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Sample records for short vegetation period

  1. Southern hemisphere searches for short period pulsars

    International Nuclear Information System (INIS)

    Manchester, R.N.

    1984-01-01

    Two searches of the southern sky for short period pulsars are briefly described. The first, made using the 64-m telescope at Parkes, is sensitive to pulsars with periods greater than about 10 ms and the second, made using the Molonglo radio telescope, has sensitivity down to periods of about 1.5 ms. Four pulsars were found in the Parkes survey and none in the Molonglo survey, although analysis of the latter is as yet incomplete. 10 references, 1 figure, 2 tables

  2. Field Optimization for short Period Undulators

    CERN Document Server

    Peiffer, P; Rossmanith, R; Schoerling, D

    2011-01-01

    Undulators dedicated to low energy electron beams, like Laser Wakefield Accelerators, require very short period lengths to achieve X-ray emission. However, at these short period length (LambdaU ~ 5 mm) it becomes difficult to reach magnetic field amplitudes that lead to a K parameter of >1, which is generally desired. Room temperature permanent magnets and even superconductive undulators using Nb-Ti as conductor material have proven insufficient to achieve the desired field amplitudes. The superconductor Nb$_{3}$Sn has the theoretical potential to achieve the desired fields. However, up to now it is limited by several technological challenges to much lower field values than theoretically predicted. An alternative idea for higher fields is to manufacture the poles of the undulator body from Holmium instead of iron or to use Nb-Ti wires with a higher superconductor/copper ratio. The advantages and challenges of the different options are compared in this contribution.

  3. Short period tidal variations of earth rotation

    Science.gov (United States)

    Yoder, C. F.; Williams, J. G.; Parke, M. E.; Dickey, J. O.

    1981-01-01

    It is explained that the tidal deformation of the earth's polar moment of inertia by the moon and sun cause periodic variations in rotation. The short period oscillations give rise to a meter-sized, diurnal signature in the lunar laser ranging data obtained at McDonald Observatory. A solution is given for the scale parameter k/C at fortnightly and monthly tidal frequencies. The results are compared with those obtained by other investigators and with a theoretical estimate which includes the effect of oceans and a decoupled fluid core.

  4. Preferred Hosts for Short-Period Exoplanets

    Science.gov (United States)

    Kohler, Susanna

    2015-12-01

    In an effort to learn more about how planets form around their host stars, a team of scientists has analyzed the population of Kepler-discovered exoplanet candidates, looking for trends in where theyre found.Planetary OccurrenceSince its launch in 2009, Kepler has found thousands of candidate exoplanets around a variety of star types. Especially intriguing is the large population of super-Earths and mini-Neptunes planets with masses between that of Earth and Neptune that have short orbital periods. How did they come to exist so close to their host star? Did they form in situ, or migrate inwards, or some combination of both processes?To constrain these formation mechanisms, a team of scientists led by Gijs Mulders (University of Arizona and NASAs NExSS coalition) analyzed the population of Kepler planet candidates that have orbital periods between 2 and 50 days.Mulders and collaborators used statistical reconstructions to find the average number of planets, within this orbital range, around each star in the Kepler field. They then determined how this planet occurrence rate changed for different spectral types and therefore the masses of the host stars: do low-mass M-dwarf stars host more or fewer planets than higher-mass, main-sequence F, G, or K stars?Challenging ModelsAuthors estimates for the occurrence rate for short-period planets of different radii around M-dwarfs (purple) and around F, G, and K-type stars (blue). [Mulders et al. 2015]The team found that M dwarfs, compared to F, G, or K stars, host about half as many large planets with orbital periods of P 50 days. But, surprisingly, they host significantly more small planets, racking up an average of 3.5 times the number of planets in the size range of 12.8 Earth-radii.Could it be that M dwarfs have a lower total mass of planets, but that mass is distributed into more, smaller planets? Apparently not: the authors show that the mass of heavy elements trapped in short-orbital-period planets is higher for M

  5. A short period undulator for MAX

    International Nuclear Information System (INIS)

    Ahola, H.; Meinander, T.

    1992-01-01

    A hybrid undulator for generation of high brilliance synchrotron radiation in the photon energy range of 60--600 eV at the 550 MeV electron storage ring MAX in Lund, Sweden has been designed and built at the Technical Research Centre of Finland in close collaboration with MAX-lab of Lund University. At the rather modest electron energy of MAX this photon energy range can be reached only by an undulator featuring a fairly short period and the smallest possible magnetic gap. Even then, higher harmonics (up to the 13th) of the radiation spectrum must be utilized. An optimization of the magnetic design resulted in a hybrid configuration of NdFeB magnets and soft iron poles with a period of 24 mm and a minimum magnetic gap of 7--10 mm. A variable-gap vacuum chamber allows reduction of the vacuum gap from a maximum of 20 mm, needed for injection, down to 6 mm during stored beam operation. A special design of this chamber permits a magnetic gap between pole tips that is only 1 mm larger than the vacuum gap. Adequate field uniformity was ensured by calibration of magnets to equal strength at their true operating point and verification of the homogeneity of their magnetization. Magnetic measurements included Hall probe scans of the undulator field and flip coil evaluations of the field integral

  6. Theoretical study of nitride short period superlattices

    Science.gov (United States)

    Gorczyca, I.; Suski, T.; Christensen, N. E.; Svane, A.

    2018-02-01

    Discussion of band gap behavior based on first principles calculations of electronic band structures for various short period nitride superlattices is presented. Binary superlattices, as InN/GaN and GaN/AlN as well as superlattices containing alloys, as InGaN/GaN, GaN/AlGaN, and GaN/InAlN are considered. Taking into account different crystallographic directions of growth (polar, semipolar and nonpolar) and different strain conditions (free-standing and pseudomorphic) all the factors influencing the band gap engineering are analyzed. Dependence on internal strain and lattice geometry is considered, but the main attention is devoted to the influence of the internal electric field and the hybridization of well and barrier wave functions. The contributions of these two important factors to band gap behavior are illustrated and estimated quantitatively. It appears that there are two interesting ranges of layer thicknesses; in one (few atomic monolayers in barriers and wells) the influence of the wave function hybridization is dominant, whereas in the other (layers thicker than roughly five to six monolayers) dependence of electric field on the band gaps is more important. The band gap behavior in superlattices is compared with the band gap dependence on composition in the corresponding ternary and quaternary alloys. It is shown that for superlattices it is possible to exceed by far the range of band gap values, which can be realized in ternary alloys. The calculated values of the band gaps are compared with the photoluminescence emission energies, when the corresponding data are available. Finally, similarities and differences between nitride and oxide polar superlattices are pointed out by comparison of wurtzite GaN/AlN and ZnO/MgO.

  7. Biodiversity of Terrestrial Vegetation during Past Warm Periods

    Science.gov (United States)

    Davies-Barnard, T.; Valdes, P. J.; Ridgwell, A.

    2016-12-01

    Previous modelling studies of vegetation have generally used a small number of plant functional types to understand how the terrestrial biosphere responds to climate changes. Whilst being useful for understanding first order climate feedbacks, this climate-envelope approach makes a lot of assumptions about past vegetation being very similar to modern. A trait-based method has the advantage for paleo modelling in that there are substantially less assumptions made. In a novel use of the trait-based dynamic vegetation model JeDi, forced with output from climate model HadCM3, we explore past biodiversity and vegetation carbon changes. We use JeDi to model an optimal 2000 combinations of fifteen different traits to enable assessment of the overall level of biodiversity as well as individual growth strategies. We assess the vegetation shifts and biodiversity changes in past greenhouse periods to better understand the impact on the terrestrial biosphere. This work provides original insights into the response of vegetation and terrestrial carbon to climate and hydrological changes in high carbon dioxide climates over time, including during the Late Permian and Cretaceous. We evaluate how the location of biodiversity hotspots and species richness in past greenhouse climates is different to the present day.

  8. The effect of short ground vegetation on terrestrial laser scans at a local scale

    Science.gov (United States)

    Fan, Lei; Powrie, William; Smethurst, Joel; Atkinson, Peter M.; Einstein, Herbert

    2014-09-01

    Terrestrial laser scanning (TLS) can record a large amount of accurate topographical information with a high spatial accuracy over a relatively short period of time. These features suggest it is a useful tool for topographical survey and surface deformation detection. However, the use of TLS to survey a terrain surface is still challenging in the presence of dense ground vegetation. The bare ground surface may not be illuminated due to signal occlusion caused by vegetation. This paper investigates vegetation-induced elevation error in TLS surveys at a local scale and its spatial pattern. An open, relatively flat area vegetated with dense grass was surveyed repeatedly under several scan conditions. A total station was used to establish an accurate representation of the bare ground surface. Local-highest-point and local-lowest-point filters were applied to the point clouds acquired for deriving vegetation height and vegetation-induced elevation error, respectively. The effects of various factors (for example, vegetation height, edge effects, incidence angle, scan resolution and location) on the error caused by vegetation are discussed. The results are of use in the planning and interpretation of TLS surveys of vegetated areas.

  9. On the short periods oscillation in relativistic stars

    International Nuclear Information System (INIS)

    Aquilano, R.; Morales, S.; Navone, H.; Sevilla, D.; Zorzi, A.

    2009-01-01

    We expand the study of neutron and strange matter stars with general relativistic formalism. We analyze the correlation with the observational data short periods oscillations in these stars, and we intend to discriminate between them.

  10. Origin of very-short orbital-period binary systems

    International Nuclear Information System (INIS)

    Miyaji, S.

    1983-01-01

    Recent observations of four close binaries have established that there is a group of very-short orbital-period (VSOP) binaries whose orbital periods are less than 60 minutes. The VSOP binaries consist of both X-ray close binaries and cataclysmic variables. Their orbital periods are too short to have a main-sequence companion. However, four binaries, none of which belongs to any globular cluster, are too abundant to be explained by the capturing mechanism of a white dwarf. Therefore it seemed to be worthwhile to present an evolutionary scenario from an original binary system which can be applied for all VSOP binaries. (Auth.)

  11. How Do Earth-Sized, Short-Period Planets Form?

    Science.gov (United States)

    Kohler, Susanna

    2017-08-01

    Matching theory to observation often requires creative detective work. In a new study, scientists have used a clever test to reveal clues about the birth of speedy, Earth-sized planets.Former Hot Jupiters?Artists impression of a hot Jupiter with an evaporating atmosphere. [NASA/Ames/JPL-Caltech]Among the many different types of exoplanets weve observed, one unusual category is that of ultra-short-period planets. These roughly Earth-sized planets speed around their host stars at incredible rates, with periods of less than a day.How do planets in this odd category form? One popular theory is that they were previously hot Jupiters, especially massive gas giants orbiting very close to their host stars. The close orbit caused the planets atmospheres to be stripped away, leaving behind only their dense cores.In a new study, a team of astronomers led by Joshua Winn (Princeton University) has found a clever way to test this theory.Planetary radius vs. orbital period for the authors three statistical samples (colored markers) and the broader sample of stars in the California Kepler Survey. [Winn et al. 2017]Testing MetallicitiesStars hosting hot Jupiters have an interesting quirk: they typically have metallicities that are significantly higher than an average planet-hosting star. It is speculated that this is because planets are born from the same materials as their host stars, and hot Jupiters require the presence of more metals to be able to form.Regardless of the cause of this trend, if ultra-short-period planets are in fact the solid cores of former hot Jupiters, then the two categories of planets should have hosts with the same metallicity distributions. The ultra-short-period-planet hosts should therefore also be weighted to higher metallicities than average planet-hosting stars.To test this, the authors make spectroscopic measurements and gather data for a sample of stellar hosts split into three categories:64 ultra-short-period planets (orbital period shorter than a

  12. Design issues for cryogenic cooling of short period superconducting undulators

    International Nuclear Information System (INIS)

    Green, M.A.; Dietderich, D.R.; Marks, S.; Prestemon, S.O.; Schlueter, R.D.

    2003-01-01

    Superconducting insertion devices, which produce periodic magnetic fields, have been built and installed in a number of synchrotron-light source storage-rings. For the most part, these devices have been wigglers, which have relatively long period lengths. This report concerns itself with the special cryogenic issues associated with short period undulators. The motivation for considering the incorporation of superconducting technology in insertion device designs is to achieve higher magnetic fields than can be achieved with more conventional permanent magnet technology. Since the peak field decreases sharply with increased magnet gap to period ratio, the cryogenic design of the magnet system is crucial. In particular, the insulation required for a warm vacuum bore device is impractical for short period undulators. This report describes the issues that are related to a cold bore (∼4 K) and an intermediate temperature bore (30 to 70 K) designs. The criteria for the use of small cryocoolers for cooling a short period undulator are presented. The problems associated with connecting small coolers to an undulator at 4.2 K are discussed

  13. Response of phytoplankton assemblages isolated for short periods ...

    African Journals Online (AJOL)

    The response of phytoplankton assemblages isolated in enclosures for short periods of time was examined in hyper-eutrophic Lake Chivero (Harare, Zimbabwe), to determine the factors that influenced the structure of the phytoplankton community, after noticing a marked decline in the dominance of Microcystis aeruginosa ...

  14. Magnetospheric Truncation, Tidal Inspiral, and the Creation of Short-period and Ultra-short-period Planets

    International Nuclear Information System (INIS)

    Lee, Eve J.; Chiang, Eugene

    2017-01-01

    Sub-Neptunes around FGKM dwarfs are evenly distributed in log orbital period down to ∼10 days, but dwindle in number at shorter periods. Both the break at ∼10 days and the slope of the occurrence rate down to ∼1 day can be attributed to the truncation of protoplanetary disks by their host star magnetospheres at corotation. We demonstrate this by deriving planet occurrence rate profiles from empirical distributions of pre-main-sequence stellar rotation periods. Observed profiles are better reproduced when planets are distributed randomly in disks—as might be expected if planets formed in situ—rather than piled up near disk edges, as would be the case if they migrated in by disk torques. Planets can be brought from disk edges to ultra-short (<1 day) periods by asynchronous equilibrium tides raised on their stars. Tidal migration can account for how ultra-short-period planets are more widely spaced than their longer-period counterparts. Our picture provides a starting point for understanding why the sub-Neptune population drops at ∼10 days regardless of whether the host star is of type FGK or early M. We predict planet occurrence rates around A stars to also break at short periods, but at ∼1 day instead of ∼10 days because A stars rotate faster than stars with lower masses (this prediction presumes that the planetesimal building blocks of planets can drift inside the dust sublimation radius).

  15. Magnetospheric Truncation, Tidal Inspiral, and the Creation of Short-period and Ultra-short-period Planets

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eve J.; Chiang, Eugene, E-mail: evelee@berkeley.edu [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

    2017-06-10

    Sub-Neptunes around FGKM dwarfs are evenly distributed in log orbital period down to ∼10 days, but dwindle in number at shorter periods. Both the break at ∼10 days and the slope of the occurrence rate down to ∼1 day can be attributed to the truncation of protoplanetary disks by their host star magnetospheres at corotation. We demonstrate this by deriving planet occurrence rate profiles from empirical distributions of pre-main-sequence stellar rotation periods. Observed profiles are better reproduced when planets are distributed randomly in disks—as might be expected if planets formed in situ—rather than piled up near disk edges, as would be the case if they migrated in by disk torques. Planets can be brought from disk edges to ultra-short (<1 day) periods by asynchronous equilibrium tides raised on their stars. Tidal migration can account for how ultra-short-period planets are more widely spaced than their longer-period counterparts. Our picture provides a starting point for understanding why the sub-Neptune population drops at ∼10 days regardless of whether the host star is of type FGK or early M. We predict planet occurrence rates around A stars to also break at short periods, but at ∼1 day instead of ∼10 days because A stars rotate faster than stars with lower masses (this prediction presumes that the planetesimal building blocks of planets can drift inside the dust sublimation radius).

  16. Planetary perturbations and the origins of short-period comets

    International Nuclear Information System (INIS)

    Quinn, T.; Tremaine, S.; Duncan, M.

    1990-01-01

    To investigate the dynamical plausibility of possible sources for the short-period comets, a representative sample of comet orbits in the field of the sun and the giant planets was integrated, with the aim to determine whether the distribution of orbits from a proposed source that reach observable perihelia (q less than 2.5 AU) matches the observed distribution of short-period orbits. It is found that the majority of the short-period comets, those with orbital period P less than 20 yr (the Jupiter family), cannot arise from isotropic orbits with perihelia near Jupiter's orbit, because the resulting observable comet orbits have the wrong distribution in period, inclination, and argument of perihelion. The simulations also show that Jupiter-family comets cannot arise from isotropic orbits with perihelia in the Uranus-Neptune region. On the other hand, a source of low-inclination Neptune-crossing orbits yields a distribution of observable Jupiter-family comets that is consistent with the data in all respects. These results imply that the Jupiter-family comets arise from a disk source in the outer solar system rather than from the Oort comet cloud. 30 refs

  17. CLATHRATE HYDRATES FORMATION IN SHORT-PERIOD COMETS

    International Nuclear Information System (INIS)

    Marboeuf, Ulysse; Mousis, Olivier; Petit, Jean-Marc; Schmitt, Bernard

    2010-01-01

    The initial composition of current models of cometary nuclei is only based on two forms of ice: crystalline ice for long-period comets and amorphous ice for short-period comets. A third form of ice, i.e., clathrate hydrate, could exist within the short-period cometary nuclei, but the area of formation of this crystalline structure in these objects has never been studied. Here, we show that the thermodynamic conditions in the interior of short-period comets allow the existence of clathrate hydrates in Halley-type comets. We show that their existence is viable in the Jupiter family comets only when the equilibrium pressure of CO clathrate hydrate is at least 1 order of magnitude lower than the usually assumed theoretical value. We calculate that the amount of volatiles that could be trapped in the clathrate hydrate layer may be orders of magnitude greater than the daily amount of gas released at the surface of the nucleus at perihelion. The formation and the destruction of the clathrate hydrate cages could then explain the diversity of composition of volatiles observed in comets, as well as some pre-perihelion outbursts. We finally show that the potential clathrate hydrate layer in comet 67P/Churyumov-Gerasimenko would, unfortunately, be deep inside the nucleus, out of reach of the Rosetta lander. However, such a clathrate hydrate layer would show up by the gas composition of the coma.

  18. Short-Period Surface Wave Based Seismic Event Relocation

    Science.gov (United States)

    White-Gaynor, A.; Cleveland, M.; Nyblade, A.; Kintner, J. A.; Homman, K.; Ammon, C. J.

    2017-12-01

    Accurate and precise seismic event locations are essential for a broad range of geophysical investigations. Superior location accuracy generally requires calibration with ground truth information, but superb relative location precision is often achievable independently. In explosion seismology, low-yield explosion monitoring relies on near-source observations, which results in a limited number of observations that challenges our ability to estimate any locations. Incorporating more distant observations means relying on data with lower signal-to-noise ratios. For small, shallow events, the short-period (roughly 1/2 to 8 s period) fundamental-mode and higher-mode Rayleigh waves (including Rg) are often the most stable and visible portion of the waveform at local distances. Cleveland and Ammon [2013] have shown that teleseismic surface waves are valuable observations for constructing precise, relative event relocations. We extend the teleseismic surface wave relocation method, and apply them to near-source distances using Rg observations from the Bighorn Arche Seismic Experiment (BASE) and the Earth Scope USArray Transportable Array (TA) seismic stations. Specifically, we present relocation results using short-period fundamental- and higher-mode Rayleigh waves (Rg) in a double-difference relative event relocation for 45 delay-fired mine blasts and 21 borehole chemical explosions. Our preliminary efforts are to explore the sensitivity of the short-period surface waves to local geologic structure, source depth, explosion magnitude (yield), and explosion characteristics (single-shot vs. distributed source, etc.). Our results show that Rg and the first few higher-mode Rayleigh wave observations can be used to constrain the relative locations of shallow low-yield events.

  19. Periodization of Carbohydrate Intake: Short-Term Effect on Performance

    Directory of Open Access Journals (Sweden)

    Laurie-Anne Marquet

    2016-11-01

    Full Text Available Background: “Sleep-low” consists of a sequential periodization of carbohydrate (CHO availability—low glycogen recovery after “train high” glycogen-depleting interval training, followed by an overnight-fast and light intensity training (“train low” the following day. This strategy leads to an upregulation of several exercise-responsive signaling proteins, but the chronic effect on performance has received less attention. We investigated the effects of short-term exposure to this strategy on endurance performance. Methods: Following training familiarization, 11 trained cyclists were divided into two groups for a one-week intervention—one group implemented three cycles of periodized CHO intake to achieve the sleep-low strategy over six training sessions (SL, CHO intake: 6 g·kg−1·day−1, whereas the control group consumed an even distribution of CHO over the day (CON. Tests were a 2 h submaximal ride and a 20 km time trial. Results: SL improved their performance (mean: +3.2%; p < 0.05 compared to CON. The improvement was associated with a change in pacing strategy with higher power output during the second part of the test. No change in substrate utilization was observed after the training period for either group. Conclusion: Implementing the “sleep-low” strategy for one week improved performance by the same magnitude previously seen in a three-week intervention, without any significant changes in selected markers of metabolism.

  20. Periodization of Carbohydrate Intake: Short-Term Effect on Performance

    Science.gov (United States)

    Marquet, Laurie-Anne; Hausswirth, Christophe; Molle, Odeline; Hawley, John A.; Burke, Louise M.; Tiollier, Eve; Brisswalter, Jeanick

    2016-01-01

    Background: “Sleep-low” consists of a sequential periodization of carbohydrate (CHO) availability—low glycogen recovery after “train high” glycogen-depleting interval training, followed by an overnight-fast and light intensity training (“train low”) the following day. This strategy leads to an upregulation of several exercise-responsive signaling proteins, but the chronic effect on performance has received less attention. We investigated the effects of short-term exposure to this strategy on endurance performance. Methods: Following training familiarization, 11 trained cyclists were divided into two groups for a one-week intervention—one group implemented three cycles of periodized CHO intake to achieve the sleep-low strategy over six training sessions (SL, CHO intake: 6 g·kg−1·day−1), whereas the control group consumed an even distribution of CHO over the day (CON). Tests were a 2 h submaximal ride and a 20 km time trial. Results: SL improved their performance (mean: +3.2%; p < 0.05) compared to CON. The improvement was associated with a change in pacing strategy with higher power output during the second part of the test. No change in substrate utilization was observed after the training period for either group. Conclusion: Implementing the “sleep-low” strategy for one week improved performance by the same magnitude previously seen in a three-week intervention, without any significant changes in selected markers of metabolism. PMID:27897989

  1. Short-term responses of decomposers and vegetation to stump removal

    Energy Technology Data Exchange (ETDEWEB)

    Kataja-aho, S.

    2011-07-01

    Stump removal has become a common practice to produce raw material for bioenergy production. It was hypothesized that stump removal is an extensive and more intense disturbance for forest ecosystems (soil decomposer organisms and vegetation) compared to traditional site preparation after clear cutting. Therefore, the effects of stump harvesting on forest soil decomposers, vegetation and nutrient dynamics in undisturbed patches of the forest soil and in exposed mineral soil were compared to the effects of the traditional site preparation method, mounding. Nematodes and enchytraeids were the only decomposer groups that were directly affected (negatively) by the stump removal. Regardless of the treatment, the abundances of most of the decomposer groups were consistently lower in the exposed mineral soil than in the intact forest soil. There was 2-3 times more exposed mineral soil in stump removal sites compared to mounding sites. When this was taken into account, the decomposer community was negatively affected by the stump removal at the forest stand level. However, the greater soil disturbance at the stump harvesting sites enhanced CO{sub 2} production, net nitrogen mineralisation and nitrification. The increased N availability and the changes in microclimate due to the disturbance probably explained the vegetation increase at the stump harvested sites. Planted Norway spruce seedlings grew faster during the first two growing periods at the stump removal sites than at the mounding sites. The seedlings had high and similar ectomycorrhizal colonization rate in both treatments. In the short-term, it is probably not the resources removed in the stumps themselves, but the degree and amount of soil disturbance during the stump harvesting procedure that affects the decomposer community and its function in the clear-felled stands. (orig.)

  2. Surface electron structure of short-period semiconductor superlattice

    International Nuclear Information System (INIS)

    Bartos, I.; Czech Academy Science, Prague,; Strasser, T.; Schattke, W.

    2004-01-01

    Full text: Semiconductor superlattices represent man-made crystals with unique physical properties. By means of the directed layer-by-layer molecular epitaxy growth their electric properties can be tailored (band structure engineering). Longer translational periodicity in the growth direction is responsible for opening of new electron energy gaps (minigaps) with surface states and resonances localized at superlattice surfaces. Similarly as for the electron structure of the bulk, a procedure enabling to modify the surface electron structure of superlattices is desirable. Short-period superlattice (GaAs) 2 (AlAs) 2 with unreconstructed (100) surface is investigated in detail. Theoretical description in terms of full eigenfunctions of individual components has to be used. The changes of electron surface state energies governed by the termination of a periodic crystalline potential, predicted on simple models, are confirmed for this system. Large surface state shifts are found in the lowest minigap of the superlattice when this is terminated in four different topmost layer configurations. The changes should be observable in angle resolved photoelectron spectroscopy as demonstrated in calculations based on the one step model of photoemission. Surface state in the center of the two dimensional Brillouin zone moves from the bottom of the minigap (for the superlattice terminated by two bilayers of GaAs) to its top (for the superlattice terminated by two bilayers of AlAs) where it becomes a resonance. No surface state/resonance is found for a termination with one bilayer of AlAs. The surface state bands behave similarly in the corresponding gaps of the k-resolved section of the electron band structure. The molecular beam epitaxy, which enables to terminate the superlattice growth with atomic layer precision, provides a way of tuning the superlattice surface electron structure by purely geometrical means. The work was supported by the Grant Agency of the Academy of Sciences

  3. New serial time codes for seismic short period and long period data acquisition systems

    International Nuclear Information System (INIS)

    Kolvankar, V.G.; Rao, D.S.

    1988-01-01

    This paper discusses a new time code for time indexing multichannel short period (1 to 25 hz) seismic event data recorded on a single track of magnetic tape in digital format and discusses its usefulness in contrast to Vela time code used in continuous analog multichannel data recording system on multitrack instrumentation tape deck. This paper also discusses another time code, used for time indexing of seismic long period (DC to 2.5 seconds) multichannel data recorded on a single track of magnetic tape in digital format. The time code decoding and display system developed to provide quick access to any desired portion of the tape in both data recording and repro duce system is also discussed. (author). 7 figs

  4. Ocular discomfort responses after short periods of contact lens wear.

    Science.gov (United States)

    Papas, Eric; Tilia, Daniel; McNally, John; de la Jara, Percy Lazon

    2015-06-01

    To investigate if contact lens-related discomfort is a function of the time of day at which lenses are worn. This was a randomized, crossover, open-label clinical trial where subjective responses, with and without contact lenses, were assessed every 2 hours during five stages (A to E). Each stage began at the time when subjects would normally have inserted their contact lenses (T0). During stage A, no lenses were worn, whereas in stage B, lenses were worn continuously for 12 hours. In stages C to E, lenses were worn for only 4 hours. Contact lenses were inserted at T0 for stage C, but for stages D and E, lenses were not inserted until T0 + 4 and T0 + 8 hours, respectively. Mixed linear models were used for statistical analysis. In the absence of contact lenses, ocular comfort and dryness remained reasonably constant throughout the observation period. Ocular comfort and dryness decreased during 12 hours of continuous lens wear and became significantly worse from the 8-hour time onward compared with insertion (p 0.05) to the first 4 hours of continuous contact lens wear. Comparing the scores of each of these stages with the no-lens response at the corresponding time showed no significant differences for comfort (p > 0.23) or dryness (p > 0.37). Short periods of wear can be experienced at any time of day without significant change in ocular discomfort and dryness. This suggests that subjective responses at the end of the day are determined by the length of time lenses are in contact with the eye, rather than the time of day at which lenses are worn.

  5. Short-term responses of wetland vegetation after liming of an Adirondack watershed

    Energy Technology Data Exchange (ETDEWEB)

    Mackun, I.R.; Leopold, D.J.; Raynal, D.J. (State Univ. of New York, Syracuse, NY (United States))

    1994-08-01

    Watershed liming has been suggested as a long-term mitigation strategy for lake acidity, particularly in areas subject to high levels of acidic deposition. However, virtually no information has been available on the impacts of liming on wetland vegetation. In 1989, 1100 Mg of limestone (83.5% CaCO[sub 3]) were aerially applied to 48% (100 ha) of the Woods Lake watershed in the west-central Adirondack region of New York as part of the first comprehensive watershed liming study in North America. We inventoried wetland vegetation in 1.0-m[sup 2] plots before liming and during the subsequent 2 yr. Within this period liming influenced the cover, frequency, or importance values of only 6 of 64 wetland taxa. The cover of Sphagnum spp. and of the cespitose sedge Carex interior decreased in control relative to limed plots, and cover of the rhizomatous sedge Cladium mariscoides increased nearly threefold in limed areas. These two sedges, which are relatively tall, are characteristic of more calcareous habitats. Cover of the grass Muhlenbergia uniflora, cover and importance were adversely affected or inhibited by lime. It is unclear whether liming directly inhibited the growth of these three small-statured species, or whether the adverse effects of lime were mediated through shifts in competitive interactions with other species. The limited responses that we observed to liming, along with changes that occurred in control plots over the study period, may indicate that in the short term watershed liming was no more of a perturbation than the environmental factors responsible for natural annual variation in wetland communities.

  6. Short-Period Binary Stars: Observations, Analyses, and Results

    CERN Document Server

    Milone, Eugene F; Hobill, David W

    2008-01-01

    Short-period binaries run the gamut from widely separated stars to black-hole pairs; in between are systems that include neutron stars and white dwarfs, and partially evolved systems such as tidally distorted and over-contact systems. These objects represent stages of evolution of binary stars, and their degrees of separation provide critical clues to how their evolutionary paths differ from that of single stars. The widest and least distorted systems provide astronomers with the essential precise data needed to study all stars: mass and radius. The interactions of binary star components, on the other hand, provide a natural laboratory to observe how the matter in these stars behaves under different and often varying physical conditions. Thus, cataclysmic variables with and without overpoweringly strong magnetic fields, and stars with densities from that found in the Sun to the degenerate matter of white dwarfs and the ultra-compact states of neutron stars and black holes are all discussed. The extensive inde...

  7. The first orbital parameters and period variation of the short-period eclipsing binary AQ Boo

    Science.gov (United States)

    Wang, Shuai; Zhang, Liyun; Pi, Qingfeng; Han, Xianming L.; Zhang, Xiliang; Lu, Hongpeng; Wang, Daimei; Li, TongAn

    2016-10-01

    We obtained the first VRI CCD light curves of the short-period contact eclipsing binary AQ Boo, which was observed on March 22 and April 19 in 2014 at Xinglong station of National Astronomical Observatories, and on January 20, 21 and February 28 in 2015 at Kunming station of Yunnan Observatories of Chinese Academy of Sciences, China. Using our six newly obtained minima and the minima that other authors obtained previously, we revised the ephemeris of AQ Boo. By fitting the O-C (observed minus calculated) values of the minima, the orbital period of AQ Boo shows a decreasing tendency P˙ = - 1.47(0.17) ×10-7 days/year. We interpret the phenomenon by mass transfer from the secondary (more massive) component to the primary (less massive) one. By using the updated Wilson & Devinney program, we also derived the photometric orbital parameters of AQ Boo for the first time. We conclude that AQ Boo is a near contact binary with a low contact factor of 14.43%, and will become an over-contact system as the mass transfer continues.

