in PTZ-induced seizures.

    Science.gov (United States)

    González-Trujano, María Eva; Martínez-González, Claudia Lizbeth; Flores-Carrillo, Maricela; Luna-Nophal, Sara Ibeth; Contreras-Murillo, Gerardo; Magdaleno-Madrigal, Víctor Manuel

    2018-01-15

    Moringa oleifera Lamarck is a species that has long been used in high demand in folk medicine, including for the treatment of epilepsy. Nevertheless, scientific studies demonstrating its anticonvulsant properties and the nature of the bioactive constituents are lacking. The aim of this study was to evaluate the anticonvulsant activities of the Moringa oleifera leaves in non-polar vs. polar extracts using behavioral and electroencephalographic (EEG) analyses in rodents. First, PTZ (80 mg/kg, i.p.)-induced tonic-clonic seizures were assayed via a dose-response (100, 200 and 300 mg/kg, i.p.) evaluation in mice. Then, a dosage of the extracts (100 or 300 mg/kg) and one metabolite (30 mg/kg, i.p.) was selected to evaluate its effect on PTZ (35 mg/kg, i.p.)-induced EEG paroxystic activities in rats compared to the effects of ethosuximide (reference anticonvulsant drug, 100 mg/kg, i.p.). Latent onset of the first paroxystic spike, first seizure and frequency as well as seizure severity, were determined using Racine's scale. Moringa oleifera ethanol and hexane extracts produced a delay in the seizure latency in mice and rats; this effect was improved in the presence of the hexane extract containing the active metabolite hexadecanoic acid. The anticonvulsant effects were corroborated in the spectral analysis by the potency of the EEG due to a reduction in the spike frequency and amplitude, as well as in the duration and severity of the seizures. The effects of the hexane extract resembled those observed in the reference antiepileptic drug ethosuximide. Moringa oleifera leaves possess anticonvulsant activities due to the complementary of the non-polar and polar constituents. However, the non-polar constituents appear to exert an important influence via the partial participation of fatty acids, providing evidence of the effects of this plant in epilepsy therapy. Copyright © 2017. Published by Elsevier GmbH.

  7. The Impact of Human Activities on Microbial Quality of Rivers in the Vhembe District, South Africa

    Directory of Open Access Journals (Sweden)

    Afsatou N. Traoré

    2016-08-01

    Full Text Available Background: Water quality testing is dictated by microbial agents found at the time of sampling in reference to their acceptable risk levels. Human activities might contaminate valuable water resources and add to the microbial load present in water bodies. Therefore, the effects of human activities on the microbial quality of rivers collected from twelve catchments in the Vhembe District in South Africa were investigated, with samples analyzed for total coliform (TC and Eschericha coli (E. coli contents. Methods: Physical parameters and various human activities were recorded for each sampling site. The Quanti-Tray® method was adopted for the assessment of TC and E. coli contents in the rivers over a two-year period. A multiplex polymerase chain (PCR method was used to characterize the strains of E. coli found. Results: The microbial quality of the rivers was poor with both TC and E. coli contents found to be over acceptable limits set by the South African Department of Water and Sanitation (DWS. No significant difference (p > 0.05 was detected between TC and E. coli risks in dry and wet seasons. All six pathogenic E. coli strains were identified and Enteroaggregative E. coli (EAEC, atypical Enteropathogenic E. coli (a-EPEC and Enterotoxigenic E. coli (ETEC were the most prevalent E. coli strains detected (respectively, 87%, 86% and 83%. Conclusions: The study indicated that contamination in the majority of sampling sites, due to human activities such as car wash, animal grazing and farming, poses health risks to communities using the rivers for various domestic chores. It is therefore recommended that more education by the respective departments is done to avert pollution of rivers and prevent health risks to the communities in the Vhembe District.

  8. The role of demographic and motivational factors on mobile commerce usage activities in South Africa

    Directory of Open Access Journals (Sweden)

    Malcolm Cullen

    2018-03-01

    Full Text Available Background: Many studies have examined the mobile commerce phenomenon and most of these have focused on understanding the organisational and environmental factors that affect its adoption. Few have examined how an individual’s characteristics and their perceived motivational appetite affect their mobile commerce usage and specifically the activities they engage in.   Objectives: This study examines the role of demographics (individuals’ characteristics and motivational factors on mobile commerce usage activities from the South African perspective.   Method: An objective approach and a positivistic stance were followed. The research model and instrument from earlier studies by Chong (2013a were contextualised to suit this study. Data collection was done through an online questionnaire, 88 responses were received and 81 used for data analysis.   Results: The findings show that age is significantly related to mobile commerce transactions, and one’s education status influences the following mobile commerce usage activities: transactions and location-based services. One’s gender influences how one uses mobile commerce. A significant relationship between all three motivational variables and mobile commerce usage activities is evident.   Conclusion: The findings provide the financial services industry and providers of mobile commerce offerings with a better understanding of the relationships between customer demographics and the mobile commerce activities they engage in. An additional variable of customer income has been identified for future studies to better understand the relationship.

  9. Physical Activity Energy Expenditure and Sarcopenia in Black South African Urban Women.

    Science.gov (United States)

    Kruger, Herculina S; Havemann-Nel, Lize; Ravyse, Chrisna; Moss, Sarah J; Tieland, Michael

    2016-03-01

    Black women are believed to be genetically less predisposed to age-related sarcopenia. The objective of this study was to investigate lifestyle factors associated with sarcopenia in black South African (SA) urban women. In a cross-sectional study, 247 women (mean age 57 y) were randomly selected. Anthropometric and sociodemographic variables, dietary intakes, and physical activity were measured. Activity was also measured by combined accelerometery/heart rate monitoring (ActiHeart), and HIV status was tested. Dual energy x-ray absorptiometry was used to measure appendicular skeletal mass (ASM). Sarcopenia was defined according to a recently derived SA cutpoint of ASM index (ASM/height squared) decreasing to 8.1% after exclusion of participants who were HIV positive. In multiple regressions with ASM index, grip strength, and gait speed, respectively, as dependent variables, only activity energy expenditure (β = .27) was significantly associated with ASM index. Age (β = -.50) and activity energy expenditure (β = .17) were significantly associated with gait speed. Age (β = -.11) and lean mass (β = .21) were significantly associated with handgrip strength. Sarcopenia was prevalent among these SA women and was associated with low physical activity energy expenditure.

  10. A Wnt5 Activity Asymmetry and Intercellular Signaling via PCP Proteins Polarize Node Cells for Left-Right Symmetry Breaking.

    Science.gov (United States)

    Minegishi, Katsura; Hashimoto, Masakazu; Ajima, Rieko; Takaoka, Katsuyoshi; Shinohara, Kyosuke; Ikawa, Yayoi; Nishimura, Hiromi; McMahon, Andrew P; Willert, Karl; Okada, Yasushi; Sasaki, Hiroshi; Shi, Dongbo; Fujimori, Toshihiko; Ohtsuka, Toshihisa; Igarashi, Yasunobu; Yamaguchi, Terry P; Shimono, Akihiko; Shiratori, Hidetaka; Hamada, Hiroshi

    2017-03-13

    Polarization of node cells along the anterior-posterior axis of mouse embryos is responsible for left-right symmetry breaking. How node cells become polarized has remained unknown, however. Wnt5a and Wnt5b are expressed posteriorly relative to the node, whereas genes for Sfrp inhibitors of Wnt signaling are expressed anteriorly. Here we show that polarization of node cells is impaired in Wnt5a -/- Wnt5b -/- and Sfrp mutant embryos, and also in the presence of a uniform distribution of Wnt5a or Sfrp1, suggesting that Wnt5 and Sfrp proteins act as instructive signals in this process. The absence of planar cell polarity (PCP) core proteins Prickle1 and Prickle2 in individual cells or local forced expression of Wnt5a perturbed polarization of neighboring wild-type cells. Our results suggest that opposing gradients of Wnt5a and Wnt5b and of their Sfrp inhibitors, together with intercellular signaling via PCP proteins, polarize node cells along the anterior-posterior axis for breaking of left-right symmetry. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. A cytoskeletal activator and inhibitor are downstream targets of the frizzled/starry night planar cell polarity pathway in the Drosophila epidermis.

    Science.gov (United States)

    Adler, Paul N

    2018-04-10

    The frizzled pathway regulates the planar polarity of epithelial cells. In insects this is manifested by the polarity of cuticular structures such as hairs (trichomes) and sensory bristles. A variety of evidence has established that this is achieved by regulating the subcellular location for activating the cytoskeleton in the epithelial cells. How this is accomplished is still poorly understood. In the best-studied tissue, the Drosophila pupal wing two important cytoskeletal regulators have been identified. One, shavenoid (sha), appears to be an activator while the second multiple wing hairs (mwh), appears to be an inhibitor. In vitro biochemistry has confirmed that the Multiple Wing Hairs protein inhibits the elongation of F-actin chains and surprisingly that it also bundles F-actin. These two activities can explain the multifaceted mwh mutant phenotype. Copyright © 2018. Published by Elsevier Ltd.

  12. A questionnaire for screening the micronutrient intake of economically active South African adults.

    Science.gov (United States)

    Senekal, Marjanne; Steyn, Nelia P; Nel, Johanna

    2009-11-01

    The aim of the present study was to develop (phase 1) and validate (phase 2) a screening questionnaire to assess the adequacy of micronutrient intake of economically active South African adults. For identification of indicator foods to be included in the screening questionnaire (phase 1), a comprehensive, eighty-six-item, quantified FFQ that reflected the food sources of thirteen selected micronutrients associated with the nutrition-related health status of South Africans was developed and completed by 554 adults of all four major ethnic groups. Resulting dietary data were subjected to stepwise regression analyses to identify indicator foods to be included in the final screening questionnaire. For validation of frequency of intake reporting of specific food items included in the screening questionnaire (phase 2), a sample of sixty-six African and eighty-four white adult volunteers of both genders completed a 7 d record as well as the screening questionnaire. The frequency of intake of specific food items derived from the two methods was then compared using Spearman correlation coefficients. Phase 1 identified thirty indicator foods that formed the basis of the screening questionnaire. In phase 2, significant correlations were found for the total group for twenty-two out of the thirty items in the questionnaire, with correlations being the best for white females and the poorest for African males and females. A screening questionnaire (thirty-item FFQ) that can be used by researchers and health professionals to assess an individual's risk of inadequate micronutrient intake was developed and validated.

  13. Triglyceride concentration and waist circumference influence alcohol-related plasminogen activator inhibitor-1 activity increase in black South Africans.

    Science.gov (United States)

    Pieters, Marlien; de Lange, Zelda; Hoekstra, Tiny; Ellis, Suria M; Kruger, Annamarie

    2010-12-01

    We investigated the association between alcohol consumption and plasminogen activator inhibitor-1 activity (PAI-1act) and fibrinogen concentration in a black South African population presenting with lower PAI-1act and higher fibrinogen than what is typically observed in white populations. We, furthermore, wanted to investigate the effect of urbanization, sex, central obesity, increased triglycerides, 4G/5G polymorphism (PAI-1 only) and BMI on the association of alcohol with PAI-1act and fibrinogen. Data from 2010 apparently healthy, randomly collected black South African volunteers from the Prospective Urban and Rural Epidemiological (PURE) study were cross-sectionally analyzed. Alcohol consumption was recorded using quantitative food frequency questionnaires and fasting blood samples were collected for biochemical analysis including PAI-1act and fibrinogen. Heavy alcohol consumption is associated with significantly increased PAI-1act, in the total population as well as in the women separately, and tended to be so in men. This alcohol-related PAI-1act increase was observed in volunteers with increased triglycerides and central obesity but not in volunteers with normal levels and waist circumference. Urbanization, the 4G/5G polymorphism and BMI did not affect the association of alcohol with PAI-1act. Moderate alcohol consumption is associated with decreased fibrinogen concentration. Sex and level of urbanization did not affect the association of alcohol with fibrinogen. Fibrinogen decreased in normal and overweight volunteers but not in obese and centrally obese volunteers following moderate alcohol consumption. Triglyceride levels and waist circumference influence alcohol-related PAI-1act increase potentially through modulating adipocyte and triglyceride-induced PAI-1 production. Obesity prevented alcohol-related fibrinogen decrease possibly by counteracting the anti-inflammatory effect of moderate alcohol consumption.

  14. Ionic polarization

    International Nuclear Information System (INIS)

    Mahan, G.D.

    1992-01-01

    Ferroelectricity occurs in many different kinds of materials. Many of the technologically important solids, which are ferroelectric, can be classified as ionic. Any microscopic theory of ferroelectricity must contain a description of local polarization forces. We have collaborated in the development of a theory of ionic polarization which is quite successful. Its basic assumption is that the polarization is derived from the properties of the individual ions. We have applied this theory successfully to diverse subjects as linear and nonlinear optical response, phonon dispersion, and piezoelectricity. We have developed numerical methods using the local Density approximation to calculate the multipole polarizabilities of ions when subject to various fields. We have also developed methods of calculating the nonlinear hyperpolarizability, and showed that it can be used to explain light scattering experiments. This paper elaborates on this polarization theory

  15. Polarization experiments

    International Nuclear Information System (INIS)

    Halzen, F.

    1977-02-01

    In a theoretical review of polarization experiments two important points are emphasized: (a) their versatility and their relevance to a large variety of aspects of hadron physics (tests of basic symmetries; a probe of strong interaction dynamics; a tool for hadron spectroscopy); (b) the wealth of experimental data on polarization parameters in pp and np scattering in the Regge language and in the diffraction language. (author)

  16. Southern Annular Mode drives multicentury wildfire activity in southern South America.

    Science.gov (United States)

    Holz, Andrés; Paritsis, Juan; Mundo, Ignacio A; Veblen, Thomas T; Kitzberger, Thomas; Williamson, Grant J; Aráoz, Ezequiel; Bustos-Schindler, Carlos; González, Mauro E; Grau, H Ricardo; Quezada, Juan M

    2017-09-05

    The Southern Annular Mode (SAM) is the main driver of climate variability at mid to high latitudes in the Southern Hemisphere, affecting wildfire activity, which in turn pollutes the air and contributes to human health problems and mortality, and potentially provides strong feedback to the climate system through emissions and land cover changes. Here we report the largest Southern Hemisphere network of annually resolved tree ring fire histories, consisting of 1,767 fire-scarred trees from 97 sites (from 22 °S to 54 °S) in southern South America (SAS), to quantify the coupling of SAM and regional wildfire variability using recently created multicentury proxy indices of SAM for the years 1531-2010 AD. We show that at interannual time scales, as well as at multidecadal time scales across 37-54 °S, latitudinal gradient elevated wildfire activity is synchronous with positive phases of the SAM over the years 1665-1995. Positive phases of the SAM are associated primarily with warm conditions in these biomass-rich forests, in which widespread fire activity depends on fuel desiccation. Climate modeling studies indicate that greenhouse gases will force SAM into its positive phase even if stratospheric ozone returns to normal levels, so that climate conditions conducive to widespread fire activity in SAS will continue throughout the 21st century.

  17. A Pilot Examination of a Mosque-Based Physical Activity Intervention for South Asian Muslim Women in Ontario, Canada.

    Science.gov (United States)

    Banerjee, Ananya Tina; Landry, Mireille; Zawi, Maha; Childerhose, Debbie; Stephens, Neil; Shafique, Ammara; Price, Jennifer

    2017-04-01

    Low levels of physical activity have been reported in South Asian Muslim women. Mosques could be beneficial in providing physical activity opportunities for Muslim women. This study examined the feasibility, acceptability and effectiveness of a mosque-based physical activity program for South Asian Muslim women in Canada. Sixty-two South Asian Muslim women participated in a 24-week mosque-based exercise intervention. Feasibility, acceptability and effectiveness of the program was evaluated by pre-post survey questions from the Duke Activity Status Index (DASI) and International Physical Activity Questionnaire among 28 women who consented to the research data collection. Nineteen women were assessed pre-and post-intervention. The women demonstrated increase in median scores of self-efficacy (90 pre vs. 100 post; p = 0.004) and the importance of engaging in regular physical activity (90 pre vs. 100 post; p = 0.01). Fewer participants were classified as inactive at the end of the intervention (42 % pre vs. 10 % post; p = 0.006). There was a mean increase in DASI scores (39.2 pre vs. 44.6 post; p = 0.06) reflecting an improvement in peak aerobic capacity and functional quality of life. Culturally relevant structured networks such as mosques are important assets when designing healthy lifestyle interventions for South Asian Muslim women.

  18. A Dual Polarization, Active, Microstrip Antenna for an Orbital Imaging Radar System Operating at L-Band

    Science.gov (United States)

    Kelly, Kenneth C.; Huang, John

    2000-01-01

    A highly successful Earth orbiting synthetic antenna aperture radar (SAR) system, known as the SIR-C mission, was carried into orbit in 1994 on a U.S. Shuttle (Space Transportation System) mission. The radar system was mounted in the cargo bay with no need to fold, or in any other way reduce the size of the antennas for launch. Weight and size were not limited for the L-Band, C-Band, and X-Band radar systems of the SIR-C radar imaging mission; the set of antennas weighed 10,500 kg, the L-Band antenna having the major share of the weight. This paper treats designing an L-Band antenna functionally similar to that used for SIR-C, but at a fraction of the cost and at a weight in the order of 250 kg. Further, the antenna must be folded to fit into the small payload shroud of low cost booster rocket systems. Over 31 square meters of antenna area is required. This low weight, foldable, electronic scanning antenna is for the proposed LightSAR radar system which is to be placed in Earth orbit on a small, dedicated space craft at the lowest possible cost for an efficient L- Band radar imaging system. This LightSAR spacecraft radar is to be continuously available for at least five operational years, and have the ability to map or repeat-map any area on earth within a few days of any request. A microstrip patch array, with microstrip transmission lines heavily employed in the aperture and in the corporate feed network, was chosen as the low cost approach for this active dual-polarization, 80 MHz (6.4%) bandwidth antenna design.

  19. Neutron activation analysis of the atmosphere content in the Central Asia south regions

    International Nuclear Information System (INIS)

    Niyazova, O.A.; Turaev, Eh.Yu.

    2001-01-01

    By the method of neutron activation analysis a atmospheric air elementary content of south regions of Uzbekistan and Turkmenistan during the 'Afghan' dust-storm were studied. Comparison with data for atmospheric air before nad after this phenomenon was carried out.It shown, that during the 'Afghan' dust-storm the elements concentration of Au, La, Na, Sm, Hg, Cs, Zn, Co is increased in to 3-4 times. Concentration of Sc and Fe is increasing into 8-9 times. In the atmosphere with the storm beginning the Ce and Cr elements are appealing, its are absent before the 'Afghan' dust-storm. The surprise result, that Br element in air during the dust storm is disappearing

  20. Glycyrrhizic Acid Promotes M1 Macrophage Polarization in Murine Bone Marrow-Derived Macrophages Associated with the Activation of JNK and NF-κB.

    Science.gov (United States)

    Mao, Yulong; Wang, Baikui; Xu, Xin; Du, Wei; Li, Weifen; Wang, Youming

    2015-01-01

    The roots and rhizomes of Glycyrrhiza species (licorice) have been widely used as natural sweeteners and herbal medicines. The aim of this study is to investigate the effect of glycyrrhizic acid (GA) from licorice on macrophage polarization. Both phenotypic and functional activities of murine bone marrow-derived macrophages (BMDMs) treated by GA were assessed. Our results showed that GA obviously increased the cell surface expression of CD80, CD86, and MHCII molecules. Meanwhile, GA upregulated the expression of CCR7 and the production of TNF-α, IL-12, IL-6, and NO (the markers of classically activated (M1) macrophages), whereas it downregulated the expression of MR, Ym1, and Arg1 (the markers of alternatively activated (M2) macrophage). The functional tests showed that GA dramatically enhanced the uptake of FITC-dextran and E. coli K88 by BMDMs and decreased the intracellular survival of E. coli K88 and S. typhimurium. Moreover, we demonstrated that JNK and NF-κB activation are required for GA-induced NO and M1-related cytokines production, while ERK1/2 pathway exhibits a regulatory effect via induction of IL-10. Together, these findings indicated that GA promoted polarization of M1 macrophages and enhanced its phagocytosis and bactericidal capacity. The results expanded our knowledge about the role of GA in macrophage polarization.

  1. 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)

  2. Hypertension and Diabetes Mellitus: A Preliminary South African Health Promotion Activity Using Service-Learning Principles.

    Science.gov (United States)

    Srinivas, Sunitha C; Paphitis, Sharli Anne

    2016-06-01

    A marked increase in the chronic non-communicable diseases such as hypertension and diabetes mellitus in the South African population is in concert with global trends. A health promotion activity carried out by pharmacy students for school learners during the Sasol National Festival of Science and Technology (SciFest) in South Africa was used as a service-learning opportunity. Pilot tested quizzes on hypertension and diabetes were used to determine the level of knowledge of attendees before and after taking the computer based quiz. Posters, information leaflets and interactive models on these two conditions were also used to reach out to the larger population. Of the 203 participants for the hypertension quiz, 169 completed both the pre- and post-intervention quizzes. Similarly, 86 of the 104 participants for the diabetes quiz, completed both the pre- and post-intervention quizzes. The results show that the post-intervention quiz resulted in a significant increase in the scores from 78.2 to 85.6 % in the case of Hypertension while a marginal increase from 94.2 to 95.5 % was obtained in the case of diabetes. The knowledge of the SciFest attendees with regard to both conditions is above average and improved further after the educational intervention. Health promotion activities which include interactive educational methods and culturally appropriate materials carried out by pharmacy students during service-learning courses are important for improving the awareness on the prevention of these chronic health conditions. Heath promotion service-learning courses can assist in addressing the health care gaps which arise because of a lack of co-ordinated efforts between NGO's and local Government to address the prevention and management of non-communicable diseases such as hypertension and diabetes mellitus.

  3. High-energy azimuthally polarized laser beam generation from an actively Q-switched Nd:YAG laser with c-cut YVO4 crystal

    Science.gov (United States)

    Guo, Jing; Zhang, Baofu; Jiao, Zhongxing; He, Guangyuan; Wang, Biao

    2018-05-01

    A high-energy, azimuthally polarized (AP) and actively Q-switched Nd:YAG laser is demonstrated. The thermal bipolar lensing effect in the Nd:YAG laser rod is used as a polarization discriminator, and a c-cut YVO4 crystal is inserted into the laser cavity to increase the mode-selecting ability of the cavity for AP mode. The laser generated AP pulses with maximum pulse energy as high as 4.2 mJ. To the best of our knowledge, this is the highest pulse energy obtained from an actively Q-switched AP laser. The pulse energy remained higher than 1 mJ over a wide range of repetition rates from 5 kHz to 25 kHz.

  4. POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths - III. Characterization of total flux density and polarization variability of relativistic jets

    Science.gov (United States)

    Agudo, Iván; Thum, Clemens; Ramakrishnan, Venkatessh; Molina, Sol N.; Casadio, Carolina; Gómez, José L.

    2018-01-01

    We report on the first results of the POLAMI (Polarimetric Monitoring of AGNs with Millimetre Wavelengths) programme, a simultaneous 3.5 and 1.3 mm full-Stokes-polarization monitoring of a sample of 36 of the brightest active galactic nuclei in the northern sky with the IRAM 30 m telescope. Through a systematic statistical study of data taken from 2006 October (from 2009 December for the case of the 1.3 mm observations) to 2014 August, we characterize the variability of the total flux density and linear polarization. We find that all sources in the sample are highly variable in total flux density at both 3.5 and 1.3 mm, as well as in spectral index, which (except in particularly prominent flares) is found to be optically thin between these two wavelengths. The total flux-density variability at 1.3 mm is found, in general, to be faster, and to have larger fractional amplitude and flatter power-spectral-density slopes than at 3.5 mm. The polarization degree is on average larger at 1.3 mm than at 3.5 mm, by a factor of 2.6. The variability of linear polarization degree is faster and has higher fractional amplitude than for total flux density, with the typical time-scales during prominent polarization peaks being significantly faster at 1.3 mm than at 3.5 mm. The polarization angle at both 3.5 and 1.3 mm is highly variable. Most of the sources show one or two excursions of >180° on time-scales from a few weeks to about a year during the course of our observations. The 3.5 and 1.3 mm polarization angle evolution follows each other rather well, although the 1.3 mm data show a clear preference to more prominent variability on the short time-scales, i.e. weeks. The data are compatible with multizone models of conical jets involving smaller emission regions for the shortest-wavelength emitting sites. Such smaller emitting regions should also be more efficient in energising particle populations, as implied by the coherent evolution of the spectral index and the total flux

  5. 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

    rains also destroy the denning habitat of ringed seals, the polar bears' primary prey. Declines in the ringed seal population would mean a loss of food for polar bears. A trend toward stronger winds and increasing ice drift observed in some parts of the Arctic over the last five decades will likely increase energy expenditures and stress levels in polar bears that spend most of their lives on drifting sea ice. Polar bears face other limiting factors as well. Historically, the main threat to polar bears has been hunting. Satisfactory monitoring information has been obtained for most polar bear populations in recent years, however there is concern about hunting in areas without formal quota systems, such as Greenland. A range of toxic pollutants, including heavy metals, radioactivity, and persistent organic pollutants (POPs) are found throughout the Arctic. Of greatest concern are the effects of POPs on polar bears, which include a general weakening of the immune system, reduced reproductive success and physical deformities. The expansion of oil development in the Arctic poses additional threats; for example, disturbances to denning females in the Arctic National Wildlife Refuge in Alaska could undermine recruitment of the Beaufort Sea polar bear population. These threats, along with other effects of human activity in the Arctic, combine to pressure polar bears and their habitat. Large carnivores are sensitive indicators of ecosystem health and can be used to define the minimum area necessary to preserve intact ecosystems. WWF has identified the polar bear as a unique symbol of the complexities and interdependencies of the arctic marine ecosystem as it works toward its goal of preserving biodiversity for future generations.

  6. Perceived Benefits, Facilitators, Disadvantages, and Barriers for Physical Activity Amongst South Asian Adolescents in India and Canada.

    Science.gov (United States)

    Rajaraman, Divya; Correa, Natasha; Punthakee, Zubin; Lear, Scott A; Jayachitra, Krishnaswamy G; Vaz, Mario; Swaminathan, Sumathi

    2015-07-01

    The purpose of this study was to understand perceived benefits, facilitators, disadvantages, and barriers for physical activity among South Asian adolescents in India and Canada. Thirteen focus group discussions with South Asian (origin) adolescent boys and girls of different nutritional status and socioeconomic status in rural and urban India and urban Canada. Across the groups, fitness and 'energy' were perceived to be major benefits of physical activity. In India, better academic performance was highlighted, while health benefits were well detailed in Canadian groups. In all settings, friends, family, and teachers were perceived as facilitators of as well as barriers to physical activity. Lack of a safe space to play was a major concern for urban adolescents, while academic pressures and preference for other sedentary recreational activities were common barriers across all groups. Girls were less likely than boys to be interested in physical activity, with girls' participation in India further limited by societal restrictions. The study suggests key areas for promotion of physical activity among South Asian adolescents: balance between academic pressure and opportunities for physical activity, especially in India; urban planning for a built environment conducive to physical activity; and gender-sensitive programming to promote girls' activity which also addresses culture-specific barriers.

  7. ELECTROMAGNETIC SCATTERING AND ANTENNA TECHNOLOGY (EMSAT) Task Order 0003: Design of a Circularly Polarized, 20 60 GHZ Active Phased Array for Wide Angle Scanning

    Science.gov (United States)

    2017-08-08

    previously published linear -to-circular polarizers. This is because the first sheet has a low inductance in the -direction, which acts as a wire-grid...GHZ Active Phased Array for Wide Angle Scanning Carl R. Pfeiffer Defense Engineering Corporation Boris Tomasic Multispectral Sensing and...GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62204F/61102F 6. AUTHOR(S) Carl R. Pfeiffer (Defense Engineering Corporation) Boris Tomasic (AFRL

  8. Estrogenic activity, selected plasticizers and potential health risks associated with bottled water in South Africa.

    Science.gov (United States)

    Aneck-Hahn, Natalie H; Van Zijl, Magdalena C; Swart, Pieter; Truebody, Barry; Genthe, Bettina; Charmier, Jessica; Jager, Christiaan De

    2018-04-01

    Potential endocrine disrupting chemicals (EDCs) are present in bottled water from various countries. In South Africa (SA), increased bottled water consumption and concomitant increases in plastic packaging create important consequences for public health. This study aimed to screen SA bottled water for estrogenic activity, selected target chemicals and assessing potential health risks. Ten bottled water brands were exposed to 20 °C and 40 °C over 10 days. Estrogenic activity was assessed using the recombinant yeast estrogen screen (YES) and the T47D-KBluc reporter gene assay. Solid phase extracts of samples were analyzed for bis(2-ethylhexyl) adipate (DEHA), selected phthalates, bisphenol-A (BPA), 4-nonylphenol (4-NP), 17β-estradiol (E 2 ), estrone (E 1 ), and ethynylestradiol (EE 2 ) using gas chromatography-mass spectrophotometry. Using a scenario-based health risk assessment, human health risks associated with bottled water consumption were evaluated. Estrogenic activity was detected at 20 °C (n = 2) and at 40 °C (n = 8). Estradiol equivalent (EEq) values ranged from 0.001 to 0.003 ng/L. BPA concentrations ranged from 0.9 ng/L to 10.06 ng/L. Although EEqs and BPA concentrations were higher in bottled water stored at 40 °C compared to 20 °C, samples posed an acceptable risk for a lifetime of exposure. Irrespective of temperature, bottled water from SA contained chemicals with acceptable health risks.

  9. Imidazole Alkaloids from the South China Sea Sponge Pericharax heteroraphis and Their Cytotoxic and Antiviral Activities

    Directory of Open Access Journals (Sweden)

    Kai-Kai Gong

    2016-01-01

    Full Text Available Marine sponges continue to serve as a rich source of alkaloids possessing interesting biological activities and often exhibiting unique structural frameworks. In the current study, chemical investigation on the marine sponge Pericharax heteroraphis collected from the South China Sea yielded one new imidazole alkaloid named naamidine J (1 along with four known ones (2–5. Their structures were established by extensive spectroscopic methods and comparison of their data with those of the related known compounds. All the isolates possessed a central 2-aminoimidazole ring, substituted by one or two functionalized benzyl groups in some combination of the C4 and C5 positions. The cytotoxicities against selected HL-60, HeLa, A549 and K562 tumor cell lines and anti-H1N1 (Influenza a virus (IAV activity for the isolates were evaluated. Compounds 1 and 2 exhibited cytotoxicities against the K562 cell line with IC50 values of 11.3 and 9.4 μM, respectively. Compound 5 exhibited weak anti-H1N1 (influenza a virus, IAV activity with an inhibition ratio of 33%.

  10. Occupational Exposures during the U-Exploration Activities at Seila Area, South Eastern Desert, Egypt

    International Nuclear Information System (INIS)

    Abdel-Razek, Y.A.; Masoud, M.S.; Hanfi, M.Y.; El-Nagdy, M.S.

    2017-01-01

    Twenty trenches distributed over a shear zone at Seila area, South Eastern Desert of Egypt were chosen to study the occupational exposures during the U-exploration activities in these trenches. The average value of the activity concentration of "2'3"8 U, "2"3"2Th and "4"0K in the studied granites are 866 , 57 and 1380 Bq.kg"-"1 respectively. These values are higher than the worldwide average of 33, 45 and 412 Bq/kg. According to these activity concentrations , trenches are divided into the non-regulated and regulated categories. The average value of the annual effective dose due to the terrestrial radionuclides is 0.306 mSv for the non-regulated trenches and 0.958 mSv for the regulated trenches corresponding to the absorbed dose rate 219 nGy.h"-"1 for the non-regulated trenches and 684 nGy.h"-"1 for the regulated trenches. The average measured annual effective dose for non-regulated and regulated trenches is 0.81 and 1.42 mSv respectively. This difference is ascribed to the geometry of the studied trenches. However, the total annual effective dose in the non-regulated and the regulated trenches is lower than the recommended value of 20 mSv

  11. Exogenous retinoic acid induces digit reduction in opossums (Monodelphis domestica) by disrupting cell death and proliferation, and apical ectodermal ridge and zone of polarizing activity function.

    Science.gov (United States)

    Molineaux, Anna C; Maier, Jennifer A; Schecker, Teresa; Sears, Karen E

    2015-03-01

    Retinoic acid (RA) is a vitamin A derivative. Exposure to exogenous RA generates congenital limb malformations (CLMs) in species from frogs to humans. These CLMs include but are not limited to oligodactyly and long-bone hypoplasia. The processes by which exogenous RA induces CLMs in mammals have been best studied in mouse, but as of yet remain unresolved. We investigated the impact of exogenous RA on the cellular and molecular development of the limbs of a nonrodent model mammal, the opossum Monodelphis domestica. Opossums exposed to exogenous retinoic acid display CLMs including oligodactly, and results are consistent with opossum development being more susceptible to RA-induced disruptions than mouse development. Exposure of developing opossums to exogenous RA leads to an increase in cell death in the limb mesenchyme that is most pronounced in the zone of polarizing activity, and a reduction in cell proliferation throughout the limb mesenchyme. Exogenous RA also disrupts the expression of Shh in the zone of polarizing activity, and Fgf8 in the apical ectodermal ridge, and other genes with roles in the regulation of limb development and cell death. Results are consistent with RA inducing CLMs in opossum limbs by disrupting the functions of the apical ectodermal ridge and zone of polarizing activity, and driving an increase in cell death and reduction of cell proliferation in the mesenchyme of the developing limb. © 2015 Wiley Periodicals, Inc.

  12. 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.)

  13. A marked animal-vegetal polarity in the localization of Na(+),K(+) -ATPase activity and its down-regulation following progesterone-induced maturation.

    Science.gov (United States)

    Mohanty, Basant Kumar; Gupta, Brij L

    2012-02-01

    The stage-VI Xenopus oocyte has a very distinct animal-vegetal polarity with structural and functional asymmetry. In this study, we show the expression and distribution pattern of Na(+),K(+) -ATPase in stage-VI oocytes, and its changes following progesterone-induced maturation. Using enzyme-specific electron microscopy phosphatase histochemistry, [(3) H]-ouabain autoradiography, and immunofluorescence cytochemistry at light microscopic level, we find that Na(+),K(+) -ATPase activity is mainly confined to the animal hemisphere. Electron microscopy histochemical results also suggest that polarized distribution of Na(+),K(+) -ATPase activity persists following progesterone-induced maturation, and it becomes gradually more polarized towards the animal pole. The time course following progesterone-induced maturation suggests that there is an initial up-regulation and then gradual down-regulation of Na(+),K(+) -ATPase activity leading to germinal vesicle breakdown (GVBD). By GVBD, the Na(+),K(+) -ATPase activity is completely down-regulated due to endocytotic removal of pump molecules from the plasma membrane into the sub-cortical region of the oocyte. This study provides the first direct evidence for a marked asymmetric localization of Na(+),K(+) -ATPase activity in any vertebrate oocyte. Here, we propose that such asymmetry in Na(+),K(+) -ATPase activity in stage-VI oocytes, and their down-regulation following progesterone-induced maturation, is likely to have a role in the active state of the germinal vesicle in stage-VI oocytes and chromosomal condensation after GVBD. Copyright © 2011 Wiley Periodicals, Inc.

  14. Occupational activities associated with a reported history of malaria among women working in small-scale agriculture in South Africa

    NARCIS (Netherlands)

    S. Naidoo (Steven); L. London (Leslie); A. Burdorf (Alex); S. Naidoo (Steven); H. Kromhout (Hans)

    2011-01-01

    textabstractMalaria-endemic agricultural communities are at risk for this disease because of crop and agricultural activities. A cross-sectional survey among women in small-scale agriculture on irrigated and dryland areas in Makhatini Flats, KwaZulu-Natal South Africa explored associations with

  15. 137Cs and 40K activity in individuals of the mullet (Mugilidae) species Liza aurata from the South Adriatic sea

    International Nuclear Information System (INIS)

    Antovic, I.; Antovic, N. M.

    2009-01-01

    The results of the 137 Cs i 40 K activity measurements in whole individuals and some organs of the mullet species Liza aurata from the South Adriatic Sea, are presented. The measurements were performed in the non-coincidence mode of counting of the multidetector spectrometer PRIPYAT-2M. (author) [sr

  16. Protest, Performance and Politics: The Use of "Nano-Media" in Social Movement Activism in South Africa

    Science.gov (United States)

    Dawson, Marcelle C.

    2012-01-01

    Considering the lack of coverage in the mass media of certain kinds of social movement activity, many movements make use of smaller scale, independent media to publicise their struggles. From the vantage point of social movements in South Africa, this paper addresses what Mojca Pajnik and John Downing call "nano-media". Based on…

  17. Alpha-type-1 polarized dendritic cells: A novel immunization tool with optimized CTL-inducing activity

    NARCIS (Netherlands)

    Mailliard, Robbie B.; Wankowicz-Kalinska, Anna; Cai, Quan; Wesa, Amy; Hilkens, Catharien M.; Kapsenberg, Martien L.; Kirkwood, John M.; Storkus, Walter J.; Kalinski, Pawel

    2004-01-01

    Using the principle of functional polarization of dendritic cells (DCs), we have developed a novel protocol to generate human DCs combining the three features critical for the induction of type-1 immunity: (a) fully mature status; (b) responsiveness to secondary lymphoid organ chemokines; and (c)

  18. Anthelmintic activity of acetone extracts from South African plants used on egg hatching of Haemonchus contortus

    Directory of Open Access Journals (Sweden)

    Gerda Fouche

    2016-07-01

    Full Text Available The nematode, Haemonchus contortus, is responsible for major economic losses in the livestock industry. The management of parasites such as H. contortus has been through the use of synthetic parasiticides. This has resulted in the presence of residues in meat and milk, which affects food safety. The development of resistance to available anthelmintics coupled with their high cost has further complicated matters. This has led to the investigation of alternative methods to manage nematodes, including the use of plants and plant extracts as a potential source of novel anthelmintics. Acetone extracts were prepared from 15 South African plant species and their anthelmintic activity determined using the egg hatch assay (EHA. The leaf extract of Cleome gynandra had the best inhibitory activity (68% ± 3% at a concentration of 2.5 mg/mL, followed by the stem extract of Maerua angolensis (65% ± 5%. The extracts had a relatively low toxicity on Vero cells determined by the MTT (3-(4,5-dimethylthiazol-2-yl-2,5- diphenyltetrazolium bromide cellular assay.

  19. Characterization of a cold-active bacterium isolated from the South Pole “Ice Tunnel”

    Energy Technology Data Exchange (ETDEWEB)

    Madigan, Michael T.; Kempher, Megan L.; Bender, Kelly S.; Sullivan, Paul; Matthew Sattley, W.; Dohnalkova, Alice C.; Joye, Samantha B.

    2017-07-05

    Abstract Extremely cold microbial habitats on Earth (those below -30 °C) are rare and have not been surveyed for microbes as extensively as environments in the 0 to -20 °C range. Using cryoprotected growth media incubated at -5 °C, we enriched a cold-active Pseudomonas species from -50 °C ice collected from a utility tunnel for wastewater pipes under Amundsen–Scott South Pole Station, Antarctica. The isolate, strain UC-1, is related to other cold-active Pseudomonas species, most notably P. psychrophila, and grew at -5 °C to +34–37 °C; growth of UC-1 at +3 °C was significantly faster than at +34 °C. Strain UC-1 synthesized a surface exopolymer and high levels of unsaturated fatty acids under cold growth conditions. A 16S rRNA gene diversity screen of the ice sample that yielded strain UC-1 revealed over 1200 operational taxonomic units (OTUs) distributed across eight major classes of Bacteria. Many of the OTUs were Clostridia and Bacteriodia and some of these were probably of wastewater origin. However, a significant fraction of the OTUs were Proteobacteria and Actinobacteria of likely environmental origin. Our results shed light on the lower temperature limits to life and the possible existence of functional microbial communities in ultra-cold environments.

  20. Perceived and objectively measured physical activity and sedentary time among South Asian women in the UK.

    Science.gov (United States)

    Curry, Whitney Babakus; Duda, Joan L; Thompson, Janice L

    2015-03-16

    Limited self-report data suggest that South Asian (SA) women fail to meet physical activity (PA) recommendations. Recent research using objective measures reveals SA women living in the UK have higher PA levels than previously reported, and a pattern of under-reporting PA and sedentary time (ST). There is limited research on SA women's understanding and experiences of PA/ST, and the cultural contexts and conditions within which they occur. Therefore the aims of this mixed-methods study were to compare perceived PA and ST to objectively measured data and explore PA- and ST-specific contexts, experiences, and sources of PA and ST amongst SA women in the UK. 24 women were purposively sampled to participate in a semi-structured interview from a larger study of 140 women who wore an accelerometer for 7 days. Demographic and anthropometric data were also collected. Notable qualitative themes on contextualisation were of adequate PA as "keeping busy" or "being healthy", and of ST as "lazy" or "resting in old age". Few participants reported being sedentary, and most believed they were sufficiently physically active. Objectively measured PA/ST indicated that 66% women were less active than perceived (with regard to duration and intensity), with none able to estimate duration of ST. Findings suggest that overall, SA women have contextualisations of PA/ST that may not coincide with those of researchers, health professionals and policy makers, and lack awareness of the intensity of PA in which they engage and the health risks of high levels of ST. These findings highlight the need for objective measures of PA and ST in this population combined with in-depth qualitative assessments to provide more accurate assessments of these behaviours. This information can subsequently be used to develop health promotion messages and interventions focusing on increasing duration and/or intensity levels of daily activities (e.g., walking, housework) and reducing ST in this population.

  1. Association between perceived built environmental attributes and physical activity among adults in South Africa

    Directory of Open Access Journals (Sweden)

    Pasmore Malambo

    2017-02-01

    Full Text Available Abstract Background To investigate the association between perceived environmental attributes and leisure-time and transport-related physical activity. Methods This was a cross-sectional survey involving 671 South Africans aged ≥35 years from urban and rural settings. International Physical Activity Questionnaire and Neighbourhood Walkability Scale were used to collect data. Multivariable logistic regressions were used to investigate the associations. Results Significant urban vs. rural differences were apparent in the distribution of most attributes of neighborhood environment. After adjusting for gender, age, setting and relevant interaction terms, proximity to local stores was significantly associated with leisure-time physical activity (OR: 4.26; 95% CI, 1.00–18.08; while proximity to transit stops (2.44; 1.48–4.02, pleasant scenery (1.93; 1.07–3.46, sidewalks (2.36; 1.25–4.44, shade from trees (2.14; 1.19–3.85, traffic (2.17; 91.21–3.91 and well-lit streets (2.01; 1.04–3.89 were significantly associated with walking for leisure. Four-way intersections (4.54; 1.54–13.43, pleasant scenery (3.84; 1.35–10.99, traffic (0.28; 0.09–0.89, sidewalks (3.75; 1.06-13.27 and crosswalks were associated with transport related physical activity. Proximity to transit stops (2.12; 1.17–3.84 and well maintained sidewalks (2.69; 2.20–10.02 were significantly associated with total physical activity. Significant interactions by setting were apparent in some of the associations. Conclusion Some, but not all attributes of a neighborhood environment were significantly associated in expected directions with the three physical activity domains in this mixed urban and rural population. This study highlights the need for policy strategies aimed at improving or maintaining these perceived environmental attributes to promote physical activity.

  2. Polarization study

    International Nuclear Information System (INIS)

    Nurushev, S.B.

    1989-01-01

    Brief review is presented of the high energy polarization study including experimental data and the theoretical descriptions. The mostimportant proposals at the biggest accelerators and the crucial technical developments are also listed which may become a main-line of spin physics. 35 refs.; 10 figs.; 4 tabs

  3. Polar Stratigraphy

    Science.gov (United States)

    1999-01-01

    These three images were taken on three different orbits over the north polar cap in April 1999. Each shows a different part of the same ice-free trough. The left and right images are separated by a distance of more than 100 kilometers (62 miles). Note the similar layers in each image.

  4. A new method based on low background instrumental neutron activation analysis for major, trace and ultra-trace element determination in atmospheric mineral dust from polar ice cores

    Energy Technology Data Exchange (ETDEWEB)

    Baccolo, Giovanni, E-mail: giovanni.baccolo@mib.infn.it [Graduate School in Polar Sciences, University of Siena, Via Laterina 8, 53100, Siena (Italy); Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Clemenza, Massimiliano [INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Department of Physics, University of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Delmonte, Barbara [Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); Maffezzoli, Niccolò [Centre for Ice and Climate, Niels Bohr Institute, Juliane Maries Vej, 30, 2100, Copenhagen (Denmark); Nastasi, Massimiliano; Previtali, Ezio [INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Department of Physics, University of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Prata, Michele; Salvini, Andrea [LENA, University of Pavia, Pavia (Italy); Maggi, Valter [Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy)

    2016-05-30

    Dust found in polar ice core samples present extremely low concentrations, in addition the availability of such samples is usually strictly limited. For these reasons the chemical and physical analysis of polar ice cores is an analytical challenge. In this work a new method based on low background instrumental neutron activation analysis (LB-INAA) for the multi-elemental characterization of the insoluble fraction of dust from polar ice cores is presented. Thanks to an accurate selection of the most proper materials and procedures it was possible to reach unprecedented analytical performances, suitable for ice core analyses. The method was applied to Antarctic ice core samples. Five samples of atmospheric dust (μg size) from ice sections of the Antarctic Talos Dome ice core were prepared and analyzed. A set of 37 elements was quantified, spanning from all the major elements (Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe) to trace ones, including 10 (La, Ce, Nd, Sm, Eu, Tb, Ho, Tm, Yb and Lu) of the 14 natural occurring lanthanides. The detection limits are in the range of 10{sup −13}–10{sup −6} g, improving previous results of 1–3 orders of magnitude depending on the element; uncertainties lies between 4% and 60%. - Highlights: • A new method based on neutron activation for the multi-elemental characterization of atmospheric dust entrapped in polar ice cores is proposed. • 37 elements were quantified in μg size dust samples with detection limits ranging from 10{sup −13} to 10{sup −6} g. • A low background approach and a clean analytical protocol improved INAA performances to unprecedented levels for multi-elemental analyses.

  5. The 1968 Edcouch-Elsa High School Walkout: Chicano Student Activism in a South Texas Community

    Science.gov (United States)

    Barrera, James B.

    2004-01-01

    A nonviolent school boycott by 192 Chicanola students in 1968 at Edcouch-Elsa high school in the Rio Grande Valley region of Deep South Texas is examined. This walkout was the first major Chicano student protest in South Texas, and was a product of the 1960s Chicano movement.

  6. EDs in the Midwest and South activate disaster plans as deadly tornadoes sweep through the region.

    Science.gov (United States)

    2012-05-01

    Hospitals in the Midwest and South activated their disaster plans in early March to deal with a phalanx of powerful tornadoes that leveled several small towns and killed at least two dozen people. Some hospitals had to activate plans for both internal and external disasters as their own facilities were threatened. One small critical-access hospital in West Liberty, KY, sustained significant damage and had to evacuate its patients to another facility. All the hospitals credit their disaster plans and practice drills with helping them to manage the crisis as efficiently as possible. Morgan County ARH Hospital in West Liberty, KY, went for several days without an operational lab or radiology department, but staff kept the ED open for absolute emergencies. Margaret Mary Community Hospital (MMCH) in Batesville, IN, received six tornado victims, but it was prepared for many more. Administrators credit advanced warning of the storms with helping them to prepare effectively, as well as to coordinate their response with other hospitals in the area. As a level 1 trauma center, the University of Louisville Hospital in Louisville, KY, received all the most seriously injured patients in the region, even while the facility itself was under a tornado warning. Staff had to route families away from the glassed-in waiting room to the basement until the tornado warning had passed. At one point during the crisis, there were 90 patients in the hospital's ED even though the department is only equipped with 29 beds. Administrators at Huntsville Hospital in Huntsville, AL, encouraged colleagues to take advantage of smaller-scale emergencies to activate parts of their disaster plans, and to focus disaster preparation drills on their hospital's top hazard vulnerabilities.

  7. Levels of 232Th activity in the South Adriatic Sea marine environment of Montenegro

    International Nuclear Information System (INIS)

    Antovic, N.M.

    2010-01-01

    232 Th activities in the South Adriatic Sea-water, surface sediment, mud with detritus, seagrass (Posidonia oceanica) samples, and the mullet (Mugilidae) species Mugil cephalus, as well as soil and sand from the Montenegrin Coast, were measured using the six-crystal spectrometer PRIPYAT-2M, which has relatively high detection efficiency and a good sensitivity, and allows a short acquisition time, and measuring samples of any shape, without preliminary preparation and calibration measurements for different sample geometries. An average 232 Th activity concentration in surface soil layer is found to be 40.33 Bq kg -1 , while in sand-4.7 Bq kg -1 . The absorbed dose rate in air due to 232 Th gamma radiation from surface soil layer ranged from 11.76 to 63.39 nGy h -1 , with a mean of 24.06 nGy h -1 . Corresponding average annual effective dose rate has been found to be 0.03 mSv y -1 . The absorbed dose rates due to the thorium gamma radiation in air at 1 m above sand surface on the Montenegrin beaches have been found to be from 0.41 to 9.08 nGy h -1 , while annual effective dose rates ranged from 0.0005 to 0.011 mSv y -1 . 232 Th activity concentration in seawater ranged from 0.06 to 0.22 Bq L -1 , as in the mullet (Mugil cephalus) whole individuals from 0.63 to 1.67 Bq kg -1 . Annual intake of 232 Th by human consumers of this fish species has been estimated to provide an effective dose of about 0.003 mSv y -1 . (author)

  8. Holocene fire activity and vegetation response in South-Eastern Iberia

    Science.gov (United States)

    Gil-Romera, Graciela; Carrión, José S.; Pausas, Juli G.; Sevilla-Callejo, Miguel; Lamb, Henry F.; Fernández, Santiago; Burjachs, Francesc

    2010-05-01

    Since fire has been recognized as an essential disturbance in Mediterranean landscapes, the study of long-term fire ecology has developed rapidly. We have reconstructed a sequence of vegetation dynamics and fire changes across south-eastern Iberia by coupling records of climate, fire, vegetation and human activities. We calculated fire activity anomalies (FAAs) in relation to 3 ka cal BP for 10-8 ka cal BP, 6 ka cal BP, 4 ka cal BP and the present. For most of the Early to the Mid-Holocene uneven, but low fire events were the main vegetation driver at high altitudes where broadleaved and coniferous trees presented a highly dynamic post-fire response. At mid-altitudes in the mainland Segura Mountains, fire activity remained relatively stable, at similar levels to recent times. We hypothesize that coastal areas, both mountains and lowlands, were more fire-prone landscapes as biomass was more likely to have accumulated than in the inland regions, triggering regular fire events. The wet and warm phase towards the Mid-Holocene (between ca 8 and 6 ka cal BP) affected the whole region and promoted the spread of mesophytic forest co-existing with Pinus, as FAAs appear strongly negative at 6 ka cal BP, with a less important role of fire. Mid and Late Holocene landscapes were shaped by an increasing aridity trend and the rise of human occupation, especially in the coastal mountains where forest disappeared from ca 2 ka cal BP. Mediterranean-type vegetation (evergreen oaks and Pinus pinaster- halepensis types) showed the fastest post-fire vegetation dynamics over time.

  9. Effects of the Observed Meridional Flow Variations since 1996 on the Sun's Polar Fields

    Science.gov (United States)

    Hathaway, David H.; Upton, Lisa

    2013-01-01

    The cause of the low and extended minimum in solar activity between Sunspot Cycles 23 and 24 was the small size of Sunspot Cycle 24 itself - small cycles start late and leave behind low minima. Cycle 24 is small because the polar fields produced during Cycle 23 were substantially weaker than those produced during the previous cycles and those (weak) polar fields are the seeds for the activity of the following cycle. The polar fields are produced by the latitudinal transport of magnetic flux that emerged in low-latitude active regions. The polar fields thus depend upon the details of both the flux emergence and the flux transport. We have measured the flux transport flows (differential rotation, meridional flow, and supergranules) since 1996 and find systematic and substantial variation in the meridional flow alone. Here we present experiments using a Surface Flux Transport Model in which magnetic field data from SOHO/MDI and SDO/HMI are assimilated into the model only at latitudes between 45-degrees north and south of the equator (this assures that the details of the active region flux emergence are well represented). This flux is then transported in both longitude and latitude by the observed flows. In one experiment the meridional flow is given by the time averaged (and north-south symmetric) meridional flow profile. In the second experiment the time-varying and north-south asymmetric meridional flow is used. Differences between the observed polar fields and those produced in these two experiments allow us to ascertain the effects of these meridional flow variations on the Sun s polar fields.

  10. A study of the geomagnetic indices asymmetry based on the interplanetary magnetic field polarities

    Science.gov (United States)

    El-Borie, M. A.; El-Taher, A. M.; Aly, N. E.; Bishara, A. A.

    2018-05-01

    Data of geomagnetic indices ( aa, Kp, Ap, and Dst) recorded near 1 AU over the period 1967-2016, have been studied based on the asymmetry between the interplanetary magnetic field (IMF) directions above and below of the heliospheric current sheet (HCS). Our results led to the following conclusions: (i) Throughout the considered period, 31 random years (62%) showed apparent asymmetries between Toward (T) and Away (A) polarity days and 19 years (38%) exhibited nearly a symmetrical behavior. The days of A polarity predominated over the T polarity days by 4.3% during the positive magnetic polarity epoch (1991-1999). While the days of T polarity exceeded the days of A polarity by 5.8% during the negative magnetic polarity epoch (2001-2012). (ii) Considerable yearly North-South (N-S) asymmetries of geomagnetic indices observed throughout the considered period. (iii) The largest toward dominant peaks for aa and Ap indices occurred in 1995 near to minimum of solar activity. Moreover, the most substantial away dominant peaks for aa and Ap indices occurred in 2003 (during the descending phase of the solar cycle 23) and in 1991 (near the maximum of solar activity cycle) respectively. (iv) The N-S asymmetry of Kp index indicated a most significant away dominant peak occurred in 2003. (v) Four of the away dominant peaks of Dst index occurred at the maxima of solar activity in the years 1980, 1990, 2000, and 2013. The largest toward dominant peak occurred in 1991 (at the reversal of IMF polarity). (vi) The geomagnetic indices ( aa, Ap, and Kp) all have northern dominance during positive magnetic polarity epoch (1971-1979), while the asymmetries shifts to the southern solar hemisphere during negative magnetic polarity epoch (2001-2012).

  11. Enhancing the Activity of Pd on Carbon Nanofibers for Deoxygenation of Amphiphilic Fatty Acid Molecules through Support Polarity

    NARCIS (Netherlands)

    Gosselink, R.W.; Xia, W.; Muhler, M.; Jong, de K.P.; Bitter, J.H.

    2013-01-01

    The influence of support polarity on Pd/CNF for the deoxygenation of fatty acids was studied. Catalysts with a low (O/C = 3.5 × 10–2 at/at from X-ray photoelectron spectroscopy (XPS)) and a high (O/C = 5.9 × 10–2 at/at from XPS) amount of oxygen containing groups on the support were prepared. The

  12. The influence of charge and the distribution of charge in the polar region of phospholipids on the activity of UDP-glucuronosyltransferase.

    Science.gov (United States)

    Zakim, D; Eibl, H

    1992-07-05

    Studies of the mechanism of lipid-induced regulation of the microsomal enzyme UDP-glucuronosyltransferase have been extended by examining the influence of charge within the polar region on the ability of lipids to activate delipidated pure enzyme. The effects of net negative charge, of charge separation in phosphocholine, and of the distribution of charge in the polar region of lipids were studied using the GT2p isoform isolated from pig liver. Prior experiments have shown that lipids with net negative charge inhibit the enzyme (Zakim, D., Cantor, M., and Eibl, H. (1988) J. Biol. Chem. 263, 5164-5169). The current experiments show that the extent of inhibition on a molar basis increases as the net negative charge increases from -1 to -2. The inhibitory effect of negatively charged lipids is on the functional state of the enzyme and is not due to electrostatic repulsion of negatively charged substrates of the enzyme. Although the inhibitory effect of net negative charge is removed when negative charge is balanced by a positive charge due to a quaternary nitrogen, neutrality of the polar region is not a sufficient condition for activation of the enzyme. In addition to a balance of charge between Pi and the quaternary nitrogen, the distance between the negative and positive charges and the orientation of the dipole created by them are critical for activation of GT2p. The negative and positive charges must be separated by the equivalent of three -CH2- groups for optimal activation by a lipid. Shortening this distance by one -CH2- unit leads to a lipid that is ineffective in activating the enzyme. Reversal of the orientation of the dipole in which the negative charge is on the polymethylene side of the lipid-water interface and the positive charge extends into water also produces a lipid that is not effective for activating GT2p. On the other hand, lipids with phosphoserine as the polar region, which has the "normal" P-N distance but carries a net negative charge, do

  13. Acid mine drainage arising from gold mining activity in Johannesburg, South Africa and environs

    International Nuclear Information System (INIS)

    Naicker, K.; Cukrowska, E.; McCarthy, T.S.

    2003-01-01

    Ground water within the mining district is heavily contaminated and acidified. - The Witwatersrand region of South Africa is famous for its gold production and a major conurbation, centred on Johannesburg, has developed as a result of mining activity. A study was undertaken of surface and ground water in a drainage system in this area. Soils were also analysed from a site within the mining district. This study revealed that the ground water within the mining district is heavily contaminated and acidified as a result of oxidation of pyrite (FeS 2 ) contained within mine tailings dumps, and has elevated concentrations of heavy metals. Where the water table is close to surface, the upper 20 cm of soil profiles are severely contaminated by heavy metals due to capillary rise and evaporation of the ground water. The polluted ground water is discharging into streams in the area and contributes up to 20% of stream discharge, causing a lowering of pH of the stream water. Much of the metal load is precipitated in the stream: Fe and Mn precipitate as a consequence of oxidation, while other heavy metals are being removed by co-precipitation. The oxidation of iron has created a redox buffer which controls the pH of the stream water. The rate of oxidation and of dilution is slow and the deleterious effect of the addition of contaminated water persists for more than 10 km beyond the source

  14. Concentrations and activity ratios of uranium isotopes in groundwater from Donana National Park, South of Spain

    International Nuclear Information System (INIS)

    Bolivar, J. P.; Olias, M.; Gonzalez-Garcia, F.; Garcia-Tenorio, R.

    2008-01-01

    The levels and distribution of natural radionuclides in groundwaters from the unconfined Almonte-Marismas aquifer, upon which Donana National Park is located, have been analysed. Most sampled points were multiple piezometers trying to study the vertical distribution of the hydrogeochemical characteristics in the aquifer. Temperature, pH, electrical conductivity, dissolved oxygen and redox potential were determined in the field. A large number of parameters, physico-chemical properties, major and minor ions, trace elements and natural radionuclides (U-isotopes, Th-isotopes, Ra-isotopes and 210 Po), were also analysed. In the southern zone, where aeolian sands crop out, water composition is of the sodium chloride type, and the lower U-isotopes concentrations have been obtained. As water circulates through the aquifer, bicarbonate and calcium concentrations increase slightly, and higher radionuclides concentrations were measured. Finally, we have demonstrated that 234 U/ 238 U activity ratios can be used as markers of the type of groundwater and bedrock, as it has been the case for old waters with marine origin confined by a marsh in the south-east part of aquifer

  15. Television viewing, reading, physical activity and brain development among young South Korean children.

    Science.gov (United States)

    Lee, Eun-Young; Spence, John C; Carson, Valerie

    2017-07-01

    To examine associations between television (TV) viewing, reading, physical activity (PA), and participation in these behaviors with caregivers, and cognitive and linguistic development among young South Korean children aged 0-5 years. Cross-sectional study. Findings are based on 1870 children in the Korea Children and Youth Survey. All measures were questionnaire-derived. Children who participated in PA for 1-3h/week and for >3h/week were more likely to show high cognitive development (OR=1.45, 95%CI: 1.06-2.00 and OR=1.58, 95%CI: 1.11-2.23; referent: 3h/day were associated with increased odds of high cognitive development (weekdays: OR=1.89, 95%CI: 1.32-2.41 and OR=2.47, 95%CI: 1.29-4.73; weekends: OR=1.87, 95%CI: 1.39-2.54 and OR=3.34, 95%CI: 1.70-6.55; referent: development (OR=1.45, 95%CI: 1.07-1.94); referent: development than those who engaged in these behaviors 1-2 times/week. Findings support emerging evidence that PA and specific types of sedentary behavior have positive impacts on brain development during early childhood. Furthermore, engaging in different types of behavior more frequently with caregivers, regardless of type, may be important for brain development. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  16. Mars polar cap: a habitat for elementary life1

    Science.gov (United States)

    Wallis, M. K.; Wickramasinghe, N. C.

    2009-04-01

    Ices in the Martian polar caps are potential habitats for various species of microorganisms. Salts in the ice and biological anti-freeze polymers maintain liquid in cracks in the ices far below 0°C, possibly down to the mean 220-240 K. Sub-surface microbial life is shielded from ultraviolet (UV) radiation, but could potentially be activated on south-facing slopes under the midday, midsummer Sun. Such life would be limited by low levels of vapour, little transport of nutrients, low light levels below a protective dirt-crust, frost accumulation at night and in shadows, and little if any active translocation of organisms. As in the Antarctic and in permafrost, movement to new habitats depends on geo-climatic changes, which for Mars's north polar cap occur on a 50 000 year scale, except for rare meteorite impacts.

  17. Investigation of the late summer Si-budget in the Sub-Antarctic and Polar Front Zones south of Tasmania (SAZ-SENSE)

    Science.gov (United States)

    Fripiat, F.; Leblanc, K.; Elskens, M.; Quéguiner, B.; Armand, L.; Cornet-Barthaux, V.; André, L.; Cardinal, D.