  8. Precessional Periods of Long and Short Foucault Pendulums

    Science.gov (United States)

    Soga, Michitoshi

    1978-01-01

    Derives the precessional period of a Foucault pendulum without using small oscillation amplitudes. Shows that if the path of the pendulum passes through the origin, the periods for differing amplitudes are essentially the same. (GA)

  9. Structure, root systems and periodicity of savanna plants and vegetations in Northern Surinam

    NARCIS (Netherlands)

    Donselaar-ten Bokkel Huinink, van W.A.E.

    1966-01-01

    From July 1958 to May 1959 an investigation was carried out of the relation between physiognomic characteristics of the vegetation and the habitat on some savannas in the vicinity of Zanderij, Surinam. Root systems, structure, periodicity and characteristics of the leaves were considered, both of

  10. Short periodic oscillations of the dwarf nova VW Hydri

    International Nuclear Information System (INIS)

    Haefner, R.; Schoembs, R.

    1977-01-01

    A coherent oscillation of approximately 88 s period and 0.m005 amplitude was detected during the decline stage at the end of the long eruption of VW Hyi in December 1975. The period changed erratically between 86 and 90 s during eight nights. There are indications that the amplitude depends on the phase of the orbital revolution. The new period favours models in which such oscillations are caused by the orbital motion of inhomogeneities in the disc. (orig.) [de

  11. Remote sensing analysis of vegetation recovery following short-interval fires in Southern California shrublands.

    Science.gov (United States)

    Meng, Ran; Dennison, Philip E; D'Antonio, Carla M; Moritz, Max A

    2014-01-01

    Increased fire frequency has been shown to promote alien plant invasions in the western United States, resulting in persistent vegetation type change. Short interval fires are widely considered to be detrimental to reestablishment of shrub species in southern California chaparral, facilitating the invasion of exotic annuals and producing "type conversion". However, supporting evidence for type conversion has largely been at local, site scales and over short post-fire time scales. Type conversion has not been shown to be persistent or widespread in chaparral, and past range improvement studies present evidence that chaparral type conversion may be difficult and a relatively rare phenomenon across the landscape. With the aid of remote sensing data covering coastal southern California and a historical wildfire dataset, the effects of short interval fires (<8 years) on chaparral recovery were evaluated by comparing areas that burned twice to adjacent areas burned only once. Twelve pairs of once- and twice-burned areas were compared using normalized burn ratio (NBR) distributions. Correlations between measures of recovery and explanatory factors (fire history, climate and elevation) were analyzed by linear regression. Reduced vegetation cover was found in some lower elevation areas that were burned twice in short interval fires, where non-sprouting species are more common. However, extensive type conversion of chaparral to grassland was not evident in this study. Most variables, with the exception of elevation, were moderately or poorly correlated with differences in vegetation recovery.

  12. Remote Sensing Analysis of Vegetation Recovery following Short-Interval Fires in Southern California Shrublands

    Science.gov (United States)

    Meng, Ran; Dennison, Philip E.; D’Antonio, Carla M.; Moritz, Max A.

    2014-01-01

    Increased fire frequency has been shown to promote alien plant invasions in the western United States, resulting in persistent vegetation type change. Short interval fires are widely considered to be detrimental to reestablishment of shrub species in southern California chaparral, facilitating the invasion of exotic annuals and producing “type conversion”. However, supporting evidence for type conversion has largely been at local, site scales and over short post-fire time scales. Type conversion has not been shown to be persistent or widespread in chaparral, and past range improvement studies present evidence that chaparral type conversion may be difficult and a relatively rare phenomenon across the landscape. With the aid of remote sensing data covering coastal southern California and a historical wildfire dataset, the effects of short interval fires (fire history, climate and elevation) were analyzed by linear regression. Reduced vegetation cover was found in some lower elevation areas that were burned twice in short interval fires, where non-sprouting species are more common. However, extensive type conversion of chaparral to grassland was not evident in this study. Most variables, with the exception of elevation, were moderately or poorly correlated with differences in vegetation recovery. PMID:25337785

  13. Studying Short-Period Comets and Long-Period Comets Detected by WISE/NEOWISE

    Science.gov (United States)

    Kramer, Emily A.; Fernández, Yanga R.; Bauer, James M.; Stevenson, Rachel; Mainzer, Amy K.; Grav, Tommy; Masiero, Joseph; Walker, Russell G.; Lisse, Carey M.

    2014-11-01

    The Wide-field Infrared Survey Explorer (WISE) mission surveyed the sky in four infrared wavelength bands (3.4, 4.6, 12 and 22-micron) between January 2010 and February 2011 [1, 2]. During the mission, WISE serendipitously observed 160 comets, including 21 newly discovered objects. About 89 of the comets observed by WISE displayed a significant dust tail in the 12 and 22-micron (thermal emission) bands, showing a wide range of activity levels and dust morphology. Since the observed objects are a mix of both long-period comets (LPCs) and short-period comets (SPCs), differences in their activity can be used to better understand the thermal evolution that each of these populations has undergone. For the comets that displayed a significant dust tail, we have estimated the sizes and ages of the particles using dynamical models based on the Finson-Probstein method [3, 4]. For a selection of 40 comets, we have then compared these models to the data using a novel tail-fitting method that allows the best-fit model to be chosen analytically rather than subjectively. For comets that were observed multiple times by WISE, the dust tail particle properties were estimated separately, and then compared. We find that the dust tails of both LPCs and SPCs are primarily comprised of ~mm to cm sized particles, which were the result of emission that occurred several months to several years prior to the observations. The LPCs nearly all have strong dust emission close to the comet's perihelion distance, and the SPCs mostly have strong dust emission close to perihelion, but some have strong dust emission well before perihelion. Acknowledgments: This publication makes use of data products from (1) WISE, which is a joint project of UCLA and JPL/Caltech, funded by NASA; and (2) NEOWISE, which is a project of JPL/Caltech, funded by the Planetary Science Division of NASA. EK was supported by a NASA Earth and Space Sciences Fellowship. RS gratefully acknowledges support from the NASA

  14. Short- and Long-Term Feedbacks on Vegetation Water Use: Unifying Evidence from Observations and Modeling

    Science.gov (United States)

    Mackay, D. S.

    2001-05-01

    Recent efforts to measure and model the interacting influences of climate, soil, and vegetation on soil water and nutrient dynamics have identified numerous important feedbacks that produce nonlinear responses. In particular, plant physiological factors that control rates of transpiration respond to soil water deficits and vapor pressure deficits (VPD) in the short-term, and to climate, nutrient cycling and disturbance in the long-term. The starting point of this presentation is the observation that in many systems, in particular forest ecosystems, conservative water use emerges as a result of short-term closure of stomata in response to high evaporative demand, and long-term vegetative canopy development under nutrient limiting conditions. Evidence for important short-term controls is presented from sap flux measurements of stand transpiration, remote sensing, and modeling of transpiration through a combination of physically-based modeling and Monte Carlo analysis. A common result is a strong association between stomatal conductance (gs) and the negative evaporative gain (∂ gs/∂ VPD) associated with the sensitivity of stomatal closure to rates of water loss. The importance of this association from the standpoint of modeling transpiration depends on the degree of canopy-atmosphere coupling. This suggests possible simplifications to future canopy component models for use in watershed and larger-scale hydrologic models for short-term processes. However, further results are presented from theoretical modeling, which suggest that feedbacks between hydrology and vegetation in current long-term (inter-annual to century) models may be too simple, as they do not capture the spatially variable nature of slow nutrient cycling in response to soil water dynamics and site history. Memory effects in the soil nutrient pools can leave lasting effects on more rapid processes associated with soil, vegetation, atmosphere coupling.

  15. Short-Period RF Undulator for a SASE Nanometer source

    International Nuclear Information System (INIS)

    Hirshfield, Jay L.

    2011-01-01

    Analysis is described towards development of a RF undulator with a period < 1 cm, an undulator parameter K of the order of unity, and a gap greater than 2.25 mm. The application for the undulator is for a SASE source to produce 1 nm wavelength radiation using a low energy electron beam in the range 1-2 GeV. Particle orbit calculations in a conventional standing-wave resonator configuration show that the presence of a co-propagating component of RF field can cause deleterious motion for the undulating electrons that can seriously degrade their radiation spectrum. To obviate this problem, resonator designs were devised in which only the counter-propagating field components interact with the particles. Two resonator configurations with the same undulator parameter K = 0.4 have been devised and are described in this report.

  16. Beamline front end for in-vacuum short period undulator at the photon factory storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Miyauchi, Hiroshi, E-mail: hiroshi.miyauchi@kek.jp [Accelerator Laboratory, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Department of Accelerator Science, School of High Energy Accelerator Science, SOKENDAI (The Graduate University for Advanced Studies), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Tahara, Toshihiro, E-mail: ttahara@post.kek.jp; Asaoka, Seiji, E-mail: seiji.asaoka@kek.jp [Accelerator Laboratory, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2016-07-27

    The straight-section upgrade project of the Photon Factory created four new short straight sections capable of housing in-vacuum short period undulators. The first to fourth short period undulators SGU#17, SGU#03, SGU#01 and SGU#15 were installed at the 2.5-GeV Photon Factory storage ring in 2005, 2006, 2009 and 2013, respectively. The beamline front end for SGU#15 is described in this paper.

  17. Long-period and short-period variations of ionospheric parameters studied from complex observations performed on Cuba

    Energy Technology Data Exchange (ETDEWEB)

    Laso, B; Lobachevskii, L A; Potapova, N I; Freizon, I A; Shapiro, B S

    1980-09-01

    Cuban data from 1978 are used to study long-period (i.e., diurnal) variations of Doppler shift on a 3000 km path at frequencies of 10 and 15 MHz these variations are related to variations of parameters on the ionospheric path. Short-period variations were also studied on the basis of Doppler shift data and vertical sounding data in the 0.000111-0.00113 Hz frequency range. The relation between the observed variations and internal gravity waves are discussed.

  18. The effect of short recovery period investment on least-cost generation system expansion

    International Nuclear Information System (INIS)

    Yiqun He; David, A.K.; Fernando, P.N.

    1995-01-01

    The effect of the short recovery period of private investment on least-cost generation system expansion is analysed, and a trade-off method for generation system expansion, which gives consideration to both the least-cost strategy and the short recovery period of private investment, is presented. First, the optimal mix of generation units under a standard recovery period for all units is established, and then the surcharge, due to the difference between the short recovery period and the standard recovery period, is calculated and shared between all units. The former is an optimization to make best use of natural resources, and the latter is a trade-off method to spread the surcharge throughout the system. (Author)

  19. A survey for very short-period planets in the Kepler data

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Brian; Stark, Christopher C.; Chambers, John [Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Adams, Elisabeth R. [Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719 (United States); Deming, Drake, E-mail: bjackson@dtm.ciw.edu [Department of Astronomy, University of Maryland at College Park, College Park, MD 20742 (United States)

    2013-12-20

    We conducted a search for very short-period transiting objects in the publicly available Kepler data set. Our preliminary survey has revealed four planetary candidates, all with orbital periods less than 12 hr. We have analyzed the data for these candidates using photometric models that include transit light curves, ellipsoidal variations, and secondary eclipses to constrain the candidates' radii, masses, and effective temperatures. Even with masses of only a few Earth masses, the candidates' short periods mean that they may induce stellar radial velocity signals (a few m s{sup –1}) detectable by currently operating facilities. The origins of such short-period planets are unclear, but we discuss the possibility that they may be the remnants of disrupted hot Jupiters. Whatever their origins, if confirmed as planets, these candidates would be among the shortest-period planets ever discovered. Such planets would be particularly amenable to discovery by the planned TESS mission.

  20. A survey for very short-period planets in the Kepler data

    International Nuclear Information System (INIS)

    Jackson, Brian; Stark, Christopher C.; Chambers, John; Adams, Elisabeth R.; Deming, Drake

    2013-01-01

    We conducted a search for very short-period transiting objects in the publicly available Kepler data set. Our preliminary survey has revealed four planetary candidates, all with orbital periods less than 12 hr. We have analyzed the data for these candidates using photometric models that include transit light curves, ellipsoidal variations, and secondary eclipses to constrain the candidates' radii, masses, and effective temperatures. Even with masses of only a few Earth masses, the candidates' short periods mean that they may induce stellar radial velocity signals (a few m s –1 ) detectable by currently operating facilities. The origins of such short-period planets are unclear, but we discuss the possibility that they may be the remnants of disrupted hot Jupiters. Whatever their origins, if confirmed as planets, these candidates would be among the shortest-period planets ever discovered. Such planets would be particularly amenable to discovery by the planned TESS mission.

  1. Staggered and short-period solutions of the saturable discrete nonlinear Schrodinger equation

    DEFF Research Database (Denmark)

    Khare, A.; Rasmussen, K.O.; Samuelsen, Mogens Rugholm

    2009-01-01

    We point out that the nonlinear Schrodinger lattice with a saturable nonlinearity also admits staggered periodic aswell as localized pulse-like solutions. Further, the same model also admits solutions with a short period. We examine the stability of these solutions and find that the staggered as ...

  2. Spectra of short-period pulsars according to the hypothesis of the two types of pulsars

    International Nuclear Information System (INIS)

    Malov, I.F.

    1985-01-01

    The lack of low-frequency turnovers in the spectra of PSR 0531+21 and 1937+21 may be expl ned if the generation of radio emission in these pulsars occurs near the light cylinder. Differences of high frequency cut-offs and spectral inoices for long-period pulsars and short-period ones are discussed

  3. A Search for Exoplanets in Short-Period Binary Star Systems

    Directory of Open Access Journals (Sweden)

    Ronald Kaitchuck

    2012-03-01

    Full Text Available This paper reports the progress of a search for exoplanets with S-type orbits in short-period binary star systems. The selected targets have stellar orbital periods of just a few days. These systems are eclipsing binaries so that exoplanet transits, if planets exist, will be highly likely. We report the results for seven binary star systems.

  4. Short interval overnight laser scanning suggest sub-circadian periodicity of tree turgor

    DEFF Research Database (Denmark)

    Zlinszky, Andras; Barfod, Anders

    2018-01-01

    in amplitude and 2-6hour periodicity. Sub-circadian process dynamics of plants were so far not in focus of research, but here we compare the findings with other published cases of short-term periodicity in leaf turgor, sap flow and especially trunk diameter. Several authors have noted overnight variations...

  5. Short interval overnight laser scanning suggests sub-circadian periodicity of tree turgor

    DEFF Research Database (Denmark)

    Zlinszky, Andras; Barfod, Anders

    2018-01-01

    in amplitude and 2-6hour periodicity. Sub-circadian process dynamics of plants were so far not in focus of research, but here we compare the findings with other published cases of short-term periodicity in leaf turgor, sap flow and especially trunk diameter. Several authors have noted overnight variations...

  6. Coherent Phonon Dynamics in Short-Period InAs/GaSb Superlattices

    OpenAIRE

    Noe, G. T.; Haugan, H. J.; Brown, G. J.; Sanders, G. D.; Stanton, C. J.; Kono, J.

    2011-01-01

    We have performed ultrafast pump-probe spectroscopy studies on a series of InAs/GaSb-based short-period superlattice (SL) samples with periods ranging from 46 \\AA to 71 \\AA. We observe two types of oscillations in the differential reflectivity with fast ($\\sim$ 1- 2 ps) and slow ($\\sim$ 24 ps) periods. The period of the fast oscillations changes with the SL period and can be explained as coherent acoustic phonons generated from carriers photoexcited within the SL. This mode provides an accura...

  7. The dual effect of vegetation green-up date and strong wind on the return period of spring dust storms.

    Science.gov (United States)

    Feng, Jieling; Li, Ning; Zhang, Zhengtao; Chen, Xi

    2017-08-15

    Vegetation phenology changes have been widely applied in the disaster risk assessments of the spring dust storms, and vegetation green-up date shifts have a strong influence on dust storms. However, the effect of earlier vegetation green-up dates due to climate warming on the evaluation of dust storms return periods remains an important, but poorly understood issue. In this study, we evaluate the spring dust storm return period (February to June) in Inner Mongolia, Northern China, using 165 observations of severe spring dust storm events from 16 weather stations, and regional vegetation green-up dates as an integrated factor from NDVI (Normalized Difference Vegetation Index), covering a period from 1982 to 2007, by building the bivariate Copula model. We found that the joint return period showed better fitting results than without considering the integrated factor when the actual dust storm return period is longer than 2years. Also, for extremely severe dust storm events, the gap between simulation result and actual return period can be narrowed up to 0.4888years by using integrated factor. Furthermore, the risk map based on the return period results shows that the Mandula, Zhurihe, Sunitezuoqi, Narenbaolige stations are identified as high risk areas. In this study area, land surface is extensively covered by grasses and shrubs, vegetation green-up date can play a significant role in restraining spring dust storm outbreaks. Therefore, we suggest that Copula method can become a useful tool for joint return period evaluation and risk analysis of severe dust storms. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Assessing onset and length of greening period in six vegetation types in Oaxaca, Mexico, using NDVI-precipitation relationships.

    Science.gov (United States)

    Gómez-Mendoza, L; Galicia, L; Cuevas-Fernández, M L; Magaña, V; Gómez, G; Palacio-Prieto, J L

    2008-07-01

    Variations in the normalized vegetation index (NDVI) for the state of Oaxaca, in southern Mexico, were analyzed in terms of precipitation anomalies for the period 1997-2003. Using 10-day averages in NDVI data, obtained from AVHRR satellite information, the response of six types of vegetation to intra-annual and inter-annual fluctuations in precipitation were examined. The onset and temporal evolution of the greening period were studied in terms of precipitation variations through spectral analysis (coherence and phase). The results indicate that extremely dry periods, such as those observed in 1997 and 2001, resulted in low values of NDVI for much of Oaxaca, while good precipitation periods produced a rapid response (20-30 days of delay) from a stressed to a non-stressed condition in most vegetation types. One of these rapid changes occurred during the transition from dry to wet conditions during the summer of 1998. As in many parts of the tropics and subtropics, the NDVI reflects low frequency variations in precipitation on several spatial scales. Even after long dry periods (2001-2002), the various regional vegetation types are capable of recovering when a good rainy season takes place, indicating that vegetation types such as the evergreen forests in the high parts of Oaxaca respond better to rainfall characteristics (timing, amount) than to temperature changes, as is the case in most mid-latitudes. This finding may be relevant to prepare climate change scenarios for forests, where increases in surface temperature and precipitation anomalies are expected.

  9. Effects of age, gender, and stimulus presentation period on visual short-term memory.

    Science.gov (United States)

    Kunimi, Mitsunobu

    2016-01-01

    This study focused on age-related changes in visual short-term memory using visual stimuli that did not allow verbal encoding. Experiment 1 examined the effects of age and the length of the stimulus presentation period on visual short-term memory function. Experiment 2 examined the effects of age, gender, and the length of the stimulus presentation period on visual short-term memory function. The worst memory performance and the largest performance difference between the age groups were observed in the shortest stimulus presentation period conditions. The performance difference between the age groups became smaller as the stimulus presentation period became longer; however, it did not completely disappear. Although gender did not have a significant effect on d' regardless of the presentation period in the young group, a significant gender-based difference was observed for stimulus presentation periods of 500 ms and 1,000 ms in the older group. This study indicates that the decline in visual short-term memory observed in the older group is due to the interaction of several factors.

  10. Vegetation

    DEFF Research Database (Denmark)

    Epstein, H.E.; Walker, D.A.; Bhatt, U.S.

    2012-01-01

    increased 20-26%. • Increasing shrub growth and range extension throughout the Low Arctic are related to winter and early growing season temperature increases. Growth of other tundra plant types, including graminoids and forbs, is increasing, while growth of mosses and lichens is decreasing. • Increases...... in vegetation (including shrub tundra expansion) and thunderstorm activity, each a result of Arctic warming, have created conditions that favor a more active Arctic fire regime....

  11. Short-period AM CVn systems as optical, X-ray and gravitational-wave sources

    NARCIS (Netherlands)

    Nelemans, G.; Yungelson, L.; Portegies Zwart, S.F.

    2004-01-01

    We model the population of AM CVn systems in the Galaxy and discuss the detectability of these systems with optical, X-ray and gravitational-wave detectors. We concentrate on the short-period (P < 1500 s) systems, some of which are expected to be in a phase of direct-impact accretion. Using a

  12. Evaluation of short-period rainfall estimates from Kalpana-1 satellite

    Indian Academy of Sciences (India)

    The INSAT Multispectral Rainfall Algorithm (IMSRA) technique for rainfall estimation, has recently been developed to meet the shortcomings of the Global Precipitation Index (GPI) technique of rainfall estimation from the data of geostationary satellites; especially for accurate short period rainfall estimates. This study ...

  13. Increasing Fruit and Vegetable Consumption during Elementary School Snack Periods Using Incentives, Prompting and Role Modeling

    Science.gov (United States)

    Bica, Lori A.; Jamelske, Eric M.; Lagorio, Carla H.

    2016-01-01

    Purpose/Objectives: American children's consumption of fruits and vegetables (FVs) does not meet current recommendations. Hence, several federally funded, school-based programs have been initiated over the last several years. One such program is the United States Department of Agriculture Fresh Fruit and Vegetable Program (FFVP), which provides…

  14. PLANET HUNTERS: ASSESSING THE KEPLER INVENTORY OF SHORT-PERIOD PLANETS

    International Nuclear Information System (INIS)

    Schwamb, Megan E.; Lintott, Chris J.; Lynn, Stuart; Smith, Arfon M.; Simpson, Robert J.; Fischer, Debra A.; Giguere, Matthew J.; Brewer, John M.; Parrish, Michael; Schawinski, Kevin

    2012-01-01

    We present the results from a search of data from the first 33.5 days of the Kepler science mission (Quarter 1) for exoplanet transits by the Planet Hunters citizen science project. Planet Hunters enlists members of the general public to visually identify transits in the publicly released Kepler light curves via the World Wide Web. Over 24,000 volunteers reviewed the Kepler Quarter 1 data set. We examine the abundance of ≥2 R ⊕ planets on short-period ( ⊕ Planet Hunters ≥85% efficient at identifying transit signals for planets with periods less than 15 days for the Kepler sample of target stars. Our high efficiency rate for simulated transits along with recovery of the majority of Kepler ≥4 R ⊕ planets suggests that the Kepler inventory of ≥4 R ⊕ short-period planets is nearly complete.

  15. New developments in fruit and vegetables consumption in the period 1999-2004 in Denmark - a quantile regression approach

    DEFF Research Database (Denmark)

    Hansen, Aslak Hedemann

    2008-01-01

    The development in the consumption of fruit and vegetables in the period 1999-2004 in Denmark was investigated using quantile regression and two previously overlooked problems were identified. First, the change in the ten percent quantile samples decreased. This could have been caused by changes ...

  16. Changes in planform geomorphology and vegetation of the Umatilla River during a 50-year period of diminishing peak flow

    Science.gov (United States)

    Hughes, M. L.; McDowell, P. F.

    2017-12-01

    The Umatilla River of northeastern Oregon is a gravel-bedded, mixed pattern, salmonid-bearing channel-floodplain system typical of the Interior Columbia River Basin. Efforts to restore native salmonids in this region since the 1980's coupled with increased scrutiny of flood- and erosion-control activities have prompted a need for better understanding of the biogemorphic implications of flood disturbances. The goals of this study are: (1) to re-examine results of earlier studies of flood impacts on the Umatilla River in light of more recent flow records, and (2) to investigate the degree to which large floods have influenced existing patterns of channel-floodplain geomorphology and vegetation. Mapping of flowing channels, bars, scoured surfaces, and vegetation within the active channel from of aerial photos bracketing flood and inter-flood periods since 1964 indicates complex and spatially variable channel changes. In general, channel scour was the most consistent response to flooding. The direction (gain/loss) and magnitude of changes in bars and vegetation within the active channel, as well as the amount of lateral channel movement and changes in sinuosity, were generally inconsistent across flood events. The removal of vegetation by scour during floods was in many areas compensated by the capture of vegetation from the floodplain by avulsion and activation of secondary channels. To date, the geomorphic impacts of the 1964-65 flood-of-record have not been replicated, despite an overall increase in the frequency of smaller floods. Expansion of riparian vegetation in recent decades has mainly occurred in areas disturbed by scour and bar deposition during the 1964-65 floods. Vegetative succession during this period has caused contraction of the active channel such that it now appears much as it did before the 1964-65 floods. These results underscore the importance of large floods as drivers of biogeormphic processes and patterns over timescales relevant to river

  17. Ultra-short period X-ray mirrors: Production and investigation

    International Nuclear Information System (INIS)

    Bibishkin, M.S.; Chkhalo, N.I.; Fraerman, A.A.; Pestov, A.E.; Prokhorov, K.A.; Salashchenko, N.N.; Vainer, Yu.A.

    2005-01-01

    Technological problems that deal with manufacturing of highly effective ultra-short (d=0.7-3.2 nm) period X-ray multilayer mirrors (MLM) are discussed in the article. In an example of Cr/Sc and W/B 4 C MLM it is experimentally shown, that the problem of periodicity and selectivity for multilayer dispersive X-ray elements has been generally solved by now. However, the problem of short-period MLM reflectivity increase related to existing of transitive borders between layers in structures remains rather urgent. The new technique of tungsten deposition using the RF source in order to decrease roughness in borders is discussed and tested. The results of measurements on wavelengths of 0.154, 0.834 and 1.759 nm are given. The RbAP crystals ordinary used in experiments and short-period W/B 4 C MLM produced are compared. The specular and non-specular characteristics of scattering on the 0.154 nm wavelengths are also measured in order to study transitive borders structures

  18. Functional Trait Changes, Productivity Shifts and Vegetation Stability in Mountain Grasslands during a Short-Term Warming.

    Science.gov (United States)

    Debouk, Haifa; de Bello, Francesco; Sebastià, Maria-Teresa

    2015-01-01

    Plant functional traits underlie vegetation responses to environmental changes such as global warming, and consequently influence ecosystem processes. While most of the existing studies focus on the effect of warming only on species diversity and productivity, we further investigated (i) how the structure of community plant functional traits in temperate grasslands respond to experimental warming, and (ii) whether species and functional diversity contribute to a greater stability of grasslands, in terms of vegetation composition and productivity. Intact vegetation turves were extracted from temperate subalpine grassland (highland) in the Eastern Pyrenees and transplanted into a warm continental, experimental site in Lleida, in Western Catalonia (lowland). The impacts of simulated warming on plant production and diversity, functional trait structure, and vegetation compositional stability were assessed. We observed an increase in biomass and a reduction in species and functional diversity under short-term warming. The functional structure of the grassland communities changed significantly, in terms of functional diversity and community-weighted means (CWM) for several traits. Acquisitive and fast-growing species with higher SLA, early flowering, erect growth habit, and rhizomatous strategy became dominant in the lowland. Productivity was significantly positively related to species, and to a lower extent, functional diversity, but productivity and stability after warming were more dependent on trait composition (CWM) than on diversity. The turves with more acquisitive species before warming changed less in composition after warming. Results suggest that (i) the short-term warming can lead to the dominance of acquisitive fast growing species over conservative species, thus reducing species richness, and (ii) the functional traits structure in grassland communities had a greater influence on the productivity and stability of the community under short-term warming

  19. Functional Trait Changes, Productivity Shifts and Vegetation Stability in Mountain Grasslands during a Short-Term Warming.

    Directory of Open Access Journals (Sweden)

    Haifa Debouk

    Full Text Available Plant functional traits underlie vegetation responses to environmental changes such as global warming, and consequently influence ecosystem processes. While most of the existing studies focus on the effect of warming only on species diversity and productivity, we further investigated (i how the structure of community plant functional traits in temperate grasslands respond to experimental warming, and (ii whether species and functional diversity contribute to a greater stability of grasslands, in terms of vegetation composition and productivity. Intact vegetation turves were extracted from temperate subalpine grassland (highland in the Eastern Pyrenees and transplanted into a warm continental, experimental site in Lleida, in Western Catalonia (lowland. The impacts of simulated warming on plant production and diversity, functional trait structure, and vegetation compositional stability were assessed. We observed an increase in biomass and a reduction in species and functional diversity under short-term warming. The functional structure of the grassland communities changed significantly, in terms of functional diversity and community-weighted means (CWM for several traits. Acquisitive and fast-growing species with higher SLA, early flowering, erect growth habit, and rhizomatous strategy became dominant in the lowland. Productivity was significantly positively related to species, and to a lower extent, functional diversity, but productivity and stability after warming were more dependent on trait composition (CWM than on diversity. The turves with more acquisitive species before warming changed less in composition after warming. Results suggest that (i the short-term warming can lead to the dominance of acquisitive fast growing species over conservative species, thus reducing species richness, and (ii the functional traits structure in grassland communities had a greater influence on the productivity and stability of the community under short

  20. COMPARATIVELY STUDY OF VARIETIES OF VEGETABLE COWPEA OF DIFFERENT BREEDING PERIODS IN PRIMORIYE REGION

    Directory of Open Access Journals (Sweden)

    P. A. Chebukin

    2016-01-01

    Full Text Available Varieties of Vigna unguiculata subsp. sesquipedalis (L. Verdc. draw breeders’ attention due to their valuable properties, form variation, particularly, among long asparagus beans. The climatic condition of South Far-East is favorable for the cultivation of cowpea. Introduction of the species expands the range of cultivated crops in the region. The aim of the study was to comparatively investigate the modern and local old accessions of cowpea in the field condition of Primoriye and also to select accessions studied suitable for cultivation in this region. Field experiments were carried out at Far-Eastern Experimental Station (VIR, Vladivostok in 2012-2015. Forty accessions of different breeding periods of time from VIR plant collection were assessed. Local varieties included into collection in 1920-1930, varieties selected in 1950-1980 and modern varieties developed after 2010 were significantly different by the morphometric characteristics such as length and width of leaf, bean length and weight, seed productivity per plant, period duration – from shoots to bean-filling and from shoots to bean-ripening. The productivity of green beans depended on different morphobiological traits. For varieties bred in 1950-1980, the correlation between seed and green bean productivity and the number of beans was observed. The yield of green beans was connected with bean length and width and the duration of vegetative period in modern varieties. The varieties bred in 1950-1980 were distinguished by their simultaneous maturation and early ripening, along with the balanced number of pods per plant and seed productivity. Modern varieties essentially exceeded the previously bred cultivars in pod length, yield capacity and duration of harvesting period. Local old varieties were distinguished by broad genetic variation, and were very important as a source of valuable traits. As a result of the study the varieties suitable for

  1. Complexity analyses show two distinct types of nonlinear dynamics in short heart period variability recordings

    Science.gov (United States)

    Porta, Alberto; Bari, Vlasta; Marchi, Andrea; De Maria, Beatrice; Cysarz, Dirk; Van Leeuwen, Peter; Takahashi, Anielle C. M.; Catai, Aparecida M.; Gnecchi-Ruscone, Tomaso

    2015-01-01

    Two diverse complexity metrics quantifying time irreversibility and local prediction, in connection with a surrogate data approach, were utilized to detect nonlinear dynamics in short heart period (HP) variability series recorded in fetuses, as a function of the gestational period, and in healthy humans, as a function of the magnitude of the orthostatic challenge. The metrics indicated the presence of two distinct types of nonlinear HP dynamics characterized by diverse ranges of time scales. These findings stress the need to render more specific the analysis of nonlinear components of HP dynamics by accounting for different temporal scales. PMID:25806002

  2. Design of a short-period superconducting undulator at KEK-PF

    Energy Technology Data Exchange (ETDEWEB)

    Ohmi, K.; Ikeda, N.; Ishii, S.