    2009-04-01

    In the surface ocean, the Si-biogeochemical budget can be estimated by the ratio between the integrated biogenic silica dissolution and production rates. However such data are scarce in the ocean mostly because of methodology limitation. This is especially true in the Sub-Antarctic Zone (SAZ) where only two profiles were measured so far, exhibiting large variation (dissolution: production ratio of 0.3 and 3.1 for spring and summer, respectively). Though, the SAZ plays a crucial role in the efficiency of the silicate pump and the fertility of the Sub-Antarctic Mode Waters which then replenish in nutrients the majority of the surface waters of the world ocean. Therefore, better constraining the dissolution: production ratios in this region will certainly improve our understanding of these processes. During the SAZ-SENSE cruise (Jan.-Feb. 2007), the Si-budget of three stations (two in the SAZ and one in the Polar Frontal Zone, PFZ, for a total of nine profiles) covering different biogeochemical properties (e.g., Fe enriched vs. depleted conditions, dominance of diatoms vs. other phytoplankton,…) was investigated. This was implemented in the framework of an exhaustive characterization of the Si-biogeochemical cycle using different parameters: PDMPO labelling, 32Si and 30Si spiked incubations, and, taxonomy. We have developed a new method for the determination of the production and dissolution rates from the 30Si isotopic dilution technique. We now measure the changes of the 30Si-abundances in particulate and liquid phases by High Resolution Sector Field Inductively Coupled Plasma Mass Spectrometer (HR-SF-ICP-MS). This method, which is faster, more sensitive and more precise than the traditional ones using an Isotope Ratio Mass Spectrometer (IRMS) or Thermal Ionization Mass Spectrometer (TIMS), will significantly aid in expanding the biogenic silica production-dissolution dataset in the ocean. The results obtained on Si budget indicate that the Si

  18. Cost-Effectiveness of Highly Active Antiretroviral Therapy in South Africa.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available BACKGROUND: Little information exists on the impact of highly active antiretroviral therapy (HAART on health-care provision in South Africa despite increasing scale-up of access to HAART and gradual reduction in HAART prices. METHODS AND FINDINGS: Use and cost of services for 265 HIV-infected adults without AIDS (World Health Organization [WHO] stage 1, 2, or 3 and 27 with AIDS (WHO stage 4 receiving HAART between 1995 and 2000 in Cape Town were compared with HIV-infected controls matched for baseline WHO stage, CD4 count, age, and socioeconomic status, who did not receive antiretroviral therapy (ART; No-ART group. Costs of service provision (January 2004 prices, US$1 = 7.6 Rand included local unit costs, and two scenarios for HAART prices for WHO recommended first-line regimens: scenario 1 used current South African public-sector ART drug prices of $730 per patient-year (PPY, whereas scenario 2 was based on the anticipated public-sector price for locally manufactured drug of $181 PPY. All analyses are presented in terms of patients without AIDS and patients with AIDS. For patients without AIDS, the mean number of inpatient days PPY was 1.08 (95% confidence interval [CI]: 0.97-1.19 for the HAART group versus 3.73 (95% CI: 3.55-3.97 for the No-ART group, and 8.71 (95% CI: 8.40-9.03 versus 4.35 (95% CI: 4.12-5.61, respectively, for mean number of outpatient visits PPY. Average service provision PPY was $950 for the No-ART group versus $1,342 and $793 PPY for the HAART group for scenario 1 and 2, respectively, whereas the incremental cost per life-year gained (LYG was $1,622 for scenario 1 and $675 for scenario 2. For patients with AIDS, mean inpatients days PPY was 2.04 (95% CI: 1.63-2.52 for the HAART versus 15.36 (95% CI: 13.97-16.85 for the No-ART group. Mean outpatient visits PPY was 7.62 (95% CI: 6.81-8.49 compared with 6.60 (95% CI: 5.69-7.62 respectively. Average service provision PPY was $3,520 for the No-ART group versus $1,513 and $964

  19. Cost-effectiveness of highly active antiretroviral therapy in South Africa.

    Directory of Open Access Journals (Sweden)

    Motasim Badri

    2006-01-01

    Full Text Available Little information exists on the impact of highly active antiretroviral therapy (HAART on health-care provision in South Africa despite increasing scale-up of access to HAART and gradual reduction in HAART prices.Use and cost of services for 265 HIV-infected adults without AIDS (World Health Organization [WHO] stage 1, 2, or 3 and 27 with AIDS (WHO stage 4 receiving HAART between 1995 and 2000 in Cape Town were compared with HIV-infected controls matched for baseline WHO stage, CD4 count, age, and socioeconomic status, who did not receive antiretroviral therapy (ART; No-ART group. Costs of service provision (January 2004 prices, USD 1 = 7.6 Rand included local unit costs, and two scenarios for HAART prices for WHO recommended first-line regimens: scenario 1 used current South African public-sector ART drug prices of $730 per patient-year (PPY, whereas scenario 2 was based on the anticipated public-sector price for locally manufactured drug of $181 PPY. All analyses are presented in terms of patients without AIDS and patients with AIDS. For patients without AIDS, the mean number of inpatient days PPY was 1.08 (95% confidence interval [CI]: 0.97-1.19 for the HAART group versus 3.73 (95% CI: 3.55-3.97 for the No-ART group, and 8.71 (95% CI: 8.40-9.03 versus 4.35 (95% CI: 4.12-5.61, respectively, for mean number of outpatient visits PPY. Average service provision PPY was $950 for the No-ART group versus $1,342 and $793 PPY for the HAART group for scenario 1 and 2, respectively, whereas the incremental cost per life-year gained (LYG was $1,622 for scenario 1 and $675 for scenario 2. For patients with AIDS, mean inpatients days PPY was 2.04 (95% CI: 1.63-2.52 for the HAART versus 15.36 (95% CI: 13.97-16.85 for the No-ART group. Mean outpatient visits PPY was 7.62 (95% CI: 6.81-8.49 compared with 6.60 (95% CI: 5.69-7.62 respectively. Average service provision PPY was $3,520 for the No-ART group versus $1,513 and $964 for the HAART group for scenario 1

  20. Perceived and Objectively Measured Physical Activity and Sedentary Time among South Asian Women in the UK

    Directory of Open Access Journals (Sweden)

    Whitney Babakus Curry

    2015-03-01

    Full Text Available Introduction: Limited self-report data suggest that South Asian (SA women fail to meet physical activity (PA recommendations. Recent research using objective measures reveals SA women living in the UK have higher PA levels than previously reported, and a pattern of under-reporting PA and sedentary time (ST. There is limited research on SA women’s understanding and experiences of PA/ST, and the cultural contexts and conditions within which they occur. Therefore the aims of this mixed-methods study were to compare perceived PA and ST to objectively measured data and explore PA- and ST-specific contexts, experiences, and sources of PA and ST amongst SA women in the UK. Methods: 24 women were purposively sampled to participate in a semi-structured interview from a larger study of 140 women who wore an accelerometer for 7 days. Demographic and anthropometric data were also collected. Results: Notable qualitative themes on contextualisation were of adequate PA as “keeping busy” or “being healthy”, and of ST as “lazy” or “resting in old age”. Few participants reported being sedentary, and most believed they were sufficiently physically active. Objectively measured PA/ST indicated that 66% women were less active than perceived (with regard to duration and intensity, with none able to estimate duration of ST. Discussion: Findings suggest that overall, SA women have contextualisations of PA/ST that may not coincide with those of researchers, health professionals and policy makers, and lack awareness of the intensity of PA in which they engage and the health risks of high levels of ST. These findings highlight the need for objective measures of PA and ST in this population combined with in-depth qualitative assessments to provide more accurate assessments of these behaviours. This information can subsequently be used to develop health promotion messages and interventions focusing on increasing duration and/or intensity levels of daily

  1. Objectively assessed physical activity and associated factors of sedentary behavior among survivors of stroke living in Cape Town, South Africa.

    Science.gov (United States)

    Joseph, Conran; Conradsson, David; Hagströmer, Maria; Lawal, Isa; Rhoda, Anthea

    2017-06-18

    To investigate objectively measured physical activity in stroke survivors living in low-income areas of Cape Town, South Africa, specifically to: (a) describe the volume of daily physical activity and time spent in different intensity levels and (b) investigate the association of factors covering the International Classification of Functioning, Disability and Health with sedentary behavior. A cross-sectional design was used, where forty-five ambulatory community-dwelling stroke survivors participated. Volume and intensity of physical activity were assessed with accelerometers for three to five consecutive days. Personal and environmental factors, along with body function and activity, were captured. Multiple linear regression was used to investigate factors associated with the percentage of days spent sedentary. The median number of steps per day was 2393, and of the average 703 minutes of wear time, 80% were spent in sedentary, 15% in light, and 5% in moderate-to-vigorous intensity physical activity. Age, stroke severity, and failing to receive outpatient rehabilitation were independently associated with sedentary, which, taken together, explained 52% of the variance. Low volumes of physical activity and high amount of sedentary time emphasize the need to develop strategies that will increase physical activity. Providing outpatient rehabilitation in a systematic manner post-stroke is a potential target of health care programs in order to reduce sedentary behavior. Implications for rehabilitation Objectively measured physical activity among community-dwelling survivors of stroke in Cape Town, South Africa was low in volume, and the majority did not meet the recommendations of 150 minutes of at least moderate intensity physical activity. The majority of stroke survivors in South Africa spent most of their time sedentary, which could further increase the risk of cardiovascular impairments. Outpatient rehabilitation should be provided to all patients after stroke

  2. Healthcare Worker Preferences for Active Tuberculosis Case Finding Programs in South Africa: A Best-Worst Scaling Choice Experiment.

    Directory of Open Access Journals (Sweden)

    Nathan N O'Hara

    Full Text Available Healthcare workers (HCWs in South Africa are at a high risk of developing active tuberculosis (TB due to their occupational exposures. This study aimed to systematically quantify and compare the preferred attributes of an active TB case finding program for HCWs in South Africa.A Best-Worst Scaling choice experiment estimated HCW's preferences using a random-effects conditional logit model. Latent class analysis (LCA was used to explore heterogeneity in preferences."No cost", "the assurance of confidentiality", "no wait" and testing at the occupational health unit at one's hospital were the most preferred attributes. LCA identified a four class model with consistent differences in preference strength. Sex, occupation, and the time since a previous TB test were statistically significant predictors of class membership.The findings support the strengthening of occupational health units in South Africa to offer free and confidential active TB case finding programs for HCWs with minimal wait times. There is considerable variation in active TB case finding preferences amongst HCWs of different gender, occupation, and testing history. Attention to heterogeneity in preferences should optimize screening utilization of target HCW populations.

  3. The empirical relationship between the managerial conduct and internal control activities in South African small, medium and micro enterprises

    Directory of Open Access Journals (Sweden)

    Juan-Pierre Bruwer

    2017-07-01

    Aim: Since a system of internal control comprises five inter-related elements, while also taking into consideration that management is ultimately responsible for the internal control in their respective business entities, which is greatly influenced by their managerial conduct, this research study placed focus on determining the relationship which exist between the managerial conduct and the internal control activities evident in South African SMMEs. Setting: This study was conducted in the Cape Metropole, South Africa by obtaining responses from 240 stakeholders of SMMEs: 120 members of management and 120 employees. Methods: In order to achieve the latter, quantitative data were collected through a questionnaire and analysed accordingly through both descriptive statistics and inferential statistics. Results: From the results, a very weak negative statistically significant relationship was identified between the managerial conduct and the internal control activities evident in South African SMMEs. Conclusion: Essentially, management and employees should revisit the internal control activities evident in their respective SMMEs through placing emphasis on those internal control activities which can be built on their control environment.

  4. Antimicrobial activity of marine organisms collected off the coast of South East India

    Digital Repository Service at National Institute of Oceanography (India)

    Rodrigues, E.; Tilvi, S.; Naik, C.G.

    In vitro antimicrobial screening of nine marine sponges (Porifera) and two seaweeds, collected from south east coast of India, against selected clinical isolates of bacteria and fungi was conducted in this study. Methanolic extracts of all...

  5. South Africa: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    De Beer, Frikkie

    2012-01-01

    South Africa has a rich cultural history with ample opportunities for Neutron Imaging to be applied in Archaeological and Palaeontological studies as depicted in the references. Through this collaboration the NI and CH communities are united to introduce neutron induced Autoradiography of paintings as new analytical technique to South Africa. The outcome is foreseen to be a database on NI techniques and applications in CH as well as and exhibition at a museum to showcase the scientific collaborations

  6. North Polar Cap

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour. In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime. The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap. Image information: VIS instrument. Latitude 86.5, Longitude 64.5 East (295.5 West). 40 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen

  7. The self as capital in the narrative economy: how biographical testimonies move activism in the Global South.

    Science.gov (United States)

    Burchardt, Marian

    2016-05-01

    This article analyses and theorises the practice of biographical storytelling of HIV-positive AIDS activists in South Africa. Combining research in illness narratives, studies of emotions in social activism and analysis of global health institutions in Africa, I explore how biographical self-narrations are deployed to facilitate access to resources and knowledge and thus acquire material and symbolic value. I illustrate my argument through the analysis of the case of an AIDS activist who became a professional biographical storyteller. Based on the analysis which I claim to represent wider dynamics in human-rights-based health activism in the Global South, I propose the concept of narrative economies by which I mean the set of exchange relationships within which biographical self-narrations circulate and produce social value for individuals and organisations. © 2015 Foundation for the Sociology of Health & Illness.

  8. Perceived and objective neighborhood support for outside of school physical activity in South African children

    Directory of Open Access Journals (Sweden)

    Monika Uys

    2016-06-01

    Full Text Available Abstract Background The neighborhood environment has the potential to influence children’s participation in physical activity. However, children’s outdoor play is controlled by parents to a great extent. This study aimed to investigate whether parents' perceptions of the neighborhood environment and the objectively measured neighborhood environment were associated with children's moderate-to-vigorous intensity physical activity (MVPA outside of school hours; and to determine if these perceptions and objective measures of the neighborhood environment differ between high and low socio-economic status (SES groups. Methods In total, 258 parents of 9–11 year-old children, recruited from the South African sample of the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE, completed a questionnaire concerning the family and neighborhood environment. Objective measures of the environment were also obtained using Geographic Information Systems (GIS. Children wore an Actigraph (GT3X+ accelerometer for 7 days to measure levels of MVPA. Multilevel regression models were used to determine the association between the neighborhood environment and MVPA out of school hours. Results Parents’ perceptions of the neighborhood physical activity facilities were positively associated with children’s MVPA before school (β = 1.50 ± 0.51, p = 0.003. Objective measures of neighborhood safety and traffic risk were associated with children’s after-school MVPA (β = −2.72 ± 1.35, p = 0.044 and β = −2.63 ± 1.26, p = 0.038, respectively. These associations were significant in the low SES group (β = −3.38 ± 1.65, p = 0.040 and β = −3.76 ± 1.61, p = 0.020, respectively, but unrelated to MVPA in the high SES group. Conclusions This study found that several of the objective measures of the neighborhood environment were significantly associated with children

  9. The Impact of Immunization Control Activities on Measles Outbreaks in Akwa Ibom State, South-South, Nigeria

    Directory of Open Access Journals (Sweden)

    Bassey Enya B

    2010-07-01

    Full Text Available Background: The increase of vaccination rates means that fewer children will be vulnerable to vaccine preventable diseases such as measles, which will invariably result in a drop in the infant mortality and morbidity rates. Objective: To assess the impact of the implementation of measles reduction strategies from 2006 to 2008 using the quarterly national program for immunization (NPI in Akwa Ibom state, Nigeria. Method: Following informed consent, individuals presenting with febrile rash illnesses were routinely bled and tested for measles specific IgM using commercially available ELISA kit-MV-ELISA (Enzygnost; Behring Diagnostics, Marburg, Germany in accordance with the manufacturer’s instructions. Results: A total of four hundred and four individuals comprising of 216 vaccinated and 188 unvaccinated, presenting with febrile rash illness were screened for measles specific IgM antibodies as indication of active infection between January 2006 and December 2008 out of which 122 (30.2% had detectable levels of measles antibodies. Among the vaccinated and unvaccinated groups, 32 (14.8% and 90 (47.9% respectively were detected with measles IgM antibodies. The highest and lowest antibody levels were detected in 2006 (vaccinated: 54.7%; unvaccinated: 78.4% and 2008 (vaccinated: 1.2%; unvaccinated: 12% respectively. The distribution of measles burden by year show an overall decline in prevalence from 70% in 2006, 8.9% in 2007 to 3.7% in 2008. While, children under the age of 5 similarly had a decline in measles incidence of 73.3%, 10.7% and 3.3% respectively. Sex distribution of infection within the 3-year period shows that more females (37.4% than males (21.2% expressed measles IgM antibodies, and active infection was detected more in the rural (31.4% than urban area (27.7%. However, findings indicate a tremendous decline in active infection in the rural areas from 67% in 2006 to 0% in 2008, and in the urban areas from 78% in 2006 to 9.3% in 2008

  10. In vitro anthelmintic activity of Heliotropium indicum, Senna fistula and Spigelia anthelmia used as worm expeller in South West Nigeria

    OpenAIRE

    Oluwakemi K. Sobiyi; A.O. Tom Ashafa

    2015-01-01

    The anthelmintic potential of Heliotropium indicum, Senna fistula and Spigelia anthelmia were investigated using nematodes larvae from sheep and adult earthworms in order to justify the folkloric claim of the plants as worm expeller in south west of Nigeria. The acetone, ethanol, hydro-alcohol and distilled water extracts showed dose-dependent anthelmintic activities at the different concentrations (0.25, 0.50, 1.0 mg/ml) when tested against nematodes larvae. The order of anthelmintic effect ...

  11. Fault displacement along the Naruto-South fault, the Median Tectonic Line active fault system in the eastern part of Shikoku, southwestern Japan

    OpenAIRE

    高田, 圭太; 中田, 高; 後藤, 秀昭; 岡田, 篤正; 原口, 強; 松木, 宏彰

    1998-01-01

    The Naruto-South fault is situated of about 1000m south of the Naruto fault, the Median Tectonic Line active fault system in the eastern part of Shikoku. We investigated fault topography and subsurface geology of this fault by interpretation of large scale aerial photographs, collecting borehole data and Geo-Slicer survey. The results obtained are as follows; 1) The Naruto-South fault runs on the Yoshino River deltaic plain at least 2.5 km long with fault scarplet. the Naruto-South fault is o...

  12. A CONCEPTUAL SYSTEMS DYNAMICS MODEL OF RESEARCH AND DEVELOPMENT ACTIVITIES IN SOUTH AFRICA

    Directory of Open Access Journals (Sweden)

    S.S. Grobbelaar

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Research and Development (R&D is one of the key sub-functions of a National System of Innovation (NSI. It is the primary point of entry for new scientific development and a key focus for industrial innovation. Recent trends show evidence of disinvestments and decay of South Africa’s R&D capacity. The problem investigated in this study is the delayed effect and influence R&D investment has on the system’s ability to produce R&D output. System Dynamics modelling is an excellent tool to assess a system’s ability to adjust to change and the impact of new decisions that have to be made. The conceptual design of a System Dynamics model of R&D activities is presented. The theoretical underpinning and main assumptions made in deriving and developing the model are also discussed.

    AFRIKAANSE OPSOMMING: Navorsing en Ontwikkeling (N&O is een van die sleutelsub-funksies van ‘n Nasionale Stelsel van Innovasie (NSI. Dit is die primêre toegangspunt vir nuwe wetenskaplike ontwikkeling en ‘n sleutelfokus vir industriële innovasie. Onlangse neigings lewer bewyse van disinvestering en agteruitgang in Suid-Afrika se N&Okapasiteit. Die probleem wat in hierdie studie ondersoek word, is die vertraagde effek en invloed wat N&O-investering op die stelsel se vermoë het om N&O-uitsette te lewer. Stelseldinamikamodellering is ‘n uitstekende gereedskapstuk om ‘n stelsel se vermoë om aan te pas by verandering te takseer en die impak van nuwe besluite wat geneem moet word te toets. Die konseptuele ontwerp van ‘n Stelseldinamikamodel van N&O-aktiwiteite word voorgehou. Die teoretiese onderbou en die hoofaannames wat gemaak is in die afleiding en ontwikkeling van die model word ook bespreek.

  13. Thyroid hormones and deiodinase activity in plasma and tissues in relation to high levels of organohalogen contaminants in East Greenland polar bears (Ursus maritimus).

    Science.gov (United States)

    Gabrielsen, Kristin Møller; Krokstad, Julie Stene; Villanger, Gro Dehli; Blair, David A D; Obregon, Maria-Jesus; Sonne, Christian; Dietz, Rune; Letcher, Robert J; Jenssen, Bjørn Munro

    2015-01-01

    Previous studies have shown relationships between organohalogen contaminants (OHCs) and circulating levels of thyroid hormones (THs) in arctic wildlife. However, there is a lack of knowledge concerning the possible functional effects of OHCs on TH status in target tissues for TH-dependent activity. The relationships between circulating (plasma) levels of OHCs and various TH variables in plasma as well as in liver, muscle and kidney tissues from East Greenland sub-adult polar bears (Ursus maritimus) sampled in 2011 (n=7) were therefore investigated. The TH variables included 3.3',5.5'-tetraiodothyronine or thyroxine (T4), 3.3',5-triiodothyronine (T3) and type 1 (D1) and type 2 (D2) deiodinase activities. Principal component analysis (PCA) combined with correlation analyses demonstrated negative relationships between individual polychlorinated biphenyls (PCBs) and their hydroxylated (OH-) metabolites and T4 in both plasma and muscle. There were both positive and negative relationships between individual OHCs and D1 and D2 activities in muscle, liver and kidney tissues. In general, PCBs, OH-PCBs and polybrominated dipehenyl ethers (PBDEs) were positively correlated to D1 and D2 activities, whereas organochlorine pesticides and byproducts (OCPs) were negatively associated with D1 and D2 activities. These results support the hypothesis that OHCs can affect TH status and action in the target tissues of polar bears. TH levels and deiodinase activities in target tissues can be sensitive endpoints for exposure of TH-disrupting compounds in arctic wildlife, and thus, tissue-specific responses in target organs should be further considered when assessing TH disruption in wildlife studies. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. The activities of hospital nursing unit managers and quality of patient care in South African hospitals: a paradox?

    Directory of Open Access Journals (Sweden)

    Susan J. Armstrong

    2015-05-01

    Full Text Available Background: Improving the quality of health care is central to the proposed health care reforms in South Africa. Nursing unit managers play a key role in coordinating patient care activities and in ensuring quality care in hospitals. Objective: This paper examines whether the activities of nursing unit managers facilitate the provision of quality patient care in South African hospitals. Methods: During 2011, a cross-sectional, descriptive study was conducted in nine randomly selected hospitals (six public, three private in two South African provinces. In each hospital, one of each of the medical, surgical, paediatric, and maternity units was selected (n=36. Following informed consent, each unit manager was observed for a period of 2 hours on the survey day and the activities recorded on a minute-by-minute basis. The activities were entered into Microsoft Excel, coded into categories, and analysed according to the time spent on activities in each category. The observation data were complemented by semi-structured interviews with the unit managers who were asked to recall their activities on the day preceding the interview. The interviews were analysed using thematic content analysis. Results: The study found that nursing unit managers spent 25.8% of their time on direct patient care, 16% on hospital administration, 14% on patient administration, 3.6% on education, 13.4% on support and communication, 3.9% on managing stock and equipment, 11.5% on staff management, and 11.8% on miscellaneous activities. There were also numerous interruptions and distractions. The semi-structured interviews revealed concordance between unit managers’ recall of the time spent on patient care, but a marked inflation of their perceived time spent on hospital administration. Conclusion: The creation of an enabling practice environment, supportive executive management, and continuing professional development are needed to enable nursing managers to lead the provision

  15. Mediation of effects of a theory-based behavioral intervention on self-reported physical activity in South African men.

    Science.gov (United States)

    Jemmott, John B; Stephens-Shields, Alisa; O'Leary, Ann; Jemmott, Loretta Sweet; Teitelman, Anne; Ngwane, Zolani; Mtose, Xoliswa

    2015-03-01

    Increasing physical activity is an important public-health goal worldwide, but there are few published mediation analyses of physical-activity interventions in low-to-middle-income countries like South Africa undergoing a health transition involving markedly increased mortality from non-communicable diseases. This article reports secondary analyses on the mediation of a theory-of-planned-behavior-based behavioral intervention that increased self-reported physical activity in a trial with 1181 men in Eastern Cape Province, South Africa. Twenty-two matched-pairs of neighborhoods were randomly selected. Within pairs, neighborhoods were randomized to a health-promotion intervention or an attention-matched control intervention with baseline, immediate-post, and 6- and 12-month post-intervention assessments. Theory-of-planned-behavior constructs measured immediately post-intervention were tested as potential mediators of the primary outcome, self-reported physical activity averaged over the 6- and 12-month post-intervention assessments, using a product-of-coefficients approach in a generalized-estimating-equations framework. Data were collected in 2007-2010. Attitude, subjective norm, self-efficacy, and intention were significant mediators of intervention-induced increases in self-reported physical activity. The descriptive norm, not affected by the intervention, was not a mediator, but predicted increased self-reported physical activity. The results suggest that interventions targeting theory-of-planned-behavior constructs may contribute to efforts to increase physical activity to reduce the burden of non-communicable diseases among South African men. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. 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.

  17. Effect of effective mass and spontaneous polarization on photocatalytic activity of wurtzite and zinc-blende ZnS

    International Nuclear Information System (INIS)

    Dong, Ming; Zhang, Jinfeng; Yu, Jiaguo

    2015-01-01

    Semiconductor zinc sulphide (ZnS) has two common phases: hexagonal wurtzite and cubic zinc-blende structures. The crystal structures, energy band structures, density of states (DOS), bond populations, and optical properties of wurtzite and zinc-blende ZnS were investigated by the density functional theory of first-principles. The similar band gaps and DOS of wurtzite and zinc-blende ZnS were found and implied the similarities in crystal structures. However, the distortion of ZnS 4 tetrahedron in wurtzite ZnS resulted in the production of spontaneous polarization and internal electric field, which was beneficial for the transfer and separation of photogenerated electrons and holes

  18. VIIRS-J1 Polarization Narrative

    Science.gov (United States)

    Waluschka, Eugene; McCorkel, Joel; McIntire, Jeff; Moyer, David; McAndrew, Brendan; Brown, Steven W.; Lykke, Keith; Butler, James; Meister, Gerhard; Thome, Kurtis J.

    2015-01-01

    The VIS/NIR bands polarization sensitivity of Joint Polar Satellite Sensor 1 (JPSS1) Visible/Infrared Imaging Radiometer Suite (VIIRS) instrument was measured using a broadband source. While polarization sensitivity for bands M5-M7, I1, and I2 was less than 2.5%, the maximum polarization sensitivity for bands M1, M2, M3, and M4 was measured to be 6.4%, 4.4%, 3.1%, and 4.3%, respectively with a polarization characterization uncertainty of less than 0.3%. A detailed polarization model indicated that the large polarization sensitivity observed in the M1 to M4 bands was mainly due to the large polarization sensitivity introduced at the leading and trailing edges of the newly manufactured VISNIR bandpass focal plane filters installed in front of the VISNIR detectors. This was confirmed by polarization measurements of bands M1 and M4 bands using monochromatic light. Discussed are the activities leading up to and including the instruments two polarization tests, some discussion of the polarization model and the model results, the role of the focal plane filters, the polarization testing of the Aft-Optics-Assembly, the testing of the polarizers at Goddard and NIST and the use of NIST's T-SIRCUS for polarization testing and associated analyses and results.

  19. Impact of Exchange Rate Movements, Global Economic Activity, and the BDI Volatility on Loaded Port Cargo Throughput in South Korea

    Directory of Open Access Journals (Sweden)

    Chang Beom Kim

    2016-12-01

    Full Text Available This study examines the effects of exchange rate movements, global economic activity, and the volatility of the Baltic Dry Index (BDI on South Korea's loaded port cargo throughput, based on monthly data for the period from January 2000 to October 2014. The results indicate that the BDI volatility has a negative effect on the loaded cargo throughput, while increases in the nominal exchange rate and in global economy activity have a positive effect. In addition, the error correction model results show that the error correction term is statistically significant with the negative sign.

  20. Key interactions by conserved polar amino acids located at the transmembrane helical boundaries in Class B GPCRs modulate activation, effector specificity and biased signalling in the glucagon-like peptide-1 receptor

    OpenAIRE

    Wootten, Denise; Reynolds, Christopher A.; Smith, Kevin J.; Mobarec, Juan C.; Furness, Sebastian G.B.; Miller, Laurence J.; Christopoulos, Arthur; Sexton, Patrick M.

    2016-01-01

    Class B GPCRs can activate multiple signalling effectors with the potential to exhibit biased agonism in response to ligand stimulation. Previously, we highlighted key TM domain polar amino acids that were crucial for the function of the GLP-1 receptor, a key therapeutic target for diabetes and obesity. Using a combination of mutagenesis, pharmacological characterisation, mathematical and computational molecular modelling, this study identifies additional highly conserved polar residues locat...

  1. Rapid paracellular transmigration of Campylobacter jejuni across polarized epithelial cells without affecting TER: role of proteolytic-active HtrA cleaving E-cadherin but not fibronectin

    LENUS (Irish Health Repository)

    Boehm, Manja

    2012-04-25

    AbstractBackgroundCampylobacter jejuni is one of the most important bacterial pathogens causing food-borne illness worldwide. Crossing the intestinal epithelial barrier and host cell entry by C. jejuni is considered the primary reason of damage to the intestinal tissue, but the molecular mechanisms as well as major bacterial and host cell factors involved in this process are still widely unclear.ResultsIn the present study, we characterized the serine protease HtrA (high-temperature requirement A) of C. jejuni as a secreted virulence factor with important proteolytic functions. Infection studies and in vitro cleavage assays showed that C. jejuni’s HtrA triggers shedding of the extracellular E-cadherin NTF domain (90 kDa) of non-polarised INT-407 and polarized MKN-28 epithelial cells, but fibronectin was not cleaved as seen for H. pylori’s HtrA. Deletion of the htrA gene in C. jejuni or expression of a protease-deficient S197A point mutant did not lead to loss of flagella or reduced bacterial motility, but led to severe defects in E-cadherin cleavage and transmigration of the bacteria across polarized MKN-28 cell layers. Unlike other highly invasive pathogens, transmigration across polarized cells by wild-type C. jejuni is highly efficient and is achieved within a few minutes of infection. Interestingly, E-cadherin cleavage by C. jejuni occurs in a limited fashion and transmigration required the intact flagella as well as HtrA protease activity, but does not reduce transepithelial electrical resistance (TER) as seen with Salmonella, Shigella, Listeria or Neisseria.ConclusionThese results suggest that HtrA-mediated E-cadherin cleavage is involved in rapid crossing of the epithelial barrier by C. jejuni via a very specific mechanism using the paracellular route to reach basolateral surfaces, but does not cleave the fibronectin receptor which is necessary for cell entry.

  2. Rapid paracellular transmigration of Campylobacter jejuni across polarized epithelial cells without affecting TER: role of proteolytic-active HtrA cleaving E-cadherin but not fibronectin.

    Science.gov (United States)

    Boehm, Manja; Hoy, Benjamin; Rohde, Manfred; Tegtmeyer, Nicole; Bæk, Kristoffer T; Oyarzabal, Omar A; Brøndsted, Lone; Wessler, Silja; Backert, Steffen

    2012-04-25

    Campylobacter jejuni is one of the most important bacterial pathogens causing food-borne illness worldwide. Crossing the intestinal epithelial barrier and host cell entry by C. jejuni is considered the primary reason of damage to the intestinal tissue, but the molecular mechanisms as well as major bacterial and host cell factors involved in this process are still widely unclear. In the present study, we characterized the serine protease HtrA (high-temperature requirement A) of C. jejuni as a secreted virulence factor with important proteolytic functions. Infection studies and in vitro cleavage assays showed that C. jejuni's HtrA triggers shedding of the extracellular E-cadherin NTF domain (90 kDa) of non-polarised INT-407 and polarized MKN-28 epithelial cells, but fibronectin was not cleaved as seen for H. pylori's HtrA. Deletion of the htrA gene in C. jejuni or expression of a protease-deficient S197A point mutant did not lead to loss of flagella or reduced bacterial motility, but led to severe defects in E-cadherin cleavage and transmigration of the bacteria across polarized MKN-28 cell layers. Unlike other highly invasive pathogens, transmigration across polarized cells by wild-type C. jejuni is highly efficient and is achieved within a few minutes of infection. Interestingly, E-cadherin cleavage by C. jejuni occurs in a limited fashion and transmigration required the intact flagella as well as HtrA protease activity, but does not reduce transepithelial electrical resistance (TER) as seen with Salmonella, Shigella, Listeria or Neisseria. These results suggest that HtrA-mediated E-cadherin cleavage is involved in rapid crossing of the epithelial barrier by C. jejuni via a very specific mechanism using the paracellular route to reach basolateral surfaces, but does not cleave the fibronectin receptor which is necessary for cell entry.

  3. Tungsten disulfide nanosheet and exonuclease III co-assisted amplification strategy for highly sensitive fluorescence polarization detection of DNA glycosylase activity

    International Nuclear Information System (INIS)

    Zhao, Jingjin; Ma, Yefei; Kong, Rongmei; Zhang, Liangliang; Yang, Wen; Zhao, Shulin

    2015-01-01

    Herein, we introduced a tungsten disulfide (WS 2 ) nanosheet and exonuclease III (Exo III) co-assisted signal amplification strategy for highly sensitive fluorescent polarization (FP) assay of DNA glycosylase activity. Two DNA glycosylases, uracil-DNA glycosylase (UDG) and human 8-oxoG DNA glycosylase 1 (hOGG1), were tested. A hairpin-structured probe (HP) which contained damaged bases in the stem was used as the substrate. The removal of damaged bases from substrate by DNA glycosylase would lower the melting temperature of HP. The HP was then opened and hybridized with a FAM dye-labeled single strand DNA (DP), generating a duplex with a recessed 3′-terminal of DP. This design facilitated the Exo III-assisted amplification by repeating the hybridization and digestion of DP, liberating numerous FAM fluorophores which could not be adsorbed on WS 2 nanosheet. Thus, the final system exhibited a small FP signal. However, in the absence of DNA glycosylases, no hybridization between DP and HP was occurred, hampering the hydrolysis of DP by Exo III. The intact DP was then adsorbed on the surface of WS 2 nanosheet that greatly amplified the mass of the labeled-FAM fluorophore, resulting in a large FP value. With the co-assisted amplification strategy, the sensitivity was substantially improved. In addition, this method was applied to detect UDG activity in cell extracts. The study of the inhibition of UDG was also performed. Furthermore, this method is simple in design, easy in implementation, and selective, which holds potential applications in the DNA glycosylase related mechanism research and molecular diagnostics. - Highlights: • A fluorescence polarization strategy for DNA glycosylase activity detection was developed. • The present method was based on WS 2 nanosheet and exonuclease III co-assisted signal amplification. • A high sensitivity and desirable selectivity were achieved. • This method provides a promising universal platform for DNA glycosylase

  4. 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

  5. Characterising fifteen years of continuous atmospheric radon activity observations at Cape Point (South Africa)

    Science.gov (United States)

    Botha, R.; Labuschagne, C.; Williams, A. G.; Bosman, G.; Brunke, E.-G.; Rossouw, A.; Lindsay, R.

    2018-03-01

    This paper describes and discusses fifteen years (1999-2013) of continuous hourly atmospheric radon (222Rn) monitoring at the coastal low-altitude Southern Hemisphere Cape Point Station in South Africa. A strong seasonal cycle is evident in the observed radon concentrations, with maxima during the winter months, when air masses arriving at the Cape Point station from over the African continental surface are more frequently observed, and minima during the summer months, when an oceanic fetch is predominant. An atmospheric mean radon activity concentration of 676 ± 2 mBq/m3 is found over the 15-year record, having a strongly skewed distribution that exhibits a large number of events falling into a compact range of low values (corresponding to oceanic air masses), and a smaller number of events with high radon values spread over a wide range (corresponding to continental air masses). The mean radon concentration from continental air masses (1 004 ± 6 mBq/m3) is about two times higher compared to oceanic air masses (479 ± 3 mBq/m3). The number of atmospheric radon events observed is strongly dependent on the wind direction. A power spectral Fast Fourier Transform analysis of the 15-year radon time series reveals prominent peaks at semi-diurnal, diurnal and annual timescales. Two inter-annual radon periodicities have been established, the diurnal 0.98 ± 0.04 day-1 and half-diurnal 2.07 ± 0.15 day-1. The annual peak reflects major seasonal changes in the patterns of offshore versus onshore flow associated with regional/hemispheric circulation patterns, whereas the diurnal and semi-diurnal peaks together reflect the influence of local nocturnal radon build-up over land, and the interplay between mesoscale sea/land breezes. The winter-time diurnal radon concentration had a significant decrease of about 200 mBq/m3 (17%) while the summer-time diurnal radon concentration revealed nearly no changes. A slow decline in the higher radon percentiles (75th and 95th) for the

  6. Polar crane

    International Nuclear Information System (INIS)

    Makosinski, S.

    1981-01-01

    In many applications polar cranes have to be repeatedly positioned with high accuracy. A guidance system is disclosed which has two pairs of guides. Each guide consists of two rollers carried by a sheave rotatable mounted on the crane bridge, the rollers being locatable one on each side of a guideway, e.g. the circular track on which the bridge runs. The pairs of guides are interconnected by respective rope loops which pass around and are locked to the respective pairs of sheaves in such a manner that movement of one guide results in equal movement of the other guide in a sense to maintain the repeatability of positioning of the centre of the bridge. A hydraulically-linked guide system is also described. (author)

  7. Experiences and Perceptions of Physical Activity Among South Asian and Anglo-Australians With Type 2 Diabetes or Cardiovascular Disease: Implications for Clinical Practice.

    Science.gov (United States)

    Gupta, Sabrina S; Aroni, Rosalie; Teede, Helena

    2017-02-01

    Research indicates that there are worryingly low levels of physical activity among South Asians compared with Anglo-Australians with type 2 diabetes and/or cardiovascular disease (CVD). We compared perceptions, barriers, and enablers of physical activity in these groups. We used a qualitative design, conducting in-depth, semistructured iterative interviews in Victoria with 57 South Asian and Anglo-Australian participants with either type 2 diabetes or CVD. While both groups exhibited knowledge of the value of physical activity in health maintenance and disease management, they wished for more specific and culturally tailored advice from clinicians about the type, duration, and intensity of physical activity required. Physical activity identities were tied to ethnic identities, with members of each group aspiring to meet the norms of their culture regarding engagement with physical activity as specific exercise or as incidental exercise. Individual personal exercise was deemed important by Anglo-Australians whereas South Asians preferred family-based physical activity.

  8. Physical activity energy expenditure and sarcopenia in black South African urban women

    NARCIS (Netherlands)

    Kruger, Herculina S.; Havemann-Nel, Lize; Ravyse, Chrisna; Moss, Sarah J.; Tieland, Michael

    2016-01-01

    Background: Black women are believed to be genetically less predisposed to age-related sarcopenia. The objective of this study was to investigate lifestyle factors associated with sarcopenia in black South African (SA) urban women. Methods: In a cross-sectional study, 247 women (mean age 57 y)

  9. Substorms and polar cap convection: the 10 January 2004 interplanetary CME case

    Directory of Open Access Journals (Sweden)

    Y. Andalsvik

    2012-01-01

    Full Text Available The expansion-contraction model of Dungey cell plasma convection has two different convection sources, i.e. reconnections at the magnetopause and in the magnetotail. The spatial-temporal structure of the nightside source is not yet well understood. In this study we shall identify temporal variations in the winter polar cap convection structure during substorm activity under steady interplanetary conditions. Substorm activity (electrojets and particle precipitations is monitored by excellent ground-satellite DMSP F15 conjunctions in the dusk-premidnight sector. We take advantage of the wide latitudinal coverage of the IMAGE chain of ground magnetometers in Svalbard – Scandinavia – Russia for the purpose of monitoring magnetic deflections associated with polar cap convection and substorm electrojets. These are augmented by direct observations of polar cap convection derived from SuperDARN radars and cross-track ion drift observations during traversals of polar cap along the dusk-dawn meridian by spacecraft DMSP F13. The interval we study is characterized by moderate, stable forcing of the magnetosphere-ionosphere system (EKL = 4.0–4.5 mV m−1; cross polar cap potential (CPCP, Φ (Boyle = 115 kV during Earth passage of an interplanetary CME (ICME, choosing an 4-h interval where the magnetic field pointed continuously south-west (Bz By By polarity of the ICME magnetic field, a clear indication of a nightside source.

  10. Diversity and Antibacterial Activities of Fungi Derived from the Gorgonian Echinogorgia rebekka from the South China Sea

    Directory of Open Access Journals (Sweden)

    Chang-Yun Wang

    2011-08-01

    Full Text Available The diversity of symbiotic fungi associated with the gorgonian coral Echinogorgia rebekka from the Weizhou coral reef in the South China Sea was investigated. Combined with morphologic traits, ITS-rDNA sequences revealed 18 fungal strains from this gorgonian. All of the 18 fungi belonged to the phylum Ascomycota and were distributed among seven genera in five orders: Eurotiales (Aspergillus and Penicillium, Pleosporales (Alternaria, Capnodiales (Cladosporium, Trichosphaeriales (Nigrospora and Hypocreales (Hypocrea and Nectria. Antibacterial activities of these fungal strains were investigated with five pathogenic bacteria. All of the 18 fungal strains displayed different levels of antibacterial activities, most of which exhibited moderate to high antibacterial activities to the Gram-positive pathogens Staphylococcus aureus and Micrococcus tetragenus, and showed relatively low bioactivities to other three pathogenic bacteria. Several fungal strains in the genera Penicillium and Cladosporium with strong antibacterial activities provide potential for further research on isolation of bioactive secondary metabolites.

  11. Diversity and antibacterial activities of fungi derived from the Gorgonian Echinogorgia rebekka from the South China Sea.

    Science.gov (United States)

    Wang, Ya-Nan; Shao, Chang-Lun; Zheng, Cai-Juan; Chen, Yi-Yan; Wang, Chang-Yun

    2011-01-01

    The diversity of symbiotic fungi associated with the gorgonian coral Echinogorgia rebekka from the Weizhou coral reef in the South China Sea was investigated. Combined with morphologic traits, ITS-rDNA sequences revealed 18 fungal strains from this gorgonian. All of the 18 fungi belonged to the phylum Ascomycota and were distributed among seven genera in five orders: Eurotiales (Aspergillus and Penicillium), Pleosporales (Alternaria), Capnodiales (Cladosporium), Trichosphaeriales (Nigrospora) and Hypocreales (Hypocrea and Nectria). Antibacterial activities of these fungal strains were investigated with five pathogenic bacteria. All of the 18 fungal strains displayed different levels of antibacterial activities, most of which exhibited moderate to high antibacterial activities to the Gram-positive pathogens Staphylococcus aureus and Micrococcus tetragenus, and showed relatively low bioactivities to other three pathogenic bacteria. Several fungal strains in the genera Penicillium and Cladosporium with strong antibacterial activities provide potential for further research on isolation of bioactive secondary metabolites.

  12. Enhanced Replication of Virulent Newcastle Disease Virus in Chicken Macrophages Is due to Polarized Activation of Cells by Inhibition of TLR7.

    Science.gov (United States)

    Zhang, Pingze; Ding, Zhuang; Liu, Xinxin; Chen, Yanyu; Li, Junjiao; Tao, Zhi; Fei, Yidong; Xue, Cong; Qian, Jing; Wang, Xueli; Li, Qingmei; Stoeger, Tobias; Chen, Jianjun; Bi, Yuhai; Yin, Renfu

    2018-01-01

    Newcastle disease (ND), caused by infections with virulent strains of Newcastle disease virus (NDV), is one of the most important infectious disease affecting wild, peridomestic, and domestic birds worldwide. Vaccines constructed from live, low-virulence (lentogenic) viruses are the most accepted prevention and control strategies for combating ND in poultry across the globe. Avian macrophages are one of the first cell lines of defense against microbial infection, responding to signals in the microenvironment. Although macrophages are considered to be one of the main target cells for NDV infection in vivo , very little is known about the ability of NDV to infect chicken macrophages, and virulence mechanisms of NDV as well as the polarized activation patterns of macrophages and correlation with viral infection and replication. In the present study, a cell culture model (chicken bone marrow macrophage cell line HD11) and three different virulence and genotypes of NDV (including class II virulent NA-1, class II lentogenic LaSota, and class I lentogenic F55) were used to solve the above underlying questions. Our data indicated that all three NDV strains had similar replication rates during the early stages of infection. Virulent NDV titers were shown to increase compared to the other lentogenic strains, and this growth was associated with a strong upregulation of both pro-inflammatory M1-like markers/cytokines and anti-inflammatory M2-like markers/cytokines in chicken macrophages. Virulent NDV was found to block toll-like receptor (TLR) 7 expression, inducing higher expression of type I interferons in chicken macrophages at the late stage of viral infection. Only virulent NDV replication can be inhibited by pretreatment with TLR7 ligand. Overall, this study demonstrated that virulent NDV activates a M1-/M2-like mixed polarized activation of chicken macrophages by inhibition of TLR7, resulting in enhanced replication compared to lentogenic viruses.

  13. Gender-Associated Perceptions of Barriers and Motivators to Physical Activity Participation in South Asian Punjabis Living in Western Canada.

    Science.gov (United States)

    Caperchione, Cristina M; Chau, Shirley; Walker, Gordon J; Mummery, W Kerry; Jennings, Cally

    2015-05-01

    Gender is a sociocultural factor known to impact the physical activity (PA) behaviors of South Asians. The purpose of this research was to examine gender-associated perceptions of barriers and motivators for PA in a South Asian population living Canada. A random sample (N = 204) of South Asian Punjabi adults (18yrs+) completed a computer assisted telephone interview concerning their perceptions to PA participation. Content analysis was used to identify relevant main themes and chi-square analysis was used to calculate gender differences. Results indicated that women more often reported a lack of time due to work and family (χ2 = 7.284, df = 1, P = .007) and a lack of motivation (χ2 = 4.982, df = 1, P = .026), yet men more often reported climate (χ2 = 7.045, df = 1, P = .008) as a barrier. Regarding motivators, men more often reported prevention and reduction of disease (χ2 = 4.451, df = 1, P = .034) and watching others perform (χ2 = 10.827, df = 1, P = .001); however, reducing weight gain (χ2 = 4.806, df = 1, P = .028) and looking like others (χ2 = 4.730, df = 1, P = .029) were reported more often by women. Gender-associated differences concerning PA are present in this population and must be considered in the design and implementation of effective interventions.

  14. Do embryonic polar bodies commit suicide?

    Science.gov (United States)

    Fabian, Dušan; Čikoš, Štefan; Rehák, Pavol; Koppel, Juraj

    2014-02-01

    The extrusion and elimination of unnecessary gametic/embryonic material is one of the key events that determines the success of further development in all living organisms. Oocytes produce the first polar body to fulfill the maturation process just before ovulation, and release the second polar body immediately after fertilization. The aim of this study was to compile a physiological overview of elimination of polar bodies during early preimplantation development in mice. Our results show that three-quarters of the first polar bodies were lost even at the zygotic stage; the 4-cell stage embryos contained only one (second) polar body, and the elimination of second polar bodies proceeded continuously during later development. Both first and second polar bodies showed several typical features of apoptosis: phosphatidylserine redistribution (observed for the first time in the first polar body), specific DNA degradation, condensed nuclear morphology, and inability to exclude cationic dye from the nucleus during the terminal stage of the apoptotic process. Caspase-3 activity was recorded only in the second polar body. From the morphological point of view, mouse polar bodies acted very similarly to damaged embryonic cells which have lost contact with their neighboring blastomeres. In conclusion, polar bodies possess all the molecular equipment necessary for triggering and executing an active suicide process. Furthermore, similarly as in dying embryonic cells, stressing external conditions (culture in vitro) might accelerate and increase the incidence of apoptotic elimination of the polar bodies in embryos.

  15. Spatio-temporal variability of lightning and convective activity over South/South-East Asia with an emphasis during El Niño and La Niña

    Science.gov (United States)

    Saha, Upal; Siingh, Devendraa; Midya, S. K.; Singh, R. P.; Singh, A. K.; Kumar, S.

    2017-11-01

    The present analysis investigates the spatio-temporal variability of the convective parameters and associated lightning flash rates during the period 1997-2013 including the El Niño and La Niña episode. It reveals that north-western and north-eastern part along the foothills of Himalayas as well as Indo-China peninsular region and South China Sea are much convective prone zones over the South/South-East Asia. The terrain/orography of the Himalayan range, the influence of cross-equatorial low-level jet and large-scale circulation during pre-monsoon and active phase of monsoon, the western Pacific Warm Pool with increased sea surface temperature as well as the solar-heating-originated local instability instigate the convective anomaly to propagate over the north-western and north eastern Indian sub-continent along with the Indo-China peninsula and South China Sea respectively. The land surfaces of the Indian sub-continent and the sea surface of South China Sea possesses significant correlation with lightning flash rates and convective parameters whereas the sea surface surrounding Indian sub-continent do not show such good correlations among them. Although, the occurrence of convective activities during the El Niño (La Niña) gets reduced (increased), the occurrence of lightning flashes gets enhanced (diminished) during this period which may be the direct consequence of warming atmosphere in relation to changing patterns of regional climate. Fig. S2 Spatial trend distribution per year of (a) LFR, (b) CAPE, (c) SCP, (d) LI, (e) CINE and (f) AT anomaly over South/South-East Asia during January-December for the years 1997-2013 (Trend is significant at 95% confidence level). Fig. S3 Correlation maps of LFR with (a) CAPE, (b) SCP, (c) CINE and (d) LI over South/South-East Asia during January-December for the years 1997-2013. Fig. S4 Synoptic wind direction patterns during (a)-(b) El Niño (May 2002 - February 2003) conditions and (c)-(d) La Niña (July 1998 - March

  16. Initiation of Extension in South China Continental Margin during the Active-Passive Margin Transition: Thermochronological and Kinematic Constraints

    Science.gov (United States)

    Zuo, X.; Chan, L. S.

    2015-12-01

    The South China continental margin is characterized by a widespread magmatic belt, prominent NE-striking faults and numerous rifted basins filled by Cretaceous-Eocene sediments. The geology denotes a transition from active to passive margin, which led to rapid modifications of crustal stress configuration and reactivation of older faults in this area. Our zircon fission-track data in this region show two episodes of exhumation: The first episode, occurring during 170-120Ma, affected local parts of the Nanling Range. The second episode, a more regional exhumation event, occurred during 115-70Ma, including the Yunkai Terrane and the Nanling Range. Numerical geodynamic modeling was conducted to simulate the subduction between the paleo-Pacific plate and the South China Block. The modeling results could explain the fact that exhumation of the granite-dominant Nanling Range occurred earlier than that of the gneiss-dominant Yunkai Terrane. In addition to the difference in rock types, the heat from Jurassic-Early Cretaceous magmatism in Nanling may have softened the upper crust, causing the area to exhume more readily than Yunkai. Numerical modeling results also indicate that (1) high lithospheric geothermal gradient, high slab dip angle and low convergence velocity favor the reversal of crustal stress state from compression to extension in the upper continental plate; (2) late Mesozoic magmatism in South China was probably caused by a slab roll-back; and (3) crustal extension could have occurred prior to the cessation of plate subduction. The inversion of stress regime in the continental crust from compression to crustal extension imply that the Late Cretaceous-early Paleogene red-bed basins in South China could have formed during the late stage of the subduction, accounting for the occurrence of volcanic events in some sedimentary basins. We propose that the rifting started as early as Late Cretaceous, probably before the cessation of subduction process.

  17. Drivers shaping the diversity and biogeography of total and active bacterial communities in the South China Sea

    Science.gov (United States)

    Zhang, Yao; Zhao, Zihao; Dai, Minhan; Jiao, Nianzhi; Herndl, Gerhard J

    2014-01-01

    To test the hypothesis that different drivers shape the diversity and biogeography of the total and active bacterial community, we examined the bacterial community composition along two transects, one from the inner Pearl River estuary to the open waters of the South China Sea (SCS) and the other from the Luzon Strait to the SCS basin, using 454 pyrosequencing of the 16S rRNA and 16S rRNA gene (V1-3 regions) and thereby characterizing the active and total bacterial community, respectively. The diversity and biogeographic patterns differed substantially between the active and total bacterial communities. Although the composition of both the total and active bacterial community was strongly correlated with environmental factors and weakly correlated with geographic distance, the active bacterial community displayed higher environmental sensitivity than the total community and particularly a greater distance effect largely caused by the active assemblage from deep waters. The 16S rRNA vs. rDNA relationships indicated that the active bacteria were low in relative abundance in the SCS. This might be due to a high competition between active bacterial taxa as indicated by our community network models. Based on these analyses, we speculate that high competition could cause some dispersal limitation of the active bacterial community resulting in a distinct distance-decay relationship. Altogether, our results indicated that the biogeographic distribution of bacteria in the SCS is the result of both environmental control and distance decay. PMID:24684298

  18. Non-farm Activities and Adoption of Improved Cassava and Beans Varieties in South- Kivu, DR Congo

    Directory of Open Access Journals (Sweden)

    Dontsop-Nguezet, PM.

    2016-01-01

    Full Text Available Non-farm activities have been generally considered as important strategy for overcoming credit constraints faced by rural households as well as for reducing poverty through income effect. This paper employs binary probit and average treatment effect to estimate the impact of participation in non-farm activities on adoption of improved cassava and beans varieties in South-Kivu, DR Congo. Results showed on one hand that the participation rate in non-farm activities in South-Kivu was 38% and 52.1% respectively for crafts and small businesses. On the other hand, the rate of adoption of new cassava and beans varieties were 14 and 28% respectively. Factors affecting the adoption rate were gender, education, household size, the presence of non-farm activities, household assets in terms of livestock owned, market access and access to the information on new technologies. These results demonstrate the tendency of rural households to include the practice of non-farm activities among their strategies for survival and diversify their sources of income or supplement farm income. Results of this study indicate a positive relationship between engagement of rural households in non-farm activities and their propensity to adopt improved varieties. There is still a huge gap between potential adoption rate and actual rate of adoption for cassava and beans improved varieties in the study area. Therefore, actors involved in the development of the agricultural sector have to be aware of the importance of these factors even when they are working for the promotion of purely agricultural activities.

  19. Reactivity Models of Hydrogen Activation by Frustrated Lewis Pairs: Synergistic Electron Transfers or Polarization by Electric Field?

    Czech Academy of Sciences Publication Activity Database

    Rokob, Tibor András; Bakó, I.; Stirling, A.; Hamza, A.; Pápai, I.

    2013-01-01

    Roč. 135, č. 11 (2013), s. 4425-4437 ISSN 0002-7863 Institutional support: RVO:61388963 Keywords : heterolytic dihydrogen activation * small-molecule activation * gaussian-basis sets Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 11.444, year: 2013

  20. An investigation of human activity and vegetation change around Mkuze Game Reserve, South Africa

    OpenAIRE

    2014-01-01

    M.A. (Geography) In the last century, the establishment of protected areas has become an important part of managing South Africa’s wilderness and wildlife. The notion of untouched protected areas is becoming contested in a time when developing nations are seeking to improve quality of life for their citizens. With the promulgation of the NEM: PAA of 2003, resource sharing with local rural communities has become an important policy guideline for protected area management authorities. An exa...

  1. Zn(3)(4-OOCC(6)H(4)PO(3))(2): A polar metal phosphonate with pillared layered structure showing SHG-activity and large dielectric anisotropy.

    Science.gov (United States)

    Li, Jin-Tang; Cao, Deng-Ke; Akutagawa, Tomoyuki; Zheng, Li-Min

    2010-10-07

    A new metal phosphonate Zn(3)(4-OOCC(6)H(4)PO(3))(2) (1) is reported which crystallizes in orthorhombic space group Pca2(1). It shows a pillared layered structure in which the {ZnO(4)}, {ZnO(5)} and {PO(3)C} polyhedra are connected through corner- or edge-sharing to form an inorganic layer in the ab plane which contains 4- and 5-member rings. These layers are pillared by the uni-oriented 4-carboxylatephenylphosphonate ligands, thus leading to a polar 3D architecture. The dielectric anisotropy measurements of a single crystal of 1 reveal that dielectric constant along the inter-layer is larger than that along the intra-layer with a ratio of about 2.3. Second harmonic generation (SHG) activity is observed.

  2. Draft genome analysis of Dietzia sp. 111N12-1, isolated from the South China Sea with bioremediation activity.

    Science.gov (United States)

    Yang, Shanjun; Yu, Mingjia; Chen, Jianming

    Dietzia sp. 111N12-1, isolated from the seawater of South China Sea, shows strong petroleum hydrocarbons degradation activity. Here, we report the draft sequence of approximately 3.7-Mbp genome of this strain. To the best of our knowledge, this is the first genome sequence of Dietzia strain isolated from the sea. The genome sequence may provide fundamental molecular information on elucidating the metabolic pathway of hydrocarbons degradation in this strain. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  3. 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)

  4. Polarization of Coronal Forbidden Lines

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao; Qu, Zhongquan [Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China); Landi Degl’Innocenti, Egidio, E-mail: sayahoro@ynao.ac.cn [Dipartimento di Astronomia e Scienza dello Spazio, Università di Firenze, Largo E. Fermi 2, I-50125 Firenze (Italy)

    2017-03-20

    Since the magnetic field is responsible for most manifestations of solar activity, one of the most challenging problems in solar physics is the diagnostics of solar magnetic fields, particularly in the outer atmosphere. To this end, it is important to develop rigorous diagnostic tools to interpret polarimetric observations in suitable spectral lines. This paper is devoted to analyzing the diagnostic content of linear polarization imaging observations in coronal forbidden lines. Although this technique is restricted to off-limb observations, it represents a significant tool to diagnose the magnetic field structure in the solar corona, where the magnetic field is intrinsically weak and still poorly known. We adopt the quantum theory of polarized line formation developed in the framework of the density matrix formalism, and synthesize images of the emergent linear polarization signal in coronal forbidden lines using potential-field source-surface magnetic field models. The influence of electronic collisions, active regions, and Thomson scattering on the linear polarization of coronal forbidden lines is also examined. It is found that active regions and Thomson scattering are capable of conspicuously influencing the orientation of the linear polarization. These effects have to be carefully taken into account to increase the accuracy of the field diagnostics. We also found that linear polarization observation in suitable lines can give valuable information on the long-term evolution of the magnetic field in the solar corona.

  5. 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

  6. 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

  7. “Be active!” Revisiting the South African food-based dietary ...

    African Journals Online (AJOL)

    The reviewed outcome measures are changes in physical activity patterns ... no improvements in physical activity, obesity or NCDs have been reported in ... Barriers that prevent children and adults from participating in regular physical activity ...

  8. 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

  9. Physical Activity and Suicide Attempt of South Korean Adolescents - Evidence from the Eight Korea Youth Risk Behaviors Web-based Survey.

    Science.gov (United States)

    Cho, Kang-Ok

    2014-12-01

    Suicide is the leading cause of death among South Korean adolescents. The purpose of this study was to examine the relationship between suicidal thoughts (ST) and suicidal attempts (SA) with the level of physical activity (PA) among South Korean adolescents. Based on data from the eighth Korea Youth Risk Behaviors Web-Based Survey, 74,186 South Korean adolescents were evaluated in terms of their relationship between meeting guidelines for vigorous PA (VPA), moderate PA (MPA), and low PA (LPA) and in respect of ST and SA status. The adjusted odds ratio in adolescents who thought about suicide increased significantly with PA levels (1.02 in males, 1.21 in females with VPA, 1.10 in males, 1.18 in females with MPA, and 1.16 in males, 1.20 in females with LPA) compared to participants who did not think about suicide. In addition, the AOR in adolescents who attempted suicide increased significantly with PA levels (1.16 in males, 1.36 in females with VPA, 1.13 in males, 1.15 in females with MPA, and 1.26 in males, 1.15 in females with LPA) compared to participants who did not attempt suicide. These results show that VPA, MPA, and LPA are positively associated with ST and SA prevention in South Korean adolescents. Therefore, to prevent suicide of South Korean adolescents, we support public health program including PA participation. Key PointsSouth Korean male adolescents, compared to female adolescents, showed relatively high values for physical activity-related variables such as vigorous, moderate, and low PA.Regardless of gender, more physical activity participation is positively associated with prevention of suicidal thought and attempts of South Korean adolescents.To prevent suicide of South Korean adolescents, we support public health program including meeting guidelines for vigorous, moderate, and low physical activity.

  10. Geochemistry and Geochronology of Ngorongoro Crater, Tanzania: Implication for Magma Evolution, Duration of Volcanic Activity and Age of the Ngorongoro N-R Geomagnetic Polarity Transition

    Science.gov (United States)

    Mollel, G. F.; Swisher, C. C.; Feigenson, M. D.; Carr, M. J.

    2005-05-01

    40Ar/39Ar dates on volcanic rocks from the Ngorongoro Crater (NC) in northern Tanzania indicate that NC activity was very short in duration lasting approximately 120 ka. Laser incremental heating experiments on lava from the bottom and top of the NC crater-wall section gave ages of 2.08 +/- 0.04 and 1.96 +/- 0.02 Ma respectively. Lavas from the same section show a change in magnetic polarity from normal (N) at the lower part to reverse (R) polarity at the upper part (Grommé et al. 1970). The new ages are about 400 ka younger than previously estimated by K-Ar technique. These new ages suggest correlation of the NC N-R polarity transition to the 2.1 Ma (N-R) Reunion-Matuyama boundary (Cande and Kent, 1995), instead of the Gauss-Matuyama boundary as proposed by Grommé et al. (1970). 87Sr/86Sr measurements on lavas from the NC section vary widely from 0.70801 in the trachydacite at the base to 0.70405 in the basaltic lava near the top. The lower part of the section is more radiogenic varying from 0.70592 to 0.70801 whereas the upper part is constrained to 0.70405 to 0.70450. The more radiogenic lower part is likely to have interacted with crustal rocks. Two possible contaminants are the Tanzanian Archean Craton to the west and the late Proterozoic Mozambican belt in the east. The crater-wall section is composed of trachydacite at the bottom that becomes trachyandesite in mid-section. The top section is mainly basaltic. Major and trace elements show an inverted geochemical signature that is typical of stratified magma chambers characterized by a silicic top and basaltic bottom. Olivine basalt at the upper part of the section has the highest Mg# (56.60) and in general the upper section is more mafic than the lower section as inferred from Mg#. The upper part of the section is high in TiO2, MgO, FeOT, and CaO wt% whereas SiO2 and K2O wt% are higher in lower part of the section. No significant variations are observed in N2O, Al2O3, P2O5 and MnO wt% up-section. Highly

  11. Education activities for environment and sustainability: A Snapshot of eight New South Wales councils

    Directory of Open Access Journals (Sweden)

    Jade Herriman

    2010-07-01

    Full Text Available This paper describes in brief the findings of a research project undertaken by the Institute for Sustainable Futures (ISF at the University of Technology, Sydney, Australia. The research was commissioned by and undertaken on behalf of the New South Wales (NSW Department of Environment, Climate Change and Water (DECCW. The aim of the project was to investigate current practices of environmental and sustainability education and engagement within local government in NSW. The research was commissioned by DECCW as the preliminary phase of a larger project that the department is planning to undertake, commencing in 2010.

  12. Monarchical Activities of the Yoruba Kings of South Western Nigeria: A Cultural Heritage in Printmaking Visual Documentary.

    Directory of Open Access Journals (Sweden)

    Emmanuel Bankole Oladumiye

    2014-10-01

    Full Text Available Printmaking is a visual documentary media of art which was used as a medium of expression in analyzing myth and mythology monarchical activities of the Yorubas in South Western Nigeria in this study. The  monarchical activities of the Yoruba Kings, is  the cultural heritage and legacy that people do guide jealously and considered to be of high cultural value. The Yoruba Kings of South Western Nigeria are traditional entity which passed through the rites of installing kings for the throne fore fathers as a leader with symbol of authority between the people and the spirit world. The kings in Yoruba kingdom is so much respected that they are seen as divine and representative of God on earth and they are exalted into the position of deity because of his monarchical duties to his subjects at large. The funfairs that accompany the monarch roles  are worth documenting using printmaking as vehicle of visual and historical expression of myths and mythologies demonstrating African culture which stands out as sacred. The discourse also relies on oral testimonies written and archival documents. The materials used for the execution of the prints are rubber, wood, plate, offset printing inks and glass which records the events as an alternative to the use of photographic documentation. The research examine the philosophy behind the monarchical roles of the Yoruba Kings in print visuals based on the cultural heritage of the Yoruba people it employs an exploratory qualitative methods rely on literature review.