    1998-06-01

    A short-period undulator using a superconducting magnet is proposed. This undulator has been designed to install in the KEK-Photon Factory 2.5-GeV or 6.5-GeV storage ring. The idea of a staggered wiggler, developed in Stanford university, is used in this undulator. The target of the period and K value of the undulator are set to be 1 cm and 1, respectively. We can obtain monochromatic photons with an energy of {approx} 5keV or {approx} 40 keV by using the undulator. (author)

  3. A superconducting short period undulator for a harmonic generation FEL experiment

    International Nuclear Information System (INIS)

    Ingold, G.; Solomon, L.; Ben-Zvi, I.; Krinsky, S.; Li, D.; Lynch, D.; Sheehan, J.; Woodle, M.; Qiu, X.Z.; Yu, L.H.

    1993-01-01

    A three stage superconducting (SC) undulator for a high gain harmonic generation (HGE) FEL experiment in the infrared is under construction at the NSLS in collaboration with Grumman Corporation. A novel undulator technology suitable for short period (6-40mm) undulators will be employed for all three stages, the modulator, the dispersive section and the radiator. The undulator triples the frequency of a 10.4μm CO 2 seed laser. So far a 27 period (one third of the final radiator) prototype radiator has been designed, built and tested

  4. Short-rotation woody-crops program. Quarterly progress report for period ending May 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, J.H.; Ranney, J.W.

    1982-04-01

    Progress of twenty projects in the Short Rotation Woody Crops Program is summarized for the period March 1 through May 31, 1981. Individual quarterly reports included from each of the projects discuss accomplishments within specific project objectives and identify recent papers and publications resulting from the research. The major project activities are species screening and genetic selection, stand establishment and cultural treatment, and harvest, collection, transportation, and storage.

  5. Short-rotation woody-crops program. Quarterly progress report for period ending August 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, J.H.; Ranney, J.W.

    1982-04-01

    Progress of twenty-one projects in the Short Rotation Woody Crops Program is summarized for the period June 1 through August 31, 1981. Individual quarterly reports included from each of the projects discuss accomplishments within specific project objectives and identify recent papers and publications resulting from the research. The major program activities are species screening and genetic selection, stand establishment and cultural treatment, and harvest, collection, transportation, and storage.

  6. Magnetoresistance calculations for a two-dimensional electron gas with unilateral short-period strong modulation

    Czech Academy of Sciences Publication Activity Database

    Výborný, Karel; Smrčka, Ludvík

    2002-01-01

    Roč. 66, č. 20 (2002), s. 205318-1 - 205318-8 ISSN 0163-1829 R&D Projects: GA ČR GA202/01/0754 Institutional research plan: CEZ:AV0Z1010914 Keywords : magnetoresistance * short-period superlattices * two-dimensional electron gas Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.327, year: 2002

  7. Hydrostatic pressure and strain effects in short period InN/GaN superlattices

    DEFF Research Database (Denmark)

    Gorczyca, I.; Suski, T.; Christensen, Niels Egede

    2012-01-01

    The electronic structures of short-period pseudomorphically grown superlattices (SLs) of the form mInN/nGaN are calculated and the band gap variation with the well and the barrier thicknesses is discussed including hydrostatic pressure effects. The calculated band gap shows a strong dependence...... strongly on the strain conditions and SL geometry, but weakly on the applied external hydrostatic pressure....

  8. Observation of short period fluctuation of CygX-1 with balloon

    International Nuclear Information System (INIS)

    Nakagawa, Michio; Sakurai, Takahisa; Uchida, Masayoshi

    1977-01-01

    CygX-1 presents very complex short period fluctuation of X-ray, therefore the hard X-ray was especially observed in 1972 and 1973 with large balloons, and the data were analyzed. This short period fluctuation and energy spectra of CygX-1 in the normal and flare time bands were compared. The observing apparatuses consisted of the 3 in diameter NaI detector and a high pressure proportional counter. The observing method is to turn the gondora alternately to the directions of source (ON) and background (OFF). As for the data analysis, the events at ON and OFF in the observation data in 1972 and 1973 were plotted for time interval. The background component is in agreement with Poisson's distribution, but source component is not. This difference for Poisson's distribution means the behavior of CygX-1. The power spectrum was analyzed, and the strong power density was observed at 5.4 x 10 -2 Hz in ON, but such power density was not observed in OFF. Accordingly this is presumed to be caused by CygX-1. The events for time interval in flare time are shown. The rise of about 2.9 σ exists at 80 msec. The count rates were compared for photon energy in the normal and flare times. The short period fluctuation of hard X-ray from CygX-1 deviates from Poisson's distribution and is different in the normal and flare times. (Nakai, Y.)

  9. Effect of lifestyle on asthma control in Japanese patients: importance of periodical exercise and raw vegetable diet.

    Science.gov (United States)

    Iikura, Motoyasu; Yi, Siyan; Ichimura, Yasunori; Hori, Ai; Izumi, Shinyu; Sugiyama, Haruhito; Kudo, Koichiro; Mizoue, Tetsuya; Kobayashi, Nobuyuki

    2013-01-01

    The avoidance of inhaled allergens or tobacco smoke has been known to have favorable effects on asthma control. However, it remains unclear whether other lifestyle-related factors are also related to asthma control. Therefore, a comprehensive study to examine the associations between various lifestyle factors and asthma control was conducted in Japanese asthmatic patients. The study subjects included 437 stable asthmatic patients recruited from our outpatient clinic over a one-year period. A written, informed consent was obtained from each participant. Asthma control was assessed using the asthma control test (ACT), and a structured questionnaire was administered to obtain information regarding lifestyle factors, including tobacco smoking, alcohol drinking, physical exercise, and diet. Both bivariate and multivariate analyses were conducted. The proportions of total control (ACT = 25), well controlled (ACT = 20-24), and poorly controlled (ACT smoking status and alcohol drinking were not associated with asthma control. On the other hand, younger age (smoking, periodical exercise (> 3 metabolic equivalents-h/week), and raw vegetable intake (> 5 units/week) were significantly associated with good asthma control by bivariate analysis. Younger age, periodical exercise, and raw vegetable intake were significantly associated with good asthma control by multiple linear regression analysis. Periodical exercise and raw vegetable intake are associated with good asthma control in Japanese patients.

  10. Characterization of vegetative and grain filling periods of winter wheat by stepwise regression procedure. II. Grain filling period

    Directory of Open Access Journals (Sweden)

    Pržulj Novo

    2011-01-01

    Full Text Available In wheat, rate and duration of dry matter accumulation and remobilization depend on genotype and growing conditions. The objective of this study was to determine the most appropriate polynomial regression of stepwise regression procedure for describing grain filling period in three winter wheat cultivars. The stepwise regression procedure showed that grain filling is a complex biological process and that it is difficult to offer a simple and appropriate polynomial equation that fits the pattern of changes in dry matter accumulation during the grain filling period, i.e., from anthesis to maximum grain weight, in winter wheat. If grain filling is to be represented with a high power polynomial, quartic and quintic equations showed to be most appropriate. In spite of certain disadvantages, a cubic equation of stepwise regression could be used for describing the pattern of winter wheat grain filling.

  11. Anomalous short period geomagnetic variations at two stations in Sri Lanka

    International Nuclear Information System (INIS)

    Kunaratnam, K.

    1986-08-01

    An analysis of the rates of change in the geomagnetic field components in the period range 20-600 sec recorded at Kondavil and Hikkaduwa, two stations in the equatorial electrojet belt near the northern and south western coasts respectively of Sri Lanka, shows anomalous variations. The results confirm induced current concentration in the Palk Strait and deflection of induced currents around the southerncoast of Sri Lanka postulated by earlier workers from observations of SSC and Bay events at Indian stations and from analogue and numerical model studies. At Kondavil, which is situated close to the geomagnetic equator, no appreciable difference in the night-time and day-time values of ΔZ/ΔH and ΔD/ΔH ratios was noticed while at Hikkaduwa, a station situated under the edge of the equatorial electrojet belt, a day-time enhancement of ΔZ/ΔH ratios was found at all periods in the observed range. An enhancement of the H component at Colombo over that at Hikkaduwa was also found at short periods, the enhancement being greater at day-time. The day-time enhancement in the ΔZ/ΔH ratios at Hikkaduwa and in the ratio of the H components at Colombo and Hikkaduwa could be due to the effect of the equatorial electrojet on the short period variations. (author)

  12. Survival of a planet in short-period Neptunian desert under effect of photoevaporation

    Science.gov (United States)

    Ionov, Dmitry E.; Pavlyuchenkov, Yaroslav N.; Shematovich, Valery I.

    2018-06-01

    Despite the identification of a great number of Jupiter-like and Earth-like planets at close-in orbits, the number of `hot Neptunes' - the planets with 0.6-18 times of Neptune mass and orbital periods less than 3 d - turned out to be very small. The corresponding region in the mass-period distribution was assigned as the `short-period Neptunian desert'. The common explanation of this fact is that the gaseous planet with few Neptune masses would not survive in the vicinity of host star due to intensive atmosphere outflow induced by heating from stellar radiation. To check this hypothesis, we performed numerical simulations of atmosphere dynamics for a hot Neptune. We adopt the previously developed self-consistent 1D model of hydrogen-helium atmosphere with suprathermal electrons accounted. The mass-loss rates as a function of orbital distances and stellar ages are presented. We conclude that the desert of short-period Neptunes could not be entirely explained by evaporation of planet atmosphere caused by the radiation from a host star. For the less massive Neptune-like planet, the estimated upper limits of the mass-loss may be consistent with the photoevaporation scenario, while the heavier Neptune-like planets could not lose the significant mass through this mechanism. We also found the significant differences between our numerical results and widely used approximate estimates of the mass-loss.

  13. Multi-band photometric study of the short-period eclipsing binary GR Boo

    Science.gov (United States)

    Wang, Daimei; Zhang, Liyun; Han, Xianming L.; Lu, Hongpeng

    2017-05-01

    We present BVRI light curves with complete phase coverage for the short-period (p = 0.377day) eclipsing binary star GR Boo. We carried out the observations using the SARA 90 cm telescope located at Kitt Peak National Observatory. We obtained six new light curve minimum times. By fitting all of the available O-C minimum times, we obtained an updated ephemeris that shows the orbital period of GR Boo is decreasing at a rate of P˙ = - 2.36 ×10-7 days/year. This decrease in its period can be explained by either mass transfer from the more massive component to the less massive one, or angular momentum exchange due to magnetic activities. We also obtained a set of revised orbital parameters using the Wilson & Devinney program. And finally, we concluded that GR Boo is a contact binary with a dark spot.

  14. Short-period oscillations in photoemission from thin films of Cr(100)

    Science.gov (United States)

    Vyalikh, Denis V.; Zahn, Peter; Richter, Manuel; Dedkov, Yu. S.; Molodtsov, S. L.

    2005-07-01

    Angle-resolved photoemission (PE) study of thin films of Cr grown on Fe(100) reveals thickness-dependent short-period oscillations of the PE intensity close to the Fermi energy at k‖˜0 . The oscillations are assigned to quantum-well states (QWS) caused by the nesting between the Fermi-surface sheets around the Γ and the X points in the Brillouin zone of antiferromagnetic Cr. The experimental data are confirmed by density-functional calculations applying a screened Korringa-Kohn-Rostoker Green’s function method. The period of the experimentally observed QWS oscillations amounts to about 2.6 monolayers and is larger than the fundamental 2-monolayer period of antiferromagnetic coupling in Cr.

  15. African vegetation controlled by tropical sea surface temperatures in the mid-Pleistocene period

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Schefuß, E.; Schouten, S.; Jansen, J.H.F.

    2003-01-01

    The dominant forcing factors for past large-scale changes in vegetation are widely debated. Changes in the distribution of C4 plants adapted to warm, dry conditions and low atmospheric CO2 concentrations have been attributed to marked changes in environmental conditions, but the relative impacts of

  16. THE SHORT ROTATION PERIOD OF HI’IAKA, HAUMEA’S LARGEST SATELLITE

    Energy Technology Data Exchange (ETDEWEB)

    Hastings, Danielle M.; Margot, Jean-Luc [University of California, Los Angeles, Department of Earth, Planetary, and Space Sciences, 595 Charles Young Drive East, Los Angeles, CA 90095 (United States); Ragozzine, Darin [Florida Institute of Technology, Department of Physics and Space Sciences, 150 West University Boulevard, Melbourne, FL 32901 (United States); Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Burkhart, Luke D.; Holman, Matthew [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fuentes, Cesar [Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Santiago (Chile); Brown, Michael E., E-mail: dhastings@g.ucla.edu [California Institute of Technology, Division of Geological and Planetary Sciences, MC 150-21, Pasadena, CA 91125 (United States)

    2016-12-01

    Hi’iaka is the larger outer satellite of the dwarf planet Haumea. Using relative photometry from the Hubble Space Telescope and Magellan and a phase dispersion minimization analysis, we have identified the rotation period of Hi’iaka to be ∼9.8 hr (double peaked). This is ∼120 times faster than its orbital period, creating new questions about the formation of this system and possible tidal evolution. The rapid rotation suggests that Hi’iaka could have a significant obliquity and spin precession that could be visible in light curves within a few years. We then turn to an investigation of what we learn about the (currently unclear) formation of the Haumea system and family based on this unexpectedly rapid rotation rate. We explore the importance of the initial semimajor axis and rotation period in tidal evolution theory and find that they strongly influence the time required to despin to synchronous rotation, relevant to understanding a wide variety of satellite and binary systems. We find that despinning tides do not necessarily lead to synchronous spin periods for Hi’iaka, even if it formed near the Roche limit. Therefore, the short rotation period of Hi’iaka does not rule out significant tidal evolution. Hi’iaka’s spin period is also consistent with formation near its current location and spin-up due to Haumea-centric impactors.

  17. Effect of lifestyle on asthma control in Japanese patients: importance of periodical exercise and raw vegetable diet.

    Directory of Open Access Journals (Sweden)

    Motoyasu Iikura

    Full Text Available BACKGROUND: The avoidance of inhaled allergens or tobacco smoke has been known to have favorable effects on asthma control. However, it remains unclear whether other lifestyle-related factors are also related to asthma control. Therefore, a comprehensive study to examine the associations between various lifestyle factors and asthma control was conducted in Japanese asthmatic patients. METHODS: The study subjects included 437 stable asthmatic patients recruited from our outpatient clinic over a one-year period. A written, informed consent was obtained from each participant. Asthma control was assessed using the asthma control test (ACT, and a structured questionnaire was administered to obtain information regarding lifestyle factors, including tobacco smoking, alcohol drinking, physical exercise, and diet. Both bivariate and multivariate analyses were conducted. RESULTS: The proportions of total control (ACT = 25, well controlled (ACT = 20-24, and poorly controlled (ACT 3 metabolic equivalents-h/week, and raw vegetable intake (> 5 units/week were significantly associated with good asthma control by bivariate analysis. Younger age, periodical exercise, and raw vegetable intake were significantly associated with good asthma control by multiple linear regression analysis. CONCLUSIONS: Periodical exercise and raw vegetable intake are associated with good asthma control in Japanese patients.

  18. QUASI-PERIODIC OSCILLATIONS AND BROADBAND VARIABILITY IN SHORT MAGNETAR BURSTS

    Energy Technology Data Exchange (ETDEWEB)

    Huppenkothen, Daniela; Watts, Anna L.; Uttley, Phil; Van der Horst, Alexander J.; Van der Klis, Michiel [Astronomical Institute ' ' Anton Pannekoek' ' , University of Amsterdam, Postbus 94249, 1090-GE Amsterdam (Netherlands); Kouveliotou, Chryssa [Office of Science and Technology, ZP12, NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Goegues, Ersin [Sabanc Latin-Small-Letter-Dotless-I University, Orhanl Latin-Small-Letter-Dotless-I -Tuzla, Istanbul 34956 (Turkey); Granot, Jonathan [The Open University of Israel, 1 University Road, P.O. Box 808, Ra' anana 43537 (Israel); Vaughan, Simon [X-Ray and Observational Astronomy Group, University of Leicester, Leicester LE1 7RH (United Kingdom); Finger, Mark H., E-mail: D.Huppenkothen@uva.nl [Universities Space Research Association, Huntsville, AL 35805 (United States)

    2013-05-01

    The discovery of quasi-periodic oscillations (QPOs) in magnetar giant flares has opened up prospects for neutron star asteroseismology. However, with only three giant flares ever recorded, and only two with data of sufficient quality to search for QPOs, such analysis is seriously data limited. We set out a procedure for doing QPO searches in the far more numerous, short, less energetic magnetar bursts. The short, transient nature of these bursts requires the implementation of sophisticated statistical techniques to make reliable inferences. Using Bayesian statistics, we model the periodogram as a combination of red noise at low frequencies and white noise at high frequencies, which we show is a conservative approach to the problem. We use empirical models to make inferences about the potential signature of periodic and QPOs at these frequencies. We compare our method with previously used techniques and find that although it is on the whole more conservative, it is also more reliable in ruling out false positives. We illustrate our Bayesian method by applying it to a sample of 27 bursts from the magnetar SGR J0501+4516 observed by the Fermi Gamma-ray Burst Monitor, and we find no evidence for the presence of QPOs in any of the bursts in the unbinned spectra, but do find a candidate detection in the binned spectra of one burst. However, whether this signal is due to a genuine quasi-periodic process, or can be attributed to unmodeled effects in the noise is at this point a matter of interpretation.

  19. Absence of a Metallicity Effect for Ultra-short-period Planets

    International Nuclear Information System (INIS)

    Winn, Joshua N.; Sanchis-Ojeda, Roberto; Isaacson, Howard; Marcy, Geoffrey W.; Rogers, Leslie; Petigura, Erik A.; Howard, Andrew W.; Schlaufman, Kevin C.; Cargile, Phillip; Hebb, Leslie

    2017-01-01

    Ultra-short-period (USP) planets are a newly recognized class of planets with periods shorter than one day and radii smaller than about 2  R ⊕ . It has been proposed that USP planets are the solid cores of hot Jupiters that have lost their gaseous envelopes due to photo-evaporation or Roche lobe overflow. We test this hypothesis by asking whether USP planets are associated with metal-rich stars, as has long been observed for hot Jupiters. We find the metallicity distributions of USP-planet and hot-Jupiter hosts to be significantly different ( p = 3 × 10 −4 ) based on Keck spectroscopy of Kepler stars. Evidently, the sample of USP planets is not dominated by the evaporated cores of hot Jupiters. The metallicity distribution of stars with USP planets is indistinguishable from that of stars with short-period planets with sizes between 2 and 4  R ⊕ . Thus, it remains possible that the USP planets are the solid cores of formerly gaseous planets that are smaller than Neptune.

  20. Absence of a Metallicity Effect for Ultra-short-period Planets

    Energy Technology Data Exchange (ETDEWEB)

    Winn, Joshua N. [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08540 (United States); Sanchis-Ojeda, Roberto; Isaacson, Howard; Marcy, Geoffrey W. [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Rogers, Leslie [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Petigura, Erik A.; Howard, Andrew W. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Schlaufman, Kevin C. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Cargile, Phillip [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Hebb, Leslie [Hobart and William Smith Colleges, Geneva, NY 14456 (United States)

    2017-08-01

    Ultra-short-period (USP) planets are a newly recognized class of planets with periods shorter than one day and radii smaller than about 2  R {sub ⊕}. It has been proposed that USP planets are the solid cores of hot Jupiters that have lost their gaseous envelopes due to photo-evaporation or Roche lobe overflow. We test this hypothesis by asking whether USP planets are associated with metal-rich stars, as has long been observed for hot Jupiters. We find the metallicity distributions of USP-planet and hot-Jupiter hosts to be significantly different ( p = 3 × 10{sup −4}) based on Keck spectroscopy of Kepler stars. Evidently, the sample of USP planets is not dominated by the evaporated cores of hot Jupiters. The metallicity distribution of stars with USP planets is indistinguishable from that of stars with short-period planets with sizes between 2 and 4  R {sub ⊕}. Thus, it remains possible that the USP planets are the solid cores of formerly gaseous planets that are smaller than Neptune.

  1. Epitaxial nanowire formation in metamorphic GaAs/GaPAs short-period superlattices

    Science.gov (United States)

    Zheng, Nan; Ahrenkiel, S. Phillip

    2017-07-01

    Metamorphic growth presents routes to novel nanomaterials with unique properties that may be suitable for a range of applications. We discuss self-assembled, epitaxial nanowires formed during metalorganic chemical vapor deposition of metamorphic GaAs/GaPAs short-period superlattices. The heterostructures incorporate strain-engineered GaPAs compositional grades on 6°-B miscut GaAs substrates. Lateral diffusion within the SPS into vertically aligned, three-dimensional columns results in nanowires extending along A directions with a lateral period of 70-90 nm. The microstructure is probed by transmission electron microscopy to confirm the presence of coherent GaAs nanowires within GaPAs barriers. The compositional profile is inferred from analysis of {200} dark-field image contrast and lattice images.

  2. Role of short periodic orbits in quantum maps with continuous openings

    Science.gov (United States)

    Prado, Carlos A.; Carlo, Gabriel G.; Benito, R. M.; Borondo, F.

    2018-04-01

    We apply a recently developed semiclassical theory of short periodic orbits to the continuously open quantum tribaker map. In this paradigmatic system the trajectories are partially bounced back according to continuous reflectivity functions. This is relevant in many situations that include optical microresonators and more complicated boundary conditions. In a perturbative regime, the shortest periodic orbits belonging to the classical repeller of the open map—a cantor set given by a region of exactly zero reflectivity—prove to be extremely robust in supporting a set of long-lived resonances of the continuously open quantum maps. Moreover, for steplike functions a significant reduction in the number needed is obtained, similarly to the completely open situation. This happens despite a strong change in the spectral properties when compared to the discontinuous reflectivity case. In order to give a more realistic interpretation of these results we compare with a Fresnel-type reflectivity function.

  3. Cooperative learning combined with short periods of lecturing: A good alternative in teaching biochemistry.

    Science.gov (United States)

    Fernández-Santander, Ana

    2008-01-01

    The informal activities of cooperative learning and short periods of lecturing has been combined and used in the university teaching of biochemistry as part of the first year course of Optics and Optometry in the academic years 2004-2005 and 2005-2006. The lessons were previously elaborated by the teacher and included all that is necessary to understand the topic (text, figures, graphics, diagrams, pictures, etc.). Additionally, a questionnaire was prepared for every chapter. All lessons contained three parts: objectives, approach and development, and the assessment of the topic. Team work, responsibility, and communication skills were some of the abilities developed with this new methodology. Students worked collaboratively in small groups of two or three following the teacher's instructions with short periods of lecturing that clarified misunderstood concepts. Homework was minimized. On comparing this combined methodology with the traditional one (only lecture), students were found to exhibit a higher satisfaction with the new method. They were more involved in the learning process and had a better attitude toward the subject. The use of this new methodology showed a significant increase in the mean score of the students' academic results. The rate of students who failed the subject was significantly inferior in comparison with those who failed in the previous years when only lecturing was applied. This combined methodology helped the teacher to observe the apprenticeship process of students better and to act as a facilitator in the process of building students' knowledge. Copyright © 2008 International Union of Biochemistry and Molecular Biology, Inc.

  4. Determination of circulation and short period fluctuation in Ilha Grande Bay (RJ, Brazil

    Directory of Open Access Journals (Sweden)

    Yoshimine Ikeda

    1980-06-01

    Full Text Available A mesosoale study was made of the Ilha Grande area. The local circulation described through -progressive vector diagrams showed a clochwise bottom circulation determined in June 1976, while in the upper 10 m the direction of the flow entering the Ilha Grande Bay was towards the center in the west and towards the Marambaia sandbank in the east side of the Bay. Short periods and amplitude fluctuations were evaluted using power spectral analysis, Fourier and Maximum Entropy Method, which showed that in the upper 10 m predominant periods decrease from 1.1h (A = 6.3cm sec-1 (position = 3C to 1.0h (A = 7.4 cm sec-1 (position = 2D and increase to 5.8h (A = 6.8 cm., sec-1 (position = ID, while at the bottom layer the predominant period increases from 0.4 h (A = 5.0 cm sec-1 (position = 3G to 6.4h (A = 7.0 cm sec-1 (position = 2G and to 4.4h (A = 7.9 cm sec-1 (position = 1G . From the original data it has been possible to determine an "intense pulsation" between 30-70 cm sec-1 in the upper 10 m with about 1.0h period and 10-20 min duration in all the stations.

  5. [The variability of vegetation beginning date of greenness period in spring in the north-south transect of eastern China based on NOAA NDVI].

    Science.gov (United States)

    Wang, Zhi; Liu, Shi-rong; Sun, Peng-sen; Guo, Zhi-hua; Zhou, Lian-di

    2010-10-01

    NDVI based on NOAA/AVHRR from 1982 to 2003 are used to monitor variable rules for the growing season in spring of vegetation in the north-south transect of eastern China (NSTEC). The following, mainly, are included: (1) The changing speed of greenness period in spring of most regions in NSTEC is slow and correlation with the year is not distinct; (2) The regions in which greenness period in spring distinctly change mainly presented an advance; (3) The regions in which inter-annual fluctuation of greenness period in spring is over 10 days were found in 3 kinds of areas: the area covered with agricultural vegetation types; the areas covered with evergreen vegetation types; the areas covered with steppe vegetation types; (4) changes of vegetation greenness period in spring have spatio-temporal patterns.

  6. The effects of UV radiation during the vegetative period on antioxidant compounds and postharvest quality of broccoli (Brassica oleracea L.).

    Science.gov (United States)

    Topcu, Yasin; Dogan, Adem; Kasimoglu, Zehra; Sahin-Nadeem, Hilal; Polat, Ersin; Erkan, Mustafa

    2015-08-01

    In this study, the effects of supplementary UV radiation during the vegetative period on antioxidant compounds, antioxidant activity and postharvest quality of broccoli heads during long term storage was studied. The broccolis were grown under three different doses of supplementary UV radiation (2.2, 8.8 and 16.4 kJ/m(2)/day) in a soilless system in a glasshouse. Harvested broccoli heads were stored at 0 °C in modified atmosphere packaging for 60 days. The supplementary UV radiation (280-315 nm) during the vegetative period significantly decreased total carotenoid, the chlorophyll a and chlorophyll b content but increased the ascorbic acid, total phenolic and flavonoid contents of broccolis. All supplementary UV treatments slightly reduced the antioxidant activity of the broccolis, however, no remarkable change was observed between 2.2 and 8.8 kJ/m(2) radiation levels. The sinigrin and glucotropaeolin contents of the broccolis were substantially increased by UV treatments. The prolonged storage period resulted in decreased ascorbic acid, total phenolic and flavonoid contents, as well as antioxidant activity. Discoloration of the heads, due to decreased chlorophyll and carotenoid contents, was also observed with prolonged storage duration. Glucosinolates levels showed an increasing tendency till the 45th day of storage, and then their levels started to decline. The weight loss of broccoli heads during storage progressively increased with storage time in all treatments. Total soluble solids, solids content and titratable acidity decreased continuously during storage. Titratable acidity was not affected by UV radiation doses during the storage time whereas soluble solids and solids content (dry matter) were significantly affected by UV doses. Supplementary UV radiation increased the lightness (L*) and chroma (C*) values of the broccoli heads. Pre-harvest UV radiation during vegetative period seems to be a promising tool for increasing the beneficial health components

  7. Vegetation and flora of short-rotation willow stands from a conservation viewpoint

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, L.

    1986-01-01

    The energy forests were studied using random 0.5 x 0.5 m quadrats in which cover for field- and bottom-layer species was recorded in a percentage scale. The data were analysed using various multivariate methods. The vegetation and flora of twelve coppices in southern Sweden were investigated. Also the succession during the establishment phase on a meadow on the west coast and on a peat bog in the east-central part of the country was studied. Moreover, the impact on fen vegetation downstream of an energy forest on a peat bog was investigated. The flora and vegetation of energy forests is dominated by common ruderal species like Cirsium arvense, Galeopsis tetrahit and Urtica dioica. Uncommon species from woodland and fen habitats are only occasionally found. The field layer of energy forests shows a clear seasonality with maximal cover in July. The species number and the composition of vegetation vary greatly between the coppices and is largely determined by the management system. Intense cultivation including fertilization and the use of herbicides depletes the flora. Long rotation times decrease both species diversity and the field-layer cover. Uncommon species are mostly found in old coppices, which also often have a rich spring flora. A change in flora and vegetation occurs when an energy forest is established. The change is great and the time needed for stabilization of the energy forest flora is long when the original flora is dissimilar to the coppice flora. Willow coppices can increase habitat diversity in regions dominated by coniferous forests or in large-scale agricultural areas. Structural heterogeneity of a stand promotes diversity of the flora. Such heterogeneity can be created if a stand is composed of a variety of willow clones, if it is harvested at intervals, contains gaps, open ditches and is surrounded by edge zones of various types.

  8. Short-term fluctuations in vegetation and phytoplankton during the Middle Eocene greenhouse climate: a 640-kyr record from the Messel oil shale (Germany)

    Science.gov (United States)

    Lenz, Olaf K.; Wilde, Volker; Riegel, Walter

    2011-11-01

    The Palaeogene was the most recent greenhouse period on Earth. Especially for the Late Palaeocene and Early Eocene, several superimposed short-term hyperthermal events have been described, including extremes such as the Palaeocene-Eocene Thermal Maximum. Major faunal and floral turnovers in the marine and terrestrial realms were recorded in association with these events. High-resolution palynological analysis of the early Middle Eocene maar lake sediments at Messel, near Darmstadt, Germany, provides an insight into the dynamics of a climax vegetation during the Middle Eocene greenhouse climate in a time span without significant climatic excursions. Numerical techniques like detrended correspondence analysis and wavelet analysis have been applied to recognize cyclic fluctuations and long-term trends in the vegetation through a time interval of approximately 640 kyr. Based on the numerical zoning of the pollen diagram, three phases in the development of the vegetation may be distinguished. Throughout these phases, the climax vegetation did not change substantially in qualitative composition, but a trend towards noticeably less humid conditions probably in combination with a drop of the water level in the lake may be recognized. A shift in algal population from the freshwater dinoflagellate cyst Messelodinium thielepfeifferae to a dominance of Botryococcus in the uppermost part of the core is interpreted as a response to changes in acidity and nutrient availability within the lake. Time series analyses of pollen assemblages show that variations in the Milankovitch range of eccentricity, obliquity and precession can be distinguished. In addition, fluctuations in the sub-Milankovitch range are indicated. This demonstrates that floral changes during steady depositional conditions in the Middle Eocene of Messel were controlled by orbital forcing.

  9. THE FREQUENCY OF LOW-MASS EXOPLANETS. III. TOWARD η+ AT SHORT PERIODS

    International Nuclear Information System (INIS)

    Wittenmyer, Robert A.; Tinney, C. G.; Bailey, J.; Horner, J.; Butler, R. P.; O'Toole, Simon J.; Jones, H. R. A.; Carter, B. D.