  13. In vitro anthelmintic activity of Heliotropium indicum, Senna fistula and Spigelia anthelmia used as worm expeller in South West Nigeria

    Directory of Open Access Journals (Sweden)

    Oluwakemi K. Sobiyi

    2015-06-01

    Full Text Available The anthelmintic potential of Heliotropium indicum, Senna fistula and Spigelia anthelmia were investigated using nematodes larvae from sheep and adult earthworms in order to justify the folkloric claim of the plants as worm expeller in south west of Nigeria. The acetone, ethanol, hydro-alcohol and distilled water extracts showed dose-dependent anthelmintic activities at the different concentrations (0.25, 0.50, 1.0 mg/ml when tested against nematodes larvae. The order of anthelmintic effect for the plants was H. indicum> S. fistula> S. anthelmia. Acetone and ethanol extracts of the three plants showed the most effective activity (100% mortality against adult earth worm (Pheretima posthuma after 30 min of exposure The reference standard drug (Vermox® showed less effectiveness compared to the medicinal plants used in the study. Overall, the study indicates that Heliotropium indicum, Senna fistula and Spigelia anthelmia are potential anthelmintic herbal drugs, which in turn validates the use of the three species as worm expellers by the Yorubas tribe of South West Nigeria.

  14. The relationship between the built environment and habitual levels of physical activity in South African older adults: a pilot study.

    Science.gov (United States)

    Kolbe-Alexander, Tracy L; Pacheco, Kyla; Tomaz, Simone A; Karpul, David; Lambert, Estelle V

    2015-05-30

    Previous research has shown that the built environment plays a role in habitual levels of physical activity (PA), however much of this research has been conducted in adults and higher income countries. The aim of this pilot study was to examine the strength of association between the built environment and PA in South African older adults. Participants were recruited (n = 44, mean age 65 ± 8.5 years) from two suburbs, representing either a high socioeconomic (HSA) or low socioeconomic area (LSA). Self-reported PA, and subjective assessments of neighborhood walkability (Neighborhood Environment Walkability Scale, NEWS) was measured. Participants wore Actigraph GT3x accelerometers to objectively quantify PA. HSA participants reported significantly more leisure-time and less transport PA. Objectively measured and self-reported MVPA was significantly higher in HSA participants. NEWS 'Land-use Mix' was negatively associated with leisure-time MVPA, (r(2) = 0.20; p leisure-time physical activity (r(2) = 0.33; p = 0.02). 'Safety from traffic' was inversely associated with travel-related PA (r(2) = 0.14, p = 0.01). None of the other NEWS scores were associated with PA for the total group. Leisure-time and transport-related PA was influenced by socio-economic status. Attributes of the perceived built environment associated with leisure-time and total MVPA in older South Africa adults were different in low- and high- income settings.

  15. Tungsten disulfide nanosheet and exonuclease III co-assisted amplification strategy for highly sensitive fluorescence polarization detection of DNA glycosylase activity

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jingjin; Ma, Yefei [Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources of Education Ministry, Guangxi Normal University, Guilin, 541004 (China); Kong, Rongmei [The Key Laboratory of Life-Organic Analysis, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165 (China); Zhang, Liangliang, E-mail: liangzhang319@163.com [Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources of Education Ministry, Guangxi Normal University, Guilin, 541004 (China); Yang, Wen; Zhao, Shulin [Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources of Education Ministry, Guangxi Normal University, Guilin, 541004 (China)

    2015-08-05

    Herein, we introduced a tungsten disulfide (WS{sub 2}) nanosheet and exonuclease III (Exo III) co-assisted signal amplification strategy for highly sensitive fluorescent polarization (FP) assay of DNA glycosylase activity. Two DNA glycosylases, uracil-DNA glycosylase (UDG) and human 8-oxoG DNA glycosylase 1 (hOGG1), were tested. A hairpin-structured probe (HP) which contained damaged bases in the stem was used as the substrate. The removal of damaged bases from substrate by DNA glycosylase would lower the melting temperature of HP. The HP was then opened and hybridized with a FAM dye-labeled single strand DNA (DP), generating a duplex with a recessed 3′-terminal of DP. This design facilitated the Exo III-assisted amplification by repeating the hybridization and digestion of DP, liberating numerous FAM fluorophores which could not be adsorbed on WS{sub 2} nanosheet. Thus, the final system exhibited a small FP signal. However, in the absence of DNA glycosylases, no hybridization between DP and HP was occurred, hampering the hydrolysis of DP by Exo III. The intact DP was then adsorbed on the surface of WS{sub 2} nanosheet that greatly amplified the mass of the labeled-FAM fluorophore, resulting in a large FP value. With the co-assisted amplification strategy, the sensitivity was substantially improved. In addition, this method was applied to detect UDG activity in cell extracts. The study of the inhibition of UDG was also performed. Furthermore, this method is simple in design, easy in implementation, and selective, which holds potential applications in the DNA glycosylase related mechanism research and molecular diagnostics. - Highlights: • A fluorescence polarization strategy for DNA glycosylase activity detection was developed. • The present method was based on WS{sub 2} nanosheet and exonuclease III co-assisted signal amplification. • A high sensitivity and desirable selectivity were achieved. • This method provides a promising universal platform for DNA

  16. What Colour Is a Polar Bear's Skin?

    Science.gov (United States)

    Truchot, Sandrine; Weber, Agathe

    2005-01-01

    The association "Participe Futur", based in France, has set up a fantastic sailing and educational adventure with the help of the International Polar Foundation. A group of scientists left the South of France on 20 March 2005 on a sailing boat named "Alcyon". They will be on board for nine months, travelling all the way from…

  17. Initiation of extension in South China continental margin during the active-passive margin transition: kinematic and thermochronological constraints

    Science.gov (United States)

    ZUO, Xuran; CHAN, Lung

    2015-04-01

    The southern South China Block is characterized by a widespread magmatic belt, prominent NE-striking fault zones and numerous rifted basins filled by Cretaceous-Eocene sediments. The geology denotes a transition from an active to a passive margin, which led to rapid modifications of crustal stress configuration and reactivation of older faults in this area. In this study, we used zircon fission-track dating (ZFT) and numerical modeling to examine the timing and kinematics of the active-passive margin transition. Our ZFT results on granitic plutons in the SW Cathaysia Block show two episodes of exhumation of the granitic plutons. The first episode, occurring during 170 Ma - 120 Ma, affected local parts of the Nanling Range. The second episode, a more regional exhumation event, occurred during 115 Ma - 70 Ma. Numerical geodynamic modeling was conducted to simulate the subduction between the paleo-Pacific plate and the South China Block. The modeling results could explain the observation based on ZFT data that exhumation of the granite-dominant Nanling Range occurred at an earlier time than the gneiss-dominant Yunkai Terrane. In addition to the difference in geology between Yunkai and Nanling, the heating from Jurassic-Early Cretaceous magmatism in the Nanling Range may have softened the upper crust, causing the area to exhume more readily. Numerical modeling results also indicate that (1) high slab dip angle, high geothermal gradient of lithosphere and low convergence velocity favor the subduction process and the reversal of crustal stress state from compression to extension in the upper plate; (2) the late Mesozoic magmatism in South China was probably caused by a slab roll-back; and (3) crustal extension could have occurred prior to the cessation of plate subduction. The inversion of stress regime in the continental crust from compression to crustal extension has shed light on the geological condition producing the red bed basins during Late Cretaceous

  18. Aaptamine Derivatives with Antifungal and Anti-HIV-1 Activities from the South China Sea Sponge Aaptos aaptos

    Directory of Open Access Journals (Sweden)

    Hao-Bing Yu

    2014-12-01

    Full Text Available Five new alkaloids of aaptamine family, compounds (1–5 and three known derivatives (6–8, have been isolated from the South China Sea sponge Aaptos aaptos. The structures of all compounds were unambiguously elucidated by spectroscopic analyses, as well as by comparison with the literature data. Compounds 1–2 are characterized with triazapyrene lactam skeleton, whereas compounds 4–5 share an imidazole-fused aaptamine moiety. These compounds were evaluated in antifungal and anti-HIV-1 assays. Compounds 3, 7, and 8 showed antifungal activity against six fungi, with MIC values in the range of 4 to 64 μg/mL. Compounds 7–8 exhibited anti-HIV-1 activity, with inhibitory rates of 88.0% and 72.3%, respectively, at a concentration of 10 μM.

  19. Resilience does not explain the dissociation between chronic pain and physical activity in South Africans living with HIV

    Directory of Open Access Journals (Sweden)

    Antonia L. Wadley

    2016-09-01

    Full Text Available Pain burden is high in people living with HIV (PLWH, but the effect of this pain on functionality is equivocal. Resilience, the ability to cope with adversity, may promote adaptation to pain, so we hypothesised that higher resilience would correlate with less pain-related impairment of activity. We recruited 197 black South African PLWH, 99 with chronic pain (CP and 98 patients without. We measured pain intensity and interference using the Brief Pain Inventory, and resilience using the Resilience Scale. Participants were generally highly resilient. Greater resilience correlated with better health-related quality of life, but not with pain intensity or interference. We also measured physical activity objectively, by actigraphy, in a subset of patients (37 with chronic pain and 31 without chronic pain, who wore accelerometers for two weeks. There was no difference in duration or intensity of activity between those with and without pain, and activity was not associated with resilience. In this sample, pain was not associated with altered physical activity. Resilience did not explain differences in pain intensity or pain interference but was associated with improved quality of life. Financial stresses and the fear of HIV stigma may have driven patients to conceal pain and to suppress its expected impairment of activity.

  20. Developing an intervention to address physical activity barriers for African-American women in the deep south (USA).

    Science.gov (United States)

    Pekmezi, Dori; Marcus, Bess; Meneses, Karen; Baskin, Monica L; Ard, Jamy D; Martin, Michelle Y; Adams, Natasia; Robinson, Cody; Demark-Wahnefried, Wendy

    2013-05-01

    To address high rates of inactivity and related chronic diseases among African-American women. Eleven focus groups on physical activity barriers for African-American women in the deep south (USA) were conducted (n = 56). Feedback guided an intervention development process. The resulting Home-Based Individually Tailored Physical Activity Print intervention was vetted with the target population in a 1-month, single arm, pre-post test demonstration trial (n = 10). Retention was high (90%). Intent-to-treat analyses indicated increases in motivational readiness for physical activity (70% of sample) and physical activity (7-day Physical Activity Recall) from baseline (mean: 89.5 min/week, standard deviation: 61.17) to 1 month (mean: 155 min/week, standard deviation: 100.86). Small improvements in fitness (6-Min Walk Test), weight and psychosocial process measures were also found. Preliminary findings show promise and call for future randomized controlled trials with larger samples to determine efficacy. Such low-cost, high-reach approaches to promoting physical activity have great potential for addressing health disparities and benefiting public health.

  1. Galectin-7 promotes proliferation and Th1/2 cells polarization toward Th1 in activated CD4+ T cells by inhibiting The TGFβ/Smad3 pathway.

    Science.gov (United States)

    Luo, Zhenlong; Ji, Yudong; Tian, Dean; Zhang, Yong; Chang, Sheng; Yang, Chao; Zhou, Hongmin; Chen, Zhonghua Klaus

    2018-06-08

    Galectin-7 (Gal-7) has been associated with cell proliferation and apoptosis. It is known that Gal-7 antagonises TGFβ-mediated effects in hepatocytes by interacting with Smad3. Previously, we have demonstrated that Gal-7 is related to CD4+ T cells responses; nevertheless, its effect and functional mechanism on CD4+ T cells responses remain unclear. The murine CD4+ T cells were respectively cultured with Gal-7, anti-CD3/CD28 mAbs, or with anti-CD3/CD28 mAbs & Gal-7. The effects of Gal-7 on proliferation and the phenotypic changes in CD4+ T cells were assessed by flow cytometry. The cytokines from CD4+ T cells were analysed by quantitative real-time PCR. Subcellular localisation and expression of Smad3 were determined by immunofluorescence staining and Western blot, respectively. Gal-7 enhanced the proliferation of activated CD4+ T cells in a dose- and β-galactoside-dependent manner. Additionally, Gal-7 treatment did not change the ratio of Th2 cells in activated CD4+ T cells, while it increased the ratio of Th1 cells. Gal-7 also induced activated CD4+ T cells to produce a higher level of IFN-γ and TNF-α and a lower level of IL-10. Moreover, Gal-7 treatment significantly accelerated nuclear export of Smad3 in activated CD4+ T cells. These results revealed a novel role of Gal-7 in promoting proliferation and Th1/2 cells polarization toward Th1 in activated CD4+ T cells by inhibiting the TGFβ/Smad3 pathway. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Suppression and excitation of MHD activity with an electrically polarized electrode at the TCABR tokamak plasma edge

    International Nuclear Information System (INIS)

    Nascimento, I.C.; Kuznetsov, Yu.K.; Guimaraes-Filho, Z.O.; Chamaa-Neto, I. El; Usuriaga, O.; Fonseca, A.M.M.; Galvao, R.M.O.; Caldas, I.L.; Severo, J.H.F.; Semenov, I.B.; Ribeiro, C.; Heller, M.V.P.; Bellintani, V.; Elizondo, J.I.; Sanada, E.

    2007-01-01

    Two reproducible regimes of tokamak operation, with excitation or suppression of MHD activity can be obtained using a voltage-biased electrode inside the edge of the TCABR tokamak. The experiment was carried out adjusting the tokamak parameters to obtain two types of discharges: with strong or weak MHD activity, without biasing in both cases. The plasma current was adjusted to cover a range of safety factor from 2.9 up to 3.5, so that when biasing was applied the magnetic island (3,1) could interact with the edge barrier. The application of biasing in subsequent discharges of each type resulted in excitation or suppression of the MHD activity. The results show that the dominant modes are m = 2, n = 1 and m = 3, n = 1 for excitation and partial suppression, respectively. In both regimes a strong decrease in the radial electric field is detected with destruction of the transport barrier and of the improved confinement caused by different mechanisms. The measurements include temporal behaviour of edge transport, turbulence, poloidal electric and magnetic fields, edge density, radial electric fields and radial profile of H α line intensity. The explanation of the excitation and suppression processes is discussed in the paper

  3. "I Don't Want My Parents' Respect Going down the Drain": South Asian, Muslim Young Women Negotiating Family and Physical Activity

    Science.gov (United States)

    Stride, Annette; Flintoff, Anne

    2017-01-01

    Young women's relationship with physical activity has been explored extensively, yet the focus is often upon young women who are White. This paper considers South Asian, Muslim young women's experiences of physical activity and how these are influenced by family. A "middle ground" feminist approach is used, drawing upon the work of Hill…

  4. Assessment of food safety risks associated with preslaughter activities during the traditional slaughter of goats in Gauteng, South Africa.

    Science.gov (United States)

    Qekwana, Nenene Daniel; Oguttu, James Wabwire

    2014-06-01

    The South African Department of Agriculture, Forestry and Fisheries estimated in 2012 that there were 2.033 million goats in the country. Of these animals, less than 0.5% are slaughtered at registered abattoirs. Although informal and traditional slaughter of goats for home consumption is permitted under the South African Meat Safety Act 40 of 2000, the responsibility for ensuring that products are safe is left to the traditional or ritual slaughter practitioners. The objective of the present study was to assess whether preslaughter activities associated with traditional or ritual slaughter promote or reduce food-associated risks and to recommend mitigation strategies for potential food safety hazards. Structured interviews were conducted with 105 selected respondents (in and around Tshwane, South Africa) who had been involved in traditional goat slaughter. Approximately 70% of goats slaughtered were obtained from sources that could be traced to ascertain the origin of the goats. None of the respondents were aware of the need for a health declaration for slaughter stock. Some slaughter practitioners (21%) perform prepurchase inspection of stock to ascertain their health status. However, this percentage is very small, and the approach is based on indigenous knowledge systems. The majority of respondents (67.6%) travelled 1 to 11 km to obtain a goat for traditional slaughter. Although approximately 70% of slaughter goats were transported by vehicles, the vehicles used did not meet the legal standard. More than two-thirds of goats were tied to a tree while waiting to be slaughtered, and the rest were held in a kraal. The holding period ranged from 1 to 72 h, but more than 70% of the animals were slaughtered within 36 h. This study revealed that traditional and ritual slaughter involves some preslaughter activities with potential to mitigate the risk of slaughtering animals that are not fit for human consumption. Such activities include prepurchase inspection, obtaining

  5. 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

  6. 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.

  7. Knockdown of connexin43-mediated regulation of the zone of polarizing activity in the developing chick limb leads to digit truncation.

    Science.gov (United States)

    Law, Lee Yong; Lin, Jun Sheng; Becker, David L; Green, Colin R

    2002-12-01

    In the developing chick wing, the use of antisense oligodeoxynucleotides to transiently knock down the expression of the gap junction protein, connexin43 (Cx43), results in limb patterning defects, including deletion of the anterior digits. To understand more about how such defects arise, the effects of transient Cx43 knockdown on the expression patterns of several genes known to play pivotal roles in limb formation were examined. Sonic hedgehog (Shh), which is normally expressed in the zone of polarizing activity (ZPA) and is required to maintain both the ZPA and the apical ectodermal ridge (AER), was found to be downregulated in treated limbs within 30 h. Bone morphogenetic protein-2 (Bmp-2), a gene downstream of Shh, was similarly downregulated. Fibroblast growth factor-8 expression, however, was unaltered 30 h after treatment but was greatly reduced at 48 h post-treatment, when the AER begins to regress. Expressions of Bmp-4 and Muscle segment homeobox-like gene (Msx-1) were not affected at any of the time points examined. Cx43 expression is therefore involved in some, but not all patterning cascades, and appears to play a role in the regulation of ZPA activity.

  8. Atmospheric loss from the dayside open polar region and its dependence on geomagnetic activity: implications for atmospheric escape on evolutionary timescales

    Directory of Open Access Journals (Sweden)

    R. Slapak

    2017-06-01

    Full Text Available We have investigated the total O+ escape rate from the dayside open polar region and its dependence on geomagnetic activity, specifically Kp. Two different escape routes of magnetospheric plasma into the solar wind, the plasma mantle, and the high-latitude dayside magnetosheath have been investigated separately. The flux of O+ in the plasma mantle is sufficiently fast to subsequently escape further down the magnetotail passing the neutral point, and it is nearly 3 times larger than that in the dayside magnetosheath. The contribution from the plasma mantle route is estimated as  ∼ 3. 9 × 1024exp(0. 45 Kp [s−1] with a 1 to 2 order of magnitude range for a given geomagnetic activity condition. The extrapolation of this result, including escape via the dayside magnetosheath, indicates an average O+ escape of 3 × 1026 s−1 for the most extreme geomagnetic storms. Assuming that the range is mainly caused by the solar EUV level, which was also larger in the past, the average O+ escape could have reached 1027–28 s−1 a few billion years ago. Integration over time suggests a total oxygen escape from ancient times until the present roughly equal to the atmospheric oxygen content today.

  9. 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

  10. Solid-phase extraction of polar pesticides from environmental water samples on graphitized carbon and Empore-activated carbon disks and on-line coupling to octadecyl-bonded silica analytical columns.

    NARCIS (Netherlands)

    Slobodník, J.; Oztekizan, O.; Lingeman, H.; Brinkman, U.A.T.

    1996-01-01

    The suitability of Empore-activated carbon disks (EACD), Envi-Carb graphitized carbon black (GCB) and CPP-50 graphitized carbon for the trace enrichment of polar pesticides from water samples was studied by means of off-line and on-line solid-phase extraction (SPE). In the off-line procedure, 0.5-2

  11. Incorporation of cerium oxide into hydroxyapatite coating regulates osteogenic activity of mesenchymal stem cell and macrophage polarization.

    Science.gov (United States)

    Li, Kai; Shen, Qingyi; Xie, Youtao; You, Mingyu; Huang, Liping; Zheng, Xuebin

    2017-02-01

    Biomedical coatings for orthopedic implants should facilitate osseointegration and mitigate implant-induced inflammatory reactions. Cerium oxide (CeO 2 ) ceramics possess anti-oxidative properties and can be used to decrease mediators of inflammation, which makes them attractive for biomedical applications. In our work, two kinds of CeO 2 incorporated hydroxyapatite coatings (HA-10Ce and HA-30Ce) were prepared via plasma spraying technique and the effects of CeO 2 addition on the responses of bone mesenchymal stem cells (BMSCs) and RAW264.7 macrophages were investigated. An increase in CeO 2 content in the HA coatings resulted in better osteogenic behaviors of BMSCs in terms of cell proliferation, alkaline phosphatase (ALP) activity and mineralized nodule formation. RT-PCR and western blot analysis suggested that the incorporation of CeO 2 may promote the osteogenic differentiation of BMSCs through the Smad-dependent BMP signaling pathway, which activated Runx2 expression and subsequently enhanced the expression of ALP and OCN. The expression profiles of macrophages cultured on the CeO 2 modified coating revealed a tendency toward a M2 phenotype, because of an upregulation of M2 surface markers (CD163 and CD206), anti-inflammatory cytokines (TNF-α and IL-6) and osteoblastogenesis-related genes (BMP2 and TGF-β1) as well as a downregulation of M1 surface markers (CCR7 and CD11c), proinflammatory cytokines (IL-10 and IL-1ra) and reactive oxygen species production. The results suggested the regulation of BMSCs behaviors and macrophage-mediated responses at the coating's surface were associated with CeO 2 incorporation. The incorporation of CeO 2 in HA coatings can be a valuable strategy to promote osteogenic responses and reduce inflammatory reactions.

  12. South Africa calls Italy: effective exchange activity through costless (Skype like) connections in the framework of the EU UNAWE project

    Science.gov (United States)

    Zanazzi, A.; Albanese, L.; Naidoo, T.

    2014-10-01

    In summer 2012 the Italian EU-UNAWE team joined with the South African team in Cape Town, working with the township schools organizing activities at school and also a teachers' training event at the SAAO Observatory. In order to involve in the exchange not only the project's experts but also to the teachers and the children, we organized Skype connections between the Cape town teachers participating in the project and the teachers in Sicily (South Italy) that also participated in one of the Italian training sessions and later between the children of the Italian school and those in Zanemfundo School (Cape Town). Thanks to this chance of seeing each other and talking directly, children have - with huge interest and participation - shared and learned methods, experiences, curiosities. They shared their prepared actual science researches, in order to understand why an equal gnomon cast different shadows at the same time in the two countries. The teachers confronted on curricula, didactic methodologies such as working with a background story during the whole school year, interdisciplinary uses of astronomy, languages etc. The EU-UNAWE project and International or Regional conferences such as LARIM are perfect chances to create exchanges between countries all around the World, and this simple communication model between children and teachers appears like an enormous resource yet to be fully exploited.

  13. Working conditions and leisure-time physical activity among waged workers in South Korea: A cross-sectional study.

    Science.gov (United States)

    Kim, Chungah; Cho, Youngtae

    2015-01-01

    Although waged workers' working conditions have notably diversified in South Korea, there is little research addressing this issue. This study explores the relationship between working conditions and engagement in leisure-time physical activities (LTPA) among waged workers in South Korea. Data from 19- to 64-year-old waged workers (men=2,562, women=1,627) from the 11th wave of the Korean Income and Labor Panel Study were included in this study. Multiple logistic regression analyses were conducted to assess the association between LTPA and working conditions by gender. More than 75% of employed persons did not participate in any type of LTPA. For male workers, those in manual, precarious, overtime, and non-shift positions were less likely to engage in LTPA, while for female workers, only manual and overtime work positions were significant factors influencing a low level of LTPA. Some negative work-related factors were associated with low LTPA, especially for male workers. Further studies should be conducted to clarify the pathways and barriers precluding engagement in LTPA due to work-related factors.

  14. Bioelectric modulation of macrophage polarization

    Science.gov (United States)

    Li, Chunmei; Levin, Michael; Kaplan, David L.

    2016-02-01

    Macrophages play a critical role in regulating wound healing and tissue regeneration by changing their polarization state in response to local microenvironmental stimuli. The native roles of polarized macrophages encompass biomaterials and tissue remodeling needs, yet harnessing or directing the polarization response has been largely absent as a potential strategy to exploit in regenerative medicine to date. Recent data have revealed that specific alteration of cells’ resting potential (Vmem) is a powerful tool to direct proliferation and differentiation in a number of complex tissues, such as limb regeneration, craniofacial patterning and tumorigenesis. In this study, we explored the bioelectric modulation of macrophage polarization by targeting ATP sensitive potassium channels (KATP). Glibenclamide (KATP blocker) and pinacidil (KATP opener) treatment not only affect macrophage polarization, but also influence the phenotype of prepolarized macrophages. Furthermore, modulation of cell membrane electrical properties can fine-tune macrophage plasticity. Glibenclamide decreased the secretion and gene expression of selected M1 markers, while pinacidil augmented M1 markers. More interestingly, glibencalmide promoted macrophage alternative activation by enhancing certain M2 markers during M2 polarization. These findings suggest that control of bioelectric properties of macrophages could offer a promising approach to regulate macrophage phenotype as a useful tool in regenerative medicine.

  15. Scheme of adaptive polarization filtering based on Kalman model

    Institute of Scientific and Technical Information of China (English)

    Song Lizhong; Qi Haiming; Qiao Xiaolin; Meng Xiande

    2006-01-01

    A new kind of adaptive polarization filtering algorithm in order to suppress the angle cheating interference for the active guidance radar is presented. The polarization characteristic of the interference is dynamically tracked by using Kalman estimator under variable environments with time. The polarization filter parameters are designed according to the polarization characteristic of the interference, and the polarization filtering is finished in the target cell. The system scheme of adaptive polarization filter is studied and the tracking performance of polarization filter and improvement of angle measurement precision are simulated. The research results demonstrate this technology can effectively suppress the angle cheating interference in guidance radar and is feasible in engineering.

  16. PPAR-gamma activation is associated with reduced liver ischemia-reperfusion injury and altered tissue-resident macrophages polarization in a mouse model.

    Science.gov (United States)

    Linares, Ivan; Farrokhi, Kaveh; Echeverri, Juan; Kaths, Johan Moritz; Kollmann, Dagmar; Hamar, Matyas; Urbanellis, Peter; Ganesh, Sujani; Adeyi, Oyedele A; Yip, Paul; Selzner, Markus; Selzner, Nazia

    2018-01-01

    PPAR-gamma (γ) is highly expressed in macrophages and its activation affects their polarization. The effect of PPAR-γ activation on Kupffer cells (KCs) and liver ischemia-reperfusion injury (IRI) has not yet been evaluated. We investigated the effect of PPAR-γ activation on KC-polarization and IRI. Seventy percent (70%) liver ischemia was induced for 60mins. PPAR-γ-agonist or vehicle was administrated before reperfusion. PPAR-γ-antagonist was used to block PPAR-γ activation. Liver injury, necrosis, and apoptosis were assessed post-reperfusion. Flow-cytometry determined KC-phenotypes (pro-inflammatory Nitric Oxide +, anti-inflammatory CD206+ and anti-inflammatory IL-10+). Liver injury assessed by serum AST was significantly decreased in PPAR-γ-agonist versus control group at all time points post reperfusion (1hr: 3092±105 vs 4469±551; p = 0.042; 6hr: 7041±1160 vs 12193±1143; p = 0.015; 12hr: 5746±328 vs 8608±1259; p = 0.049). Furthermore, liver apoptosis measured by TUNEL-staining was significantly reduced in PPAR-γ-agonist versus control group post reperfusion (1hr:2.46±0.49 vs 6.90±0.85%;p = 0.001; 6hr:26.40±2.93 vs 50.13±8.29%; p = 0.048). H&E staining demonstrated less necrosis in PPAR-γ-agonist versus control group (24hr:26.66±4.78 vs 45.62±4.57%; p = 0.032). The percentage of pro-inflammatory NO+ KCs was significantly lower at all post reperfusion time points in the PPAR-γ-agonist versus control group (1hr:28.49±4.99 vs 53.54±9.15%; p = 0.040; 6hr:5.51±0.54 vs 31.12±9.58%; p = 0.009; 24hr:4.15±1.50 vs 17.10±4.77%; p = 0.043). In contrast, percentage of anti-inflammatory CD206+ KCs was significantly higher in PPAR-γ-agonist versus control group prior to IRI (8.62±0.96 vs 4.88 ±0.50%; p = 0.04). Administration of PPAR-γ-antagonist reversed the beneficial effects on AST, apoptosis, and pro-inflammatory NO+ KCs. PPAR-γ activation reduces IRI and decreases the pro-inflammatory NO+ Kupffer cells. PPAR-γ activation can become an

  17. Geologic history of the polar regions of Mars based on Mars Global survey data. I. Noachian and Hesperian Periods

    Science.gov (United States)

    Tanaka, K.L.; Kolb, E.J.

    2001-01-01

    During the Noachian Period, the south polar region of Mars underwent intense cratering, construction of three groups of volcanoes, widespread contractional deformation, resurfacing of low areas, and local dissection of valley networks; no evidence for polar deposits, ice sheets, or glaciation is recognized. South polar Hesperian geology is broadly characterized by waning impacts, volcanism, and tectonism. Emplacement of the polar Dorsa Argentea Formation (DAF) occurred during the Hesperian Period. Mars Orbiter Laser Altimeter topographic data and Mars Orbiter Camera images elucidate stratigraphic, morphologic, and topographic relations, permitting the dividing of the DAF into eight members, which surround and underlie about half of the Amazonian south polar layered deposits. The lobate fronts and lack of typical volcanic-flow morphology of the six plains units indicate that they may be made up of debris flows. We think that these flows, tens of meters to 200 m thick, may have originated by the discharge of huge volumes of slurry fluidized by ground water or liquid CO2, perhaps triggered by local impacts, igneous activity, or basal melting beneath polar deposits. The cavi and rugged members include irregular depressions that penetrate the subsurface; some of the pits have raised rims. The depressions may have formed by collapse due to expulsion of subsurface material in which local explosive activity built up the raised rims. Further, smaller eruptions of volatile-rich material may have resulted in narrow, sinuous channel deposits within aggrading fine-grained unconsolidated material perhaps produced by gaseous discharge of subsurface volatiles; preferential erosion of the latter material could have produced the Dorsa Argentea-type ginuous ridges associated mainly with the DAF. Alternatively, the ridges may be eskers, but the lack of associated glacial and fluvial morphologies casts doubt on this interpretation. The knobby, degraded materials forming Scandia Colles

  18. Role of wind forcing and eddy activity in the intraseasonal variability of the barrier layer in the South China Sea

    Science.gov (United States)

    Liang, Zhanlin; Xie, Qiang; Zeng, Lili; Wang, Dongxiao

    2018-03-01

    In addition to widely discussed seasonal variability, the barrier layer (BL) of the South China Sea (SCS) also exhibits significant intraseasonal variability (ISV) and plays an important role in the upper heat and salt balances. The characteristics and mechanisms of spatiotemporal variations in the BL are investigated using an eddy-resolving ocean model OFES (OGCM For the Earth Simulator) ouput and related atmospheric and oceanic processes. The active intraseasonal BL variability in the SCS occurs mainly during the late summer/autumn and winter and exhibits remarkable differences between these two periods. The BL ISV in late summer/autumn occurs in the southern basin, while in winter, it is limited to the northwestern basin. To further discuss the evolution and driving thermodynamic mechanisms, we quantify the processes that control the variability of intraseasonal BL. Different mechanisms for the intraseasonal BL variability for these two active periods are investigated based on the case study and composite analysis. During late summer/autumn, the active BL in the southern basin is generated by advected and local freshwater, and then decays rapidly with the enhanced wind. In winter, anticyclonic eddy activity is associated with the evolution of the BL by affecting the thermocline and halocline variations, while wind stress and wind stress curl have no obvious influence on BL.

  19. Physical activity and screen time in children and adolescents in a medium size town in the South of Brazil.

    Science.gov (United States)

    Greca, João Paulo de Aguiar; Silva, Diego Augusto Santos; Loch, Mathias Roberto

    2016-09-01

    To analyze the associations between sex and age with behaviour related to physical activity practice and sedentary behaviour in children and adolescents. A cross-sectional study with 480 (236 boys) subjects enrolled in a public school in the city of Londrina, in the south of Brazil, aged 8-17 years. Measures of physical activity, sports practice and screen times were obtained using the Physical Activity Questionnaire for Older Children. The Mann-Whitney U test was used to compare variables between boys and girls. The Chi squared test was used for categorical analysis and Poisson regression was used to identify prevalence. Girls (69.6%; PR=1.05 [0.99-1.12]) spent more time with sedentary behaviour than boys (62.2%). Boys (80%; PR=0.95 [0.92-0.98]) were more physically active than girls (91%). Older students aged 13-17 showed a higher prevalence of physical inactivity (91.4%; PR=1.06 [1.02-1.10]) and time spent with sedentary behaviour of ≥2h/day (71.8%; PR=0.91 [0.85-0.97]) when compared to younger peers aged 8-12 (78.7 and 58.5%, respectively). The prevalence of physical inactivity was higher in girls. Older students spent more screen time in comparison to younger students. Copyright © 2016 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  20. Study on surface morphology and physicochemical properties of raw and activated South African coal and coal fly ash

    Science.gov (United States)

    Mishra, S. B.; Langwenya, S. P.; Mamba, B. B.; Balakrishnan, M.

    South African coal and coal fly ash were selected as the raw materials to be used for study of their morphology and physicochemical properties and their respective activated carbons for adsorption applications. Coal and fly ash were individually steam activated at a temperature range of 550-1000 °C for 1 h in a muffle furnace using cylindrical stainless steel containers. Scanning electron micrographs revealed a change in surface morphology with more mineral matter available on the surface of the coal particles due to increased devolatilization. However, in the case of fly ash, the macerals coalesced to form agglomerates and the presence of unburnt carbon constituted pores of diameter between 50 and 100 nm. The BET surface area of coal improved significantly from 5.31 to 52.12 m 2/g whereas in case of fly ash the surface area of the raw sample which was originally 0.59 m 2/g and upon activation increased only up to 2.04 m 2/g. The chemical composition of the fly ash confirmed that silica was the major component which was approximately 60% by weight fraction. The impact of this study was to highlight the importance of using raw materials such as coal and a waste product, in the form of coal ash, in order to produce affordable activated carbon that can be used in drinking water treatment. This would therefore ensure that the quality of water supplied to communities for drinking is not contaminated especially by toxic organic compounds.

  1. The binding activity of Mel-18 at the Il17a promoter is regulated by the integrated signals of the TCR and polarizing cytokines.

    Science.gov (United States)

    Hod-Dvorai, Reut; Jacob, Eyal; Boyko, Yulia; Avni, Orly

    2011-08-01

    We have previously shown that in differentiated T-helper (Th)1 and Th2 cells, polycomb group (PcG) proteins are associated differentially with the promoters of the signature cytokine genes. The correlation of the binding activity of PcG proteins with gene expression is unusual, since they are well known as epigenetic regulators that maintain transcriptional silencing. Here we show that in Th17 cells, the more phenotypically flexible Th lineage, the PcG proteins Mel-18 and less strikingly Ezh2 are associated differentially with the Il17a promoter. Using the RNAi approach, we found that Mel-18 and Ezh2 positively regulate the expression of Il17a and Il17f. The inducible binding of Mel-18 and Ezh2 at the Il17a promoter was dependent on signaling pathways downstream of the TCR. However, a continuous presence of TGF-β, the cytokine that is necessary to maintain Il17a expression, was required to preserve the binding activity of Mel-18, but not of Ezh2, following restimulation. The binding of Mel-18 at the Il17a promoter was correlated with the recruitment of the lineage-specifying transcription factor RORγt. Altogether, our results suggest that in Th17 cells the TCR and polarizing cytokines synergize to modulate the binding activity of Mel-18 at the Il17a promoter, and consequently to facilitate Il17a expression. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Self-Reported Physical Activity is Not a Valid Method for Measuring Physical Activity in 15-Year-Old South African Boys and Girls

    Directory of Open Access Journals (Sweden)

    Makama Andries Monyeki

    2018-06-01

    Full Text Available Physical activity plays an important role in the prevention of chronic lifestyle-related diseases. The development of valid instruments for the assessment of physical activity remains a challenge in field studies. The purpose of the present study was therefore to determine the level of agreement between physical activity objectively measured by the ActiHeart® (Cambridge Neurotechnology Ltd, Cambridge, UK device and subjectively reported physical activity by means of the International Physical Activity Questionnaire Short Form (IPAQ-SF among adolescents attending schools in the Tlokwe Local Municipality, South Africa. A cross-sectional study design was used with a total of 63 boys and 45 girls aged 15 years who took part in the Physical Activity and Health Longitudinal Study (PHALS. Stature and weight were measured according to standard International Society for the Advancement of Kinanthropometry (ISAK protocols. Objective physical activity (PA was measured by a combined heart rate and accelerometer device (ActiHeart® for seven consecutive days. Time spent in moderate-to-vigorous intensity physical activity (MVPA was assessed. Subjective physical activity was assessed with the self-reported IPAQ-SF. Objective PA indicated that 93% of the participants were inactive and only 6% were highly active. The IPAQ-SF showed that 24% were inactive, with 57% active. A non-significant correlation (r = 0.11; p = 0.29 between the ActiHeart® measure of activity energy expenditure (AEE and total physical activity (IPAQ-SF was observed. The Bland–Altman plot showed no agreement between the two measurement instruments and also a variation in the level of equivalence. When Cohen’s kappa (κ was run to determine the agreement between the two measurement instruments for estimated physical activity, a poor agreement (κ = 0.011, p < 0.005 between the two was found. The poor level of agreement between the objective measure of physical activity (ActiHeart® and

  3. Characterizing the subsurface geology in and around the U.S. Army Camp Stanley Storage Activity, south-central Texas

    Science.gov (United States)

    Blome, Charles D.; Clark, Allan K.

    2018-02-15

    Several U.S. Geological Survey projects, supported by the National Cooperative Geologic Mapping Program, have used multi-disciplinary approaches over a 14-year period to reveal the surface and subsurface geologic frameworks of the Edwards and Trinity aquifers of central Texas and the Arbuckle-Simpson aquifer of south-central Oklahoma. Some of the project achievements include advancements in hydrostratigraphic mapping, three-dimensional subsurface framework modeling, and airborne geophysical surveys as well as new methodologies that link geologic and groundwater flow models. One area where some of these milestones were achieved was in and around the U.S. Army Camp Stanley Storage Activity, located in north­western Bexar County, Texas, about 19 miles north­west of downtown San Antonio.

  4. 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)

  5. Uncovering the Protostars in Serpens South with ALMA: Continuum Sources and Their Outflow Activity

    Science.gov (United States)

    Plunkett, Adele; Arce, H.; Corder, S.; Dunham, M.

    2017-06-01

    Serpens South is an appealing protostellar cluster to study due the combination of several factors: (1) a high protostar fraction that shows evidence for very recent and ongoing star formation; (2) iconic clustered star formation along a filamentary structure; (3) its relative proximity within a few hundred parsecs. An effective study requires the sensitivity, angular and spectral resolution, and mapping capabilities recently provided with ALMA. Here we present a multi-faceted data set acquired from Cycles 1 through 3 with ALMA, including maps of continuum sources and molecular outflows throughout the region, as well as a more focused kinematical study of the protostar that is the strongest continuum source at the cluster center. Together these data span spatial scales over several orders of magnitude, allowing us to investigate the outflow-driving sources and the impact of the outflows on the cluster environment. Currently, we focus on the census of protostars in the cluster center, numbering about 20, including low-flux, low-mass sources never before detected in mm-wavelengths and evidence for multiplicity that was previously unresolved.

  6. Waste-management activities for groundwater protection, Savannah River Plant, Aiken, South Carolina

    International Nuclear Information System (INIS)

    1987-12-01

    Management of hazardous, low-level radioactive, and mixed waste for groundwater protection at the Savannah River Plant (SRP), Aiken, South Carolina is proposed. The preferred disposal alternative would involve modification of the SRP waste-management program to comply with all groundwater-protection requirements by implementing the following actions: (1) removal of wastes at selected existing waste sites to the extent practicable and implementing closure and groundwater remedial actions as required by applicable state and federal regulations; (2) establishment of a combination of retrievable storage, above ground, and below ground disposal facilities; and (3) continuation of the use of seepage and containment basins for the periodic discharge of reactor disassembly-basin purge. Groundwater contamination of aquifers would be controlled, improving on-site groundwater as well as surface water quality. Associated public health risks, as well as risks associated with atmospheric releases, would be reduced. Risks from releases of transuranic and high level wastes, volatile organic compounds, heavy metals, radionuclides, and other miscellaneous chemical would be contained. Some sites would be removed from public use. Other adverse impacts could include local and transitory on-site groundwater drawdown effects and minor short-term terrestrial impacts due to the use of borrow pits for backfill. Wildlife-habitat impacts could result due to land clearing and development

  7. A Comparative Study on the Antioxidant Activity of Commonly Used South Asian Herbs

    Directory of Open Access Journals (Sweden)

    Viduranga Waisundara

    2013-10-01

    Full Text Available The antioxidant activities of curry leaves, fenugreek seeds, Indian malabar leaves, red silk cotton tree leaves, cowitch leaves, holyfruit tree leaves, and black mustard seeds were compared. Their effects on reactive oxygen species (ROS and superoxide dismutase (SOD activity were investigated. The Oxygen Radical Absorbance Capacity (ORAC assay determined the antioxidant potential of the extracts, while the ROS scavenging ability was explored in hyperglycemia-induced human umbilical vein endothelial cells (HUVECs. The SOD assay determined if the extracts stimulated the enzyme activity in the HUVECs. Curry leaf and fenugreek extracts had high ORAC values and superior free radical scavenging abilities compared with the rest of the extracts. The curry leaf extract had also increased the SOD activity. Fenugreek extract had not increased the SOD activity of the HUVECs. Thus, the two herbs displayed two distinct pathways of action for scavenging of ROS.

  8. Experiment of Industrial Waste Absorption using Activated Carbon from Coal of Tanjung Tabalong, South Kalimantan

    Directory of Open Access Journals (Sweden)

    M. Ulum Gani

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v6i4.130Activated carbon made from Tanjung Tabalong coal was investigated its absorption capability to organic and inorganic elements in industrial waste. Coal was carbonized at low temperature of 600C to produce semicoke, and then was activated at temperature of 700C with activation time of 120 minutes with water steam flow. The absorption capability of activated carbon to chemical oxygen demand (COD was performed using 2.5 and 9.0 g activated carbon for 250 ml and 300 ml COD waste respectively. The agitation time of each experiment were 30, 60, and 90 minutes. Atomic absorption spectrophotometer (AAS was used to analyze the COD waste. The result shows that 2.5 g activated carbon could absorb COD waste ranging from 6.9-67.5 %, while the utilization of 9 g could absorb COD waste ranging from 88.9 - 100 %. The more activated carbon and the longer time of agitation used in this experiment, the more the absorption of COD waste.

  9. QUALITY OF LIFE, PERCEIVED STIGMA, ACTIVITY AND PARTICIPATION OF PEOPLE WITH LEPROSY-RELATED DISABILITIES IN SOUTH-EAST NEPAL

    Directory of Open Access Journals (Sweden)

    Huib Cornielje

    2011-05-01

    Full Text Available In Nepal, many people live with leprosy-related disabilities. The objective of this study was to evaluate differences in socio-economic characteristics, quality of life (QOL, perceived stigma, activity and participation among people affected by leprosy as a group and between this group and the general population, and to identify prime determinants of QOL among the leprosy-affected people. People with leprosy-related disabilities (N=100; 54DGI/46DGII and community controls (N=100 were selected from Morang district, South-East Nepal, using quota sampling. QOL, perceived stigma and participation and activity limitations were measured using the Nepali abbreviated version of the World Health Organisation Quality of Life (WHOQOL assessment and the Nepali versions of the Jacoby Scale, Participation Scale and Green Pastures Activity Scale (GPAS, respectively. Total QOL, participation and activity levels of people affected by leprosy were worse than those of the general population. Regression analysis showed that the ability to maintain a family, satisfaction with health, vocational training, sex, activity and participation limitations (the latter for QOL only, perceived stigma and living situation (i.e. joint family, type of house were significantly associated with a deterioration in QOL and higher participation restriction in one or both of the grading groups. There is an urgent need for interventions focused on quick referral of people with leprosy, to minimize the development of visible impairments, and social rehabilitation. The latter can be achieved by creating more public awareness, providing (financial support for income generating projects and /or vocational training to leprosy- affected people, and by encouraging them to be involved in all community development activities. The current results indicate that such measures would help improve the quality of life of people with leprosy-related disabilities.DOI 10.5463/DCID.v22i1.15

  10. Modeling optical and UV polarization of AGNs. IV. Polarization timing

    Science.gov (United States)

    Rojas Lobos, P. A.; Goosmann, R. W.; Marin, F.; Savić, D.

    2018-03-01

    Context. Optical observations cannot resolve the structure of active galactic nuclei (AGN), and a unified model for AGN was inferred mostly from indirect methods, such as spectroscopy and variability studies. Optical reverberation mapping allowed us to constrain the spatial dimension of the broad emission line region and thereby to measure the mass of supermassive black holes. Recently, reverberation was also applied to the polarized signal emerging from different AGN components. In principle, this should allow us to measure the spatial dimensions of the sub-parsec reprocessing media. Aim. We conduct numerical modeling of polarization reverberation and provide theoretical predictions for the polarization time lag induced by different AGN components. The model parameters are adjusted to the observational appearance of the Seyfert 1 galaxy NGC 4151. Methods: We modeled scattering-induced polarization and tested different geometries for the circumnuclear dust component. Our tests included the effects of clumpiness and different dust prescriptions. To further extend the model, we also explored the effects of additional ionized winds stretched along the polar direction, and of an equatorial scattering ring that is responsible for the polarization angle observed in pole-on AGN. The simulations were run using a time-dependent version of the STOKES code. Results: Our modeling confirms the previously found polarization characteristics as a function of the observer`s viewing angle. When the dust adopts a flared-disk geometry, the lags reveal a clear difference between type 1 and type 2 AGN. This distinction is less clear for a torus geometry where the time lag is more sensitive to the geometry and optical depth of the inner surface layers of the funnel. The presence of a scattering equatorial ring and ionized outflows increased the recorded polarization time lags, and the polar outflows smooths out dependence on viewing angle, especially for the higher optical depth of the

  11. South Africa

    International Nuclear Information System (INIS)

    2002-01-01

    This document provides information on the status of institutional and financial arrangements in South Africa for the long term management of HLW and SNF, It includes the following elements: A consistent set of requirements for the technical and legal infrastructure including: funding, liability, institutional control, records management, and research activities; An organizational structure with clearly defined responsibilities; and Provisions for participation by interested parties in decisions and outcomes

  12. Chemistry and Selective Tumor Cell Growth Inhibitory Activity of Polyketides from the South China Sea Sponge Plakortis sp.

    Science.gov (United States)

    Li, Jiao; Li, Cui; Riccio, Raffaele; Lauro, Gianluigi; Bifulco, Giuseppe; Li, Tie-Jun; Tang, Hua; Zhuang, Chun-Lin; Ma, Hao; Sun, Peng; Zhang, Wen

    2017-05-03

    Simplextone E ( 1 ), a new metabolite of polyketide origin, was isolated with eight known analogues ( 2 - 9 ) from the South China Sea sponge Plakortis sp. The relative configuration of the new compound was elucidated by a detailed analysis of the spectroscopic data and quantum mechanical calculation of NMR chemical shifts, aided by the newly reported DP4+ approach. Its absolute configuration was determined by the TDDFT/ECD calculation. Simplextone E ( 1 ) is proven to be one of the isomers of simplextone D. The absolute configuration at C-8 in alkyl chain of plakortone Q ( 2 ) was also assigned based on the NMR calculation. In the preliminary in vitro bioassay, compounds 6 and 7 showed a selective growth inhibitory activity against HCT-116 human colon cancer cells with IC 50 values of 8.3 ± 2.4 and 8.4 ± 2.3 μM, corresponding to that of the positive control, adriamycin (IC 50 4.1 μM). The two compounds also showed selective activities towards MCF-7 human breast cancer and K562 human erythroleukemia cells while compound 3 only displayed weak activity against K562 cells.

  13. Permian-Triassic thermal anomaly of the active margin of South America as a result of plate kinematics reorganization

    Science.gov (United States)

    Riel, Nicolas; Jaillard, Etienne; Guillot, Stéphane; Martelat, Jean-Emmanuel; Braun, Jean

    2013-04-01

    From Permian to Triassic times, tectonic plate reorganization provoked Pangaea breakup, counterclockwise rotation of Gondwana, closing of the Paleo-Tethys Ocean and opening of the Neo-Tethys oceanic realm. Meanwhile, the switch from arc volcanism to widespread S-type magmatism along the western South American active margin around 275-265 Ma is symptomatic of the onset of a large-scale Permian-Triassic thermal anomaly (PTTA)affecting the whole margin. Here we report metamorphic and U-Pb geochronological results from the El Oro metamorphic complex in the forearc zone of southwestern Ecuador, which recorded the last step, at 230-225 Ma, of the PTTA. The change in the drift direction of Gondwana from north to east at ca. 270 Ma was related to plate reorganization and provoked the verticalization of the subducted Panthalassa slab. As the slab verticalized, strong heat advection produced a high heat flow beneath the active margin inducing the development of a huge thermal anomaly responsible for the PTTA, which lasted 30 Ma. This voluminous magmatic activity culminated at the Permian-Triassic boundary, and may have contributed to the degradation of life conditions on the Earth surface.

  14. Microbial enzyme activities of peatland soils in south central Alaska lowlands

    Science.gov (United States)

    Microbial enzyme activities related to carbon and nutrient acquisition were measured on Alaskan peatland soils as indicators of nutrient limitation and biochemical sustainability. Peat decomposition is mediated by microorganisms and enzymes that in turn are limited by various ph...

  15. Phytochemistry and in vitro pharmacological activities of South African Vitex (Verbenaceae) species

    CSIR Research Space (South Africa)

    Nyiligira, E

    2008-10-01

    Full Text Available in order to validate their traditional use to treat a wide range of ailments such as malaria, wounds, skin diseases and body pains. The antimicrobial activity was assessed using the minimum inhibitory concentration assay. Through bioactivity...

  16. Diasporic Activism and the Mediations of “Home”: South Asian Voices in Canadian Drama

    Directory of Open Access Journals (Sweden)

    Nandi Bhatia

    2012-11-01

    Full Text Available Critical analyses of literatures of the Indian diaspora discuss the “home” of origin as a subtext and a site to which diasporas aspire to return even though it remains an unachievable ideal that is refracted through nostalgic retellings of a space that remains at best “imaginary” (Mishra 2007. Alternatively, some critics, as Roger Waldinger and David Fitzgerald point out, view diasporas’ relationship with the homeland in terms of “loyalty,” obscuring in the process the antagonisms that may arise depending upon one’s circumstances, antagonisms that produce “interactions” between homes of residence and those of origin (2012. In South Asian drama in Canada, many of the concerns regarding race, multiculturalism, job discrimination and violence against women and other marginalized groups are propelled by their links to the playwrights’ “home” of origin. With attention to selected plays, this paper will analyze how the networks between home and spaces of residence in multicultural Canada come alive on theatre stages through visual motifs, actors, props, and photographic collages, which confront the different trajectories of “home” that resurface in these plays. Through live scenes of imagination that speak to spectators, several plays under discussion in this essay expose how, while providing emotional sustenance for some, the baggage of “home” may also pose challenges in the home of residence. So the questions I raise are: How does home appear? To what end? And what does returning “home” teach us about the inequalities and injustices underlying the current global order?

  17. In vitro biological activity and essential oil composition of four indigenous South African Helichrysum species.

    Science.gov (United States)

    Lourens, A C U; Reddy, D; Başer, K H C; Viljoen, A M; Van Vuuren, S F

    2004-12-01

    Helichrysum species are used widely to treat various medical conditions. In this study, the anti-microbial, anti-oxidant (DPPH assay) and anti-inflammatory activity (5-lipoxygenase assay) of Helichrysum dasyanthum, Helichrysum felinum, Helichrysum excisum and Helichrysum petiolare were investigated. The essential oil compositions of these species were determined. The acetone and methanol extracts as well as the essential oils exhibited activity against Gram-positive bacteria, while both the methanol and acetone extracts of all four species were active in the anti-oxidant assay. The essential oils, on the other hand, displayed activity in the 5-lipoxygenase assay, which was used as an indication of anti-inflammatory activity. Two extracts exhibited promising activity in the anti-microbial assay, the acetone extract of Helichrysum dasyanthum with a MIC value of 15.63 microg/ml and the methanol extract of Helichrysum excisum with a MIC value of 62.5 microg/ml. The acetone extract of Helichrysum dasyanthum was the most active free radical scavenger in the DPPH assay (IC(50) of 9.53 microg/ml) while values for the anti-inflammatory activity of the essential oils ranged between 25 and 32 microg/ml. The essential oil compositions of three species (Helichrysum dasyanthum, Helichrysum excisum and Helichrysum petiolare) were dominated by the presence of monoterpenes such as alpha-pinene, 1,8-cineole and p-cymene. In the oil of Helichrysum felinum, monoterpenes were largely absent. Its profile consisted of a variety of sesquiterpenes in low concentrations with beta-caryophyllene dominating.

  18. Should physical activity recommendations be ethnicity-specific? Evidence from a cross-sectional study of South Asian and European men.

    Directory of Open Access Journals (Sweden)

    Carlos A Celis-Morales

    Full Text Available Expert bodies and health organisations recommend that adults undertake at least 150 min.week(-1 of moderate-intensity physical activity (MPA. However, the underpinning data largely emanate from studies of populations of European descent. It is unclear whether this level of activity is appropriate for other ethnic groups, particularly South Asians, who have increased cardio-metabolic disease risk compared to Europeans. The aim of this study was to explore the level of MPA required in South Asians to confer a similar cardio-metabolic risk profile to that observed in Europeans undertaking the currently recommended MPA level of 150 min.week(-1.Seventy-five South Asian and 83 European men, aged 40-70, without cardiovascular disease or diabetes had fasted blood taken, blood pressure measured, physical activity assessed objectively (using accelerometry, and anthropometric measures made. Factor analysis was used to summarise measured risk biomarkers into underlying latent 'factors' for glycaemia, insulin resistance, lipid metabolism, blood pressure, and overall cardio-metabolic risk. Age-adjusted regression models were used to determine the equivalent level of MPA (in bouts of ≥ 10 minutes in South Asians needed to elicit the same value in each factor as Europeans undertaking 150 min.week(-1 MPA.For all factors, except blood pressure, equivalent MPA values in South Asians were significantly higher than 150 min.week(-1; the equivalent MPA value for the overall cardio-metabolic risk factor was 266 (95% CI 185-347 min.week(-1.South Asian men may need to undertake greater levels of MPA than Europeans to exhibit a similar cardio-metabolic risk profile, suggesting that a conceptual case can be made for ethnicity-specific physical activity guidance. Further study is needed to extend these findings to women and to replicate them prospectively in a larger cohort.

  19. Variations in the polar cap area during intervals of substorm activity on 20-21 March 1990 deduced from AMIE convection patterns

    Directory of Open Access Journals (Sweden)

    J. R. Taylor

    1996-09-01

    Full Text Available The dynamic behaviour of the northern polar cap area is studied employing Northern Hemisphere electric potential patterns derived by the Assimilative Mapping of Ionospheric Electrodynamics (AMIE procedure. The rate of change in area of the polar cap, which can be defined as the region of magnetospheric field lines open to the interplanetary magnetic field (IMF, has been calculated during two intervals when the IMF had an approximately constant southward component (1100–2200 UT, 20 March 1990 and 1300–2100 UT, 21 March 1990. The estimates of the polar cap area are based on the approximation of the polar cap boundary by the flow reversal boundary. The change in the polar cap area is then compared to the predicted expansion rate based on a simple application of Faraday\\'s Law. Furthermore, timings of magnetospheric substorms are also related to changes in the polar cap area. Once the convection electric field reconfigures following a southward turning of the IMF, the growth rate of the observed polar cap boundary is consistent with that predicted by Faraday\\'s Law. A delay of typically 20 min to 50 min is observed between a substorm expansion phase onset and a reduction in the polar cap area. Such a delay is consistent with a synthesis between the near Earth neutral line and current disruption models of magnetospheric substorms in which the dipolarisation in the magnetotail may act as a trigger for reconnection. These delays may represent a propagation time between near geosynchronous orbit dipolarisation and subsequent reconnection further down tail. We estimate, from these delays, that the neutral X line occurs between ~35RE and ~75RE downstream in the tail.

  20. Diet and Physical Activity Interventions to Prevent or Treat Obesity in South Asian Children and Adults: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Tamara Brown

    2015-01-01

    Full Text Available Background and Aims: The metabolic risks associated with obesity are greater for South Asian populations compared with White or other ethnic groups, and levels of obesity in childhood are known to track into adulthood. Tackling obesity in South Asians is therefore a high priority. The rationale for this systematic review is the suggestion that there may be differential effectiveness in diet and physical activity interventions in South Asian populations compared with other ethnicities. The research territory of the present review is an emergent, rather than mature, field of enquiry, but is urgently needed. Thus the aim of this systematic review and meta-analysis was to assess the effectiveness of diet and physical activity interventions to prevent or treat obesity in South Asians living in or outside of South Asia and to describe the characteristics of effective interventions. Methods: Systematic review of any type of lifestyle intervention, of any length of follow-up that reported any anthropometric measure for children or adults of South Asian ethnicity. There was no restriction on the type of comparator; randomised controlled trials, controlled clinical trials, and before-after studies were included. A comprehensive search strategy was implemented in five electronic databases: ASSIA, Cochrane Controlled Trials Register, Embase, Medline and Social Sciences Citation Index. The search was limited to English language abstracts published between January 2006 and January 2014. References were screened; data extraction and quality assessment were carried out by two reviewers. Results are presented in narrative synthesis and meta-analysis. Results: Twenty-nine studies were included, seven children, 21 adult and one mixed age. No studies in children under six were identified. Sixteen studies were conducted in South Asia, ten in Europe and three in USA. Effective or promising trials include physical activity interventions in South Asian men in Norway

  1. Tungsten behaviour under anodic polarization

    International Nuclear Information System (INIS)

    Vas'ko, A.T.; Patsyuk, F.N.

    1980-01-01

    Electrochemical investigations have been carried out to identify the state of elements of the tungsten galvanic coating. Active zones on anode polarization curves in the hydrogen region of galvanic tungsten are established. The difference in the behaviour of monocrystal and galvanic tungsten electrodes is shown to be connected with the oxidation of hydrogen in the galvanic sediment

  2. Antibacterial activity of crude extracts of some South African medicinal plants against multidrug resistant etiological agents of diarrhoea.

    Science.gov (United States)

    Bisi-Johnson, Mary A; Obi, Chikwelu L; Samuel, Babatunde B; Eloff, Jacobus N; Okoh, Anthony I

    2017-06-19

    This study evaluated the antibacterial activity of some plants used in folklore medicine to treat diarrhoea in the Eastern Cape Province, South Africa. The acetone extracts of Acacia mearnsii De Wild., Aloe arborescens Mill., A. striata Haw., Cyathula uncinulata (Schrad.) Schinz, Eucomis autumnalis (Mill.) Chitt., E. comosa (Houtt.) Wehrh., Hermbstaedtia odorata (Burch. ex Moq.) T.Cooke, Hydnora africana Thunb, Hypoxis latifolia Wight, Pelargonium sidoides DC, Psidium guajava L and Schizocarphus nervosus (Burch.) van der Merwe were screened against Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, multi-resistant Salmonella enterica serovar Isangi, S. typhi, S. enterica serovar Typhimurium, Shigella flexneri type 1b and Sh. sonnei phase II. A qualitative phytochemical screening of the plants extracts was by thin layer chromatography. Plants extracts were screened for antibacterial activity using serial dilution microplate technique and bioautography. The TLC fingerprint indicated the presence of terpenoids and flavonoids in the herbs. Most of the tested organisms were sensitive to the crude acetone extracts with minimum inhibitory concentration (MIC) values ranging from 0.018-2.5 mg/mℓ. Extracts of A. striata, C. uncinulata, E. autumnalis and P. guajava were more active against enteropathogens. S. aureus and Sh. flexneri were the most sensitive isolates to the crude extracts but of significance is the antibacterial activity of A. arborescens and P. guajava against a confirmed extended spectrum betalactamase positive S. enterica serovar Typhimurium. The presence of bioactive compounds and the antibacterial activity of some of the selected herbs against multidrug resistant enteric agents corroborate assertions by traditional healers on their efficacies.

  3. 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)

  4. Polarization of a periodic solar microwave burst

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, P [Universidade Mackenzie, Sao Paulo (Brazil). Centro de Radio-Astronomia e Astrofisica

    1976-09-01

    No fluctuations in polarization have been found during a 7 GHz solar burst showing 17s periodic pulses in intensity. Polarization effects can be produced by the propagation media in the active centre, which are not affected directly by the burst source, but situated more deeply than the observed heights at that microwave frequency.

  5. Human dignity and the future of the voluntary active euthanasia debate in South Africa.

    Science.gov (United States)

    Jordaan, Donrich W

    2017-04-25

    The issue of voluntary active euthanasia was thrust into the public policy arena by the Stransham-Ford lawsuit. The High Court legalised voluntary active euthanasia - however, ostensibly only in the specific case of Mr Stransham-Ford. The Supreme Court of Appeal overturned the High Court judgment on technical grounds, not on the merits. This means that in future the courts can be approached again to consider the legalisation of voluntary active euthanasia. As such, Stransham-Ford presents a learning opportunity for both sides of the legalisation divide. In particular, conceptual errors pertaining to human dignity were made in Stransham-Ford, and can be avoided in future. In this article, I identify these errors and propose the following three corrective principles to inform future debate on the subject: (i) human dignity is violable; (ii) human suffering violates human dignity; and (iii) the 'natural' causes of suffering due to terminal illness do not exclude the application of human dignity.

  6. Techniques in polarization physics

    International Nuclear Information System (INIS)

    Clausnitzer, G.

    1974-01-01

    A review of the current status of the technical tools necessary to perform different kinds of polarization experiments is presented, and the absolute and relative accuracy with which data can be obtained is discussed. A description of polarized targets and sources of polarized fast neutrons is included. Applications of polarization techniques to other fields is mentioned briefly. (14 figures, 3 tables, 110 references) (U.S.)

  7. The mass miniature chest radiography programme in Cape Town, South Africa, 1948-1994: The impact of active tuberculosis case finding

    NARCIS (Netherlands)

    Hermans, S. M.; Andrews, J. R.; Bekker, L.-G.; Wood, R.