    2011-01-01

    Determining the occurrence rate of 'super-Earth' planets (m sin i + ) is a critically important step on the path toward determining the frequency of Earth-like planets (η + ), and hence the uniqueness of our solar system. Current radial-velocity surveys, achieving precisions of 1 m s -1 , are now able to detect super-Earths and provide meaningful estimates of their occurrence rate. We present an analysis of 67 solar-type stars from the Anglo-Australian Planet Search specifically targeted for very high precision observations. When corrected for incompleteness, we find that the planet occurrence rate increases sharply with decreasing planetary mass. Our results are consistent with those from other surveys: in periods shorter than 50 days, we find that 3.0% of stars host a giant (msin i > 100 M + ) planet, and that 17.4% of stars host a planet with msin i + . The preponderance of low-mass planets in short-period orbits is in conflict with formation simulations in which the majority of super-Earths reside at larger orbital distances. This work gives a hint as to the size of η + , but to make meaningful predictions on the frequency of terrestrial planets in longer, potentially habitable orbits, low-mass terrestrial planet searches at periods of 100-200 days must be made an urgent priority for ground-based Doppler planet searches in the years ahead.

  10. SOHO/SWAN OBSERVATIONS OF SHORT-PERIOD SPACECRAFT TARGET COMETS

    International Nuclear Information System (INIS)

    Combi, M. R.; Lee, Y.; Patel, T. S.; Maekinen, J. T. T.; Bertaux, J.-L.; Quemerais, E.

    2011-01-01

    SWAN, the Solar Wind ANisotropies all-sky hydrogen Lyα camera on the Solar and Heliospheric Observatory spacecraft that makes all-sky images of interplanetary neutral hydrogen, has an ongoing campaign to make special observations of comets, both short- and long-period ones, in addition to the serendipitous observations of comets as part of the all-sky monitoring program. We report here on a study of several short-period comets that were detected by SWAN: 21P/Giacobini-Zinner (1998 and 2005 apparitions), 19P/Borrelly (2001 apparition), 81P/Wild 2 (1997 apparition), and 103P/Hartley 2 (1997 apparition). SWAN observes comets over long continuous stretches of their visible apparitions and therefore provides excellent temporal coverage of the water production. For some of the observations we are also able to analyze an entire sequence of images over many days to several weeks/months using our time-resolved model and extract daily average water production rates over continuous periods of several days to months. The short-term (outburst) and long-term behavior can be correlated with other observations. The overall long-term variation is examined in light of seasonal effects seen in the pre- to post-perihelion differences. For 21P/Giacobini-Zinner and 81P/Wild 2 the activity variations over each apparition were more continuously monitored but nonetheless consistent with previous observations. For 19P/Borrelly we found a very steep variation of water production rates, again consistent with some previous observations, and a variation over six months around perihelion that was reasonably consistent with the spin-axis model of Schleicher et al. and the illumination of the main active areas. During the 1997-1998 apparition of 103P/Hartley 2, the target comet of the EPOXI mission (the Deep Impact extended mission), we found a variation with heliocentric distance (∼r -3.6 ) that was almost as steep as 19P/Borrelly and, given the small measured radius near aphelion, this places

  11. Vegetation cover, tidal amplitude and land area predict short-term marsh vulnerability in Coastal Louisiana

    Science.gov (United States)

    Schoolmaster, Donald; Stagg, Camille L.; Sharp, Leigh Anne; McGinnis, Tommy S.; Wood, Bernard; Piazza, Sarai

    2018-01-01

    The loss of coastal marshes is a topic of great concern, because these habitats provide tangible ecosystem services and are at risk from sea-level rise and human activities. In recent years, significant effort has gone into understanding and modeling the relationships between the biological and physical factors that contribute to marsh stability. Simulation-based process models suggest that marsh stability is the product of a complex feedback between sediment supply, flooding regime and vegetation response, resulting in elevation gains sufficient to match the combination of relative sea-level rise and losses from erosion. However, there have been few direct, empirical tests of these models, because long-term datasets that have captured sufficient numbers of marsh loss events in the context of a rigorous monitoring program are rare. We use a multi-year data set collected by the Coastwide Reference Monitoring System (CRMS) that includes transitions of monitored vegetation plots to open water to build and test a predictive model of near-term marsh vulnerability. We found that despite the conclusions of previous process models, elevation change had no ability to predict the transition of vegetated marsh to open water. However, we found that the processes that drive elevation change were significant predictors of transitions. Specifically, vegetation cover in prior year, land area in the surrounding 1 km2 (an estimate of marsh fragmentation), and the interaction of tidal amplitude and position in tidal frame were all significant factors predicting marsh loss. This suggests that 1) elevation change is likely better a predictor of marsh loss at time scales longer than we consider in this study and 2) the significant predictive factors affect marsh vulnerability through pathways other than elevation change, such as resistance to erosion. In addition, we found that, while sensitivity of marsh vulnerability to the predictive factors varied spatially across coastal Louisiana

  12. LAND SURFACE TEMPERATURES ESTIMATED ON GROUNDOBSERVED DATA AND SATELLITE IMAGES, DURING THE VEGETATION PERIOD IN THE OLTENIA PLAIN

    Directory of Open Access Journals (Sweden)

    ONŢEL IRINA

    2015-03-01

    Full Text Available The purpose of this study is to analyze the land surface temperatures by using climatological and remote sensing data during the vegetation period in the Oltenia Plain. The data used in this study refer both to climatological data (namely monthly and seasonal air and soil temperatures, and to remote sensing data delivered by MODIS Land Surface Temperature (LST, with a spatial resolution of 1 km. The analyzed period spans from 2000 to 2013 and the vegetation period considered is April-September. As main results, there were observed four years with high temperatures, namely 2000 (20.4oC-air T, 24.6oC soil T, and 26oC LST, 2003 (20.2oC air T, 23.9oC soil T and 24.5oC LST, 2007 (20.5oC air T, 24.3oC soil T and 25oC LST and 2012 (21.3oC air T, 25.7oC soil T and 26.5oC LST. The correlations between air temperature, soil temperature and LST were statisticaly significant. The diference between air temperature and soil temperature values ranked within 3-4oC, while the difference between soil temperature and land surface temperature obtained from MODIS images was about 0.8oC. Spatially, the highest temperatures were recorded on the Leu-Rotunda Field, the Caracal Plain and the Nedeia Field, and pretty high variations of observed temperatures seemed to depend on vegetation cover. The MODIS images represent one of the most important types of satellite data available for free, which can be successfully used in determining the climatic parameters and can help to predict the changes in plant activity, due to weather phenomena.

  13. Feed intake and activity level of two broiler genotypes foraging different types of vegetation in the finishing period

    DEFF Research Database (Denmark)

    de Almeida, Gustavo Fonseca; Hinrichsen, Lena Karina; Horsted, Klaus

    2012-01-01

    A study was performed with 2 broiler genotypes (slow and medium growth) restricted in supplementary feed and foraging 2 different mixed vegetations (grass/clover or chicory) to identify possible benefits of herbage on nutrition during the finishing period (80 to 113 d of age). Three hundred birds...... were included in a 2 × 2 factorial design with groups of 25 birds replicated 3 times. The use of outdoor areas, performance, and forage intake were investigated. To identify possible differences in foraging activity, the use of the range was monitored one day per week at 4 different times of the day...

  14. Regeneration after fire in campo rupestre : Short- and long-term vegetation dynamics

    OpenAIRE

    Le Stradic , Soizig; Hernandez , Pauline; Fernandes , Geraldo Wilson; Buisson , Elise

    2018-01-01

    International audience; The Cerrado (Brazilian savanna) is the second largest biome in Brazil, covering 22% of the country, and campo rupestre is one of the most biodiverse ecosystem. Campo rupestre are extremely old mountaintop tropical ecosystems, composed of a mosaic of herbaceous, shrubland and savanna vegetation, generally located above 900 m above sea level characterized by shallow, acidic and nutrient-poor soils. In the context of increased land-use changes, effective conservation and ...

  15. Ultra-short-period WC/SiC multilayer coatings for x-ray applications

    International Nuclear Information System (INIS)

    Fernández-Perea, Mónica; Pivovaroff, Mike J.; Soufli, Regina; Alameda, Jennifer; Mirkarimi, Paul; Descalle, Marie-Anne; Baker, Sherry L.; McCarville, Tom; Ziock, Klaus; Hornback, Donald; Romaine, Suzanne; Bruni, Ric; Zhong, Zhong; Honkimäki, Veijo; Ziegler, Eric; Christensen, Finn E.; Jakobsen, Anders C.

    2013-01-01

    Multilayer coatings enhance x-ray mirror performance at incidence angles steeper than the critical angle, allowing for improved flux, design flexibility and facilitating alignment. In an attempt to extend the use of multilayer coatings to photon energies higher than previously achieved, we have developed multilayers with ultra-short periods between 1 and 2 nm based on the material system WC/SiC. This material system was selected because it possesses very sharp and stable interfaces. In this article, we show highlights from a series of experiments performed in order to characterize the stress, microstructure and morphology of the multilayer films, as well as their reflective performance at photon energies from 8 to 384 keV

  16. The Colorado Ultraviolet Transit Experiment (CUTE): Observing Mass Loss on Short-Period Exoplanets

    Science.gov (United States)

    Egan, Arika; Fleming, Brian; France, Kevin

    2018-06-01

    The Colorado Ultraviolet Transit Experiment (CUTE) is an NUV spectrograph packaged into a 6U CubeSat, designed to characterize the interaction between exoplanetary atmospheres and their host stars. CUTE will conduct a transit spectroscopy survey, gathering data over multiple transits on more than 12 short-period exoplanets with a range of masses and radii. The instrument will characterize the spectral properties of the transit light curves to atomic and molecular absorption features predicted to exist in the upper atmospheres of these planets, including Mg I, Mg II, Fe II, and OH. The shape and evolution of these spectral light curves will be used to quantify mass loss rates, the stellar drives of that mass loss, and the possible existence of exoplanetary magnetic fiends. This poster presents the science motivation for CUTE, planned observation and data analysis methods, and expected results.

  17. Short-term vegetation change on rehabilitated peatland on Rietvlei Nature Reserve

    Directory of Open Access Journals (Sweden)

    C.E. Venter

    2003-12-01

    Full Text Available Natural peatlands occur on the Rietvlei Nature Reserve. Before the Pretoria City Council acquired the land, these peatlands were mined by private land-owners. Ditches were constructed to drain the area for mining and the peatlands became desicrated. Later the area was proclaimed as a nature reserve and has since then been managed as such. Rehabilitation of the drained peatland on Rietvlei Nature Reserve first started in 2000 as a Working for Water project. The aim of the rehabilitation was to close the ditches and rewet the peatland, to enable possible revival of the peatland. A baseline vegetation survey was undertaken during the summer (March to April of 2001 to determine the nature of the pioneer communities that established on the rehabilitated area. This survey was repeated during the summer (March to April of 2002 to detect changes in the vegetation. The same sample plots were used on both occasions. The initial pioneer vegetation was mostly composed of weedy annuals.

  18. THE VERY SHORT PERIOD M DWARF BINARY SDSS J001641-000925

    Energy Technology Data Exchange (ETDEWEB)

    Davenport, James R. A.; Becker, Andrew C.; Hawley, Suzanne L.; Gunning, Heather C.; Munshi, Ferah A.; Albright, Meagan [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); West, Andrew A. [Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Bochanski, John J. [Astronomy and Astrophysics Department, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Holtzman, Jon [Department of Astronomy, New Mexico State University, Box 30001, Las Cruces, NM 88003 (United States); Hilton, Eric J., E-mail: jrad@astro.washington.edu [Department of Geology and Geophysics and Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

    2013-02-10

    We present follow-up observations and analysis of the recently discovered short period low-mass eclipsing binary, SDSS J001641-000925. With an orbital period of 0.19856 days, this system has one of the shortest known periods for an M dwarf binary system. Medium-resolution spectroscopy and multi-band photometry for the system are presented. Markov Chain Monte Carlo modeling of the light curves and radial velocities yields estimated masses for the stars of M {sub 1} = 0.54 {+-} 0.07 M {sub Sun} and M {sub 2} = 0.34 {+-} 0.04 M {sub Sun }, and radii of R {sub 1} = 0.68 {+-} 0.03 R {sub Sun} and R {sub 2} = 0.58 {+-} 0.03 R {sub Sun }, respectively. This solution places both components above the critical Roche overfill limit, providing strong evidence that SDSS J001641-000925 is the first verified M-dwarf contact binary system. Within the follow-up spectroscopy we find signatures of non-solid body rotation velocities, which we interpret as evidence for mass transfer or loss within the system. In addition, our photometry samples the system over nine years, and we find strong evidence for period decay at the rate of P-dot {approx} 8 s yr{sup -1}. Both of these signatures raise the intriguing possibility that the system is in over-contact, and actively losing angular momentum, likely through mass loss. This places SDSS J001641-000925 as not just the first M-dwarf over-contact binary, but one of the few systems of any spectral type known to be actively undergoing coalescence. Further study of SDSS J001641-000925 is ongoing to verify the nature of the system, which may prove to be a unique astrophysical laboratory.

  19. Short-term Periodization Models: Effects on Strength and Speed-strength Performance.

    Science.gov (United States)

    Hartmann, Hagen; Wirth, Klaus; Keiner, Michael; Mickel, Christoph; Sander, Andre; Szilvas, Elena

    2015-10-01

    Dividing training objectives into consecutive phases to gain morphological adaptations (hypertrophy phase) and neural adaptations (strength and power phases) is called strength-power periodization (SPP). These phases differ in program variables (volume, intensity, and exercise choice or type) and use stepwise intensity progression and concomitant decreasing volume, converging to peak intensity (peaking phase). Undulating periodization strategies rotate these program variables in a bi-weekly, weekly, or daily fashion. The following review addresses the effects of different short-term periodization models on strength and speed-strength both with subjects of different performance levels and with competitive athletes from different sports who use a particular periodization model during off-season, pre-season, and in-season conditioning. In most periodization studies, it is obvious that the strength endurance sessions are characterized by repetition zones (12-15 repetitions) that induce muscle hypertrophy in persons with a low performance level. Strictly speaking, when examining subjects with a low training level, many periodization studies include mainly hypertrophy sessions interspersed with heavy strength/power sessions. Studies have demonstrated equal or statistically significant higher gains in maximal strength for daily undulating periodization compared with SPP in subjects with a low to moderate performance level. The relatively short intervention period and the lack of concomitant sports conditioning call into question the practical value of these findings for competitive athletes. Possibly owing to differences in mesocycle length, conditioning programs, and program variables, competitive athletes either maintained or improved strength and/or speed-strength performance by integrating daily undulating periodization and SPP during off-season, pre-season and in-season conditioning. In high-performance sports, high-repetition strength training (>15) should be

  20. A Comparison of Three Gap Filling Techniques for Eddy Covariance Net Carbon Fluxes in Short Vegetation Ecosystems

    Directory of Open Access Journals (Sweden)

    Xiaosong Zhao

    2015-01-01

    Full Text Available Missing data is an inevitable problem when measuring CO2, water, and energy fluxes between biosphere and atmosphere by eddy covariance systems. To find the optimum gap-filling method for short vegetations, we review three-methods mean diurnal variation (MDV, look-up tables (LUT, and nonlinear regression (NLR for estimating missing values of net ecosystem CO2 exchange (NEE in eddy covariance time series and evaluate their performance for different artificial gap scenarios based on benchmark datasets from marsh and cropland sites in China. The cumulative errors for three methods have no consistent bias trends, which ranged between −30 and +30 mgCO2 m−2 from May to October at three sites. To reduce sum bias in maximum, combined gap-filling methods were selected for short vegetation. The NLR or LUT method was selected after plant rapidly increasing in spring and before the end of plant growing, and MDV method was used to the other stage. The sum relative error (SRE of optimum method ranged between −2 and +4% for four-gap level at three sites, except for 55% gaps at soybean site, which also obviously reduced standard deviation of error.

  1. Born dry in the photoevaporation desert: Kepler's ultra-short-period planets formed water-poor

    Science.gov (United States)

    Lopez, Eric D.

    2017-11-01

    Recent surveys have uncovered an exciting new population of ultra-short-period (USP) planets with orbital periods less than a day. These planets typically have radii ≲1.5 R⊕, indicating that they likely have rocky compositions. This stands in contrast to the overall distribution of planets out to ∼100 d, which is dominated by low-density sub-Neptunes above 2 R⊕, which must have gaseous envelopes to explain their size. However, on the USP orbits, planets are bombarded by intense levels of photoionizing radiation and consequently gaseous sub-Neptunes are extremely vulnerable to losing their envelopes to atmospheric photoevaporation. Using models of planet evolution, I show that the rocky USP planets can easily be produced as the evaporated remnants of sub-Neptunes with H/He envelopes and that we can therefore understand the observed dearth of USP sub-Neptunes as a natural consequence of photoevaporation. Critically however, planets on USP orbits could often retain their envelopes if they are formed with very high-metallicity water-dominated envelopes. Such water-rich planets would commonly be ≳2 R⊕ today, which is inconsistent with the observed evaporation desert, indicating that most USP planets likely formed from water-poor material within the snow-line. Finally, I examine the special case of 55 Cancri e and its possible composition in the light of recent observations, and discuss the prospects for further characterizing this population with future observations.

  2. Raman analysis of phonon modes in a short period AlN/GaN superlattice

    Science.gov (United States)

    Sarkar, Ketaki; Datta, Debopam; Gosztola, David J.; Shi, Fengyuan; Nicholls, Alan; Stroscio, Michael A.; Dutta, Mitra

    2018-03-01

    AlN/GaN-based optoelectronic devices have been the subject of intense research underlying the commercialization of efficient devices. Areas of considerable interest are the study of their lattice dynamics, phonon transport, and electron-phonon interactions specific to the interface of these heterostructures which results in additional optical phonon modes known as interface phonon modes. In this study, the framework of the dielectric continuum model (DCM) has been used to compare and analyze the optical phonon modes obtained from experimental Raman scattering measurements on AlN/GaN short-period superlattices. We have observed the localized E2(high), A1(LO) and the E1(TO) modes in superlattice measurements at frequencies shifted from their bulk values. To the best of our knowledge, the nanostructures used in these studies are among the smallest yielding useful Raman signatures for the interface modes. In addition, we have also identified an additional spread of interface phonon modes in the TO range resulting from the superlattice periodicity. The Raman signature contribution from the underlying AlxGa1-xN ternary has also been observed and analyzed. A temperature calibration was done based on Stokes/anti-Stokes ratio of A1(LO) using Raman spectroscopy in a broad operating temperature range. Good agreement between the experimental results and theoretically calculated calibration plot predicted using Bose-Einstein statistics was obtained.

  3. Effects of various uranium leaching procedures on soil: Short-term vegetation growth and physiology. Progress report, April 1994

    International Nuclear Information System (INIS)

    Edwards, N.T.

    1994-08-01

    Significant volumes of soil containing elevated levels of uranium exist in the eastern United States. The contamination resulted from the development of the nuclear industry in the United States requiring a large variety of uranium products. The contaminated soil poses a collection and disposal problem of a magnitude that justifies the development of decontamination methods. Consequently, the Department of Energy (DOE) Office of Technology Development formed the Uranium Soils Integrated Demonstration (USID) program to address the problem. The fundamental goal of the USID task group has been the selective extraction/leaching or removal of uranium from soil faster, cheaper, and safer than what can be done using current conventional technologies. The objective is to selectively remove uranium from soil without seriously degrading the soil's physicochemical characteristics and without generating waste that is difficult to manage and/or dispose of. However, procedures developed for removing uranium from contaminated soil have involved harsh chemical treatments that affect the physicochemical properties of the soil. The questions are (1) are the changes in soil properties severe enough to destroy the soil's capacity to support and sustain vegetation growth and survival? and (2) what amendments might be made to the leached soil to return it to a reasonable vegetation production capacity? This study examines the vegetation-support capacity of soil that had been chemically leached to remove uranium. The approach is to conduct short-term germination and phytotoxicity tests for evaluating soils after they are subjected to various leaching procedures followed by longer term pot studies on successfully leached soils that show the greatest capacity to support plant growth. This report details the results from germination and short-term phytotoxicity testing of soils that underwent a variety of leaching procedures at the bench scale at ORNL and at the pilot plant at Fernald

  4. Use of 7Be to document soil erosion associated with a short period of extreme rainfall

    International Nuclear Information System (INIS)

    Sepulveda, A.; Schuller, P.; Walling, D.E.; Castillo, A.

    2008-01-01

    Intensification and expansion of agricultural production since the 1970s have increased soil erosion problems in south-central Chile. Quantitative information on soil loss is needed for erosion risk assessment and to establish the effectiveness of improved land management practices. Since information from traditional sources, such as erosion plots, is limited, attention has been directed to the use of environmental radionuclides for documenting erosion rates. Cs-137 has been successfully utilised for this purpose, but only provides information on medium-term erosion rates. There is also a need to document event-related soil erosion. This paper outlines the basis for using 7 Be measurements to document short-term erosion and reports its successful use for quantifying the erosion that occurred within an arable field, as a result of a period of heavy rainfall (400 mm in 27 days) occurring in May 2005. The study field had been under a no-till, no-burning system for 18 years, but immediately prior to the period of heavy rainfall the harvest residues were burnt. The erosion recorded therefore reflected both the extreme nature of the rainfall and the effects of the burning in increasing surface runoff and erosion. The sampled area corresponded to that used previously by the authors to document the medium-term erosion rates associated with both conventional tillage and the subsequent switch to a no-till system. Comparisons between the erosion documented for the period of heavy rainfall in 2005 with these medium-term erosion rates permits some tentative conclusions regarding the importance of extreme events and the impact of burning in increasing the erosion associated with the no-till system

  5. Towards a Fundamental Understanding of Short Period Eclipsing Binary Systems Using Kepler Data

    Science.gov (United States)

    Prsa, Andrej

    Kepler's ultra-high precision photometry is revolutionizing stellar astrophysics. We are seeing intrinsic phenomena on an unprecedented scale, and interpreting them is both a challenge and an exciting privilege. Eclipsing binary stars are of particular significance for stellar astrophysics because precise modeling leads to fundamental parameters of the orbiting components: masses, radii, temperatures and luminosities to better than 1-2%. On top of that, eclipsing binaries are ideal physical laboratories for studying other physical phenomena, such as asteroseismic properties, chromospheric activity, proximity effects, mass transfer in close binaries, etc. Because of the eclipses, the basic geometry is well constrained, but a follow-up spectroscopy is required to get the dynamical masses and the absolute scale of the system. A conjunction of Kepler photometry and ground- based spectroscopy is a treasure trove for eclipsing binary star astrophysics. This proposal focuses on a carefully selected set of 100 short period eclipsing binary stars. The fundamental goal of the project is to study the intrinsic astrophysical effects typical of short period binaries in great detail, utilizing Kepler photometry and follow-up spectroscopy to devise a robust and consistent set of modeling results. The complementing spectroscopy is being secured from 3 approved and fully funded programs: the NOAO 4-m echelle spectroscopy at Kitt Peak (30 nights; PI Prsa), the 10- m Hobby-Eberly Telescope high-resolution spectroscopy (PI Mahadevan), and the 2.5-m Sloan Digital Sky Survey III spectroscopy (PI Mahadevan). The targets are prioritized by the projected scientific yield. Short period detached binaries host low-mass (K- and M- type) components for which the mass-radius relationship is sparsely populated and still poorly understood, as the radii appear up to 20% larger than predicted by the population models. We demonstrate the spectroscopic detection viability in the secondary

  6. The Very Short Period M Dwarf Binary SDSS J001641-000925

    Science.gov (United States)

    Davenport, James R. A.; Becker, Andrew C.; West, Andrew A.; Bochanski, John J.; Hawley, Suzanne L.; Holtzman, Jon; Gunning, Heather C.; Hilton, Eric J.; Munshi, Ferah A.; Albright, Meagan

    2013-02-01

    We present follow-up observations and analysis of the recently discovered short period low-mass eclipsing binary, SDSS J001641-000925. With an orbital period of 0.19856 days, this system has one of the shortest known periods for an M dwarf binary system. Medium-resolution spectroscopy and multi-band photometry for the system are presented. Markov Chain Monte Carlo modeling of the light curves and radial velocities yields estimated masses for the stars of M 1 = 0.54 ± 0.07 M ⊙ and M 2 = 0.34 ± 0.04 M ⊙, and radii of R 1 = 0.68 ± 0.03 R ⊙ and R 2 = 0.58 ± 0.03 R ⊙, respectively. This solution places both components above the critical Roche overfill limit, providing strong evidence that SDSS J001641-000925 is the first verified M-dwarf contact binary system. Within the follow-up spectroscopy we find signatures of non-solid body rotation velocities, which we interpret as evidence for mass transfer or loss within the system. In addition, our photometry samples the system over nine years, and we find strong evidence for period decay at the rate of \\dot{P}\\sim 8 s yr-1. Both of these signatures raise the intriguing possibility that the system is in over-contact, and actively losing angular momentum, likely through mass loss. This places SDSS J001641-000925 as not just the first M-dwarf over-contact binary, but one of the few systems of any spectral type known to be actively undergoing coalescence. Further study of SDSS J001641-000925 is ongoing to verify the nature of the system, which may prove to be a unique astrophysical laboratory. Based on observations obtained with the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research Consortium. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. Support for the design and construction of the Magellan Echellette Spectrograph was received from the Observatories of the Carnegie Institution of Washington, the

  7. Estimating return periods of extreme values from relatively short time series of winds

    Science.gov (United States)

    Jonasson, Kristjan; Agustsson, Halfdan; Rognvaldsson, Olafur; Arfeuille, Gilles

    2013-04-01

    An important factor for determining the prospect of individual wind farm sites is the frequency of extreme winds at hub height. Here, extreme winds are defined as the value of the highest 10 minutes averaged wind speed with a 50 year return period, i.e. annual exceeding probability of 2% (Rodrigo, 2010). A frequently applied method to estimate winds in the lowest few hundred meters above ground is to extrapolate observed 10-meter winds logarithmically to higher altitudes. Recent study by Drechsel et al. (2012) showed however that this methodology is not as accurate as interpolating simulated results from the global ECMWF numerical weather prediction (NWP) model to the desired height. Observations of persistent low level jets near Colima in SW-Mexico also show that the logarithmic approach can give highly inaccurate results for some regions (Arfeuille et al., 2012). To address these shortcomings of limited, and/or poorly representative, observations and extrapolations of winds one can use NWP models to dynamically scale down relatively coarse resolution atmospheric analysis. In the case of limited computing resources one has typically to make a compromise between spatial resolution and the duration of the simulated period, both of which can limit the quality of the wind farm siting. A common method to estimate maximum winds is to fit an extreme value distribution (e.g. Gumbel, gev or Pareto) to the maximum values of each year of available data, or the tail of these values. If data are only available for a short period, e.g. 10 or 15 years, then this will give a rather inaccurate estimate. It is possible to deal with this problem by utilizing monthly or weekly maxima, but this introduces new problems: seasonal variation, autocorrelation of neighboring values, and increased discrepancy between data and fitted distribution. We introduce a new method to estimate return periods of extreme values of winds at hub height from relatively short time series of winds, simulated

  8. Textured dysprosium and gadolinium poles for high-field, short-period hybrid undulators

    International Nuclear Information System (INIS)

    Murokh, Alex; Solovyov, Vyacheslav; Agustsson, Ron; O'Shea, Finn H.; Chubar, Oleg; Chen, Yung; Grandsaert, Thomas

    2014-01-01

    We discuss the feasibility of enhancement of the gap field in a short-period hybrid undulator by using pole inserts with the saturation inductance B s , over that of iron, 2 T. Dysprosium metal, with the saturation inductance of 3.4 T below 90 K, and Gadolinium with B s =2.7 T, appear as good candidates as the optimized pole material. However, due to the high magnetic anisotropy of Dy, such a high level of magnetization can only be realized when the external field lies in the basal plane. This implies that the pole has to be single-crystalline or highly textured. Considering that growing large, >10mm, Dy single crystals is difficult, we propose secondary recrystallization as a method to induce the required texture in thin Dy and Gd foils. The textured foils can be stacked to produce pole inserts of the desired geometry and orientation. Results of small-scale processing and magnetic measurements of thin (20–60 μ) foils provide evidence that the required texture quality can be achieved by a relatively simple sequence of heat-treatments and cold rolling. The advantage of textured Dy and Gd poles is demonstrated in a several period test undulator. -- Highlights: • Textured rare-earth materials for use as undulator pole materials. • We measure the development of texture in Dy and Gd. • We compare the rare-earth materials with high saturation steel in undulators. • Thin sheets of Dy and Gd materials perform similar to single crystals

  9. Fire incidence on vegetation in Cundinamarca and Bogota D.C. (Colombia) during the 2001 - 2010 period

    International Nuclear Information System (INIS)

    Amaya Villabona, Diego; Armenteras Pascual, Dolores

    2012-01-01

    This work aims to use remote sensing as a method for determining fire dynamics in the department of Cundinamarca and the city of Bogota D.C. in Colombia, by analyzing the temporal and spatial distribution of fires and the different types of vegetation affected in the 2001 - 2010 period. Based on modis fire hotspots, we found that the pattern fires in the study area are within the national standard, which includes increased number of events during the dry seasons (January - March and July-September). The fire incidence is caused by low rainfall that complements the root causes of ignition, which are mainly started by human intervention. The most affected populations are Caparrapi with 159 fires; Bogota with 152 fires and Guaduas with 101 fires. Bogota recorded most of their fires within protected areas in the south, in the area of Sumapaz. Sumapaz national park (84), followed by the district integrated management Cuchilla de San Antonio (21) and protective forest reserve Paramo Grande (9). Among the vegetation affected we can find grasses, shrubs, bushes and mosaics, emphasizing high values of impact on vegetation of paramo and subparamo. The central and northwestern parts, south and southeast parts of the department are those with more outbreaks, and most of them are between 0 to 1,000 masl and 3,000 to 4,000 masl. Finally active fires in the study area follow a pattern associated to the climate and in particular to the dry season but also show an altitudinal pattern. National and regional protected areas are effective against fires.

  10. Rice to vegetables: short- versus long-term impact of land-use change on the indigenous soil microbial community.

    Science.gov (United States)

    Sun, Bo; Dong, Zhi-Xing; Zhang, Xue-Xian; Li, Yun; Cao, Hui; Cui, Zong-Li

    2011-08-01

    OV soil have the lowest score of diversity (H = 3.48). The low level of bacterial diversity in OV soil was supported by sequencing of ten randomly selected 16S rDNA clones from each of the three rDNA libraries. Phylogenetic analysis showed that all the ten OV clones belonged to Proteobacteria with eight in the gamma-subdivision and two in the alpha-subdivision. In contrast, the ten clones from NV and OP soils were classified into four and eight bacterial classes or unclassified groups, respectively. Taken together, our data suggest that land-use change from rice to vegetables resulted in a decrease of bacterial diversity and soil biomass despite an increase in the abundance of culturable microorganisms and, moreover, the decrease of bacterial diversity occurred during long-term rather than short-term vegetable cultivation.

  11. Vegetative filter strips efficiency controlling soil loss and trapping herbicides in two olive orchards at the short-term

    Science.gov (United States)

    de Luna, Elena; Guzmán, Gema; Gómez, José A.