    2016-01-01

    Tuberculosis (TB) control programmes rely mainly on passive detection of symptomatic individuals. The resurgence of TB has rekindled interest in active case finding. Cape Town (South Africa) had a mass miniature radiography (MMR) screening programme from 1948 to 1994. To evaluate screening coverage,

  8. Polarized Moessbauer transitions

    International Nuclear Information System (INIS)

    Barb, D.

    1975-01-01

    Theoretical aspects of the emission, absorption and scattering of polarized gamma rays are reviewed for a general case of combined magnetic and electric hyperfine interactions; various possibilities of obtaining polarized gamma sources are described and examples are given of the applications of Moessbauer spectroscopy with polarized gamma rays in solving problems of solid state physics. (A.K.)

  9. 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...

  10. Calculation of polarization effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1983-09-01

    Basically there are two areas of accelerator applications that involve beam polarization. One is the acceleration of a polarized beam (most likely a proton beam) in a synchrotron. Another concerns polarized beams in an electron storage ring. In both areas, numerical techniques have been very useful

  11. IMPACT OF BT ( BACILLUS THURINGIENSIS ) CROPS ON BAT ACTIVITY IN SOUTH TEXAS AGROECOSYSTEMS

    Science.gov (United States)

    The widespread adoption of transgenic insecticidal crops raises concerns that nontarget species may be harmed and food webs disrupted. The goal of this research is to determine how transgenic Bt (Bacillus thuringiensis) crops impact the activity of Brazilian freetailed bats (Tada...

  12. Volatile constituents and biological activities of the leaf and root of Echinacea species from South Africa

    Directory of Open Access Journals (Sweden)

    M. Nyalambisa

    2017-03-01

    It is concluded that root and leaf of this Echinacea species contain volatile oils which varied in their yield and chemical compositions. The essential root oil is non-toxic orally and it demonstrated significant anti-inflammatory and analgesic activities in laboratory animals.

  13. Delineation of Urban Active Faults Using Multi-scale Gravity Analysis in Shenzhen, South China

    Science.gov (United States)

    Xu, C.; Liu, X.

    2015-12-01

    In fact, many cities in the world are established on the active faults. As the rapid urban development, thousands of large facilities, such as ultrahigh buildings, supersized bridges, railway, and so on, are built near or on the faults, which may change the balance of faults and induce urban earthquake. Therefore, it is significant to delineate effectively the faults for urban planning construction and social sustainable development. Due to dense buildings in urban area, the ordinary approaches to identify active faults, like geological survey, artificial seismic exploration and electromagnetic exploration, are not convenient to be carried out. Gravity, reflecting the mass distribution of the Earth's interior, provides a more efficient and convenient method to delineate urban faults. The present study is an attempt to propose a novel gravity method, multi-scale gravity analysis, for identifying urban active faults and determining their stability. Firstly, the gravity anomalies are decomposed by wavelet multi-scale analysis. Secondly, based on the decomposed gravity anomalies, the crust is layered and the multilayer horizontal tectonic stress is inverted. Lastly, the decomposed anomalies and the inverted horizontal tectonic stress are used to infer the distribution and stability of main active faults. For validating our method, a case study on active faults in Shenzhen City is processed. The results show that the distribution of decomposed gravity anomalies and multilayer horizontal tectonic stress are controlled significantly by the strike of the main faults and can be used to infer depths of the faults. The main faults in Shenzhen may range from 4km to 20km in the depth. Each layer of the crust is nearly equipressure since the horizontal tectonic stress has small amplitude. It indicates that the main faults in Shenzhen are relatively stable and have no serious impact on planning and construction of the city.

  14. Proximate, mineral composition and antioxidant activity of traditional small millets cultivated and consumed in Rayalaseema region of south India.

    Science.gov (United States)

    Vali Pasha, Kotwal; Ratnavathi, Chamarthy Venkata; Ajani, Jayanna; Raju, Dugyala; Manoj Kumar, Sriramoju; Beedu, Sashidhar Rao

    2018-01-01

    Millets are a diverse group of small seeded grasses, widely grown around the world as cereal foods. This communication details the proximate, mineral profile and antioxidant activity of six different small millets (Finger, Foxtail, Proso, Little, Barnyard and Kodo millets) and their 21 cultivars that are traditionally cultivated and consumed in the region of Ralayaseema, south India. The proximate analysis revealed that these millets are rich in protein, fat, ash (mineral), total dietary fibre and total phenols with appreciable antioxidant activity. However, starch and amylose content was comparatively lower as compared to major millet sorghum. ICP-MS analysis of small millets demonstrated that they are rich in minerals such as Ca, P, K, Mg, Fe, Cu, Zn, Mn, Cr, Mo and Se. Finger and kodo millets were found to be nutritionally superior over other small millets. The results suggest that small millets have a potential to provide food security and can combat micronutrient malnutrition. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  15. 226Ra activity in the mullet species Liza aurata and South Adriatic sea marine environment of Montenegro

    International Nuclear Information System (INIS)

    Antovic, N. M.; Antovic, I.; Svrkota, N.

    2010-01-01

    226 Ra activity in the South Adriatic Sea-water, surface sediment, mud with detritus, sea-grass (Posidonia oceanica) samples and the mullet (Mugilidae) species Liza aurata, as well as soil and sand from the Montenegrin Coast-was measured using the six-crystal gamma-coincidence spectrometer PRIPYAT-2M. The results are used for calculation of the absorbed (and annual effective) dose rates in air due to the 226 Ra gamma radiation. The absorbed dose rates ranged from 5.94 to 97.16 nGy h -1 (soil) and from 0.65 to 7.65 nGy h -1 (sand). In seawater 226 Ra activity is found to be from 0.08 to 0.15 Bq l -1 , while in whole L. aurata individuals from 0.58 to 1.97 Bq kg -1 . Annual intake of 226 Ra by human consumers of this fish species has been estimated to provide an effective dose of 0.006 mSv y -1 . (authors)

  16. Promoting physical activity among children and youth in disadvantaged South Australian CALD communities through alternative community sport opportunities.

    Science.gov (United States)

    Rosso, Edoardo; McGrath, Richard

    2016-02-29

    Issue addressed: Recently arrived migrants and refugees from a culturally and linguistically diverse background (CALD) may be particularly vulnerable to social exclusion. Participation in sport is endorsed as a vehicle to ease the resettlement process; however, in Australia, this is often thought as a simple matter of integration into existing sport structures (e.g. clubs). This approach fails to place actual community needs at the centre of sport engagement efforts. Methods: A consultation framework was established with South Australian CALD community leaders and organisations to scope needs for community-based alternatives to participation in traditional sport (e.g. clubs), co-design a suitable community sport program and pilot it in five communities. Interviews and questionnaire surveys were conducted with participants, community representatives, stakeholders and volunteers. Results: Regular, free soccer activities engaged 263 young people from a great variety of nationalities, including over 50% refugees, in secondary state school and community-based sites. Conclusion: Alternative community sport programs can provide a basic but valuable forum to promote physical activity and associated well being in CALD and refugee communities. So what?: Alternative approaches can extend the health benefits of sport participation to disadvantaged children and youth who are excluded from traditional sport participation opportunities.

  17. Dissolved organic phosphorus utilization and alkaline phosphatase activity of the dinoflagellate Gymnodinium impudicum isolated from the South Sea of Korea

    Science.gov (United States)

    Oh, Seok Jin; Kwon, Hyeong Kyu; Noh, Il Hyeon; Yang, Han-Soeb

    2010-09-01

    This study investigated alkaline phosphatase (APase) activity and dissolved organic and inorganic phosphorus utilization by the harmful dinoflagellate Gymnodinium impudicum (Fraga et Bravo) Hansen et Moestrup isolated from the South Sea of Korea. Under conditions of limited phosphorus, observation of growth kinetics in batch culture yielded a maximum growth rate (μmax) of 0.41 /day and a half saturation constant (Ks) of 0.71 μM. In time-course experiments, APase was induced as dissolved inorganic phosphorus (DIP) concentrations fell below 0.83 μM, a threshold near the estimated Ks; APase activity increased with further DIP depletion to a maximum of 0.70 pmol/cell/h in the senescent phase. Thus, Ks may be an important index of the threshold DIP concentration for APase induction. G. impudicum utilizes a wide variety of dissolved organic phosphorus compounds in addition to DIP. These results suggest that DIP limitation in the Southern Sea of Korea may have led to the spread of G. impudicum along with the harmful dinoflagellate Cochlodinium polykrikoides in recent years.

  18. Diversity and antibacterial activity of culturable actinobacteria isolated from five species of the South China Sea gorgonian corals.

    Science.gov (United States)

    Zhang, Xiao-Yong; He, Fei; Wang, Guang-Hua; Bao, Jie; Xu, Xin-Ya; Qi, Shu-Hua

    2013-06-01

    This study describes the diversity and antibacterial activity of culturable actinobacteria isolated from five species of gorgonian corals (Echinogorgia aurantiaca, Melitodes squamata, Muricella flexuosa, Subergorgia suberosa, and Verrucella umbraculum) collected in shallow water of the South China Sea. A total of 123 actinobacterial isolates were recovered using ten different isolation media, and assigned to 11 genera, including Streptomyces and Micromonospora as the dominant genera, followed by Nocardia, Verrucosispora, Nocardiopsis, Rhodococcus, Pseudonocardia, Agrococcus, Saccharomonospora, Saccharopolyspora and Dietzia. Comparable analysis indicated that the numbers of actinobacterial genera and isolates from the five gorgonian coral species varied significantly. It was found that 72 isolates displayed antibacterial activity against at least one indicator bacterium, and the antibacterial strains isolated from different gorgonians had almost the same proportion (~50 %). These results provide direct evidence for the hypotheses that gorgonian coral species contain large and diverse communities of actinobacteria, and suggest that many gorgonian-associated actinobacteria could produce some antibacterial agents to protect their hosts against pathogens. To our knowledge, this is the first report about the diversity of culturable actinobacteria isolated from gorgonian corals.

  19. Overview of calibration and validation activities for the EUMETSAT polar system: second generation (EPS-SG) visible/infrared imager (METimage)

    Science.gov (United States)

    Phillips, P.; Bonsignori, R.; Schlüssel, P.; Schmülling, F.; Spezzi, L.; Watts, P.; Zerfowski, I.

    2016-10-01

    The EPS-SG Visible/Infrared Imaging (VII) mission is dedicated to supporting the optical imagery user needs for Numerical Weather Prediction (NWP), Nowcasting (NWC) and climate in the timeframe beyond 2020. The VII mission is fulfilled by the METimage instrument, developed by the German Space Agency (DLR) and funded by the German government and EUMETSAT. Following on from an important list of predecessors such as the Advanced Very High Resolution Radiometer (AVHRR) and the Moderate resolution Imaging Spectro-radiometer (MODIS), METimage will fly in the mid-morning orbit of the Joint Polar System, whilst the early-afternoon orbits are served by the JPSS (U.S. Joint Polar Satellite System) Visible Infrared Imager Radiometer Suite (VIIRS). METimage itself is a cross-purpose medium resolution, multi-spectral optical imager, measuring the optical spectrum of radiation emitted and reflected by the Earth from a low-altitude sun synchronous orbit over a minimum swath width of 2700 km. The top of the atmosphere outgoing radiance will be sampled every 500 m (at nadir) with measurements made in 20 spectral channels ranging from 443 nm in the visible up to 13.345 μm in the thermal infrared. The three major objectives of the EPS-SG METimage calibration and validation activities are: • Verification of the instrument performances through continuous in-flight calibration and characterisation, including monitoring of long term stability. • Provision of validated level 1 and level 2 METimage products. • Revision of product processing facilities, i.e. algorithms and auxiliary data sets, to assure that products conform with user requirements, and then, if possible, exceed user expectations. This paper will describe the overall Calibration and Validation (Cal/Val) logic and the methods adopted to ensure that the METimage data products meet performance specifications for the lifetime of the mission. Such methods include inter-comparisons with other missions through simultaneous

  20. Social Pedagogy in South Africa: holding the tension between academia and activism

    Directory of Open Access Journals (Sweden)

    Astrid Von Kotze

    2015-12-01

    Full Text Available ‘Social pedagogy’ is not a familiar term in South Africa. Instead, everything to do with education outside or beyond schooling is subsumed under ‘adult education’. Community education or alterna- tives are generally known as ‘radical’ or ‘popular’ education’ concerned with social, economic and political transformation. Based on the pedagogy of Paulo Freire and participatory development paradigms these are rooted in the mass democratic struggles against apartheid. This paper is based on extensive research by the authors as participant observers and activists, conducted over many years into university-based adult education on the one hand, and praxis outside academic institutions, on the other. The authors have a his- tory of engagement in worker education, and key elements of education in the non-racial trade union move- ment as one of the most important organised forces of internal political resistance are suggested as informing curricula of university-based adult education.Since 1994 and the change to democracy, adult education departments in universities have increasingly been eroded or disappeared as separate departments or programmes. Like elsewhere in the north, we have witnessed the undermining and increased professionalization and institutionalization of adult education across contexts – and with it a marked reduction in radical outlook and purpose. However, the method- ological approach has remained committed to participation and dialogue, and, with the waning of commu- nity-based students who bring with them extensive experience from the field, there is a consistent emphasis on other, practice-based knowledges through guest educators, and by sending students to design and con- duct research and small interventions, at community level.Popular education outside the university takes numerous forms, and as an 18-month research project has shown, there are still many initiatives that target members of working class

  1. Feminist Collective Activism in Telangana, South India: Exemplary by the Andhra Pradesh Mahila Samatha Society

    OpenAIRE

    Ms Julia Guenther

    2014-01-01

    This research aims at contributing to the ongoing debate of feminist standpoint epistemology by introducing a study on feminist collective activism in Sangareddy and Yellareddy, two districts of the newly established 29th state of India, Telangana. The purpose here is to document the work of two sanghams (collectives) by the Andhra Pradesh Mahila Samatha Society (APMSS). The focus lies on songs created by Dalit and indigenous women, which are used as a form of, protest against societal and ge...

  2. In vitro antiplasmodial activity of ethanolic extracts of South Indian medicinal plants against Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Sundaram Ravikumar

    2012-06-01

    Full Text Available Objective: To explore the antiplasmodial potential of Catharanthus roseus L (C. roseus, Coccinea grandis (C. grandis, Thevetia peruviana (T. peruviana, Prosopis juliflora (P. juliflora, Acacia nilotica (A. nilotica, Azadirachta indica (A. indica (Abr. Juss and Morinda pubescens (M. pubescens. Methods: The C. roseus L, C. grandis, T. peruviana, P. juliflora, A. nilotica, A. indica (Abr. Juss and M. pubescens were collected from Ramanathapuram District, Tamil Nadu, India and the extraction was carried out in ethanol. The filter sterilized extracts (100, 50, 25, 12.5, 6.25 and 3.125 毺 g/mL were tested for antiplasmodial activity against Plasmodium falciparum. The phytochemical constituents in the potential extracts were also detected. Results: Of the selected plants species, the bark extract of A. indica (Abr. Juss showed excellent antiplasmodial activity (IC50 29.77 毺 g/mL followed by leaf extract of A. indica (Abr. Juss (IC50 47.20 毺 g/mL and leaf extract of C. roseus L (IC50 49.63 毺 g/mL. The leaf, bark and flower extracts of P. juliflora showed IC50 values of more than 100 毺 g/mL. Statistical analysis reveals significant antiplasmodial activity (P<0.01 between the concentrations and time of exposure. Additionally, no chemical injury was found in the erythrocytes incubated with the ethanolic extract of all the tested plants. The in vitro antiplasmodial activity might be due to the presence of alkaloids, glycosides, carbohydrates, flavonoids, phenols, saponins, triterpenoids, proteins and tannins in the ethanolic extracts of the tested plants. Conclusions: The ethanolic bark extracts of A. indica (Abr. Juss possess lead compounds for the development of antiplasmodial drugs.

  3. Evaluation of wild herbivore faeces from South Africa as a potential source of hydrolytically active microorganisms

    CSIR Research Space (South Africa)

    Ndlela, LL

    2016-02-01

    Full Text Available once hydrolysis (FDA) or reduction (TTC) occurred. The fluorescein diacetate assay operates on the princi- ple of hydrolytic release of two acetate groups via ester bond cleavage by free and membrane-bound hydrolytic enzymes, yielding the yellow... hydrolytic enzymes such as amylases can cleave its ester bonds as well (Lundgren 1981; Green et  al. 2006). The FDA hydrolysis assay has also been utilised and recommended as an efficient method to estimate active cells within environmental samples...

  4. Observations of wave activity in the ionosphere over South Africa in geomagnetically quiet and disturbed periods

    Czech Academy of Sciences Publication Activity Database

    Šindelářová, Tereza; Mošna, Zbyšek; Burešová, Dalia; Chum, Jaroslav; McKinnell, L.- A.; Athieno, R.

    2012-01-01

    Roč. 50, č. 2 (2012), s. 182-195 ISSN 0273-1177 R&D Projects: GA ČR(CZ) GAP209/12/2440 Institutional support: RVO:68378289 Keywords : Waves in the ionosphere * HF Doppler type sounding * Geomagnetic activity Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.183, year: 2012 http://www.sciencedirect.com/science/article/pii/S0273117712002591

  5. Human dignity and the future of the voluntary active euthanasia debate in South Africa

    Directory of Open Access Journals (Sweden)

    Donrich W Jordaan

    2017-05-01

    Full Text Available The issue of voluntary active euthanasia was thrust into the public policy arena by the Stransham-Ford lawsuit. The High Court legalised voluntary active euthanasia – however, ostensibly only in the specific case of Mr Stransham-Ford. The Supreme Court of Appeal overturned the High Court judgment on technical grounds, not on the merits. This means that in future the courts can be approached again to consider the legalisation of voluntary active euthanasia. As such, Stransham-Ford presents a learning opportunity for both sides of the legalisation divide. In particular, conceptual errors pertaining to human dignity were made in Stransham-Ford, and can be avoided in future. In this article, I identify these errors and propose the following three corrective principles to inform future debate on the subject: (i human dignity is violable; (ii human suffering violates human dignity; and (iii the ‘natural’ causes of suffering due to terminal illness do not exclude the application of human dignity.

  6. Cytotoxic, Virucidal, and Antiviral Activity of South American Plant and Algae Extracts

    Directory of Open Access Journals (Sweden)

    Paula Faral-Tello

    2012-01-01

    Full Text Available Herpes simplex virus type 1 (HSV-1 infection has a prevalence of 70% in the human population. Treatment is based on acyclovir, valacyclovir, and foscarnet, three drugs that share the same mechanism of action and of which resistant strains have been isolated from patients. In this aspect, innovative drug therapies are required. Natural products offer unlimited opportunities for the discovery of antiviral compounds. In this study, 28 extracts corresponding to 24 plant species and 4 alga species were assayed in vitro to detect antiviral activity against HSV-1. Six of the methanolic extracts inactivated viral particles by direct interaction and 14 presented antiviral activity when incubated with cells already infected. Most interesting antiviral activity values obtained are those of Limonium brasiliense, Psidium guajava, and Phyllanthus niruri, which inhibit HSV-1 replication in vitro with 50% effective concentration (EC50 values of 185, 118, and 60 μg/mL, respectively. For these extracts toxicity values were calculated and therefore selectivity indexes (SI obtained. Further characterization of the bioactive components of antiviral plants will pave the way for the discovery of new compounds against HSV-1.

  7. Acceleration of polarized particles

    International Nuclear Information System (INIS)

    Buon, J.

    1992-05-01

    The spin kinetics of polarized beams in circular accelerators is reviewed in the case of spin-1/2 particles (electrons and protons) with emphasis on the depolarization phenomena. The acceleration of polarized proton beams in synchrotrons is described together with the cures applied to reduce depolarization, including the use of 'Siberian Snakes'. The in-situ polarization of electrons in storage rings due to synchrotron radiation is studied as well as depolarization in presence of ring imperfections. The applications of electron polarization to accurately calibrate the rings in energy and to use polarized beams in colliding-beam experiments are reviewed. (author) 76 refs., 19 figs., 1 tab

  8. Comparison of telomere length in black and white teachers from South Africa: the sympathetic activity and ambulatory blood pressure in Africans study.

    Science.gov (United States)

    von Känel, Roland; Malan, Nico T; Hamer, Mark; Malan, Leoné

    2015-01-01

    Telomere length is a marker of biological aging that has been linked to cardiovascular disease risk. The black South African population is witnessing a tremendous increase in the prevalence of cardiovascular disease, part of which might be explained through urbanization. We compared telomere length between black South Africans and white South Africans and examined which biological and psychosocial variables played a role in ethnic difference in telomere length. We measured leukocyte telomere length in 161 black South African teachers and 180 white South African teachers aged 23 to 66 years without a history of atherothrombotic vascular disease. Age, sex, years having lived in the area, human immunodeficiency virus (HIV) infection, hypertension, body mass index, dyslipidemia, hemoglobin A1c, C-reactive protein, smoking, physical activity, alcohol abuse, depressive symptoms, psychological distress, and work stress were considered as covariates. Black participants had shorter (median, interquartile range) relative telomere length (0.79, 0.70-0.95) than did white participants (1.06, 0.87-1.21; p < .001), and this difference changed very little after adjusting for covariates. In fully adjusted models, age (p < .001), male sex (p = .011), and HIV positive status (p = .023) were associated with shorter telomere length. Ethnicity did not significantly interact with any covariates in determining telomere length, including psychosocial characteristics. Black South Africans showed markedly shorter telomeres than did white South African counterparts. Age, male sex, and HIV status were associated with shorter telomere length. No interactions between ethnicity and biomedical or psychosocial factors were found. Ethnic difference in telomere length might primarily be explained by genetic factors.

  9. Knowledge and beliefs about nutrition and physical activity during pregnancy in women from South Auckland region, New Zealand.

    Science.gov (United States)

    Okesene-Gafa, Karaponi; Chelimo, Carol; Chua, Shireen; Henning, Marcus; McCowan, Lesley

    2016-10-01

    Approximately 60% of women in South Auckland, a culturally diverse region in New Zealand, become pregnant with a high body mass index. However, little is known about these women's knowledge of nutrition and physical activity during pregnancy. To assess knowledge of nutrition and physical activity during pregnancy, factors influencing eating habits and the willingness to participate in a nutritional intervention. A total of 422 women completed the survey in late pregnancy between September and December 2013. Multivariable logistic regression investigated factors associated with infrequent healthy eating, adjusting for ethnicity and gestation at questionnaire completion. Ethnicity of participants was Māori (24.2%), Pacific (40.5%), Asian (12.8%) and European/Others (21.8%). Most (95.0%) reported receiving information about healthy eating while pregnant and 61% reported eating healthy frequently or very frequently. Forty-four point three per cent reported eating more in pregnancy; the commonest reasons were cravings and 'eating for two'. The adjusted odd ratios (aORs) indicated that the self-reported factors associated with infrequent healthy eating in this sample were Māori (aOR 17.66; 95% CI 8.49-36.77) and Pacific ethnicity (aOR 14.54; 95% CI 7.32-28.88); parity ≥3 (aOR 2.09; 95%CI 1.26-3.48); obesity (aOR 2.84; 95% CI 1.35-5.97); unplanned pregnancy (aOR 1.95; 95%CI 1.18-3.22); and eating takeaways ≥3 times/week (aOR 4.46; 95%CI 1.88-10.56). Of women sampled, 83.4% would likely/very likely participate in a nutritional intervention. Self-reported factors associated with infrequent healthy eating in pregnancy were identified in this sample. Our findings will assist development of a nutritional intervention for pregnant women in South Auckland. © 2016 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

  10. Polarization effects. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Courant, E.

    1981-01-01

    The use of polarized proton beams in ISABELLE is important for several general reasons: (1) With a single longitudinally polarized proton beam, effects involving parity violation can be identified and hence processes involving weak interactions can be separated from those involving strong and electromagnetic interactions. (2) Spin effects are important in the strong interactions and can be useful for testing QCD. The technique for obtaining polarized proton beams in ISABELLE appears promising, particularly in view of the present development of a polarized proton beam for the AGS. Projections for the luminosity in ISABELLE for collisions of polarized protons - one or both beams polarized with longitudinal or transverse polarization - range from 1/100 to 1 times the luminosity for unpolarized protons.

  11. The Physics of Polarization

    Science.gov (United States)

    Landi Degl'Innocenti, Egidio

    2015-10-01

    The introductory lecture that has been delivered at this Symposium is a condensed version of an extended course held by the author at the XII Canary Island Winter School from November 13 to November 21, 2000. The full series of lectures can be found in Landi Degl'Innocenti (2002). The original reference is organized in 20 Sections that are here itemized: 1. Introduction, 2. Description of polarized radiation, 3. Polarization and optical devices: Jones calculus and Muller matrices, 4. The Fresnel equations, 5. Dichroism and anomalous dispersion, 6. Polarization in everyday life, 7. Polarization due to radiating charges, 8. The linear antenna, 9. Thomson scattering, 10. Rayleigh scattering, 11. A digression on Mie scattering, 12. Bremsstrahlung radiation, 13. Cyclotron radiation, 14. Synchrotron radiation, 15. Polarization in spectral lines, 16. Density matrix and atomic polarization, 17. Radiative transfer and statistical equilibrium equations, 18. The amplification condition in polarized radiative transfer, and 19. Coupling radiative transfer and statistical equilibrium equations.

  12. Physical Activity and Suicide Attempt of South Korean Adolescents - Evidence from the Eight Korea Youth Risk Behaviors Web-based Survey

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    Kang-Ok Cho

    2014-12-01

    Full Text Available Suicide is the leading cause of death among South Korean adolescents. The purpose of this study was to examine the relationship between suicidal thoughts (ST and suicidal attempts (SA with the level of physical activity (PA among South Korean adolescents. Based on data from the eighth Korea Youth Risk Behaviors Web-Based Survey, 74,186 South Korean adolescents were evaluated in terms of their relationship between meeting guidelines for vigorous PA (VPA, moderate PA (MPA, and low PA (LPA and in respect of ST and SA status. The adjusted odds ratio in adolescents who thought about suicide increased significantly with PA levels (1.02 in males, 1.21 in females with VPA, 1.10 in males, 1.18 in females with MPA, and 1.16 in males, 1.20 in females with LPA compared to participants who did not think about suicide. In addition, the AOR in adolescents who attempted suicide increased significantly with PA levels (1.16 in males, 1.36 in females with VPA, 1.13 in males, 1.15 in females with MPA, and 1.26 in males, 1.15 in females with LPA compared to participants who did not attempt suicide. These results show that VPA, MPA, and LPA are positively associated with ST and SA prevention in South Korean adolescents. Therefore, to prevent suicide of South Korean adolescents, we support public health program including PA participation.

  13. Training in Dietary Practices and Physical Activity to Improve Health among South Asian Medical Students

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    Divyanshi Shani

    2014-01-01

    Full Text Available Introduction. We designed a pilot intervention to test the effect of a training program on the dietary and physical activities of medical students after weekly group discussions about healthy living, maintaining a healthy diet, and healthy lifestyle. Methods. Two groups of students from first and second years of medical school were selected with the intervention group having high BMI (overweight or obese while control group had normal BMI. An eight-week educational intervention was completed. A closed Facebook group ensured continuous communication. Results. Out of 42 participants, 19 were controls and 21 received educational training. Male : female ratio was 1 : 1.7 in control group and 1 : 1.3 in intervention group. The mean (SD weight gain in controls (1.16 Kg, SD = 1.51 was higher than that in intervention (0.13 Kg, SD=3.22 group (P=0.2. The average reduction in caloric intake was higher in control group (117.85, SD=258.48 vis-a-vis the intervention group (73.22, SD = 266.84 (P=0.61. Conclusion. Educational intervention in small groups for bringing about behavioral changes towards dietary, nutrition, and physical activity can lead to changes in the target population. The short duration of our study was a limitation which should be overcome in future studies.

  14. Business Activities of South Ukraine During the Economic Crisis of 1900–1903 Years

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    O. Babicheva

    2016-02-01

    Full Text Available The present article shows the activities of entrepreneurs in Southern Ukraine during the global economic crisis of 1900–1903 years. They greatly affected the socio-economic life of the country. After the economic crisis of heavy industry spread throughout the region and contributed to the emergence of a number of negative factors such as lack of resources, decline and stagnation in metallurgy, machine in order to get help, especially economic. It is proved that the government of the Russian Empire played the role of defender, protector of interests of the most influential entrepreneurs steel. They assisted individual industrialists, which was to provide government contracts, cash flows in the steel industry, provide favorable loans and subsidies for obtaining favorable terms. But such a condescending attitude the Russian Empire carried out solely to establish control in the steel industry, regulate the activities of entrepreneurs. Undoubtedly, during the crisis significantly decreased profit breeders, so the latter tried most of the losses on to the workers. At steel mills reduced production volumes, which led to the closure of factories, increasing the intensity of labor, lower wages, worse off workers, mass unemployment.

  15. North-south asymmetry of solar activity as a superposition of two realizations - the sign and absolute value

    Science.gov (United States)

    Badalyan, O. G.; Obridko, V. N.

    2017-07-01

    Context. Since the occurrence of north-south asymmetry (NSA) of alternating sign may be determined by different mechanisms, the frequency and amplitude characteristics of this phenomenon should be considered separately. Aims: We propose a new approach to the description of the NSA of solar activity. Methods: The asymmetry defined as A = (N-S)/(N + S) (where N and S are, respectively, the indices of activity of the northern and southern hemispheres) is treated as a superposition of two functions: the sign of asymmetry (signature) and its absolute value (modulus). This approach is applied to the analysis of the NSA of sunspot group areas for the period 1874-2013. Results: We show that the sign of asymmetry provides information on the behavior of the asymmetry. In particular, it displays quasi-periodic variation with a period of 12 yr and quasi-biennial oscillations as the asymmetry itself. The statistics of the so-called monochrome intervals (long periods of positive or negative asymmetry) are considered and it is shown that the distribution of these intervals is described by the random distribution law. This means that the dynamo mechanisms governing the cyclic variation of solar activity must involve random processes. At the same time, the asymmetry modulus has completely different statistical properties and is probably associated with processes that determine the amplitude of the cycle. One can reliably isolate an 11-yr cycle in the behavior of the asymmetry absolute value shifted by half a period with respect to the Wolf numbers. It is shown that the asymmetry modulus has a significant prognostic value: the higher the maximum of the asymmetry modulus, the lower the following Wolf number maximum. Conclusions: A fundamental nature of this concept of NSA is discussed in the context of the general methodology of cognizing the world. It is supposed that the proposed description of the NSA will help clarify the nature of this phenomenon.

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

    Science.gov (United States)

    Misra, Himanshu; Soni, Manish; Silawat, Narendra; Mehta, Darshana; Mehta, B. K.; Jain, D. C.

    2011-01-01

    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 Stevia extract was found to antagonize the necrotic action of alloxan and thus had a re-vitalizing effect on β-cells of pancreas. PMID:21687353

  17. North-South asymmetry of interplanetary plasma and solar parameters

    International Nuclear Information System (INIS)

    El-Borie, M. A.

    2001-01-01

    Data of interplanetary plasma (field magnitude, solar wind speed, ion plasma density and temperature) and solar parameters (sunspot number, solar radio flux, and geomagnetic index) over the period 1965-1991, have been used to examine the asymmetry between the solar field north and south of the heliospheric current sheet (HCS). The dependence of N-S asymmetry of field magnitude (B) upon the interplanetary solar polarities is statistically insignificant. There is no clear indication for the presence of N-S asymmetry in the grand-average field magnitude over the solar cycles. During the period 1981-89 (qA<0; negative solar polarity state), the solar plasma was more dense and cooler south of the HCS than north of it. The solar flux component of toward field vector is larger in magnitude than those of away field vector during the qA<0 epoch, and no asymmetry observed in the qA<0 epoch. Furthermore, the sign of the N-S asymmetry in the solar activity depends positively upon the solar polarity state. In addition, it was studied the N-S asymmetry of solar parameters near the HCS, throughout the periods of northern and southern hemispheres were more active than the other. Some asymmetries (with respect to the HCS) in plasma parameters existed during the periods of southern hemisphere predominance

  18. Polarization-dependent optics using gauge-field metamaterials

    International Nuclear Information System (INIS)

    Liu, Fu; Xiao, Shiyi; Li, Jensen; Wang, Saisai; Hang, Zhi Hong

    2015-01-01

    We show that effective gauge field for photons with polarization-split dispersion surfaces, being realized using uniaxial metamaterials, can be used for polarization control with unique opportunities. The metamaterials with the proposed gauge field correspond to a special choice of eigenpolarizations on the Poincaré sphere as pseudo-spins, in contrary to those from either conventional birefringent crystals or optical active media. It gives rise to all-angle polarization control and a generic route to manipulate photon trajectories or polarizations in the pseudo-spin domain. As demonstrations, we show beam splitting (birefringent polarizer), all-angle polarization control, unidirectional polarization filter, and interferometer as various polarization control devices in the pseudo-spin domain. We expect that more polarization-dependent devices can be designed under the same framework

  19. Recent eolian activity and paleoclimate fluctuations in the Ferris Lost Soldier Area, South-Central Wyoming

    Science.gov (United States)

    Gaylord, D. R.

    1983-09-01

    The Ferris Dune Fields were examined. Sand dunes are especially valuable in paleoclimate reconstructions because they: (1) bury and preserve datable materials and artifacts; (2) respond to even subtle changes in wind velocity and direction as reflected both in external morphology and internal structures; and (3) remain unconsolidated, making them amenable to easy textural and compositional examination. The valley of Clear Creek in the Ferris Dunes reveals a relatively continuous Holocene section of interbedded dune and interdunal pond deposits. Radiocarbon dates from the interdunal pond strata at Clear Creek, theoretical sand dune migration rates, compositional analysis of periglacial sand wedges, and relative dating of actively migrating parabolic dunes reveals a general sequence of geologic-climatic events that affected the Ferris-Lost Soldier area. The most recent major reactivaton of dunes occurred approximately 290 years ago.

  20. 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.)

  1. Concentrations and activity ratios of uranium isotopes in groundwater from Doñana National Park, South of Spain

    Science.gov (United States)

    Bolívar, J. P.; Olías, M.; González-García, F.; García-Tenorio, R.

    2008-08-01

    The levels and distribution of natural radionuclides in groundwaters from the unconfined Almonte-Marismas aquifer, upon which Doñana National Park is located, have been analysed. Most sampled points were multiple piezometers trying to study the vertical distribution of the hydrogeochemical characteristics in the aquifer. Temperature, pH, electrical conductivity, dissolved oxygen and redox potential were determined in the field. A large number of parameters, physico-chemical properties, major and minor ions, trace elements and natural radionuclides (U-isotopes, Th-isotopes, Ra-isotopes and 210Po), were also analysed. In the southern zone, where aeolian sands crop out, water composition is of the sodium chloride type, and the lower U-isotopes concentrations have been obtained. As water circulates through the aquifer, bicarbonate and calcium concentrations increase slightly, and higher radionuclides concentrations were measured. Finally, we have demonstrated that 234U/238U activity ratios can be used as markers of the type of groundwater and bedrock, as it has been the case for old waters with marine origin confined by a marsh in the south-east part of aquifer.

  2. 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.

  3. Chronic active EBV infection: the experience of the Samsung Medical Center in South Korea.

    Science.gov (United States)

    Lee, Tae-Hee; Ko, Young-Hyeh

    Chronic active EBV infection (CAEBV) of T-cell or NK-cell type is an EBV+ polyclonal, oligoclonal or often monoclonal lymphoproliferative disorder (LPD) recognized as representing the spectrum of EBV-associated T-cell and NK-cell LPD with different clinical presentations; one systemic and two cutaneous disorders including hydroa vacciniforme-like T-cell LPD and mosquito bite hypersensitivity. The systemic form of the disease is characterized by fever, persistent hepatitis, hepatosplenomegaly and lymphadenopathy, which shows varying degrees of clinical severity depending on the immune response of the host and the EBV viral load. We described the clinicopathological findings of two children with CAEBV with a brief review of the literature. Recognition of the disease is important for adequate management of the patient. EBV analysis should be included in the principal diagnostic tests for febrile children. Copyright © 2015 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

  4. Feminist Collective Activism in Telangana, South India: Exemplary by the Andhra Pradesh Mahila Samatha Society

    Directory of Open Access Journals (Sweden)

    Ms Julia Guenther

    2014-11-01

    Full Text Available This research aims at contributing to the ongoing debate of feminist standpoint epistemology by introducing a study on feminist collective activism in Sangareddy and Yellareddy, two districts of the newly established 29th state of India, Telangana. The purpose here is to document the work of two sanghams (collectives by the Andhra Pradesh Mahila Samatha Society (APMSS. The focus lies on songs created by Dalit and indigenous women, which are used as a form of, protest against societal and gender inequality. Those songs contribute in making a positive difference on a local level. Analysis of two group interviews strengthens this argument. The sanghams have shown that despite all societal differences, solidarity among women for a common cause can make a difference in combating social issues on a local level. Taking the APMSS as an example, this research shows that the use of a holistic approach to education to support women in their responses to social issues has an overall positive effect on women. Furthermore, and most importantly, women are strengthened in believing that their life-experiences matter. My research shows that literacy is not necessarily needed to be a successful advocate for women´s rights. What is needed, however, is an understanding of local contexts, social issues and ultimately the ability to link them to life-experiences.

  5. Mercury speciation and dispersion from an active gold mine at the West Wits area, South Africa.

    Science.gov (United States)

    Lusilao-Makiese, J G; Tessier, E; Amouroux, D; Tutu, H; Chimuka, L; Weiersbye, I; Cukrowska, E M

    2016-01-01

    Total mercury (HgTOT), inorganic mercury (IHg), and methylmercury (MHg) were determined in dry season waters, sediments, and tailings from an active mine which has long history of gold exploitation. Although HgTOT in waters was generally low (0.03 to 19.60 ng L(-1)), the majority of the samples had proportions of MHg of at least 90 % of HgTOT which denotes a substantial methylation potential of the mine watersheds. Mercury was relatively high in tailing materials (up to 867 μg kg(-1)) and also in the mine sediments (up to 837 μg kg(-1)) especially in samples collected near tailing storage facilities and within a receiving water dam. Sediment profiles revealed mercury enrichment and enhanced methylation rate at deeper layers. The presence of IHg and decaying plants (organic matter) in the watersheds as well as the anoxic conditions of bulk sediments are believed to be some of the key factors favoring the mercury methylation at the site.

  6. Increased Arctic sea ice drift alters adult female polar bear movements and energetics.

    Science.gov (United States)

    Durner, George M; Douglas, David C; Albeke, Shannon E; Whiteman, John P; Amstrup, Steven C; Richardson, Evan; Wilson, Ryan R; Ben-David, Merav

    2017-09-01

    Recent reductions in thickness and extent have increased drift rates of Arctic sea ice. Increased ice drift could significantly affect the movements and the energy balance of polar bears (Ursus maritimus) which forage, nearly exclusively, on this substrate. We used radio-tracking and ice drift data to quantify the influence of increased drift on bear movements, and we modeled the consequences for energy demands of adult females in the Beaufort and Chukchi seas during two periods with different sea ice characteristics. Westward and northward drift of the sea ice used by polar bears in both regions increased between 1987-1998 and 1999-2013. To remain within their home ranges, polar bears responded to the higher westward ice drift with greater eastward movements, while their movements north in the spring and south in fall were frequently aided by ice motion. To compensate for more rapid westward ice drift in recent years, polar bears covered greater daily distances either by increasing their time spent active (7.6%-9.6%) or by increasing their travel speed (8.5%-8.9%). This increased their calculated annual energy expenditure by 1.8%-3.6% (depending on region and reproductive status), a cost that could be met by capturing an additional 1-3 seals/year. Polar bears selected similar habitats in both periods, indicating that faster drift did not alter habitat preferences. Compounding reduced foraging opportunities that result from habitat loss; changes in ice drift, and associated activity increases, likely exacerbate the physiological stress experienced by polar bears in a warming Arctic. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  7. Polar Compounds Isolated from the Leaves of Albertisia delagoensis (Menispermaceae

    Directory of Open Access Journals (Sweden)

    Jia Li

    2011-11-01

    Full Text Available Aqueous infusions of the leaves of the shrub Albertisia delagoensis (Menispermaceae are used in South Africa in traditional Zulu medicine to alleviate a variety of symptoms, including fever, and intestinal problems. We report the analysis of such an aqueous extract using the HPLC-NMR technique. A number of polar compounds were identified, including proto-quercitol, nicotinic acid, allantoic acid, 3,4-dihydroxy-benzoic acid, phthalic acid and the aporphine alkaloid derivative roemrefidine. Allantoic acid and roemrefidine have been fully characterised by 1H- and 13C-NMR and mass spectrometry. Earlier reports of antiplasmodial activity of roemrefidine and of A. delagoensis extracts are correlated with this study and with the antipyretic properties of neutral aqueous extracts.

  8. Acylphloroglucinol Derivatives from the South African Helichrysum niveum and Their Biological Activities

    Directory of Open Access Journals (Sweden)

    Olugbenga K. Popoola

    2015-09-01

    Full Text Available Phytochemical investigation of aerial parts of Helichrysum niveum (H. niveum using different chromatographic methods including semi-preparative HPLC afforded three new (1–3 and six known (4–10 acylphloroglucinols alongside a known dialcohol triterpene (11. The structures of the isolated compounds were characterized accordingly as 1-benzoyl-3 (3-methylbut-2-enylacetate-phloroglucinol (helinivene A, 1, 1-benzoyl-3 (2S-hydroxyl-3-methylbut-3-enyl-phloroglucinol (helinivene B, 2, 8-(2-methylpropanone-3S,5,7-trihydroxyl-2,2-dimethoxychromane (helinivene C, 3, 1-(2-methylbutanone-4-O-prenyl-phloroglucinol (4, 1-(2-methylpropanone-4-O-prennyl-phloroglucinol (5, 1-(butanone-3-prenyl-phloroglucinol (6, 1-(2-methylbutanone-3-prenyl-phloroglucinol (7, 1-butanone-3-(3-methylbut-2-enylacetate-phloroglucinol (8, 1-(2-methylpropanone-3-prenylphloroglucinol (9, caespitate (10, and 3β-24-dihydroxyterexer-14-ene (11. Excellent total antioxidant capacities were demonstrated by helinivenes A and B (1 and 2 when measured as oxygen radicals absorbance capacity (ORAC, ferric-ion reducing antioxidant power (FRAP, trolox equivalent absorbance capacity (TEAC and including the inhibition of Fe2+-induced lipid peroxidation (IC50 = 5.12 ± 0.90; 3.55 ± 1.92 µg/mL, while anti-tyrosinase activity at IC50 = 35.63 ± 4.67 and 26.72 ± 5.05 µg/mL were also observed for 1 and 2, respectively. This is the first chemical and in vitro biological study on H. niveum. These findings underpin new perspectives for the exploitation of these natural phenolic compounds in applications such as in the natural cosmeceutical and pharmaceutical sectors.

  9. Acylphloroglucinol Derivatives from the South African Helichrysum niveum and Their Biological Activities.

    Science.gov (United States)

    Popoola, Olugbenga K; Marnewick, Jeanine L; Rautenbach, Fanie; Iwuoha, Emmanuel I; Hussein, Ahmed A

    2015-09-18

    Phytochemical investigation of aerial parts of Helichrysum niveum (H. niveum) using different chromatographic methods including semi-preparative HPLC afforded three new (1-3) and six known (4-10) acylphloroglucinols alongside a known dialcohol triterpene (11). The structures of the isolated compounds were characterized accordingly as 1-benzoyl-3 (3-methylbut-2-enylacetate)-phloroglucinol (helinivene A, 1), 1-benzoyl-3 (2S-hydroxyl-3-methylbut-3-enyl)-phloroglucinol (helinivene B, 2), 8-(2-methylpropanone)-3S,5,7-trihydroxyl-2,2-dimethoxychromane (helinivene C, 3), 1-(2-methylbutanone)-4-O-prenyl-phloroglucinol (4), 1-(2-methylpropanone)-4-O-prennyl-phloroglucinol (5), 1-(butanone)-3-prenyl-phloroglucinol (6), 1-(2-methylbutanone)-3-prenyl-phloroglucinol (7), 1-butanone-3-(3-methylbut-2-enylacetate)-phloroglucinol (8), 1-(2-methylpropanone)-3-prenylphloroglucinol (9), caespitate (10), and 3β-24-dihydroxyterexer-14-ene (11). Excellent total antioxidant capacities were demonstrated by helinivenes A and B (1 and 2) when measured as oxygen radicals absorbance capacity (ORAC), ferric-ion reducing antioxidant power (FRAP), trolox equivalent absorbance capacity (TEAC) and including the inhibition of Fe(2+)-induced lipid peroxidation (IC50 = 5.12 ± 0.90; 3.55 ± 1.92) µg/mL, while anti-tyrosinase activity at IC50 = 35.63 ± 4.67 and 26.72 ± 5.05 µg/mL were also observed for 1 and 2, respectively. This is the first chemical and in vitro biological study on H. niveum. These findings underpin new perspectives for the exploitation of these natural phenolic compounds in applications such as in the natural cosmeceutical and pharmaceutical sectors.

  10. Reliability and Validity of a Questionnaire for Physical Activity Assessment in South American Children and Adolescents: The SAYCARE Study.

    Science.gov (United States)

    Nascimento-Ferreira, Marcus Vinícius; De Moraes, Augusto César Ferreira; Toazza-Oliveira, Paulo Vinícius; Forjaz, Claudia L M; Aristizabal, Juan Carlos; Santaliesra-Pasías, Alba M; Lepera, Candela; Nascimento-Junior, Walter Viana; Skapino, Estela; Delgado, Carlos Alberto; Moreno, Luis Alberto; Carvalho, Heráclito Barbosa

    2018-03-01

    The objective of this article is to test the reliability and validity of the new and innovative physical activity (PA) questionnaire. Subsamples from the South American Youth/Child Cardiovascular and Environment Study (SAYCARE) study were included to examine its reliability (children: n = 161; adolescents: n = 177) and validity (children: n = 82; adolescents: n = 60). The questionnaire consists of three dimensions of PA (leisure, active commuting, and school) performed during the last week. To assess its validity, the subjects wore accelerometers for at least 3 days and 8 h/d (at least one weekend day). The reliability was analyzed by correlation coefficients. In addition, Bland-Altman analysis and a multilevel regression were applied to estimate the measurement bias, limits of agreement, and influence of contextual variables. In children, the questionnaire showed consistent reliability (ρ = 0.56) and moderate validity (ρ = 0.46), and the contextual variable variance explained 43.0% with -22.9 min/d bias. In adolescents, the reliability was higher (ρ = 0.76) and the validity was almost excellent (ρ = 0.88), with 66.7% of the variance explained by city level with 16.0 min/d PA bias. The SAYCARE PA questionnaire shows acceptable (in children) to strong (in adolescents) reliability and strong validity in the measurement of PA in the pediatric population from low- to middle-income countries. © 2018 The Obesity Society.

  11. Economic Activities, Illness Pattern and Utilisation of Health Care Facilities in the Rural Population of Kwazulu-Natal, South Africa

    Science.gov (United States)

    2009-01-01

    ABSTRACT Background The study was undertaken among the rural and black communities of the Uthungulu health district of the KwaZulu-Natal province, South Africa. Method A cross-sectional community-based descriptive study was conducted. A multi-stage sampling strategy was adopted to obtain a representative sample of the communities. Results The mean age of the population was 27 years and majority was female (54%). Among the adult population only 30% were educated, 19% were engaged in some form of economic activities while 9% were in the formal employment sector. The average monthly income per household was R1 301 (95% CI, R1 283; R1 308). The illnesses were reported by 27% of the total population over a period of one month. Notably higher rates of female individuals (29%) were sick compared to males (24%, p < 0.001). The rates of illnesses among adult females (39%) were also significantly higher than among males (31%, p < 0.009). Most of them (69%) attended primary health care (PHC) clinics for medical services, while 67% reported chronic conditions. Age (OR = 1.4), gender (OR = 0.711), education (OR = 0.64) and economic activities (OR = 1.9) were found to be associated with being ill or not. Conclusion The rural black communities are underdeveloped and deprived, which results in higher prevalence of illnesses; however, the utilisation of PHC facilities is comparatively higher than in the rest of the province and other parts of the country. Interventions to improve community health care services among the deprived population should be focused through public health strategies such as all-encompassing PHC that includes health promotion, education and basic essential amenities.

  12. Early interglacial carbonate-dilution events in the South China Sea: Implications for strengthened typhoon activities over subtropical East Asia

    Science.gov (United States)

    Huang, Enqing; Tian, Jun; Qiao, Peijun; Wan, Sui; Xie, Xin; Yang, Wenguang

    2015-10-01

    A compilation of many late Quaternary marine sediment records from the northern South China Sea (SCS) continental slope confirms 15-50% reductions in sedimentary calcium carbonate concentrations between 11.0 and 8.5 ka BP in the early Holocene. This low carbonate% event occurred at a time when the regional sea level rose from -50 m to -10 m, which drowned large areas of continental shelves especially those near and within the Taiwan Strait. This event is associated with a significant increase in bulk sedimentation rates on the upper continental slope and the relative abundance of fine-grained detritus. Sediment provenance analyses suggest a dominant terrigenous input from Taiwan and a minor contribution from Luzon during the low carbonate% event, similar to the background terrigenous deposition in other periods of the Holocene. Two comparable low carbonate% events, respectively from the beginning of marine isotope stages 5.5 and 7.3, have also been recognized, pointing to similar causal factors. While carbonate dissolution and carbonate accumulation rate should not have been responsible, increased terrigenous input and dilution is considered as the main cause for the recurrent low carbonate% events in early interglacials. We further hypothesize that, during early interglacials, fluvial sediment discharge from Taiwan and Luzon intensified due to stronger typhoon activities, and massive fine-grained sediments from these two end members may have been transported to the northern SCS continental slope via surface and deep ocean currents. The conjecture of strengthened typhoon activities over East Asia during the early Holocene is supported by high ocean heat contents in the West Pacific Warm Pool area with the prevailing La Niña-like conditions.

  13. Characteristics of cloud-to-ground lightning activity over Seoul, South Korea in relation to an urban effect

    Directory of Open Access Journals (Sweden)

    S. K. Kar

    2007-11-01

    Full Text Available Cloud-to-ground (CG lightning flash data collected by the lightning detection network installed at the Korean Meteorological Administration (KMA have been used to study the urban effect on lightning activity over and around Seoul, the largest metropolitan city of South Korea, for the period of 1989–1999. Negative and positive flash density and the percentage of positive flashes have been calculated. Calculation reveals that an enhancement of approximately 60% and 42% are observed, respectively, for negative and positive flash density over and downwind of the city. The percentage decrease of positive flashes occurs over and downwind of Seoul and the amount of decrease is nearly 20% compared to upwind values. The results are in good agreement with those obtained by Steiger et al. (2002 and Westcott (1995. CG lightning activities have also been considered in relation to annual averages of PM10 (particulate matter with an aerodynamic diameter smaller than 10 μm and sulphur dioxide (SO2 concentrations. Interesting results are found, indicating that the higher concentration of SO2 contributes to the enhancement of CG lightning flashes. On the other hand, the contribution from PM10 concentration has not appeared in this study to be as significant as SO2 in the enhancement of CG lightning flashes. Correlation coefficients of 0.33 and 0.64 are found between the change in CG lightning flashes and the PM10 and SO2, respectively, for upwind to downwind areas, suggesting a significant influence of the increased concentration of SO2 on the enhancement of CG flashes.

  14. Estrogenic activity, chemical levels and health risk assessment of municipal distribution point water from Pretoria and Cape Town, South Africa.

    Science.gov (United States)

    Van Zijl, Magdalena Catherina; Aneck-Hahn, Natalie Hildegard; Swart, Pieter; Hayward, Stefan; Genthe, Bettina; De Jager, Christiaan

    2017-11-01

    Endocrine disrupting chemicals (EDCs) are ubiquitous in the environment and have been detected in drinking water from various countries. Although various water treatment processes can remove EDCs, chemicals can also migrate from pipes that transport water and contaminate drinking water. This study investigated the estrogenic activity in drinking water from various distribution points in Pretoria (City of Tshwane) (n = 40) and Cape Town (n = 40), South Africa, using the recombinant yeast estrogen screen (YES) and the T47D-KBluc reporter gene assay. The samples were collected seasonally over four sampling periods. The samples were also analysed for bisphenol A (BPA), nonylphenol (NP), di(2-ethylhexyl) adipate (DEHA), dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), diisononylphthalate (DINP), 17β-estradiol (E 2 ), estrone (E 1 ) and ethynylestradiol (EE 2 ) using ultra-performance liquid chromatography-tandem mass spectrophotometry (UPLC-MS/MS). This was followed by a scenario based health risk assessment to assess the carcinogenic and toxic human health risks associated with the consumption of distribution point water. None of the water extracts from the distribution points were above the detection limit in the YES bioassay, but the EEq values ranged from 0.002 to 0.114 ng/L using the T47D-KBluc bioassay. BPA, DEHA, DBP, DEHP, DINP E 1 , E 2, and EE 2 were detected in distribution point water samples. NP was below the detection limit for all the samples. The estrogenic activity and levels of target chemicals were comparable to the levels found in other countries. Overall the health risk assessment revealed acceptable health and carcinogenic risks associated with the consumption of distribution point water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Multiphoton polarization Bremsstrahlung effect

    International Nuclear Information System (INIS)

    Golovinskij, P.A.

    2001-01-01

    A general approach to induced polarization effects was formulated on the basis of theory of many particles in a strong periodic field. Correlation with the perturbation theory is shown and the types of effective polarization potentials both for isolated atoms and ions, and for ions in plasma, are provided. State of art in the theory of forced polarization Bremsstrahlung effect is analyzed and some outlooks for further experimental and theoretical studies are outlined [ru

  16. Perspectives on enhancing physical activity and diet for health promotion among at-risk urban UK South Asian communities: a qualitative study.

    Science.gov (United States)

    Cross-Bardell, Laura; George, Tracey; Bhoday, Mandeep; Tuomainen, Helena; Qureshi, Nadeem; Kai, Joe

    2015-02-27

    To explore perspectives on enhancing physical activity and diet among South Asians in urban deprived communities at high risk of chronic disease and to inform development of culturally appropriate health promotion intervention. Qualitative study using semistructured one-to-one and family group interviews with thematic analysis of data. Urban disadvantaged communities in the East Midlands of the UK. 45 respondents, including 34 people of South Asian origin (16 at-risk individuals, six family groups involving 18 relatives), of mainly Pakistani and Indian origin, including 16 non-English speakers; and 11 health professionals working locally with communities of concern. South Asian participants underlined the challenges of requiring family members across generations to engage in modifying dietary behaviours, and the central role of communal eating of traditional 'Asian' food in their cultural lives. Barriers to increasing physical activity included cost, personal safety and lack of time outside of long working hours and carer commitments. However, increasing walking activity was regarded as feasible by both community and health professional participants. Respondents emphasised using a social approach for potential interventions, undertaking activity with family or friends and with bilingual community peers to facilitate engagement, motivation and support. Spoken content and delivery of interventions was favoured, including personal stories and multilingual audio-visual information; within local informal rather than provider settings, including the home; and aided by pedometers for self-monitoring. Focusing on physical activity by increasing walking may hold promise as health promotion in this deprived South Asian community context. Further intervention development, with exploration of feasibility and acceptability of the social approach and elements suggested, is merited. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted

  17. Skills training through hands-on practical activities in civil technology – a case study of three technical schools in South Africa

    Directory of Open Access Journals (Sweden)

    Mogale Maeko

    2014-12-01

    Full Text Available Skills training for Civil Technology learners in South African schools, is an aspect entrenched in the Civil Technology policy document in order to produce skilled personnel for a sustainable economy. Practical activities through the Practical Assessment Task (PAT are national requirements for all practical-based subjects from grades 10–12 in South African schools. The purpose of this study was to investigate the status of Civil Technology practical activities in three South African schools in the Eastern Cape Province. Purposive sampling was used to identify 41 learners and 3 teachers to participate in the study. Questionnaires, semi-structured interviews and observation as data collection methods were instruments used to collect data. The study has found that learners exit grade 12 without basic practical hands-on skills. Civil Technology practical activities were found to be inadequately offered in the three schools investigated. Educators should be well-trained by higher education institutions (HEIs to conduct practical activities with learners so that these learners are equipped with marketable skills in order to contribute to a sustainable economy after grade 12. Technology teacher education and training should include regular exposure and visits to relevant industries in order for teachers to keep abreast with the latest technological developments. The supply of equipment to schools should be coupled with routine maintenance of the equipment.

  18. 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.

  19. Airborne Laser Polarization Sensor

    Science.gov (United States)

    Kalshoven, James, Jr.; Dabney, Philip

    1991-01-01

    Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

  20. Polarization of Be stars

    International Nuclear Information System (INIS)

    Johns, M.W.

    1975-01-01

    Linear polarization of starlight may be produced by electron scattering in the extended atmospheres of early type stars. Techniques are investigated for the measurement and interpretation of this polarization. Polarimetric observations were made of twelve visual double star systems in which at least one member was a B type star as a means of separating the intrinsic stellar polarization from the polarization produced in the interstellar medium. Four of the double stars contained a Be star. Evidence for intrinsic polarization was found in five systems including two of the Be systems, one double star with a short period eclipsing binary, and two systems containing only normal early type stars for which emission lines have not been previously reported. The interpretation of these observations in terms of individual stellar polarizations and their wavelength dependence is discussed. The theoretical basis for the intrinsic polarization of early type stars is explored with a model for the disk-like extended atmospheres of Be stars. Details of a polarimeter for the measurement of the linear polarization of astronomical point sources are also presented with narrow band (Δ lambda = 100A) measurements of the polarization of γ Cas from lambda 4000 to lambda 5800

  1. Polarization at SLC

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1988-07-01

    The SLAC Linear Collider has been designed to readily accommodate polarized electron beams. Considerable effort has been made to implement a polarized source, a spin rotation system, and a system to monitor the beam polarization. Nearly all major components have been fabricated. At the current time, several source and polarimeter components have been installed. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. It is expected that a beam polarization of 45% will be achieved with no loss in luminosity. 13 refs., 15 figs

  2. Peroxisome proliferator activated receptor gamma polymorphism Pro12Ala in polycystic ovary syndrome (PCOS of South Indian Population

    Directory of Open Access Journals (Sweden)

    Raichel Jacob

    2016-05-01

    Conclusion: PPARγ2 gene Pro12Ala polymorphism was supposed to be susceptible genes in PCOS. The present study demonstrated that there is a statistical difference between the distributions of PPAR gamma Pro12Ala polymorphism in South Indian Population.

  3. The empirical relationship between the managerial conduct and internal control activities in South African small, medium and micro enterprises

    OpenAIRE

    Juan-Pierre Bruwer; Philna Coetzee; Jacolize Meiring

    2017-01-01

    Background: Although South African small, medium and micro enterprises (SMMEs) play an imperative role in the stimulation of the national economy, previous research studies show that these business entities have severe sustainability problems as approximately 75% of them fail after being in operation for only 3 years. The latter dispensation is pinned on the belief that South African SMMEs make use of inadequate and ineffective internal control systems. Aim: Since a system of internal cont...

  4. Polar transport in plants mediated by membrane transporters: focus on mechanisms of polar auxin transport.

    Science.gov (United States)

    Naramoto, Satoshi

    2017-12-01

    Directional cell-to-cell transport of functional molecules, called polar transport, enables plants to sense and respond to developmental and environmental signals. Transporters that localize to plasma membranes (PMs) in a polar manner are key components of these systems. PIN-FORMED (PIN) auxin efflux carriers, which are the most studied polar-localized PM proteins, are implicated in the polar transport of auxin that in turn regulates plant development and tropic growth. In this review, the regulatory mechanisms underlying polar localization of PINs, control of auxin efflux activity, and PIN abundance at PMs are considered. Up to date information on polar-localized nutrient transporters that regulate directional nutrient movement from soil into the root vasculature is also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Perspectives on enhancing physical activity and diet for health promotion among at-risk urban UK South Asian communities: a qualitative study

    OpenAIRE

    Cross-Bardell, Laura; George, Tracey; Bhoday, Mandeep; Tuomainen, Helena; Qureshi, Nadeem; Kai, Joe

    2015-01-01

    Objectives \\ud \\ud To explore perspectives on enhancing physical activity and diet among South Asians in urban deprived communities at high risk of chronic disease and to inform development of culturally appropriate health promotion intervention. \\ud \\ud Design\\ud \\ud Qualitative study using semistructured one-to-one and family group interviews with thematic analysis of data. \\ud \\ud \\ud Setting \\ud \\ud Urban disadvantaged communities in the East Midlands of the UK. \\ud \\ud \\ud Participants \\...

  6. Unprecedented evidence for high viral abundance and lytic activity in coral reef waters of the South Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Jérôme P. Payet

    2014-09-01

    Full Text Available Despite nutrient-depleted conditions, coral reef waters harbor abundant and diverse microbes; as major agents of microbial mortality, viruses are likely to influence microbial processes in these ecosystems. However, little is known about marine viruses in these rapidly changing ecosystems. Here we examined spatial and short-term temporal variability in marine viral abundance and viral lytic activity across various reef habitats surrounding Moorea Island (French Polynesia in the South Pacific. Water samples were collected along 4 regional cross-reef transects and during a time-series in Opunohu Bay. Results revealed high viral abundance (range: 5.6 x 106 – 3.6 x 107 viruses ml-1 and lytic viral production (range: 1.5 x 109 – 9.2 x 1010 viruses l-1 d-1. Flow cytometry revealed that viral assemblages were composed of three subsets that each displayed distinct spatiotemporal relationships with nutrient concentrations and autotrophic and heterotrophic microbial abundances. The results highlight dynamic shifts in viral community structure and imply that each of these three subsets is ecologically important and likely to infect distinct microbial hosts in reef waters. Based on viral-reduction approach, we estimate that lytic viruses were responsible for the removal of ca. 24% to 367% of bacterial standing stock d-1 and the release of ca. 1.1 to 62 µg of organic carbon l-1 d-1 in reef waters. Overall, this work demonstrates the highly dynamic distribution of viruses and their critical roles in controlling microbial mortality and nutrient cycling in coral reef water ecosystems.

  7. A COMPTON-THICK ACTIVE GALACTIC NUCLEUS AT z ∼ 5 IN THE 4 Ms CHANDRA DEEP FIELD SOUTH

    International Nuclear Information System (INIS)

    Gilli, R.; Comastri, A.; Su, J.; Norman, C.; Vignali, C.; Tozzi, P.; Rosati, P.; Mainieri, V.; Stiavelli, M.; Brandt, W. N.; Xue, Y. Q.; Luo, B.; Castellano, M.; Fontana, A.; Fiore, F.; Ptak, A.

    2011-01-01

    We report the discovery of a Compton-thick active galactic nucleus (AGN) at z = 4.76 in the 4 Ms Chandra Deep Field South. This object was selected as a V-band dropout in HST/ACS images and previously recognized as an AGN from o