    2014-05-01

    The optimization of water use in a semi-arid climate is based on an optimal use of rainwater adopting management practices that prevent and/or control runoff. This is a key point for increasing the economic and environmental sustainability of agriculture due to the minimization of diffuse pollution associated to runoff and to sediment and chemical transport. One strategy is the establishment of vegetative filters strips that prevent pesticides (Stehle et al. 2011), herbicides (Vianello et al. 2005), fertilizers (Withers et al. 2009) and runoff-sediment (Campo-Bescós et al. 2013) from entering streams or surface water reservoirs. To evaluate the short-term risks associated with the use of herbicides a trial was designed in two olive groves located in Benacazón (Sevilla) and Cabra (Córdoba) both with an average steepness of 11%. Two different management systems were evaluated, bare soil and bare soil with vegetative filter strips. Pre-emergence herbicides were applied and analysed at the beginning of the trial by chromatography GC-MS and after each rainfall event both in soil and sediment. Runoff and soil losses were measured, as well. The results obtained from this study show that soil management practices such as, the use of vegetative filter strips results in a reduction of soil losses and runoff. This it is translated in the improvement of soil quality and a reduction of water pollution caused by the use of herbicides. This information will improve the understanding of insufficiently known aspects and it will help to increase the knowledge for a better implementation of sustainable management practices at a farm scale and at larger temporal scale. References: Campo-Bescós, M. A., Muñoz-Carpena, R., & Kiker, G. (2013) Influencia del suelo en la eficiencia de la implantación de filtros verdes en un distrito de riego por superficie en medio árido. En Estudios de la Zona no Saturada del Suelo, Vol. XI: 183-187. Stehle, S., Elsaesser, D., Gregoire, C., Imfeld

  12. Observation of a Short Period Quasi-periodic Pulsation in Solar X-Ray, Microwave, and EUV Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pankaj; Cho, Kyung-Suk [Korea Astronomy and Space Science Institute (KASI), Daejeon, 305-348 (Korea, Republic of); Nakariakov, Valery M., E-mail: pankaj@kasi.re.kr [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, CV4 7AL (United Kingdom)

    2017-02-10

    This paper presents the multiwavelength analysis of a 13 s quasi-periodic pulsation (QPP) observed in hard X-ray (12–300 keV) and microwave (4.9–34 GHz) emissions during a C-class flare that occurred on 2015 September 21. Atmospheric Image Assembly (AIA) 304 and 171 Å images show an emerging loop/flux tube (L1) moving radially outward, which interacts with the preexisting structures within the active region (AR). The QPP was observed during the expansion of and rising motion of L1. The Nobeyama Radioheliograph microwave images in 17/34 GHz channels reveal a single radio source that was co-spatial with a neighboring loop (L2). In addition, using AIA 304 Å images, we detected intensity oscillations in the legs of L2 with a period of about 26 s. A similar oscillation period was observed in the GOES soft X-ray flux derivative. This oscillation period seems to increase with time. We suggest that the observed QPP is most likely generated by the interaction between L2 and L3 observed in the AIA hot channels (131 and 94 Å). The merging speed of loops L2 and L3 was ∼35 km s{sup −1}. L1 was destroyed possibly by its interaction with preexisting structures in the AR, and produced a cool jet with the speed of ∼106–118 km s{sup −1} associated with a narrow CME (∼770 km s{sup −1}). Another mechanism of the QPP in terms of a sausage oscillation of the loop (L2) is also possible.

  13. A neutral network based technique for short-term forecasting of anomalous load periods

    Energy Technology Data Exchange (ETDEWEB)

    Sforna, M [ENEL, s.p.a, Italian Power Company (Italy); Lamedica, R; Prudenzi, A [Rome Univ. ` La Sapienza` , Rome (Italy); Caciotta, M; Orsolini Cencelli, V [Rome Univ. III, Rome (Italy)

    1995-01-01

    The paper illustrates a part of the research activity conducted by authors in the field of electric Short Term Load Forecasting (STLF) based on Artificial Neural Network (ANN) architectures. Previous experiences with basic ANN architectures have shown that, even though these architecture provide results comparable with those obtained by human operators for most normal days, they evidence some accuracy deficiencies when applied to `anomalous` load conditions occurring during holidays and long weekends. For these periods a specific procedure based upon a combined (unsupervised/supervised) approach has been proposed. The unsupervised stage provides a preventive classification of the historical load data by means of a Kohonen`s Self Organizing Map (SOM). The supervised stage, performing the proper forecasting activity, is obtained by using a multi-layer percept ron with a back propagation learning algorithm similar to the ones above mentioned. The unconventional use of information deriving from the classification stage permits the proposed procedure to obtain a relevant enhancement of the forecast accuracy for anomalous load situations.

  14. Ontogeny of sensorimotor gating and short-term memory processing throughout the adolescent period in rats

    Directory of Open Access Journals (Sweden)

    Anja A. Goepfrich

    2017-06-01

    Full Text Available Adolescence and puberty are highly susceptible developmental periods during which the neuronal organization and maturation of the brain is completed. The endocannabinoid (eCB system, which is well known to modulate cognitive processing, undergoes profound and transient developmental changes during adolescence. With the present study we were aiming to examine the ontogeny of cognitive skills throughout adolescence in male rats and clarify the potential modulatory role of CB1 receptor signalling. Cognitive skills were assessed repeatedly every 10th day in rats throughout adolescence. All animals were tested for object recognition memory and prepulse inhibition of the acoustic startle reflex. Although cognitive performance in short-term memory as well as sensorimotor gating abilities were decreased during puberty compared to adulthood, both tasks were found to show different developmental trajectories throughout adolescence. A low dose of the CB1 receptor antagonist/inverse agonist SR141716 was found to improve recognition memory specifically in pubertal animals while not affecting behavioral performance at other ages tested. The present findings demonstrate that the developmental trajectory of cognitive abilities does not occur linearly for all cognitive processes and is strongly influenced by pubertal maturation. Developmental alterations within the eCB system at puberty onset may be involved in these changes in cognitive processing.

  15. Planet X as the source of the periodic and steady-state flux of short period comets

    International Nuclear Information System (INIS)

    Matese, J.J.; Whitmire, D.P.

    1986-01-01

    The cratering and fossil records suggest that impacts on the earth have been modulated with a period of roughly 30 Myr. In the Planet X model, this modulation is the result of the interaction of Planet X with a primordial disk of planetesimals lying beyond the orbit of Neptune. In this paper, observational and theoretical evidence supporting the existence of Planet X and the planetesimal disk is briefly reviewed, and the constraints on the orbit parameters of Planet X and the disk parameters which must be satisfied to ensure consistency with observational limits are discussed

  16. Short-term vegetation response following mechanical control of saltcedar (Tamarix spp.) on the Virgin River, Nevada, USA

    Science.gov (United States)

    Ostoja, Steven M.; Brooks, Matthew L.; Dudley, Tom; Lee, Steven R.

    2014-01-01

    Tamarisk (a.k.a. saltcedar, Tamarix spp.) is an invasive plant species that occurs throughout western riparian and wetland ecosystems. It is implicated in alterations of ecosystem structure and function and is the subject of many local control projects, including removal using heavy equipment. We evaluated short-term vegetation responses to mechanical Tamarix spp. removal at sites ranging from 2 to 5 yr post-treatment along the Virgin River in Nevada, USA. Treatments resulted in lower density and cover (but not eradication) of Tamarix spp., increased cover of the native shrub Pluchea sericia (arrow weed), decreased density and cover of all woody species combined, increased density of both native annual forbs and the nonnative annual Salsola tragus (prickly Russian-thistle), and lower density of nonnative annual grasses. The treated plots had lower mean woody species richness, but greater herbaceous species richness and diversity. Among herbaceous species, native taxa increased in richness whereas nonnative species increased in both species richness and diversity. Thus, efforts to remove Tamarix,/i> spp. at the Virgin River reduced vegetative cover contributing to fuel loads and probability of fire, and resulted in positive effects for native plant diversity, with mixed effects on other nonnative species. However, absolute abundances of native species

  17. Magneto-transport studies of InAs/GaSb short period superlattices

    International Nuclear Information System (INIS)

    Broadley, Victoria Jane

    2002-01-01

    This thesis studies the transport properties of short period semiconducting InAs/GaSb superlattices in the presence of strong electric and magnetic fields applied parallel to the growth axis. Electrical transport parallel to the growth axis occurs through the superlattice miniband, which have widths varying from three to 30meV. Resonant scattering between confined Landau levels and Stark levels is observed at low temperatures (4.2K). In addition LO-phonon assisted scattering between Landau levels is observed in both type-I GaAs/AIAs and type-ll inAs/GaSb superlattices, which are enhanced in the type-ll system due to the strong interband coupling. K·p band structure calculations show that the interband coupling causes the superlattice miniband energy dispersion to be strongly dependent on the in-plane wavevector and the applied magnetic field. For large applied electric fields, where the miniband is split into discrete Stark levels, strong stark-cyclotron resonance (SCR) features are observed, which occur when the Landau level separation equals to the stark level separation. These resonances are enhanced when compared to SCR in type-I superlattices due to the suppression of miniband conduction in higher lying Landau levels. At low electric fields electrical transport through the superlattice miniband yields characteristic miniband transport features, which are modelled using the Esaki-Tsu miniband transport model. Strong electron - LO-phonon scattering is also observed in InAs/GaSb superlattices, where we report the first observation of miniband transport assisted via the emission of LO-phonons between stark levels in adjacent wells. Below 50K thermally activated behaviour is reported and at high magnetic fields (in the quantum limit) complete localisation of carriers is observed. In this regime LO-phonon delocalised transport in also observed. (author)

  18. Nitrogen fertilization and yield formation of potato during a short growing period

    Directory of Open Access Journals (Sweden)

    L. MUSTONEN

    2008-12-01

    Full Text Available The effects various rates of nitrogen application on accumulation of dry matter and nitrogen in potato (Solanum tuberosum L. were studied during a short growing period of 140–180 days, at MTT Agrifood Research Finland in 2000–2001. The treatments were 0, 60 and 120 kg N ha-1 and the potato cultivars tested were Van Gogh and Nicola. Four successive harvests were made during the course of the experiment to monitor changes in the accumulation of dry matter and nitrogen over the season. Applications of nitrogen substantially increased haulm dry matter accumulation and to an even greater extent their nitrogen contents. The highest dry matter values were generally registered at 120 kg N ha-1. Dry matter and nitrogen content of haulms started to decline during the later part of season and most nitrogen was relocated to tubers. The results suggest that an application of only 60 kg N ha-1 was sufficient to promote rapid canopy development and there were only small reductions in dry matter and nitrogen accumulation until late in the season when the canopy started to senesce as nitrogen supply diminished. Tuber yield, plant dry matter and nitrogen accumulation at maturity were related to crop nitrogen supply. Although application of the high rate, 120 N kg ha-1, resulted in a significant increase in dry matter accumulation, this was not reflected in the profit because the higher nitrogen application reduced dry matter content of tubers by 2.6% in 2000 and by 1.1% in 2001 relative to the use of 60 kg N ha-1. Apparent fertilizer nitrogen recovery values on a whole plant basis ranged from 53 to 75%. The proportion of fertilizer recovered in tubers clearly declined with increase in nitrogen supply.;

  19. The Conceptual Model of Calculating the Return Period of the Costs for Creation of the Enterprise’s Economic Security Service in the Short-Term Period

    Directory of Open Access Journals (Sweden)

    Melikhova Tetiana O.

    2018-03-01

    Full Text Available Determination of the return period of the costs, advanced for the creation of economic security service of enterprise during a year, involves consideration of interaction of the conditional money flow, accumulated for a certain number of months, and the constant costs. The main component of the constant costs are the annual depreciation deductions. The return period is considered as gross, net, valid, and specified. The gross (net, valid, and specified return period is the time, wherein the gross conditional money flow, equal to the advanced costs, will be accumulated. The gross return period, taking account of the effect of time factor, is proposed to be defined as the ratio of annual depreciation deductions increased by the annual compounding coefficient to the conditional average monthly gross money flow, increased by the average monthly inflation index. As for the short-term period, a relationship between the gross, net, valid, and specified return periods of the costs, advanced to the creation of the economic security service, has been identified. The net (valid, specified return period is equal to the gross period adjusted to the coefficient of excess of the gross conditional money flow, accumulated in the gross period, over the net (valid, specified conditional cash flow.

  20. Tidally distorted exoplanets: Density corrections for short-period hot-Jupiters based solely on observable parameters

    Energy Technology Data Exchange (ETDEWEB)

    Burton, J. R.; Watson, C. A.; Fitzsimmons, A.; Moulds, V. [Astrophysics Research Centre, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Pollacco, D.; Wheatley, P. J. [Department of Physics and Astronomy, University of Warwick, Coventry CV4 7AL (United Kingdom); Littlefair, S. P., E-mail: jburton04@qub.ac.uk [Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH (United Kingdom)

    2014-07-10

    The close proximity of short-period hot-Jupiters to their parent star means they are subject to extreme tidal forces. This has a profound effect on their structure and, as a result, density measurements that assume that the planet is spherical can be incorrect. We have simulated the tidally distorted surface for 34 known short-period hot-Jupiters, assuming surfaces of constant gravitational equipotential for the planet, and the resulting densities have been calculated based only on observed parameters of the exoplanet systems. Comparing these results to the density values, assuming the planets are spherical, shows that there is an appreciable change in the measured density for planets with very short periods (typically less than two days). For one of the shortest-period systems, WASP-19b, we determine a decrease in bulk density of 12% from the spherical case and, for the majority of systems in this study, this value is in the range of 1%-5%. On the other hand, we also find cases where the distortion is negligible (relative to the measurement errors on the planetary parameters) even in the cases of some very short period systems, depending on the mass ratio and planetary radius. For high-density gas planets requiring apparently anomalously large core masses, density corrections due to tidal deformation could become important for the shortest-period systems.

  1. Short term fluctuations and succession trends in tropical floodplain vegetation measured by correspondence analysis

    Directory of Open Access Journals (Sweden)

    Anderson Medeiros dos Santos

    2008-08-01

    Full Text Available The aim of this work was to study the aquatic macrophytes community development to distinguish the fluctuations from succession trends at different temporal and spatial scales in the Upper Paraná River floodplain. The samples were collected quarterly from May 2000 to March 2002 in seven lakes with different degrees of connectivity from the main river channel and analyzed by between-class correspondence analysis. It was difficult to establish any pattern of community development at local scale but at a higher level of organization, disconnected lakes were characterized by fluctuation of the floristic composition. Connected lakes showed a straight trajectory, indicating that succession was occurring at these sites. Probably the income of propagules and diaspores from the river into connected lakes was the driving force of the observed change in community composition.Trabalhos sobre sucessão ecológica foram realizados principalmente com ecologia vegetal de plantas terrestres, onde a maioria das teorias foram concebidas. Poucos estudos abordam a vegetação de áreas alagáveis especialmente no Brasil. Este trabalho investigou o desenvolvimento da comunidade de macrófitas aquáticas tentando distinguir flutuações populacionais de tendências sucessionais em diferentes escalas temporal e espacial na planície de inundação do Alto Rio Paraná. As amostras foram coletadas a cada três meses, de maio de 2000 a março de 2002, em 7 lagoas com diferentes graus de conectividade com a calha principal dos rios, e analisadas pela análise de correspondência (CA entre-classes. Foi difícil estabelecer qualquer padrão de desenvolvimento da comunidade sob uma escala local, mas em uma escala mais ampla, as lagoas desconectadas foram caracterizadas pela flutuação da composição florística. As lagoas conectadas apresentaram uma trajetória retilínea no diagrama da CA, indicando que a sucessão estava ocorrendo nestes locais. Provavelmente, o aporte

  2. Toward 2D Seismic Wavefield Monitoring: Seismic Gradiometry for Long-Period Seismogram and Short-Period Seismogram Envelope applied to the Hi-net Array

    Science.gov (United States)

    Maeda, T.; Nishida, K.; Takagi, R.; Obara, K.

    2015-12-01

    The high-sensitive seismograph network Japan (Hi-net) operated by National Research Institute for Earth Science and Disaster Prevention (NIED) has about 800 stations with average separation of 20 km. We can observe long-period seismic wave propagation as a 2D wavefield with station separations shorter than wavelength. In contrast, short-period waves are quite incoherent at stations, however, their envelope shapes resemble at neighbor stations. Therefore, we may be able to extract seismic wave energy propagation by seismogram envelope analysis. We attempted to characterize seismic waveform at long-period and its envelope at short-period as 2D wavefield by applying seismic gradiometry. We applied the seismic gradiometry to a synthetic long-period (20-50s) dataset prepared by numerical simulation in realistic 3D medium at the Hi-net station layout. Wave amplitude and its spatial derivatives are estimated by using data at nearby stations. The slowness vector, the radiation pattern and the geometrical spreading are extracted from estimated velocity, displacement and its spatial derivatives. For short-periods at shorter than 1 s, seismogram envelope shows temporal and spatial broadening through scattering by medium heterogeneity. It is expected that envelope shape may be coherent among nearby stations. Based on this idea, we applied the same method to the time-integration of seismogram envelope to estimate its spatial derivatives. Together with seismogram envelope, we succeeded in estimating the slowness vector from the seismogram envelope as well as long-period waveforms by synthetic test, without using phase information. Our preliminarily results show that the seismic gradiometry suits the Hi-net to extract wave propagation characteristics both at long and short periods. This method is appealing that it can estimate waves at homogeneous grid to monitor seismic wave as a wavefield. It is promising to obtain phase velocity variation from direct waves, and to grasp wave

  3. Intensive measurements of gas, water, and energy exchange between vegetation and troposphere during the MONTES Campaign in a vegetation gradient from short semi-desertic shrublands to tall wet temperate forests in the NW Mediterranean basin

    Science.gov (United States)

    MONTES (“Woodlands”) was a multidisciplinary international field campaign aimed at measuring energy, water and especially gas exchange between vegetation and atmosphere in a gradient from short semi-desertic shrublands to tall wet temperate forests in NE Spain in the North Wester...

  4. Intensive measurements of gas, water, and energy exchange between vegetation and troposhere during the MONTES campaign in a vegetation gradient from short semi-desertic shrublands to tall wet temperate forests in the NW Mediterranean Basin

    NARCIS (Netherlands)

    Penuelas, J.; Guenther, A.; Rapparini, F.; Llusia, J.; Vilà-Guerau De Arellano, J.

    2013-01-01

    MONTES (“Woodlands”) was a multidisciplinary international field campaign aimed at measuring energy, water and especially gas exchange between vegetation and atmosphere in a gradient from short semi-desertic shrublands to tall wet temperate forests in NE Spain in the North Western Mediterranean

  5. Impact of high temperature and short period annealing on SnS films deposited by E-beam evaporation

    International Nuclear Information System (INIS)

    Gedi, Sreedevi; Reddy, Vasudeva Reddy Minnam; Kang, Jeong-yoon; Jeon, Chan-Wook

    2017-01-01

    Highlights: • Preparation SnS films using electron beam evaporation at room temperature. • SnS films were annealed at a high temperaure for different short period of times. • The films showed highly oriented (111) planes with orthorhombic crystal structure. • Surface morphology showed bigger and faceted grains embedded in orthorombic. • The TEM confirmed that big orthorombic slabs had single-crystalline nature. - Abstract: Thin films of SnS were deposited on Mo-substrate using electron beam evaporation at room temperature. As-deposited SnS films were annealed at a constant high temperaure of 860 K for different short period of times, 1 min, 3 min, and 5 min. The impact of heat treatment period on the physical properties of SnS films was investigated using appropriate characterization tools. XRD analysis revealed that the films were highly oriented along (111) plane with orthorhombic crystal structure. Surface morphology of as-deposited SnS films showed an identical leaf texture where as the annealed films showed large orthorombic slab shape grains in adidition to the leaf shape grains, which indicates the significance of short period annealing at high temperature. The transmission electron microscopy confirmed that those large orthorombic slabs had single-crystalline nature. The results emphasized that the short period annealing treatment at high temperature stimulated the growth of film towards the single crystallinity.

  6. Impact of high temperature and short period annealing on SnS films deposited by E-beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Gedi, Sreedevi; Reddy, Vasudeva Reddy Minnam; Kang, Jeong-yoon; Jeon, Chan-Wook, E-mail: cwjeon@ynu.ac.kr

    2017-04-30

    Highlights: • Preparation SnS films using electron beam evaporation at room temperature. • SnS films were annealed at a high temperaure for different short period of times. • The films showed highly oriented (111) planes with orthorhombic crystal structure. • Surface morphology showed bigger and faceted grains embedded in orthorombic. • The TEM confirmed that big orthorombic slabs had single-crystalline nature. - Abstract: Thin films of SnS were deposited on Mo-substrate using electron beam evaporation at room temperature. As-deposited SnS films were annealed at a constant high temperaure of 860 K for different short period of times, 1 min, 3 min, and 5 min. The impact of heat treatment period on the physical properties of SnS films was investigated using appropriate characterization tools. XRD analysis revealed that the films were highly oriented along (111) plane with orthorhombic crystal structure. Surface morphology of as-deposited SnS films showed an identical leaf texture where as the annealed films showed large orthorombic slab shape grains in adidition to the leaf shape grains, which indicates the significance of short period annealing at high temperature. The transmission electron microscopy confirmed that those large orthorombic slabs had single-crystalline nature. The results emphasized that the short period annealing treatment at high temperature stimulated the growth of film towards the single crystallinity.

  7. Seismic Site Effects from the Seafloor Motion Recorded by the Short-period Ocean Bottom Seismometers

    Science.gov (United States)

    Lin, J. Y.; Cheng, W. B.; Chin, S. J.; Hsu, S. K.; Dong, J. J.

    2014-12-01

    For decades, it has been mentioned that submarine slope failures are spatially linked to the presence of gas hydrates/gas-charged sediments. When triggered by earthquakes, oversteepen and instable sediments may prompt breakouts of the slopes containing gas hydrates and cause submarine landslides and tsunamis. Widely distributed BSRs have been observed in the area offshore of southwestern Taiwan where the active accretionary complex meets with the passive China continental margin. In the region, large or small scale landslides were also reported based on seismic interpretations. In order to clarify the link between earthquake, landslide and the presence of gas hydrate, we evaluate the response of seafloor sediments in regard to passive dynamic loads. Horizontal-to-vertical (H/V) spectral ratios are used to characterize the local sediment response. Ambient noise as well as distant earthquakes are used as generators of the passive dynamic loads. Based on this study, we aim to characterize the site in terms of its physical properties and the local site effect produced by shallow marine sediments. The results show that the maximum H/V ratios appeared in the range of 5-10 Hz, where the horizontal amplitudes increased by an order of magnitude relative to the vertical amplitude. The stations located in the northwestern part of study area were characterized by another relatively small peak at proximately 2 Hz, which may indicates the presence of a discontinuity of sediments. For most stations, the H/V ratios estimated based on the earthquake (i.e. strong input signal) and noise (background, micro-seismic noise) records were characterized by different pattern. No distinct peak is observed for the H/V pattern calculated during earthquakes. This phenomenon may suggest that no clear sedimentary boundary exist when a stronger motion applies. Estimating H/V spectral ratios of data recorded by the seven short period OBSs (Ocean Bottom Seismometer) deployed in the southwest Taiwan

  8. Comparison of 226Ra nuclide from soil by three woody species Betula pendula, Sambucus nigra and Alnus glutinosa during the vegetation period

    International Nuclear Information System (INIS)

    Soudek, Petr; Petrova, Sarka; Benesova, Dagmar; Tykva, Richard; Vankova, Radomira; Vanek, Tomas

    2007-01-01

    The uptake of 226 Ra from the contaminated soil was compared in three woody species: alder (Alnus glutinosa), birch (Betula pendula) and elder (Sambucus nigra). The 226 Ra activities increased during the vegetation periods (in 2003, 2004 and 2005) both in the leaves and flowers + seeds. The highest accumulation was found in birch, reaching 0.41 Bq/g DW in the leaves (at the end of the vegetation period in 2003). The lowest 226 Ra accumulation was determined in alder. The extent of 226 Ra accumulation in the leaves of woody species demonstrates that these pioneer woody species can be used as remediation alternative to the use of herbs, provided that the removal of fallen leaves could be achieved in the end of vegetation period

  9. A short period of high-intensity interval training improves skeletal muscle mitochondrial function and pulmonary oxygen uptake kinetics

    DEFF Research Database (Denmark)

    Christensen, Peter Møller; Jacobs, Robert A; Bonne, Thomas Christian

    2016-01-01

    The aim of the present study was to examine whether improvements in pulmonary V̇O2 kinetics following a short period of high-intensity training (HIT) would be associated with improved skeletal muscle mitochondrial function. Ten untrained male volunteers (age: 26 ± 2; mean ± SD) performed six HIT...

  10. Capability of simultaneous Rayleigh LiDAR and O2 airglow measurements in exploring the short period wave characteristics

    Science.gov (United States)

    Taori, Alok; Raghunath, Karnam; Jayaraman, Achuthan

    We use combination of simultaneous measurements made with Rayleigh lidar and O2 airglow monitoring to improve lidar investigation capability to cover a higher altitude range. We feed instantaneous O2 airglow temperatures instead the model values at the top altitude for subsequent integration method of temperature retrieval using Rayleigh lidar back scattered signals. Using this method, errors in the lidar temperature estimates converges at higher altitudes indicating better altitude coverage compared to regular methods where model temperatures are used instead of real-time measurements. This improvement enables the measurements of short period waves at upper mesospheric altitudes (~90 km). With two case studies, we show that above 60 km the few short period wave amplitude drastically increases while, some of the short period wave show either damping or saturation. We claim that by using such combined measurements, a significant and cost effective progress can be made in the understanding of short period wave processes which are important for the coupling across the different atmospheric regions.

  11. Impact of marine inundation after a period of drought on the lakeshore vegetation of Lake St Lucia, South Africa : resilience of estuarine vegetation

    NARCIS (Netherlands)

    Sieben, E. J. J.; Ellery, W. N.; Dullo, B. W.; Grootjans, A. P.

    The shore of Lake St Lucia in the vicinity of Catalina Bay, in the southern part of the lake, receives freshwater input as surface and groundwater seepage from the adjacent elevated coastal plain. Vegetation, water quality and landform were recorded on the lakeshore and on the dry lakebed near one

  12. MODEL RECONSTRUCTION OF THE VEGETATION COVER OF THE SOUTH OF THE WEST SIBERIAN PLAIN FROM THE LATE PALEOLITHIC PERIOD UNTIL THE LATE XIX CENTURY

    Directory of Open Access Journals (Sweden)

    М. А. Kharitonenkov

    2016-06-01

    Full Text Available Model reconstruction of vegetation cover of the south of the West Siberian Plain from the late Pleistocene to the modern era has been carried out on the basis of the associated chronological analysis of paleontological, archaeological and paleoclimate data. We have determined the starting point of active vegetation transformation in the south of the West Siberian Plain as a result of tradition-bound exploitation of natural resources. Periods of maximum anthropogenic load – peak and relative recession – on vegetation cover, acting as a further determinant factor, have been determined in this study for the first time. Comprehensive analysis and new understanding of palynological, paleozoological, archaeological and paleoclimate data in terms of theoretical synecology confirmed the notions on the determinant role of the anthropogenic factor in the transformation of the Pleistocene forest-meadow-steppe vegetation into contemporary communities of the southern taiga, the subtaiga and the forest-steppe of the West Siberian Plain.

  13. Development of Speech Fluency over a Short Period of Time: Effects of Pedagogic Intervention

    Science.gov (United States)

    Tavakoli, Parvaneh; Campbell, Colin; McCormack, Joan

    2016-01-01

    This study investigates the effects of a short-term pedagogic intervention on development of second language (L2) fluency among learners studying English for academic purposes at a UK university. It also examines the interaction between development of fluency and complexity and accuracy. Through a pretest and posttest design, data were collected…

  14. Short (

    NARCIS (Netherlands)

    Telleman, Gerdien; den Hartog, Laurens

    2013-01-01

    Aim: This systematic review assessed the implant survival rate of short (<10 mm) dental implants installed in partially edentulous patients. A case report of a short implant in the posterior region have been added. Materials and methods: A search was conducted in the electronic databases of MEDLINE

  15. Post-wildfire recovery of riparian vegetation during a period of water scarcity in the southwestern USA

    Science.gov (United States)

    D. Max Smith; Deborah M. Finch; Christian Gunning; Roy Jemison; Jeffrey F. Kelly

    2009-01-01

    Wildland fires occur with increasing frequency in southwestern riparian forests, yet little is known about the effects of fire on populations of native and exotic vegetation. From 2003 to 2006, we monitored recovering woody vegetation in wildfire sites in the bosque (riparian forest) along the Middle Rio Grande of central New Mexico, USA. To examine recovery potential...

  16. Determination of short chain carboxylic acids in vegetable oils and fats using ion exclusion chromatography electrospray ionization mass spectrometry.

    Science.gov (United States)

    Viidanoja, Jyrki

    2015-02-27

    A new method for quantification of short chain C1-C6 carboxylic acids in vegetable oils and fats by employing Liquid Chromatography Mass Spectrometry (LC-MS) has been developed. The method requires minor sample preparation and applies non-conventional Electrospray Ionization (ESI) liquid phase chemistry. Samples are first dissolved in chloroform and then extracted using water that has been spiked with stable isotope labeled internal standards that are used for signal normalization and absolute quantification of selected acids. The analytes are separated using Ion Exclusion Chromatography (IEC) and detected with Electrospray Ionization Mass Spectrometry (ESI-MS) as deprotonated molecules. Prior to ionization the eluent that contains hydrochloric acid is modified post-column to ensure good ionization efficiency of the analytes. The averaged within run precision and between run precision were generally lower than 8%. The accuracy was between 85 and 115% for most of the analytes. The Lower Limit of Quantification (LLOQ) ranged from 0.006 to 7mg/kg. It is shown that this method offers good selectivity in cases where UV detection fails to produce reliable results. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Levels of short chain chlorinated paraffins in pine needles and bark and their vegetation-air partitioning in urban areas.

    Science.gov (United States)

    Wang, Thanh; Yu, Junchao; Han, Shanlong; Wang, Yawei; Jiang, Guibin

    2015-01-01

    Short chain chlorinated paraffins (SCCPs) have been of considerable concern in recent years due to their high production volumes, environmental persistency and potential for long range atmospheric transport. Vegetation can take up considerable amounts of semivolatile organic compounds from the atmosphere and can act as indicators of local contamination. Paired pine needles and bark were sampled around Beijing during winter and summertime to investigate the distribution of SCCPs in urban areas. Levels in bark samples ranged 5.79-37.5 μg/g on a lipid normalized basis (lw) with a geometric mean (GM) of 16.9 μg/g lw whereas levels were 3.03-40.8 (GM 11.8) μ/g lw for needles. Average congener group abundance profiles showed equal contribution of all four carbon groups (C(10-13)) in wintertime where as higher abundances of C(10) and C(11) groups were found during summer. Uptake of SCCPs occurred mainly via kinetically limited gaseous deposition and particle bound deposition in the investigated area.

  18. Nature of short-period microtremors on the cliff-like ground. part 6; Gakechi kinbo no tanshuki bido. 6

    Energy Technology Data Exchange (ETDEWEB)

    Maiguma, T; Kimura, Y [Waseda University, Tokyo (Japan). School of Science and Engineering; Yasui, [Toda Corp., Tokyo, (Japan)

    1997-10-22

    Short-period microtremors were observed on the cliff-like ground to discuss vibration characteristics of the ground. It is known that damage of an earthquake becomes especially serious in the vicinity of the cliff-like ground with steep slopes. The present investigation has performed observations on short-period microtremors in two cliff-like grounds, one with a height of about 17 m and an inclination angle of about 55 degrees, and another with a height of 11 m and an inclination angle of about 60 degrees. The areas of the investigation are the Musashino tableland of the Pleistocene era covered by the Kanto loam bed, and the Oritate area (a farm land) with the cliff-like ground which has been formed as a result of erosion of a river terrace consisted of a gravel bed. The observation was carried out with nine moving coil type vibration converters having a natural period of one second installed for horizontal movements and seven converters installed for vertical movements. The result of the investigation revealed that, at the Musashino tableland, no noticeable influence of the cliff-like ground was recognized in the short-period microtremors; at the Oritate area, the spectra of the horizontal movements vary largely with vibrating directions; and the cliff effect can be seen in microtremors with frequencies from 5 Hz to 9 Hz. 5 refs., 9 figs.

  19. The influence of sowing period and seeding norm on autumn vegetation, winter hardiness and yield of winter cereal crops

    Directory of Open Access Journals (Sweden)

    Potapova G. N.

    2017-10-01

    Full Text Available the winter wheat and triticale in the middle part of the Ural Mountains haven’t been seeded before. The technology of winter crop cultivation should be improved due to the production of new varieties of winter rye. Winter hardiness and yield of winter rye are higher in comparison with winter triticale and especially with winter wheat. The sowing period and the seeding rate influence the amount of yield and winter hardiness. The winter hardiness of winter cereals and the yield of the rye variety Iset sowed on August 25 and the yield of the triticale variety Bashkir short-stalked and wheat Kazanskaya 560 sowed on August 15 were higher. It is important to sow winter grain in local conditions in the second half of August. The sowing this period allows to provide plants with the necessary amount of positive temperatures (450–500 °C. This helps the plants to form 3–4 shoots of tillering and a mass of 10 dry plants reaching 3–5 grams. The winter grain crops in the middle part of the Ural Mountains should be sown with seeding rates of 6 and 7 million of sprouting grains per 1 ha, and the seeds must be cultivated with fungicidal preparation before seeding.

  20. Phenology Shifts at Start vs. End of Growing Season in Temperate Vegetation Over the Northern Hemisphere for the Period 1982-2008

    Science.gov (United States)

    Jeong, Su-Jong; Ho, Chang-Hoi; Gim, Hyeon-Ju; Brown, Molley E.

    2011-01-01

    Changes in vegetative growing seasons are dominant indicators of the dynamic response of ecosystems to climate change. Therefore, knowledge of growing seasons over the past decades is essential to predict ecosystem changes. In this study, the long-term changes in the growing seasons of temperate vegetation over the Northern Hemisphere were examined by analyzing satellite-measured normalized difference vegetation index and reanalysis temperature during 1982 2008. Results showed that the length of the growing season (LOS) increased over the analysis period; however, the role of changes at the start of the growing season (SOS) and at the end of the growing season (EOS) differed depending on the time period. On a hemispheric scale, SOS advanced by 5.2 days in the early period (1982-1999) but advanced by only 0.2 days in the later period (2000-2008). EOS was delayed by 4.3 days in the early period, and it was further delayed by another 2.3 days in the later period. The difference between SOS and EOS in the later period was due to less warming during the preseason (January-April) before SOS compared with the magnitude of warming in the preseason (June September) before EOS. At a regional scale, delayed EOS in later periods was shown. In North America, EOS was delayed by 8.1 days in the early period and delayed by another 1.3 days in the later period. In Europe, the delayed EOS by 8.2 days was more significant than the advanced SOS by 3.2 days in the later period. However, in East Asia, the overall increase in LOS during the early period was weakened in the later period. Admitting regional heterogeneity, changes in hemispheric features suggest that the longer-lasting vegetation growth in recent decades can be attributed to extended leaf senescence in autumn rather than earlier spring leaf-out. Keywords: climate change, growing season, NDVI (normalized difference vegetation index), Northern Hemisphere, phenology,

  1. Closeout of IE Bulletin 79-12: short-period scrams at boiling-water reactors. Final report

    International Nuclear Information System (INIS)

    DeBevac, C.J.; Holland, R.A.

    1985-03-01

    IE Circular 77-07 was issued on April 14, 1977 because of the occurrence of short period scram events at Dresden Unit 2 on December 28, 1976 and at Monticello on February 23, 1977. The circular advised BWR plants to revise their control rod withdrawal sequences and operating procedures to reduce the likelihood of future short period scrams. However, similar events continued to occur. These included events at Oyster Creek on December 14, 1978; at Browns Ferry Unit 1 on January 18, 1979; and at Hatch Unit 1 on January 31, 1979. As a result of these events, IE Bulletin 79-12 was issued on May 31, 1979. This bulletin required a written response from licensees of GE-designed BWRs regarding specific actions listed in the bulletin. All of the licensees responded in a satisfactory manner. No similar events have been reported since IE Bulletin 79-12 was issued

  2. A high-average power tapered FEL amplifier at submillimeter frequencies using sheet electron beams and short-period wigglers

    International Nuclear Information System (INIS)

    Bidwell, S.W.; Radack, D.J.; Antonsen, T.M. Jr.; Booske, J.H.; Carmel, Y.; Destler, W.W.; Granatstein, V.L.; Levush, B.; Latham, P.E.; Zhang, Z.X.

    1990-01-01

    A high-average-power FEL amplifier operating at submillimeter frequencies is under development at the University of Maryland. Program goals are to produce a CW, ∼1 MW, FEL amplifier source at frequencies between 280 GHz and 560 GHz. To this end, a high-gain, high-efficiency, tapered FEL amplifier using a sheet electron beam and a short-period (superconducting) wiggler has been chosen. Development of this amplifier is progressing in three stages: (1) beam propagation through a long length (∼1 m) of short period (λ ω = 1 cm) wiggler, (2) demonstration of a proof-of-principle amplifier experiment at 98 GHz, and (3) designs of a superconducting tapered FEL amplifier meeting the ultimate design goal specifications. 17 refs., 1 fig., 1 tab

  3. Kinetic Monte Carlo simulation of phase-precipitation versus instability behavior in short period FeCr superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Martínez, F.J. [UCAM, Universidad Católica de Murcia, Campus de los Jerónimos, 30107 Guadalupe (Murcia) (Spain); Castejón-Mochón, J.F., E-mail: jfcastejon@ucam.edu [UCAM, Universidad Católica de Murcia, Campus de los Jerónimos, 30107 Guadalupe (Murcia) (Spain); Castrillo, P.; Berenguer-Vidal, R. [UCAM, Universidad Católica de Murcia, Campus de los Jerónimos, 30107 Guadalupe (Murcia) (Spain); Dopico, I.; Martin-Bragado, I. [IMDEA Materials Institute, Eric Kandel 2, 28906 Getafe (Madrid) (Spain)

    2017-02-15

    The structural evolution of FeCr superlattices has been studied using a quasi-atomistic Object Kinetic Monte Carlo model. Superlattices with different spatial periods have been simulated for anneal durations from few hours to several months at 500 °C. Relatively-long period superlattices stabilize into Fe-rich and Cr-rich layers with compositions close to those of bulk α and α′ phases. In contrast, superlattices with very short periods (4, 5, 6 nm) are observed to undergo instability and, for long annealing times, evolve into three-dimensionally decomposed regions, in qualitative agreement to recent experimental observations. The instability onset is delayed as the spatial period increases, and it occurs via interface roughness. This evolution can be explained as a minimization of the free-energy associated to the α/α′ interfaces. A comprehensive description of the evolution dynamics of FeCr-based structures is obtained with our model.

  4. Physiological Responses of Bambara Groundnut (Vigna subterranea L. Verdc) to Short Periods of Water Stress During Different Developmental Stages

    OpenAIRE

    R. Vurayai; V. Emongor and B. Moseki

    2011-01-01

    The study was conducted to evaluate the responses of bambara groundnut (Vigna subterranea L. Verdc) to short periods of water stress imposed at different growth stages, and the recuperative ability of the species from drought stress. A major problem associated with Bambara groundnut production is its very low yields due to intra-seasonal and inter-seasonal variability in rainfall in semi-arid regions. The response pattern of physiological processes to water stress imposed at different growth ...

  5. The Spatial and Temporal Dynamics of Remotely-sensed Vegetation Phenology in Central Asia in the 1982-2011 Period

    Czech Academy of Sciences Publication Activity Database

    Bohovič, Roman; Dobrovolný, Petr; Klein, D.

    2016-01-01

    Roč. 2016, č. 49 (2016), s. 279-299 ISSN 2279-7254 Institutional support: RVO:67179843 Keywords : Phenology * vegetation dynamics * NDVI * GIMMS * Central Asia * SOS Subject RIV: EH - Ecology, Behaviour Impact factor: 1.533, year: 2016

  6. Short Term Strategies for a Dynamic Multi-Period Routing Problem

    NARCIS (Netherlands)

    Angelelli, E.; Bianchessi, N.; Mansini, R.; Speranza, M. G.

    2009-01-01

    We consider a Dynamic Multi-Period Routing Problem (DMPRP) faced by a company which deals with on-line pick-up requests and has to serve them by a fleet of uncapacitated vehicles over a finite time horizon. When a request is issued, a deadline of a given number of days d ≤ 2 is associated to it: if

  7. On-Farm Study on Intercropping of Hybrid Maize with Different Short Duration Vegetables in the Charland of Tangail

    Directory of Open Access Journals (Sweden)

    MA Rahaman, MM Rahman, S Roy, M Ahmed, MS Bhuyan

    2015-12-01

    Full Text Available An experiment was conducted in charland at the Multi Location Testing (MLT site Bhuapur, Tangail during 2012-13 and 2013-14 under AEZ-8 to find out the suitable intercropping system of hybrid maize with different short duration vegetables with economic return. The experiment was laid out in RCB design with six dispersed (six farmers’ field replications. The hybrid maize (ver. BARI Hybrid maize-7, potato (Diamant, spinach (local, red amaranth (BARI Lalsak-1, Radish (BARI Mula-1 were used as the planting materials. Five treatment combinations viz. T1= Sole Maize, T2= 100% Maize (maize paired row + Potato (var. Diamant, T3= 100% Maize (maize paired row + Spinach (var. local, T4= 100% Maize (maize paired row + Red amaranth (var. BARI Lalshak-1 and T5= 100% Maize (Maize paired row + Radish (var. BARI Mula-1 were studied. Maize grain yield in intercropped combination varied from 5.59-7.62 t ha-1. But the highest grain yield (8.17 t ha-1 was obtained from sole maize. Maize equivalent yields in the intercrops situation ranged from 11.39-19.68 t ha-1 where highest maize equivalent yield 19.68 t ha-1 was recorded from the treatment T3 (100 % maize + spinach. The same combinations also gave highest gross return (Tk. 373930 ha-1 and gross margin (Tk. 258585 ha-1 as well as benefit cost ratio (3.24. Though highest grain yield was recorded from sole maize but equivalent yield and economic return was much lower than the treatment T3.

  8. Short communication: study of immune parameters in three Greek dairy sheep breeds during the periparturient period.

    Science.gov (United States)

    Theodorou, G; Fragou, S; Chronopoulou, R; Kominakis, A; Rogdakis, E; Politis, I

    2007-12-01

    The objective of the present study was to evaluate whether immunosuppression occurs in 3 different Greek dairy sheep breeds during the periparturient period. A total of 33 ewes from 3 breeds [i.e., the low-producing Boutsiko breed (n = 11), which is highly adaptable to harsh environments; the high-producing but environmentally fragile Chios breed (n = 11); and an intermediate synthetic breed (50% Boutsiko, 25% Arta, and 25% Chios, n = 11)] were used. Blood samples were collected at 18 and 2 d before parturition and at 15 d after parturition. Total cell-associated and membrane-bound urokinase plasminogen activator (U-PA) activity, free U-PA binding sites on cellular membranes, and superoxide anion (SA) production by activated phagocytes were determined. Results indicated that all immune parameters measured remained constant during the periparturient period for the Boutsiko breed. In contrast, there were reductions in total cell-associated and membrane-bound U-PA activity by both monocytes-macrophages and neutrophils and in SA production by monocytes-macrophages at d 2 before parturition for the Chios breed. In the synthetic breed, there were reductions in total cell-associated and membrane-bound U-PA activity by monocytes-macrophages and in SA production by both monocytes-macrophages and neutrophils at d 15 after parturition. Thus, mild immunosuppression during the periparturient period was observed in the 2 breeds with the highest milk production.

  9. A large outbreak of Listeria monocytogenes infection with short incubation period in a tertiary care hospital.

    Science.gov (United States)

    Johnsen, Bjørn Odd; Lingaas, Egil; Torfoss, Dag; Strøm, Erik H; Nordøy, Ingvild

    2010-12-01

    Listeria monocytogenes is a foodborne pathogen with a high mortality rate. We report a large, nosocomial outbreak of Listeria monocytogenes infection. Patients with L. monocytogenes isolated from a sterile site, or from faeces when diarrhoea and fever were present, were included. Clinical data were collected from the patient records. The incubation period was calculated as the time between exposure and start of symptoms. Seventeen patients (11 women, median age 64 years) were infected of whom 15 patients were at increased risk for listeriosis. Eleven patients received empiric antibiotic treatment, eight of them with cephalosporins. Three patients died with a resulting mortality rate of 18%. The source of the outbreak was a Camembert cheese made from pasteurised milk containing up to 360 million colony forming units per portion. The median incubation period was 3-4 days. The incubation period in this outbreak was significantly shorter than previously reported, a fact that may be due to the high number of ingested bacteria. Furthermore, food restrictions in hospitals seem warranted, as do treatment with antibiotics effective against L. monocytogenes in at-risk populations. Copyright © 2010 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  10. Propagation of short-period gravity waves at high-latitudes during the MaCWAVE winter campaign

    Directory of Open Access Journals (Sweden)

    K. Nielsen

    2006-07-01

    Full Text Available As part of the MaCWAVE (Mountain and Convective Waves Ascending Vertically winter campaign an all-sky monochromatic CCD imager has been used to investigate the properties of short-period mesospheric gravity waves at high northern latitudes. Sequential measurements of several nightglow emissions were made from Esrange, Sweden, during a limited period from 27–31 January 2003. Coincident wind measurements over the altitude range (~80–100 km using two meteor radar systems located at Esrange and Andenes have been used to perform a novel investigation of the intrinsic properties of five distinct wave events observed during this period. Additional lidar and MSIS model temperature data have been used to investigate their nature (i.e. freely propagating or ducted. Four of these extensive wave events were found to be freely propagating with potential source regions to the north of Scandinavia. No evidence was found for strong orographic forcing by short-period waves in the airglow emission layers. The fifth event was most unusual exhibiting an extensive, but much smaller and variable wavelength pattern that appeared to be embedded in the background wind field. Coincident wind measurements indicated the presence of a strong shear suggesting this event was probably due to a large-scale Kelvin-Helmholtz instability.

  11. Non-radial oscillations of rotating stars and their relevance to the short-period oscillations of cataclysmic variables

    International Nuclear Information System (INIS)

    Papaloizou, J.; Pringle, J.E.

    1978-01-01

    The usual hypothesis, that the short-period coherent oscillations seen in cataclysmic variables are attributable to g modes in a slowly rotating white dwarf, is considered. It is shown that this hypothesis is untenable for three main reasons: (i) the observed periods are too short for reasonable white dwarf models, (ii) the observed variability of the oscillations is too rapid and (iii) the expected rotation of the white dwarf, due to accretion, invalidates the slow rotation assumption on which standard g-mode theory is based. The low-frequency spectrum of a rotating pulsating star is investigated taking the effects of rotation fully into account. In this case there are two sets of low-frequency modes, the g modes, and modes similar to Rossby waves in the Earth's atmosphere and oceans, which are designated r modes. Typical periods for such modes are 1/m times the rotation period of the white dwarfs outer layers (m is the aximuthal wavenumber). It is concluded that non-radial oscillations of rotating white dwarfs can account for the properties of the oscillations seen in dwarf novae. Application of these results to other systems is also discussed. (author)

  12. Toxigenic Vibrio cholerae O1 in vegetables and fish raised in wastewater irrigated fields and stabilization ponds during a non-cholera outbreak period in Morogoro, Tanzania

    DEFF Research Database (Denmark)

    Hounmanou, Yaovi M G; Mdegela, Robinson H; Dougnon, Tamègnon V

    2016-01-01

    gene (tcpA) and the haemolysin gene (hlyA). RESULTS: The prevalence of V. cholerae in wastewater, vegetables and fish was 36.7, 21.7 and 23.3 %, respectively. Two isolates from fish gills were V. cholerae O1 and tested positive for ctx and tcpA. One of these contained in addition the hlyA gene while......BACKGROUND: Cholera, one of the world's deadliest infectious diseases, remains rampant and frequent in Tanzania and thus hinders existing control measures. The present study was undertaken to evaluate the occurrence of toxigenic Vibrio cholerae O1 in wastewater, fish and vegetables during a non......-outbreak period in Morogoro, Tanzania. METHODS: From October 2014 to February 2015, 60 wastewater samples, 60 fish samples from sewage stabilization ponds and 60 wastewater irrigated vegetable samples were collected. Samples were cultured for identification of V. cholerae using conventional bacteriological...

  13. First Kepler results on compact pulsators - V. Slowly pulsating subdwarf B stars in short-period binaries

    DEFF Research Database (Denmark)

    Kawaler, Stephen D.; Reed, Michael D.; Østensen, Roy H.

    2010-01-01

    of sdB stars with a close M-dwarf companion with orbital periods of less than half a day. Because the orbital period is so short, the stars should be in synchronous rotation, and if so, the rotation period should imprint itself on the multiplet structure of the pulsations. However, we do not find clear......The survey phase of the Kepler Mission includes a number of hot subdwarf B (sdB) stars to search for non-radial pulsations. We present our analysis of two sdB stars that are found to be g-mode pulsators of the V1093 Her class. These two stars also display the distinct irradiation effect typical...... evidence for such rotational splitting. Though the stars do show some frequency spacings that are consistent with synchronous rotation, they also display multiplets with splittings that are much smaller. Longer-duration time series photometry will be needed to determine if those small splittings...

  14. Compensatory growth response of rainbow trout Oncorhynchus mykiss Walbaum following short starvation periods

    Science.gov (United States)

    Azodi, Maryam; Ebrahimi, Eisa; Farhadian, Omidvar; Mahboobi-Soofiani, Nasrollah; Morshedi, Vahid

    2015-07-01

    This sixty-day study was performed to determine the effects of short-term starvation and re-feeding cycles on growth, feeding performances and body composition of rainbow trout ( Oncorhynchus mykiss). Three hundred trout fingerlings with an average initial weight of 17.5±0.06 g were randomly distributed in 15 circular fiberglass tanks. The fish were exposed to 5 different feeding regimes; control: continuously fed twice daily to apparent satiation; T1: starved for 1 day and re-fed for 2 days; T2: starved for 1 day and re-fed for 4 days; T3: starved for 3 days and re-fed for 12 days; T4: starved for 4 days and re-fed for 16 days. At the end of the experiment, growth performance, feed utilization, whole body ash and moisture contents were not significantly ( P>0.05) different among the treatments. However, whole body protein content in T3 was significantly higher than other treatments ( Ptrout culture.

  15. Short-period atmospheric gravity waves - A study of their statistical properties and source mechanisms

    Science.gov (United States)

    Gedzelman, S. D.

    1983-01-01

    Gravity waves for the one year period beginning 19 October 1976 around Palisades, New York, are investigated to determine their statistical properties and sources. The waves have typical periods of 10 min, pressure amplitudes of 3 Pa and velocities of 30 m/s. In general, the largest, amplitude waves occur during late fall and early winter when the upper tropospheric winds directly overhead are fastest and the static stability of the lower troposphere is greatest. Mean wave amplitudes correlate highly with the product of the mean maximum wind speed and the mean low level stratification directly aloft. A distinct diurnal variation of wave amplitudes with the largest waves occurring in the pre-dawn hours is also observed as a result of the increased static stability then. The majority of waves are generated by shear instability; however, a number of waves are generated by distant sources such as nuclear detonations or large thunderstorms. The waves with distant sources can be distinguished on the basis of their generally much higher coherency across the grid and velocities that depart markedly from the wind velocity at any point in the sounding.

  16. Non-thyroid cancer in Northern Ukraine in the post-Chernobyl period: Short report.

    Science.gov (United States)

    Hatch, M; Ostroumova, E; Brenner, A; Federenko, Z; Gorokh, Y; Zvinchuk, O; Shpak, V; Tereschenko, V; Tronko, M; Mabuchi, K

    2015-06-01

    The Chernobyl nuclear power plant accident in Ukraine in 1986 led to widespread radioactive releases into the environment - primarily of radioiodines and cesium - heavily affecting the northern portions of the country, with settlement-averaged thyroid doses estimated to range from 10 mGy to more than 10 Gy. The increased risk of thyroid cancer among exposed children and adolescents is well established but the impact of radioactive contamination on the risk of other types of cancer is much less certain. To provide data on a public health issue of major importance, we have analyzed the incidence of non-thyroid cancers during the post-Chernobyl period in a well-defined cohort of 13,203 individuals who were <18 years of age at the time of the accident. The report is based on standardized incidence ratio (SIR) analysis of 43 non-thyroid cancers identified through linkage with the National Cancer Registry of Ukraine for the period 1998 through 2009. We compared the observed and expected number of cases in three cancer groupings: all solid cancers excluding thyroid, leukemia, and lymphoma. Our analyses found no evidence of a statistically significant elevation in cancer risks in this cohort exposed at radiosensitive ages, although the cancer trends, particularly for leukemia (SIR=1.92, 95% confidence interval: 0.69; 4.13), should continue to be monitored. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Short period sound speed oscillation measured by intensive XBT survey and its role on GNSS/acoustic positioning

    Science.gov (United States)

    Kido, M.; Matsui, R.; Imano, M.; Honsho, C.

    2017-12-01

    In the GNSS/acoustic measurement, sound speed in ocean plays a key role of accuracy of final positioning. We have shown than longer period sound speed undulation can be properly estimated from GNSS-A analysis itself in our previous work. In this work, we have carried out intensive XBT measurement to get temporal variation of sound speed in short period to be compared with GNSS-A derived one. In the individual temperature profile obtained by intensive XBT measurements (10 minutes interval up to 12 times of cast), clear vertical oscillation up to 20 m of amplitude in the shallow part were observed. These can be interpreted as gravitational internal wave with short-period and hence short wavelength anomaly. Kido et al. (2007) proposed that horizontal variation of the ocean structure can be considered employing five or more transponders at once if the structure is expressed by two quantities, i.e., horizontal gradient in x/y directions. However, this hypothesis requires that the variation must has a large spatial scale (> 2-5km) so that the horizontal variation can be regarded as linear within the extent of acoustic path to seafloor transponders. Therefore the wavelength of the above observed internal wave is getting important. The observed period of internal wave was 30-60 minute. However its wavelength cannot be directly measured. It must be estimate based on density profile of water column. In the comparison between sound speed change and positioning, the delay of their phases were 90 degree, which indicates that most steep horizontal slope of internal wave correspond to largest apparent positioning shift.

  18. Evaluating the performance of water purification in a vegetated groundwater recharge basin maintained by short-term pulsed infiltration events.

    Science.gov (United States)

    Mindl, Birgit; Hofer, Julia; Kellermann, Claudia; Stichler, Willibald; Teichmann, Günter; Psenner, Roland; Danielopol, Dan L; Neudorfer, Wolfgang; Griebler, Christian

    2015-01-01

    Infiltration of surface water constitutes an important pillar in artificial groundwater recharge. However, insufficient transformation of organic carbon and nutrients, as well as clogging of sediments often cause major problems. The attenuation efficiency of dissolved organic carbon (DOC), nutrients and pathogens versus the risk of bioclogging for intermittent recharge were studied in an infiltration basin covered with different kinds of macrovegetation. The quality and concentration of organic carbon, major nutrients, as well as bacterial biomass, activity and diversity in the surface water, the porewater, and the sediment matrix were monitored over one recharge period. Additionally, the numbers of viral particles and Escherichia coli were assessed. Our study showed a fast establishment of high microbial activity. DOC and nutrients have sustainably been reduced within 1.2 m of sediment passage. Numbers of E. coli, which were high in the topmost centimetres of sediment porewater, dropped below the detection limit. Reed cover was found to be advantageous over bushes and trees, since it supported higher microbial activities along with a good infiltration and purification performance. Short-term infiltration periods of several days followed by a break of similar time were found suitable for providing high recharge rates, and good water purification without the risk of bioclogging.

  19. Tailoring of the electrical and thermal properties using ultra-short period non-symmetric superlattices

    Directory of Open Access Journals (Sweden)

    Paulina Komar

    2016-10-01

    Full Text Available Thermoelectric modules based on half-Heusler compounds offer a cheap and clean way to create eco-friendly electrical energy from waste heat. Here we study the impact of the period composition on the electrical and thermal properties in non-symmetric superlattices, where the ratio of components varies according to (TiNiSnn:(HfNiSn6−n, and 0 ⩽ n ⩽ 6 unit cells. The thermal conductivity (κ showed a strong dependence on the material content achieving a minimum value for n = 3, whereas the highest value of the figure of merit ZT was achieved for n = 4. The measured κ can be well modeled using non-symmetric strain relaxation applied to the model of the series of thermal resistances.

  20. A Population of planetary systems characterized by short-period, Earth-sized planets

    Science.gov (United States)

    Steffen, Jason H.; Coughlin, Jeffrey L.

    2016-01-01

    We analyze data from the Quarter 1–17 Data Release 24 (Q1–Q17 DR24) planet candidate catalog from NASA’s Kepler mission, specifically comparing systems with single transiting planets to systems with multiple transiting planets, and identify a population of exoplanets with a necessarily distinct system architecture. Such an architecture likely indicates a different branch in their evolutionary past relative to the typical Kepler system. The key feature of these planetary systems is an isolated, Earth-sized planet with a roughly 1-d orbital period. We estimate that at least 24 of the 144 systems we examined (≳17%) are members of this population. Accounting for detection efficiency, such planetary systems occur with a frequency similar to the hot Jupiters. PMID:27790984

  1. A Population of planetary systems characterized by short-period, Earth-sized planets.

    Science.gov (United States)

    Steffen, Jason H; Coughlin, Jeffrey L

    2016-10-25

    We analyze data from the Quarter 1-17 Data Release 24 (Q1-Q17 DR24) planet candidate catalog from NASA's Kepler mission, specifically comparing systems with single transiting planets to systems with multiple transiting planets, and identify a population of exoplanets with a necessarily distinct system architecture. Such an architecture likely indicates a different branch in their evolutionary past relative to the typical Kepler system. The key feature of these planetary systems is an isolated, Earth-sized planet with a roughly 1-d orbital period. We estimate that at least 24 of the 144 systems we examined ([Formula: see text]17%) are members of this population. Accounting for detection efficiency, such planetary systems occur with a frequency similar to the hot Jupiters.

  2. Biomass production of dense direct-seeded lodgepole pine (Pinus contorta) at short rotation periods

    Energy Technology Data Exchange (ETDEWEB)

    Backlund, I.; Bergsten, U.

    2012-07-01

    Lodgepole pine (Pinus contorta) is a fast-growing species that is suitable for producing woody biomass in Nordic countries. Direct seeding of this species is cheaper than planting and creates dense, stable stands. The objective of this study was to quantify the stem volume and biomass production of direct seeded lodgepole pine stands grown under different site conditions with different stem densities, at an age that would permit extensive harvesting of biomass. A circle-plot inventory was performed in 16 of the oldest direct seeded lodgepole pine stands in mid-northern Sweden. Stemwood production of almost 200 m{sup 3}/ha was achieved on average on the best sites, rising to about 300 m{sup 3}/ha for the best circle-plots within 30 years of direct seeding despite the fact that pre-commercial thinning was made once or twice. This corresponds to 100 and 140 tons of dry weight biomass/ha, respectively. Higher stand stem densities ({>=}3000 st/ha) yielded more biomass with only slight reductions in diameter at breast height. The development of stem volume with respect to dominant height in direct seeded stands was becoming comparable to that in planted stands with similar spacing. It therefore seems that there is an unutilized potential for cost-effectively growing lodgepole pine in dense stands for biomass production after direct seeding. It may be possible to devise regimes for short(er) rotation forestry that would yield substantial amount of inexpensive biomass for biorefineries within a few decades. (orig.)

  3. Vegetation response to the "African Humid Period" termination in Central Cameroon (7° N – new pollen insight from Lake Mbalang

    Directory of Open Access Journals (Sweden)

    M. Servant

    2010-05-01

    Full Text Available A new pollen sequence from the Lake Mbalang (7°19´ N, 13°44´ E, 1110 m a.s.l. located on the eastern Adamawa plateau, in Central Cameroon, is presented in this paper to analyze the Holocene African Humid Period (AHP termination and related vegetation changes at 7° N in tropical Africa, completing an important transect for exploring shifts in the northern margin of the African Monsoon. This sequence, spanning the last 7000 cal yr BP, shows that the vegetation response to this transitional climatic period was marked by significant successional changes within the broad context of long-term aridification. Semi-deciduous/sub-montane forest retreat in this area is initially registered as early as ca. 6100 cal yr BP and modern savannah was definitely established at ca. 3000 cal yr BP and stabilized at ca. 2400 cal yr BP; but a slight forest regeneration episode is observed between ca. 5200 and ca. 4200 cal yr BP. In this area with modern high rainfall, increasing in the length of the dry season during the AHP termination linked to a contraction of the northern margin of the Intertropical Convergence Zone (ITCZ from ca. 6100 cal yr BP onward, probably associated with decreasing in cloud cover and/or fog frequency, has primarily controlled vegetation dynamics and above all the disappearance of the forested environment on the Adamawa plateau. Compared to previous studies undertaken in northern tropical and Central Africa, this work clearly shows that the response of vegetation to transitional periods between climatic extremes such as the AHP termination might be different in timing, mode and amplitude according to the regional climate of the study sites, but also according to the stability of vegetation before and during these climatic transitions.

  4. BVRI Photometric Study of the Short Period, Solar Type, Semi-Detached Binary, NSVS 10083189

    Science.gov (United States)

    Samec, Ronald G.; Caton, Daniel B.; Olsen, Amber; Faulkner, Danny R.; Hill, Robert L.

    2017-06-01

    Precision BVRcIc light curves of NSVS 5066754 were taken on 11 nights in February through April 2015 at Dark Sky Observatory in North Carolina with the 0.81-m reflector of Appalachian State University and on 1 night on the SARA 1-m reflector at Kitt Peak National Observatory in remote mode. It is an ~ F8V eclipsing binary with a period of 0.4542238 (2) d.Seven times of minimum light were calculated, for 5 primary and 2 secondary eclipses from our present observations:HJD I = 2457067.75453±0.0003, 2457088.64907±0.0001, 2457089.55708±0.0001, 2457098.64163±0.0004, 24557113.63117±0.0002HJD II = 2457066.61874±0.0008, 2457067.52329±0.0017.In addition, seven observations at minima were introduced as low weighted times of minimum light taken from archived NSVS Data.The following decreasing quadratic ephemeris was determined from all available times of minimum light in this study covering some 15 years:JD Hel MinI = 2457089.55665±0.00054d + 0.4542179±0. 0000006 X E -0.00000000049±0.00000000005 × E2We note that this result has a strong level of confidence. This again gives evidence that the components are coming into contact possibly due to magnetic braking as indicated by dark spot activity on the binary.We initially modeled the B,V,R,I curves simultaneously with the Wilson-Devinney program in a shallow contact configuration (mode 3) as indicated by our Binary Maker 3 fits. This led to a near but non-contact configuration. Next, the general Mode 2 was used to give clues regarding the configuration. During this investigation, the primary component came into contact while the secondary star remained detached. Next, a solution was determined in a semidetached, mode 4 state (larger component filling its critical lobe and the secondary under filing. This may indicate that NSVS 10083189 is coming into contact for the first time. The mode and the period change corroborate.Our semi-detached, near contact solution, gave a mass ratio of 0.58, with component temperatures of

  5. Short and long periodic atmospheric variations between 25 and 200 km

    Science.gov (United States)

    Justus, C. G.; Woodrum, A.

    1973-01-01

    Previously collected data on atmospheric pressure, density, temperature and winds between 25 and 200 km from sources including Meteorological Rocket Network data, ROBIN falling sphere data, grenade release and pitot tube data, meteor winds, chemical release winds, satellite data, and others were analyzed by a daily difference method and results on the distribution statistics, magnitude, and spatial structure of gravity wave and planetary wave atmospheric variations are presented. Time structure of the gravity wave variations were determined by the analysis of residuals from harmonic analysis of time series data. Planetary wave contributions in the 25-85 km range were discovered and found to have significant height and latitudinal variation. Long period planetary waves, and seasonal variations were also computed by harmonic analysis. Revised height variations of the gravity wave contributions in the 25 to 85 km height range were computed. An engineering method and design values for gravity wave magnitudes and wave lengths are given to be used for such tasks as evaluating the effects on the dynamical heating, stability and control of spacecraft such as the space shuttle vehicle in launch or reentry trajectories.

  6. Probability Estimates of Solar Proton Doses During Periods of Low Sunspot Number for Short Duration Missions

    Science.gov (United States)

    Atwell, William; Tylka, Allan J.; Dietrich, William F.; Rojdev, Kristina; Matzkind, Courtney

    2016-01-01

    In an earlier paper presented at ICES in 2015, we investigated solar particle event (SPE) radiation exposures (absorbed dose) to small, thinly-shielded spacecraft during a period when the monthly smoothed sunspot number (SSN) was less than 30. Although such months are generally considered "solar-quiet", SPEs observed during these months even include Ground Level Events, the most energetic type of SPE. In this paper, we add to previous study those SPEs that occurred in 1973-2015 when the SSN was greater than 30 but less than 50. Based on the observable energy range of the solar protons, we classify the event as GLEs, sub-GLEs, and sub-sub-GLEs, all of which are potential contributors to the radiation hazard. We use the spectra of these events to construct a probabilistic model of the absorbed dose due to solar protons when SSN < 50 at various confidence levels for various depths of shielding and for various mission durations. We provide plots and tables of solar proton-induced absorbed dose as functions of confidence level, shielding thickness, and mission-duration that will be useful to system designers.

  7. Magnetic field topology of the cool, active, short-period binary system σ2 Coronae Borealis

    Science.gov (United States)

    Rosén, L.; Kochukhov, O.; Alecian, E.; Neiner, C.; Morin, J.; Wade, G. A.; BinaMIcS Collaboration

    2018-06-01

    Aims: The goal of this work is to study the cool, active binary star σ2 CrB, focussing on its magnetic field. The two F9-G0 components of this system are tidally locked and in a close orbit, increasing the chance of interaction between their magnetospheres. Methods: We used Stokes IV data from the twin spectropolarimeters Narval at the TBL and ESPaDOnS at the CFHT. The least-squares deconvolution multi-line technique was used to increase the signal-to-noise ratio of the data. We then applied a new binary Zeeman-Doppler imaging code to reconstruct simultaneously the magnetic topology and brightness distribution of both components of σ2 CrB. This analysis was carried out for two observational epochs in 2014 and 2017. Results: A previously unconfirmed magnetic field of the primary star has been securely detected. At the same time, the polarisation signatures of the secondary appear to have a systematically larger amplitude than that of the primary. This corresponds to a stronger magnetic field, for which the magnetic energy of the secondary exceeds that of the primary by a factor of 3.3-5.7. While the magnetic energy is similar for the secondary star in the two epochs, the magnetic energy is about twice as high in 2017 for the primary. The magnetic field topology of the two stars in the earlier epoch (2014) is very different. The fractions of energy in the dipole and quadrupole components of the secondary are similar and thereafter decrease with increasing harmonic angular degree ℓ. At the same time, for the primary the fraction of energy in the dipole component is low and the maximum energy contribution comes from ℓ = 4. However, in the 2017 epoch both stars have similar field topologies and a systematically decreasing energy with increasing ℓ. In the earlier epoch, the magnetic field at the visible pole appears to be of opposite polarity for the primary and secondary, suggesting linked magnetospheres. The apparent rotational periods of both σ2 Cr

  8. Interfacial electronic charge transfer and density of states in short period Cu/Cr multilayers; TOPICAL

    International Nuclear Information System (INIS)

    Barbee, T W; Bello, A F; Klepeis, J E; Van Buuren, T

    1999-01-01

    Nanometer period metallic multilayers are ideal structures to investigate electronic phenomena at interfaces between metal films since interfacial atoms comprise a large atomic fraction of the samples. The Cu/Cr binary pair is especially suited to study the interfaces in metals since these elements are mutually insoluble, thus eliminating mixing effects and compound formation and the lattice mismatch is very small. This allows the fabrication of high structural quality Cu/Cr multilayers that have a structure which can be approximated in calculations based on idealized atomic arrangements. The electronic structure of the Cu and the Cr layers in several samples of thin Cu/Cr multilayers were studied using x-ray absorption spectroscopy (XAS). Total electron yield was measured and used to study the white lines at the Cu L(sub 2) and L(sub 3) absorption edges. The white lines at the Cu absorption edges are strongly related to the unoccupied d-orbitals and are used to calculate the amount of charge transfer between the Cr and Cu atoms in interfaces. Analysis of the Cu white lines show a charge transfer of 0.026 electrons/interfacial Cu atom to the interfacial Cr atoms. In the Cu XAS spectra we also observe a van Hove singularity between the L(sub 2) and L(sub 3) absorption edges as expected from the structural analysis. The absorption spectra are compared to partial density of states obtained from a full-potential linear muffin-tin orbital calculation. The calculations support the presence of charge transfer and indicate that it is localized to the first two interfacial layers in both Cu and Cr

  9. Influence of temperature of the short-period heat treatment on mechanical properties of the NiTi alloy

    Directory of Open Access Journals (Sweden)

    Jaroslav Čapek

    2014-01-01

    Full Text Available The equiatomic alloy of nickel and titanium, known as nitinol, possesses unique properties such as superelasticity, pseudoplasticity, shape memory, while maintaining good corrosion resistance and sufficient biocompatibility. Therefore it is used for production of various devices including surgery implants. Heat treatment of nickel-rich NiTi alloys can result in precipitation of nickel-rich phases, which strongly influence tensile and fatigue behaviour of the material.In this work we have studied influence of short-period heat treatment on tensile behaviour and fatigue life of the NiTi (50.9 at. % Ni wire intended for fabrication of surgery stents.

  10. Magnetic Activity and Period Variation Studies of the Short-period Eclipsing Binaries. II. V1101 Her, AD Phe, and NSV 455 (J011636.15-394955.7)

    Science.gov (United States)

    Pi, Qing-feng; Zhang, Li-yun; Bi, Shao-lan; Han, Xianming L.; Wang, Dai-mei; Lu, Hong-peng

    2017-12-01

    In this paper, we present new BVRI light curves of short-period contact eclipsing binaries V1101 Her and AD Phe from our observations carried out from 2014 to 2015 using the SARA KP and SARA CT telescopes. There is an eclipsing binary located at α(2000) = 01h16m36.ˢ15 and δ(2000) = -39°49‧55.″7 in the field of view of AD Phe. We derived an updated ephemeris and found there a cyclic variation overlaying a continuous period increase (V1101 Her) and decrease (AD Phe). This kind of cyclic variation may be attributed to the light time effect via the presence of the third body or magnetic activity cycle. The orbital period increase suggests that V1101 Her is undergoing a mass-transfer from the primary to the secondary component (dM 1/dt = 2.64(±0.11) × 10-6 M ⊙ yr-1) with the third body (P 3 = 13.9(±1.9) years), or 2.81(±0.07) × 10-6 M ⊙ yr-1 for an increase andmagnetic cycle (12.4(±0.5) years). The long-term period decrease suggests that AD Phe is undergoing a mass-transfer from the secondary component to the primary component at a rate of -8.04(±0.09) × 10-8 M ⊙ yr-1 for a period decrease and the third body (P 3 = 56.2(±0.8) years), or -7.11(±0.04) × 10-8 M ⊙ yr-1 for a decrease and magnetic cycle (50.3(±0.5) years). We determined their orbital and geometrical parameters. For AD Phe, we simultaneously analyzed our BVRI light curves and the spectroscopic observations obtained by Duerbeck & Rucinski. The spectral type of V1101 Her was classified as G0 ± 2V by LAMOST stellar spectra survey. The asymmetry of the R-band light curve of AD Phe obtained by McFarlane & Hilditch in 1987 is explained by a cool spot on the primary component.

  11. A simple model for yield prediction of rice based on vegetation index derived from satellite and AMeDAS data during ripening period

    International Nuclear Information System (INIS)

    Wakiyama, Y.; Inoue, K.; Nakazono, K.

    2003-01-01

    The present study was conducted to show a simple model for rice yield predicting by using a vegetation index (NDVI) derived from satellite and meteorological data. In a field experiment, the relationship between the vegetation index and radiation absorbed by the rice canopy was investigated from transplanting to maturity. Their correlation held. This result revealed that the vegetation index could be used as a measure of absorptance of solar radiation by rice canopy. NDVI multiplied by solar radiation (SR) every day was accumulated (Σ(SR·NDVI)) from the field experiment. Σ(SR·NDVI) was plotted against above ground dry matter. It was obvious that they had a strong relationship. Rice yield largely depends on solar radiation and air temperature during the ripening period. Air temperature affects dry matter production. Relationships between Y SR -1 (Y: rice yield, SR: solar radiation) and mean air temperature were investigated from meteorological data and statistical data on rice yield. There was an optimum air temperature, 21.3°C, for ripening. When it was near 21.3°C in the ripening period, the rice yield was higher. We proposed a simple model for yield prediction of rice based on these results. The model is composed with SR·NDVI and the optimum air temperature. Vegetation index was derived from 3 years, LANDSAT TM data in Toyama, Ishikawa, Fukui and Nagano prefectures at heading. The meteorological data was used from AMeDAS data. The model was described as follows: Y = 0.728 SR·NDVI−2.04(T−21.3) 2 + 282 (r 2 = 0.65, n = 43) where Y is rice yield (kg 10a -1 ), SR is solar radiation (MJ m -2 ) during the ripening period (from 10 days before heading to 30 days after heading), T is mean air temperature (°C) during the ripening period. RMSE was 33.7kg 10a -1 . The model revealed good precision. (author)

  12. Interfacial intermixing in InAs/GaSb short-period-superlattices grown by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Luna, E.; Satpati, B.; Trampert, A.; Rodriguez, J. B.; Baranov, A. N.; Tournie, E.

    2010-01-01

    The unique properties of the noncommon-atom InAs/GaSb short-period-superlattices (SPSL) strongly depend on the interface structure. These interfaces are characterized using transmission electron microscopy (TEM). The compositional sharpness is obtained from the comparison of the experimental contrast in g 002 two-beam dark-field TEM images with simulated intensity profiles, which are calculated assuming that the element distribution profiles are described by sigmoidal functions. The interfacial intermixing, defined by the chemical width, is obtained for SPSL with different periods and layer thicknesses, even in the extreme case of nominally less than 3 ML thick InAs layers. Nominal 1 ML InSb layers intentionally inserted are also identified.

  13. On the use of volumetric strain meters to infer additional characteristics of short-period seismic radiation

    Science.gov (United States)

    Borcherdt, R.D.; Johnston, M.J.S.; Glassmoyer, G.

    1989-01-01

    Volumetric strain meters (Sacks-Evertson design) are installed at 15 sites along the San Andreas fault system, to monitor long-term strain changes for earthquake prediction. Deployment of portable broadband, high-resolution digital recorders (GEOS) at several of the sites extends the detection band for volumetric strain to periods shorter than 5 ?? 10-2 sec and permits the simultaneous observation of seismic radiation fields using conventional short-period pendulum seismometers. Recordings of local and regional earthquakes indicate that dilatometers respond to P energy but not direct shear energy and that straingrams can be used to resolve superimposed reflect P and S waves for inference of wave characteristics not permitted by either sensor alone. Simultaneous measurements of incident P- and S-wave amplitudes are used to introduce a technique for single-station estimates of wave field inhomogeneity, free-surface reflection coefficients and local material P velocity. -from Authors

  14. CHANGES IN 137 CS CONCENTRATIONS IN SOIL AND VEGETATION ON THE FLOODPLAIN OF THE SAVANNAH RIVER OVER A 30 YEAR PERIOD

    Energy Technology Data Exchange (ETDEWEB)

    Paller, M.; Jannik, T.; Fledderman, P.

    2007-12-12

    {sup 137}Cs released during 1954-1974 from nuclear production reactors on the Savannah River Site, a US Department of Energy nuclear materials production site in South Carolina, contaminated a portion of the Savannah River floodplain known as Creek Plantation. {sup 137}Cs activity concentrations have been measured in Creek Plantation since 1974 making it possible to calculate effective half-lives for {sup 137}Cs in soil and vegetation and assess the spatial distribution of contaminants on the floodplain. Activity concentrations in soil and vegetation were higher near the center of the floodplain than near the edges as a result of frequent inundation coupled with the presence of low areas that trapped contaminated sediments. {sup 137}Cs activity was highest near the soil surface, but depth related differences diminished with time as a likely result of downward diffusion or leaching. Activity concentrations in vegetation were significantly related to concentrations in soil. The plant to soil concentration ratio (dry weight) averaged 0.49 and exhibited a slight but significant tendency to decrease with time. The effective half-lives for {sup 137}Cs in shallow (0-7.6 cm) soil and in vegetation were 14.9 (95% CI = 12.5-17.3) years and 11.6 (95% CI = 9.1-14.1) years, respectively, and rates of {sup 137}Cs removal from shallow soil and vegetation did not differ significantly among sampling locations. Potential health risks on the Creek Plantation floodplain have declined more rapidly than expected on the basis of radioactive decay alone because of the relatively short effective half-life of {sup 137}Cs.

  15. Layering of Structure in the North American Upper Mantle: Combining Short Period Constraints and Full Waveform Tomography

    Science.gov (United States)

    Roy, C.; Calo, M.; Bodin, T.; Romanowicz, B. A.

    2016-12-01

    Recent receiver function (RF) studies of the north American craton suggest the presence of layering within the cratonic lithosphere with significant lateral variations in the depth. However, the location and character of these discontinuities depends on assumptions made on a background 3D velocity model. On the other hand, the implementation of the Spectral Element Method (SEM) for the computation of the seismic wavefield in 3D structures is allowing improved resolution of volumetric structure in full waveform tomography. The corresponding computations are however very heavy and limit our ability to attain short enough periods to resolve short scale features such as the existence and lateral variations of discontinuities. In order to overcome these limitations, we have developed a methodology that combines full waveform inversion tomography and information provided by short period seismic observables. In a first step we constructed a 3D discontinuous radially anisotropic starting model combining 1D models calculated using RF and L and R wave dispersion data in a Bayesian framework using trans-dimensional MCMC inversion at a collection of 30 stations across the north American continent (Calò et al., 2016). This model was then interpolated and smoothed using a procedure based on residual homogenization (Capdeville et al. 2013) and serves as input model for full waveform tomography using a three-component waveform dataset previously collected (Yuan et al., 2014). The homogenization is necessary to avoid meshing problems and heavy SEM computations. In a second step, several iterations of the full waveform inversion are performed until convergence, using a regional SEM code for forward computations (RegSEM, Cupillard et al., 2012). Results of the inversion are volumetric velocity perturbations around the homogenized starting model, which are then added to the discontinuous 3D starting model. The final result is a multiscale discontinuous model containing both short and

  16. Short-period volcanic gas precursors to phreatic eruptions: Insights from Poás Volcano, Costa Rica

    Science.gov (United States)

    de Moor, Maarten; Aiuppa, Alessandro; Pacheco, Javier; Avard, Geoffroy; Kern, Christoph; Liuzzo, Marco; Martinez, Maria; Giudice, Gaetano; Fischer, Tobias P.

    2016-01-01

    Volcanic eruptions involving interaction with water are amongst the most violent and unpredictable geologic phenomena on Earth. Phreatic eruptions are exceptionally difficult to forecast by traditional geophysical techniques. Here we report on short-term precursory variations in gas emissions related to phreatic blasts at Poás volcano, Costa Rica, as measured with an in situ multiple gas analyzer that was deployed at the edge of the erupting lake. Gas emitted from this hyper-acid crater lake approaches magmatic values of SO2/CO2 1–6 days prior to eruption. The SO2 flux derived from magmatic degassing through the lake is measureable by differential optical absorption spectrometry (sporadic campaign measurements), which allows us to constrain lake gas output and input for the major gas species during eruptive and non-eruptive periods. We can further calculate power supply to the hydrothermal system using volatile mass balance and thermodynamics, which indicates that the magmatic heat flux into the shallow hydrothermal system increases from ∼27 MW during quiescence to ∼59 MW during periods of phreatic events. These transient pulses of gas and heat from the deeper magmatic system generate both phreatic eruptions and the observed short-term changes in gas composition, because at high gas flux scrubbing of sulfur by the hydrothermal system is both kinetically and thermodynamically inhibited whereas CO2gas is always essentially inert in hyperacid conditions. Thus, the SO2/CO2 of lake emissions approaches magmatic values as gas and power supply to the sub-limnic hydrothermal system increase, vaporizing fluids and priming the hydrothermal system for eruption. Our results suggest that high-frequency real-time gas monitoring could provide useful short-term eruptive precursors at volcanoes prone to phreatic explosions.

  17. CSI 2264: CHARACTERIZING YOUNG STARS IN NGC 2264 WITH SHORT-DURATION PERIODIC FLUX DIPS IN THEIR LIGHT CURVES

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, John; Cody, Ann Marie; Rebull, Luisa; Plavchan, Peter; Carey, Sean [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); McGinnis, Pauline; Alencar, Silvia H. P. [Departamento de Física—ICEx—UFMG, Av. Antônio Carlos, 6627, 30270-901, Belo Horizonte, MG (Brazil); Hillenbrand, Lynne A.; Carpenter, John [Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States); Turner, Neal J. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Terebey, Susan [Department of Physics and Astronomy, 5151 State University Drive, California State University at Los Angeles, Los Angeles, CA 90032 (United States); Morales-Calderón, María [Centro de Astrobiología, Dpto. de Astrofísica, INTA-CSIC, PO BOX 78, E-28691, ESAC Campus, Villanueva de la Cañada, Madrid (Spain); Bouvier, Jerome; Venuti, Laura [Université de Grenoble, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG), F-38000 Grenoble (France); CNRS, IPAG, F-38000 Grenoble (France); Hartmann, Lee; Calvet, Nuria [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48105 (United States); Micela, Giusi; Flaccomio, Ettore [INAF—Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, I-90134, Palermo (Italy); Song, Inseok [Department of Physics and Astronomy, The University of Georgia, Athens, GA 30602–2451 (United States); Gutermuth, Rob, E-mail: stauffer@ipac.caltech.edu [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); and others

    2015-04-15

    We identify nine young stellar objects (YSOs) in the NGC 2264 star-forming region with optical CoRoT light curves exhibiting short-duration, shallow periodic flux dips. All of these stars have infrared excesses that are consistent with their having inner disk walls near the Keplerian co-rotation radius. The repeating photometric dips have FWHMs generally less than 1 day, depths almost always less than 15%, and periods (3 < P < 11 days) consistent with dust near the Keplerian co-rotation period. The flux dips vary considerably in their depth from epoch to epoch, but usually persist for several weeks and, in two cases, were present in data collected in successive years. For several of these stars, we also measure the photospheric rotation period and find that the rotation and dip periods are the same, as predicted by standard “disk-locking” models. We attribute these flux dips to clumps of material in or near the inner disk wall, passing through our line of sight to the stellar photosphere. In some cases, these dips are also present in simultaneous Spitzer IRAC light curves at 3.6 and 4.5 microns. We characterize the properties of these dips, and compare the stars with light curves exhibiting this behavior to other classes of YSOs in NGC 2264. A number of physical mechanisms could locally increase the dust scale height near the inner disk wall, and we discuss several of those mechanisms; the most plausible mechanisms are either a disk warp due to interaction with the stellar magnetic field or dust entrained in funnel-flow accretion columns arising near the inner disk wall.

  18. CSI 2264: CHARACTERIZING YOUNG STARS IN NGC 2264 WITH SHORT-DURATION PERIODIC FLUX DIPS IN THEIR LIGHT CURVES

    International Nuclear Information System (INIS)

    Stauffer, John; Cody, Ann Marie; Rebull, Luisa; Plavchan, Peter; Carey, Sean; McGinnis, Pauline; Alencar, Silvia H. P.; Hillenbrand, Lynne A.; Carpenter, John; Turner, Neal J.; Terebey, Susan; Morales-Calderón, María; Bouvier, Jerome; Venuti, Laura; Hartmann, Lee; Calvet, Nuria; Micela, Giusi; Flaccomio, Ettore; Song, Inseok; Gutermuth, Rob

    2015-01-01

    We identify nine young stellar objects (YSOs) in the NGC 2264 star-forming region with optical CoRoT light curves exhibiting short-duration, shallow periodic flux dips. All of these stars have infrared excesses that are consistent with their having inner disk walls near the Keplerian co-rotation radius. The repeating photometric dips have FWHMs generally less than 1 day, depths almost always less than 15%, and periods (3 < P < 11 days) consistent with dust near the Keplerian co-rotation period. The flux dips vary considerably in their depth from epoch to epoch, but usually persist for several weeks and, in two cases, were present in data collected in successive years. For several of these stars, we also measure the photospheric rotation period and find that the rotation and dip periods are the same, as predicted by standard “disk-locking” models. We attribute these flux dips to clumps of material in or near the inner disk wall, passing through our line of sight to the stellar photosphere. In some cases, these dips are also present in simultaneous Spitzer IRAC light curves at 3.6 and 4.5 microns. We characterize the properties of these dips, and compare the stars with light curves exhibiting this behavior to other classes of YSOs in NGC 2264. A number of physical mechanisms could locally increase the dust scale height near the inner disk wall, and we discuss several of those mechanisms; the most plausible mechanisms are either a disk warp due to interaction with the stellar magnetic field or dust entrained in funnel-flow accretion columns arising near the inner disk wall

  19. PHOTOMETRIC STUDIES OF THREE NEGLECTED SHORT-PERIOD CONTACT BINARIES GN BOOTIS, BL LEONIS, AND V1918 CYGNI

    International Nuclear Information System (INIS)

    Yang, Y.-G.; Dai, H.-F.; Qian, S.-B.

    2013-01-01

    We present new photometry for three short-period contact binaries, GN Boo, BL Leo, and V1918 Cyg, observed from 2008 December to 2012 April using several small telescopes in China. Photometric models were deduced from new observations using the updated Wilson-Devinney Code. The results show that GN Boo and BL Leo are W-type contact binaries, while V1918 Cyg is an A-type one. The mass ratios and fill-out factors are q = 0.320(± 0.002) and f = 5.8(± 0.1)% for GN Boo, q = 0.476(± 0.005) and f = 21.3(± 1.1)% for BL Leo, q = 0.264(± 0.002), and f = 49.7(± 0.7)% for V1918 Cyg, respectively. From the (O – C) curves, it is discovered that the orbital periods of three binaries have varied in a complicated way, i.e., cyclic oscillation for GN Boo, long-term period decrease for BL Leo, and both for V1918 Cyg. The cyclic variations for GN Boo and V1918 Cyg may probably be attributed to the magnetic activity of the primary component or light-time effect due to the third body. Meanwhile, the secular period decreases for BL Leo and V1918 Cyg may result from mass transfer from the primary to the secondary, accompanying the mass and angular momentum loss from the central system. Finally, GN Boo, BL Leo, and V1918 Cyg will evolve into deep contact binaries. Additionally, a statistical study of 37 contact binaries with decreasing periods is given. We obtained the relations of q – f and q – dln P/dt, and preliminarily determined the mass loss rate of dln M/dt from the binary system.

  20. PG 0308 + 096 and PG 1026 + 002 - Two new short period binary stars resulting from common-envelope evolution

    Science.gov (United States)

    Saffer, Rex A.; Wade, Richard A.; Liebert, James; Green, Richard F.; Sion, Edward M.; Bechtold, J.; Foss, Diana; Kidder, K.

    1993-01-01

    Ultraviolet spectroscopy, optical spectroscopy, and spectrophotometry have been used to study the excess UV stars PG 0308 + 096 and PG 1026 + 002. Both objects are short-period binary systems, each containing a DA white dwarf star and a dM star. Orbital periods of approximately 0.284 day for PG 0308 + 096, and aproximately 0.597 day for PG 1026, have been found by spectroscopic analysis of the H-alpha emission line. Ly-alpha and Balmer line profile fitting were used to estimate the mass of white dwarf stars; mass estimates for the dM stars are based on their spectral types. The orbital inclinations are derived from these masses, the periods, and amplitudes of the H-alpha radial velocity curves. The equivalent width of the H-alpha emission line, in each binary system, varies with the orbital phase in such a manner as to imply that it arises, in large part at least, from the hemisphere of the M star that faces the white dwarf star.

  1. Exercise during Short-Term and Long-Term Continuous Exposure to Hypoxia Exacerbates Sleep-Related Periodic Breathing

    Science.gov (United States)

    Tellez, Helio Fernandez; Morrison, Shawnda A.; Neyt, Xavier; Mairesse, Olivier; Piacentini, Maria Francesca; Macdonald-Nethercott, Eoin; Pangerc, Andrej; Dolenc-Groselj, Leja; Eiken, Ola; Pattyn, Nathalie; Mekjavic, Igor B.; Meeusen, Romain

    2016-01-01

    Study Objectives: Exposure to hypoxia elevates chemosensitivity, which can lead to periodic breathing. Exercise impacts gas exchange, altering chemosensitivity; however, interactions between sleep, exercise and chronic hypoxic exposure have not been examined. This study investigated whether exercise exacerbates sleep-related periodic breathing in hypoxia. Methods: Two experimental phases. Short-Term Phase: a laboratory controlled, group-design study in which 16 active, healthy men (age: 25 ± 3 y, height: 1.79 ± 0.06 m, mass: 74 ± 8 kg) were confined to a normobaric hypoxic environment (FIO2 = 0.139 ± 0.003, 4,000 m) for 10 days, after random assignment to a sedentary (control, CON) or cycle-exercise group (EX). Long-Term Phase: conducted at the Concordia Antarctic Research Station (3,800 m equivalent at the Equator) where 14 men (age: 36 ± 9 y, height: 1.77 ± 0.09 m, mass: 75 ± 10 kg) lived for 12–14 months, continuously confined. Participants were stratified post hoc based on self-reported physical activity levels. We quantified apnea-hypopnea index (AHI) and physical activity variables. Results: Short-Term Phase: mean AHI scores were significantly elevated in the EX group compared to CON (Night1 = CON: 39 ± 51, EX: 91 ± 59; Night10 = CON: 32 ± 32, EX: 92 ± 48; P = 0.046). Long-Term Phase: AHI was correlated to mean exercise time (R2 = 0.4857; P = 0.008) and the coefficient of variation in night oxyhemoglobin saturation (SpO2; R2 = 0.3062; P = 0.049). Conclusions: Data indicate that exercise (physical activity) per se affects night SpO2 concentrations and AHI after a minimum of two bouts of moderate-intensity hypoxic exercise, while habitual physical activity in hypobaric hypoxic confinement affects breathing during sleep, up to 13+ months' duration Citation: Tellez HF, Morrison SA, Neyt X, Mairesse O, Piacentini MF, Macdonald-Nethercott E, Pangerc A, Dolenc-Groselj L, Eiken O, Pattyn N, Mekjavic IB, Meeusen R. Exercise during short-term and long

  2. A passive method for the determination of the equilibrium factor between radon gas and its short period progeny

    International Nuclear Information System (INIS)

    Lopez, Fabio O.; Canoba, Analia C.

    2001-01-01

    Due to the radiological importance of 222 Rn gas and its progeny of short period it is extremely necessary to count with an adequate methodology for the determination of its concentration in the different atmospheres in which human activity is developed. In this work a method was developed to determine the concentration of 222 Rn gas and the equilibrium factor between the concentration of the gas and its descendants, by means of a single device that has two Makrofol passive tracks detector. This device is completely passive and integrating, conditions that make it very appropriate to be used in any atmospheres in which human activity is developed, for example in houses, schools, places of work, underground mines, etc. (author)

  3. Short-range order in alloys of nickel with the elements of group VIII of the periodic table

    International Nuclear Information System (INIS)

    Khwaja, F.A.

    1981-08-01

    Experimental measurements of the diffuse X-ray scattering intensity were performed on alloys of Ni with Rh and Os. The atomic short-range order (SRO) parameters αsub(i) and the size-effect parameters βsub(i) were calculated from these measurements. It is established that SRO and size-effect exist in Ni-Rh and Ni-Os alloys analogously as in a few other alloys of Ni with the elements of group VIII of the periodic table. The experimental data was interpreted theoretically by calculating the interaction energies from the pseudo-potentials and the effective valencies of the individual components of the systems studied. It was found that theoretically calculated values of the interaction energies for these alloys are inconsistent with the experimentally determined sign of the SRO parameter. (author)

  4. Quasi-periodic oscillations in short recurring bursts of the soft gamma repeater J1550–5418

    Energy Technology Data Exchange (ETDEWEB)

    Huppenkothen, D.; D' Angelo, C.; Watts, A. L.; Heil, L.; Van der Klis, M.; Van der Horst, A. J. [Astronomical Institute " Anton Pannekoek," University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Kouveliotou, C. [Astrophysics Office, ZP 12, NASA-Marshall Space Flight Center, Huntsville, AL 35812 (United States); Baring, M. G. [Department of Physics and Astronomy, Rice University, MS-108, P.O. Box 1892, Houston, TX 77251 (United States); Göğüş, E.; Kaneko, Y. [SabancıUniversity, Orhanlı-Tuzla, İstanbul 34956 (Turkey); Granot, J. [Department of Natural Sciences, The Open University of Israel, 1 University Road, P.O. Box 808, Ra' anana 43537 (Israel); Lin, L. [François Arago Centre, APC, 10 rue Alice Domon et Léonie Duquet, F-75205 Paris (France); Von Kienlin, A. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany); Younes, G., E-mail: D.Huppenkothen@uva.nl [NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States)

    2014-06-01

    The discovery of quasi-periodic oscillations (QPOs) in magnetar giant flares has opened up prospects for neutron star asteroseismology. The scarcity of giant flares makes a search for QPOs in the shorter, far more numerous bursts from soft gamma repeaters (SGRs) desirable. In Huppenkothen et al., we developed a Bayesian method for searching for QPOs in short magnetar bursts, taking into account the effects of the complicated burst structure, and have shown its feasibility on a small sample of bursts. Here we apply the same method to a much larger sample from a burst storm of 286 bursts from SGR J1550–5418. We report a candidate signal at 260 Hz in a search of the individual bursts, which is fairly broad. We also find two QPOs at ∼93 Hz, and one at 127 Hz, when averaging periodograms from a number of bursts in individual triggers, at frequencies close to QPOs previously observed in magnetar giant flares. Finally, for the first time, we explore the overall burst variability in the sample and report a weak anti-correlation between the power-law index of the broadband model characterizing aperiodic burst variability and the burst duration: shorter bursts have steeper power-law indices than longer bursts. This indicates that longer bursts vary over a broader range of timescales and are not simply longer versions of the short bursts.

  5. Genome variability of foot-and-mouth disease virus during the short period of the 2010 epidemic in Japan.

    Science.gov (United States)

    Nishi, Tatsuya; Yamada, Manabu; Fukai, Katsuhiko; Shimada, Nobuaki; Morioka, Kazuki; Yoshida, Kazuo; Sakamoto, Kenichi; Kanno, Toru; Yamakawa, Makoto

    2017-02-01

    Foot-and-mouth disease virus (FMDV) is highly contagious and has a high mutation rate, leading to extensive genetic variation. To investigate how FMDV genetically evolves over a short period of an epidemic after initial introduction into an FMD-free area, whole L-fragment sequences of 104 FMDVs isolated from the 2010 epidemic in Japan, which continued for less than three months were determined and phylogenetically and comparatively analyzed. Phylogenetic analysis of whole L-fragment sequences showed that these isolates were classified into a single group, indicating that FMDV was introduced into Japan in the epidemic via a single introduction. Nucleotide sequences of 104 virus isolates showed more than 99.56% pairwise identity rates without any genetic deletion or insertion, although no sequences were completely identical with each other. These results indicate that genetic substitutions of FMDV occurred gradually and constantly during the epidemic and generation of an extensive mutant virus could have been prevented by rapid eradication strategy. From comparative analysis of variability of each FMDV protein coding region, VP4 and 2C regions showed the highest average identity rates and invariant rates, and were confirmed as highly conserved. In contrast, the protein coding regions VP2 and VP1 were confirmed to be highly variable regions with the lowest average identity rates and invariant rates, respectively. Our data demonstrate the importance of rapid eradication strategy in an FMD epidemic and provide valuable information on the genome variability of FMDV during the short period of an epidemic. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Study of short-period RS Canum Venaticorum and W Ursae Majoris binary systems: The global nature of Hα

    International Nuclear Information System (INIS)

    Barden, S.C.

    1985-01-01

    I present the rotation versus emission characteristics of the Hα line for several short-period (P -5 ) and the Rossby number (the ratio between the rotational period and the convective time scale) is seen for those components showing emission. Such a correlation suggests that the Hα line is a good diagnostic for the study of the magnetic-related activity in late-type stellar systems. Plotting the L/sub Halpha//L/sub bol/ against a measure of the tidal amplitude of Scharlemann shows that the activity of the W UMa secondary components may be shut off by the tidal forces of the primaries. The shut-off appears in those components having a tidal amplitude > or approx. =0.02. It is, however, unclear whether the tidal damping of the differential rotation is the sole mechanism responsible for the shut-off of the Hα emission, as the activity damping may also be attributable to the contact nature of the W UMa systems

  7. Performance of a reactor containing denitrifying immobilized biomass in removing ethanol and aromatic hydrocarbons (BTEX) in a short operating period

    International Nuclear Information System (INIS)

    Gusmao, Valquiria Ribeiro; Chinalia, Fabio Alexandre; Sakamoto, Isabel Kimiko; Varesche, Maria Bernadete Amancio

    2007-01-01

    A horizontal-flow anaerobic immobilized biomass reactor (HAIB) containing denitrifying biomass was evaluated with respect to its ability to remove, separately and in a short operating period (30 days), organic matter, nitrate, and the hydrocarbons benzene (41.4 mg L -1 ), toluene (27.8 mg L -1 ), ethylbenzene (31.1 mg L -1 ), o-xylene (28.5 mg L -1 ), m-xylene (28.4 mg L -1 ) and p-xylene (32.1 mg L -1 ). The purified culture, which was grown in the presence of the specific hydrocarbon, was used as the source of cells to be immobilized in the polyurethane foam. After 30 days of operation, the foam was removed and a new immobilized biomass was grown in the presence of another hydrocarbon. The average hydrocarbon removal efficiency attained was 97%. The organic matter, especially ethanol, was removed with an average efficiency of 83% at a mean influent concentration of 1185.0 mg L -1 . A concomitant removal of 97% of nitrate was observed for a mean influent concentration of 423.4 mg L -1 . The independent removal of each hydrocarbon demonstrated that these contaminants can be biodegraded separately, without the need for a compound to be the primary substrate for the degradation of another. This study proposes the application of the system for treatment of areas contaminated with these compounds, with substitution and formation of a biofilm in a 30-day period

  8. The Discovery and Mass Measurement of a New Ultra-short-period Planet: K2-131b

    Science.gov (United States)

    Dai, Fei; Winn, Joshua N.; Gandolfi, Davide; Wang, Sharon X.; Teske, Johanna K.; Burt, Jennifer; Albrecht, Simon; Barragán, Oscar; Cochran, William D.; Endl, Michael; Fridlund, Malcolm; Hatzes, Artie P.; Hirano, Teruyuki; Hirsch, Lea A.; Johnson, Marshall C.; Justesen, Anders Bo; Livingston, John; Persson, Carina M.; Prieto-Arranz, Jorge; Vanderburg, Andrew; Alonso, Roi; Antoniciello, Giuliano; Arriagada, Pamela; Butler, R. P.; Cabrera, Juan; Crane, Jeffrey D.; Cusano, Felice; Csizmadia, Szilárd; Deeg, Hans; Dieterich, Sergio B.; Eigmüller, Philipp; Erikson, Anders; Everett, Mark E.; Fukui, Akihiko; Grziwa, Sascha; Guenther, Eike W.; Henry, Gregory W.; Howell, Steve B.; Johnson, John Asher; Korth, Judith; Kuzuhara, Masayuki; Narita, Norio; Nespral, David; Nowak, Grzegorz; Palle, Enric; Pätzold, Martin; Rauer, Heike; Montañés Rodríguez, Pilar; Shectman, Stephen A.; Smith, Alexis M. S.; Thompson, Ian B.; Van Eylen, Vincent; Williamson, Michael W.; Wittenmyer, Robert A.

    2017-12-01

    We report the discovery of a new ultra-short-period planet and summarize the properties of all such planets for which the mass and radius have been measured. The new planet, K2-131b, was discovered in K2 Campaign 10. It has a radius of {1.81}-0.12+0.16 {R}\\oplus and orbits a G dwarf with a period of 8.9 hr. Radial velocities obtained with Magellan/PFS and TNG/HARPS-N show evidence for stellar activity along with orbital motion. We determined the planetary mass using two different methods: (1) the “floating chunk offset” method, based only on changes in velocity observed on the same night; and (2) a Gaussian process regression based on both the radial velocity and photometric time series. The results are consistent and lead to a mass measurement of 6.5+/- 1.6 {M}\\oplus and a mean density of {6.0}-2.7+3.0 g cm-3.

  9. Lithospheric layering in the North American craton revealed by including Short Period Constraints in Full Waveform Tomography

    Science.gov (United States)

    Roy, C.; Calo, M.; Bodin, T.; Romanowicz, B. A.

    2017-12-01

    Recent receiver function studies of the North American craton suggest the presence of significant layering within the cratonic lithosphere, with significant lateral variations in the depth of the velocity discontinuities. These structural boundaries have been confirmed recently using a transdimensional Markov Chain Monte Carlo approach (TMCMC), inverting surface wave dispersion data and converted phases simultaneously (Calò et al., 2016; Roy and Romanowicz 2017). The lateral resolution of upper mantle structure can be improved with a high density of broadband seismic stations, or with a sparse network using full waveform inversion based on numerical wavefield computation methods such as the Spectral Element Method (SEM). However, inverting for discontinuities with strong topography such as MLDS's or LAB, presents challenges in an inversion framework, both computationally, due to the short periods required, and from the point of view of stability of the inversion. To overcome these limitations, and to improve resolution of layering in the upper mantle, we are developing a methodology that combines full waveform inversion tomography and information provided by short period seismic observables. We have extended the 30 1D radially anisotropic shear velocity profiles of Calò et al. 2016 to several other stations, for which we used a recent shear velocity model (Clouzet et al., 2017) as constraint in the modeling. These 1D profiles, including both isotropic and anisotropic discontinuities in the upper mantle (above 300 km depth) are then used to build a 3D starting model for the full waveform tomographic inversion. This model is built after 1) homogenization of the layered 1D models and 2) interpolation between the 1D smooth profiles and the model of Clouzet et al. 2017, resulting in a smooth 3D starting model. Waveforms used in the inversion are filtered at periods longer than 30s. We use the SEM code "RegSEM" for forward computations and a quasi-Newton inversion

  10. MARVELS-1b: A SHORT-PERIOD, BROWN DWARF DESERT CANDIDATE FROM THE SDSS-III MARVELS PLANET SEARCH

    International Nuclear Information System (INIS)

    Lee, Brian L.; Ge Jian; Fleming, Scott W.; Mahadevan, Suvrath; Sivarani, Thirupathi; Stassun, Keivan G.; Gary, Bruce; Pepper, Joshua; Gaudi, B. Scott; Eastman, Jason D.; Siverd, Robert J.; Barnes, Rory; Laws, Chris; Wisniewski, John P.; Wright, Jason; Ghezzi, Luan; Ogando, Ricardo L. C.; Maia, Marcio A. G.; Da Costa, Luiz Nicolaci; Porto de Mello, G. F.

    2011-01-01

    We present a new short-period brown dwarf (BD) candidate around the star TYC 1240-00945-1. This candidate was discovered in the first year of the Multi-object APO Radial Velocity Exoplanets Large-area Survey (MARVELS), which is part of the Sloan Digital Sky Survey (SDSS) III, and we designate the BD as MARVELS-1b. MARVELS uses the technique of dispersed fixed-delay interferometery to simultaneously obtain radial velocity (RV) measurements for 60 objects per field using a single, custom-built instrument that is fiber fed from the SDSS 2.5 m telescope. From our 20 RV measurements spread over a ∼370 day time baseline, we derive a Keplerian orbital fit with semi-amplitude K = 2.533 ± 0.025 km s -1 , period P = 5.8953 ± 0.0004 days, and eccentricity consistent with circular. Independent follow-up RV data confirm the orbit. Adopting a mass of 1.37 ± 0.11 M sun for the slightly evolved F9 host star, we infer that the companion has a minimum mass of 28.0 ± 1.5 M Jup , a semimajor axis 0.071 ± 0.002 AU assuming an edge-on orbit, and is probably tidally synchronized. We find no evidence for coherent intrinsic variability of the host star at the period of the companion at levels greater than a few millimagnitudes. The companion has an a priori transit probability of ∼14%. Although we find no evidence for transits, we cannot definitively rule them out for companion radii ∼ Jup .

  11. Training Load, Physical Performance, Biochemical Markers, and Psychological Stress During A Short Preparatory Period in Brazilian Elite Male Volleyball Players.

    Science.gov (United States)

    Horta, Thiago A G; Bara Filho, Maurício G; Coimbra, Danilo R; Miranda, R; Werneck, Francisco Z

    2017-12-11

    The aim of this study was to assess the relationship between training load (TL) and physical performance, biochemical markers, and psychological stress during a short preparatory period (PP) in Brazilian elite male volleyball players. Twelve volleyball players from a team competing in the Brazilian Men's Volleyball Super League were enrolled (26.9 ± 4.6 years). Countermovement Jump (CMJ), Creatine Kinase (CK), Testosterone (T), Cortisol (Cr), T/Cr ratio, and Recovery and Stress Questionnaire for Athletes (RESTQ-Sport) were collected at baseline, after 2, 4, and 6 week. TL was quantified daily using the Rating of Perceived Exertion (RPE). Differences were noted between Total Weekly TL (TWTL) (F3,33 = 50.907; p = 0.0001), CK (F3,33 = 16.157; p = 0.0001), and T (F3,33 = 3.283; p = 0.03). No differences were seen in CMJ (F3,33 = 1.821; p = 0.16), Cr (F3,33 = 2.409; p = 0.08), or T/Cr ratio (F3,33 = 1.527; p = 0.23). The RESTQ-Sport demonstrated differences between moments in Social Stress (F3,33 = 2.297; p = 0.04; Eta = 0.25), Success (F3,33 = 4.350; p = 0.01; Eta = 0.19), General Well-being (F3,33 = 4.465; p = 0.01; Eta = 0.36), and Injury (F3,33 = 2.792; p = 0.05; Eta = 0.62). The results showed a significant correlations of small to moderate magnitude between TWTL and CK (r = 0.32; p = 0.05). In conclusion, a short PP in volleyball leads to increased TL, CK level, and psychological stress. TL was related with the increase of CK, suggesting muscle damage without increased of physical performance.

  12. The ACER pollen and charcoal database: a global resource to document vegetation and fire response to abrupt climate changes during the last glacial period

    Science.gov (United States)

    Sánchez Goñi, María Fernanda; Desprat, Stéphanie; Daniau, Anne-Laure; Bassinot, Frank C.; Polanco-Martínez, Josué M.; Harrison, Sandy P.; Allen, Judy R. M.; Anderson, R. Scott; Behling, Hermann; Bonnefille, Raymonde; Burjachs, Francesc; Carrión, José S.; Cheddadi, Rachid; Clark, James S.; Combourieu-Nebout, Nathalie; Mustaphi, Colin. J. Courtney; Debusk, Georg H.; Dupont, Lydie M.; Finch, Jemma M.; Fletcher, William J.; Giardini, Marco; González, Catalina; Gosling, William D.; Grigg, Laurie D.; Grimm, Eric C.; Hayashi, Ryoma; Helmens, Karin; Heusser, Linda E.; Hill, Trevor; Hope, Geoffrey; Huntley, Brian; Igarashi, Yaeko; Irino, Tomohisa; Jacobs, Bonnie; Jiménez-Moreno, Gonzalo; Kawai, Sayuri; Kershaw, A. Peter; Kumon, Fujio; Lawson, Ian T.; Ledru, Marie-Pierre; Lézine, Anne-Marie; Liew, Ping Mei; Magri, Donatella; Marchant, Robert; Margari, Vasiliki; Mayle, Francis E.; Merna McKenzie, G.; Moss, Patrick; Müller, Stefanie; Müller, Ulrich C.; Naughton, Filipa; Newnham, Rewi M.; Oba, Tadamichi; Pérez-Obiol, Ramón; Pini, Roberta; Ravazzi, Cesare; Roucoux, Katy H.; Rucina, Stephen M.; Scott, Louis; Takahara, Hikaru; Tzedakis, Polichronis C.; Urrego, Dunia H.; van Geel, Bas; Valencia, B. Guido; Vandergoes, Marcus J.; Vincens, Annie; Whitlock, Cathy L.; Willard, Debra A.; Yamamoto, Masanobu

    2017-09-01

    Quaternary records provide an opportunity to examine the nature of the vegetation and fire responses to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st-century. The best documented examples of rapid climate change in the past are the warming events associated with the Dansgaard-Oeschger (D-O) cycles during the last glacial period, which were sufficiently large to have had a potential feedback through changes in albedo and greenhouse gas emissions on climate. Previous reconstructions of vegetation and fire changes during the D-O cycles used independently constructed age models, making it difficult to compare the changes between different sites and regions. Here, we present the ACER (Abrupt Climate Changes and Environmental Responses) global database, which includes 93 pollen records from the last glacial period (73-15 ka) with a temporal resolution better than 1000 years, 32 of which also provide charcoal records. A harmonized and consistent chronology based on radiometric dating (14C, 234U/230Th, optically stimulated luminescence (OSL), 40Ar/39Ar-dated tephra layers) has been constructed for 86 of these records, although in some cases additional information was derived using common control points based on event stratigraphy. The ACER database compiles metadata including geospatial and dating information, pollen and charcoal counts, and pollen percentages of the characteristic biomes and is archived in Microsoft AccessTM at PANGAEA.870867" target="_blank">https://doi.org/10.1594/PANGAEA.870867.

  13. Waveform correlation and coherence of short-period seismic noise within Gauribidanur array with implications for event detection

    International Nuclear Information System (INIS)

    Bhadauria, Y.S.; Arora, S.K.

    1995-01-01

    In continuation with our effort to model the short-period micro seismic noise at the seismic array at Gauribidanur (GBA), we have examined in detail time-correlation and spectral coherence of the noise field within the array space. This has implications of maximum possible improvement in signal-to-noise ratio (SNR) relevant to event detection. The basis of this study is about a hundred representative wide-band noise samples collected from GBA throughout the year 1992. Both time-structured correlation as well as coherence of the noise waveforms are found to be practically independent of the inter element distances within the array, and they exhibit strong temporal and spectral stability. It turns out that the noise is largely incoherent at frequencies ranging upwards from 2 Hz; the coherency coefficient tends to increase in the lower frequency range attaining a maximum of 0.6 close to 0.5 Hz. While the maximum absolute cross-correlation also diminishes with increasing frequency, the zero-lag cross-correlation is found to be insensitive to frequency filtering regardless of the pass band. An extremely small value of -0.01 of the zero-lag correlation and a comparatively higher year-round average estimate at 0.15 of the maximum absolute time-lagged correlation yields an SNR improvement varying between a probable high of 4.1 and a low of 2.3 for the full 20-element array. 19 refs., 6 figs

  14. Nature of short-period microtremors on the cliff-like ground. 3; Gakechi kinbo no tanshuki bido . 3

    Energy Technology Data Exchange (ETDEWEB)

    Maiguma, T; Matsuzawa, H [Saitama University, Saitama (Japan). Faculty of Engineering

    1996-05-01

    Vibration characteristics were investigated of the ground in the vicinity of a cliff-like sharp slope. Short-period microtremors were observed in the vicinity of an artificially made cliff-like test ground, height 8m and inclination 90{degree}, and a natural cliff, height approximately 9m and inclination approximately 35{degree}. The artificial cliff was reinforced by a virtually vertical retaining wall of concrete, and the ground was prepared for testing with a belt approximately 20m wide and 50m long along the cliff face. All the vibration components were simultaneously measured at measuring spots that were located 5-40m apart from the cliff end and orientated perpendicular to the cliff face. It was then found that in case of artificial cliff there is a conspicuous 3.1Hz prevalent ground vibration in the component squarely meeting the cliff face, that the prevalent ground vibration is not particularly great near the cliff end because the retaining wall and the ground are artificially prepared, that there is no influence of the cliff-like ground in the ground vibration parallel to or vertical along the cliff face, and that in case of natural ground there are no vibration characteristic proper to a cliff-like ground in any of the vibration components. 3 refs., 7 figs.

  15. Evidence of negative electrorefraction in type-II GaAs/GaAlAs short-period superlattice

    International Nuclear Information System (INIS)

    Shchukin, V A; Ledentsov, N N; Karachinsky, L Ya; Novikov, I I; Egorov, A Yu; Blokhin, S A; Maximov, M V; Gordeev, N Yu; Kulagina, M M; Ustinov, V M

    2015-01-01

    A type-II GaAs/GaAlAs short-period superlattice (SPSL) used as an electro-optic medium for the spectral range 820–850 nm is studied in a vertical microcavity geometry. SPSL is sandwiched between two GaAlAs distributed Bragg reflectors. Optical power reflectance (OR) spectra are measured as a function of applied reverse bias at different tilt angles and temperatures. All spectra reveal a blue shift of the reflectivity dip upon applied voltage which evidences a negative electrorefraction of the electro-optic medium. The shift enhances up to ∼0.6 nm once the exciton resonance is brought close to the wavelength of the reflectivity dip. As opposed to those modulators based on quantum–confined Stark effect, no increased absorption is observed at an applied bias, because the integrated intensity of the reflectivity dip in the OR spectra is virtually constant. This indicates a low absorption loss with applied bias and consequently a high potential for the increased dynamic range of the related modulator. (paper)

  16. Nature of short-period microtremors on the cliff-like ground. Part 4; Gakechi kinbo no tanshuki bido. 4

    Energy Technology Data Exchange (ETDEWEB)

    Maiguma, T; Yoshiike, T [Waseda University, Tokyo (Japan). School of Science and Engineering

    1996-10-01

    Microtremors were measured on the cliff-like ground with a height about 10 m, to examine the vibration characteristics. Test field-1 near Akabane, Kita-ku, Tokyo is located in a part of Musashino plateau covered with Kanto loam on its surface, and has relatively sound ground. Test field-2 at Machida is located in the western part of Tama hills, and also has Kanto loam on its surface. For the cliff-like ground with inclined angle 70{degree} at Akabane, remarkably predominant frequency 3.2 Hz was observed for the microtremors in the direction perpendicular to the cliff surface. However, this predominant vibration did not become larger due to the damping effects of the reinforcement walls near the end of cliff and the large trees on the cliff. Influence of the cliff-like ground was scarcely observed in the microtremors spectrum in both the directions parallel and vertical to the cliff-surface. From the observation of microtremors with short period on the cliff-like ground with inclined angle around 32{degree} at Machida, influence of cliff-like ground was not observed in the microtremors spectrum in all of the vibrating directions perpendicular, parallel and vertical to the cliff surface. 3 refs., 10 figs.

  17. Optical properties of spontaneous lateral composition modulation in AlAs/InAs short-period superlattices

    International Nuclear Information System (INIS)

    Francoeur, S.; Zhang, Yong; Norman, A. G.; Alsina, F.; Mascarenhas, A.; Reno, J. L.; Jones, E. D.; Lee, S. R.; Follstaedt, D. M.

    2000-01-01

    The effect of lateral composition modulation, spontaneously generated during the epitaxial growth of an AlAs/InAs short-period superlattice, on the electronic band structure is investigated using phototransmission and photoluminescence spectroscopy. Compared with uniform layers of identical average composition, the presence of the composition modulation considerably reduces the band-gap energy and produces strongly polarized emission and absorption spectra. We demonstrate that the dominant polarization direction can selectively be aligned along the [1(bar sign)10] or [010] crystallographic directions. In compressively strained samples, the use of (001) InP substrates slightly miscut toward (111)A or (101) resulted in modulation directions along [110] or [100], respectively, and dominant polarization directions along a direction orthogonal to the respective composition modulation. Band-gap reductions as high as 350 and 310 meV are obtained for samples with composition modulation along [110] and [100], respectively. Ratios of polarized intensities up to 26 are observed in transmission spectra. (c) 2000 American Institute of Physics

  18. Production of well-matured compost from night-soil sludge by an extremely short period of thermophilic composting.

    Science.gov (United States)

    Nakasaki, Kiyohiko; Ohtaki, Akihito; Takemoto, Minoru; Fujiwara, Shunrokuro

    2011-03-01

    The effect of various operational conditions on the decomposition of organic material during the composting of night-soil treatment sludge was quantitatively examined. The optimum composting conditions were found to be a temperature of ca. 60°C and an initial pH value of 8. Rapid decomposition of organic matter ceased by the sixth day of composting under these optimum conditions, and the final value of the cumulative emission of carbon (E(C)), which represents the degree of organic matter decomposition, was less than 40%, indicating that the sludge contained only a small amount of easily degradable organic material. A plant growth assay using Komatsuna (Brassica campestris L. var. rapiferafroug) in a 1/5000a standard cultivation pot was then conducted for the compost at various degrees of organic matter decomposition: the raw composting material, the final compost obtained on day 6, and the 2 intermediate compost products (i.e., E(C)=10% and 20%). It was found that the larger the E(C), the greater the yield of Komatsuna growth. It was also found that 6 days of composting is sufficient to promote Komatsuna growth at the standard loading level, which is equivalent to a 1.5 g N/pot, since the promotion effect was as high as that obtained using chemical fertilizer. It can therefore be concluded that well-matured compost could be obtained in a short period of time (i.e., as early as 6 days), when night-soil sludge is composted under optimum conditions. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. InN/GaN short-period superlattices as ordered InGaN ternary alloys

    International Nuclear Information System (INIS)

    Kusakabe, Kazuhide; Imai, Daichi; Wang, Ke; Yoshikawa, Akihiko

    2016-01-01

    Coherent (InN) 1 /(GaN) n short-period superlattices (SPSs) were successfully grown through dynamic atomic layer epitaxy (D-ALEp) mode by RF-plasma molecular beam epitaxy (MBE), where GaN layer thicknesses n were thinned down to 4 monolayer (ML). After this achievement, we demonstrated quasi-ternary InGaN behavior in their photoluminescence (PL) spectra for the first time. It was found interestingly that GaN layer thickness of n = 4 ML was the criterion both for structural control and continuum-band formation. Although highly lattice-mismatched InN/GaN interfaces easily introduce relaxation in (InN) 1 /(GaN) 4 SPSs during growth depending on the dynamic surface stoichiometry condition, this problem was overcome by precise control/removal of fluid-like residual In/Ga metals on the growth front with in-situ monitoring method. The (InN) 1 /(GaN) n SPSs with n ≥ 7 ML showed a constant PL peak energy around 3.2 eV at 12 K, reflecting discrete electron/hole wavefunctions. On the other hand, the (InN) 1 /(GaN) 4 SPSs indicated the red-shifted PL peak at 2.93 eV at 12 K, which was attributed to the continuum-band state with increasing in the overlap of electrons/hole wavefunctions. This result is concluded that the (InN) 1 /(GaN) 4 SPSs can be considered as ordered InGaN alloys. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. The ACER pollen and charcoal database: a global resource to document vegetation and fire response to abrupt climate changes during the last glacial period

    Directory of Open Access Journals (Sweden)

    M. F. Sánchez Goñi

    2017-09-01

    Full Text Available Quaternary records provide an opportunity to examine the nature of the vegetation and fire responses to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st-century. The best documented examples of rapid climate change in the past are the warming events associated with the Dansgaard–Oeschger (D–O cycles during the last glacial period, which were sufficiently large to have had a potential feedback through changes in albedo and greenhouse gas emissions on climate. Previous reconstructions of vegetation and fire changes during the D–O cycles used independently constructed age models, making it difficult to compare the changes between different sites and regions. Here, we present the ACER (Abrupt Climate Changes and Environmental Responses global database, which includes 93 pollen records from the last glacial period (73–15 ka with a temporal resolution better than 1000 years, 32 of which also provide charcoal records. A harmonized and consistent chronology based on radiometric dating (14C, 234U∕230Th, optically stimulated luminescence (OSL, 40Ar∕39Ar-dated tephra layers has been constructed for 86 of these records, although in some cases additional information was derived using common control points based on event stratigraphy. The ACER database compiles metadata including geospatial and dating information, pollen and charcoal counts, and pollen percentages of the characteristic biomes and is archived in Microsoft AccessTM at https://doi.org/10.1594/PANGAEA.870867.

  1. Intensive measurements of gas, water, and energy exchange between vegetation and troposphere during the MONTES campaign in a vegetation gradient from short semi-desertic shrublands to tall wet temperate forests in the NW Mediterranean Basin

    Science.gov (United States)

    Peñuelas, J.; Guenther, A.; Rapparini, F.; Llusia, J.; Filella, I.; Seco, R.; Estiarte, M.; Mejia-Chang, M.; Ogaya, R.; Ibañez, J.; Sardans, J.; Castaño, L. M.; Turnipseed, A.; Duhl, T.; Harley, P.; Vila, J.; Estavillo, J. M.; Menéndez, S.; Facini, O.; Baraldi, R.; Geron, C.; Mak, J.; Patton, E. G.; Jiang, X.; Greenberg, J.

    2013-08-01

    MONTES (“Woodlands”) was a multidisciplinary international field campaign aimed at measuring energy, water and especially gas exchange between vegetation and atmosphere in a gradient from short semi-desertic shrublands to tall wet temperate forests in NE Spain in the North Western Mediterranean Basin (WMB). The measurements were performed at a semidesertic area (Monegros), at a coastal Mediterranean shrubland area (Garraf), at a typical Mediterranean holm oak forest area (Prades) and at a wet temperate beech forest (Montseny) during spring (April 2010) under optimal plant physiological conditions in driest-warmest sites and during summer (July 2010) with drought and heat stresses in the driest-warmest sites and optimal conditions in the wettest-coolest site. The objective of this campaign was to study the differences in gas, water and energy exchange occurring at different vegetation coverages and biomasses. Particular attention was devoted to quantitatively understand the exchange of biogenic volatile organic compounds (BVOCs) because of their biological and environmental effects in the WMB. A wide range of instruments (GC-MS, PTR-MS, meteorological sensors, O3 monitors,…) and vertical platforms such as masts, tethered balloons and aircraft were used to characterize the gas, water and energy exchange at increasing footprint areas by measuring vertical profiles. In this paper we provide an overview of the MONTES campaign: the objectives, the characterization of the biomass and gas, water and energy exchange in the 4 sites-areas using satellite data, the estimation of isoprene and monoterpene emissions using MEGAN model, the measurements performed and the first results. The isoprene and monoterpene emission rates estimated with MEGAN and emission factors measured at the foliar level for the dominant species ranged from about 0 to 0.2 mg m-2 h-1 in April. The warmer temperature in July resulted in higher model estimates from about 0 to ca. 1.6 mg m-2 h-1 for

  2. Nitrogen Nutrition Improves the Potential of Wheat (Triticum aestivum L.) to Alleviate the Effects of Drought Stress during Vegetative Growth Periods.

    Science.gov (United States)

    Abid, Muhammad; Tian, Zhongwei; Ata-Ul-Karim, Syed Tahir; Cui, Yakun; Liu, Yang; Zahoor, Rizwan; Jiang, Dong; Dai, Tingbo

    2016-01-01

    Efficient nitrogen (N) nutrition has the potential to alleviate drought stress in crops by maintaining metabolic activities even at low tissue water potential. This study was aimed to understand the potential of N to minimize the effects of drought stress applied/occur during tillering (Feekes stage 2) and jointing (Feekes stage 6) growth stages of wheat by observing the regulations and limitations of physiological activities, crop growth rate during drought periods as well as final grain yields at maturity. In present study, pot cultured plants of a wheat cultivar Yangmai-16 were exposed to three water levels [severe stress at 35-40% field capacity (FC), moderate stress at 55-60% FC and well-watered at 75-80% FC] under two N rates (0.24 g and 0.16 g/kg soil). The results showed that the plants under severe drought stress accompanied by low N exhibited highly downregulated photosynthesis, and chlorophyll (Chl) fluorescence during the drought stress periods, and showed an accelerated grain filling rate with shortened grain filling duration (GFD) at post-anthesis, and reduced grain yields. Severe drought-stressed plants especially at jointing, exhibited lower Chl and Rubisco contents, lower efficiency of photosystem II and greater grain yield reductions. In contrast, drought-stressed plants under higher N showed tolerance to drought stress by maintaining higher leaf water potential, Chl and Rubisco content; lower lipid peroxidation associated with higher superoxide dismutase and ascorbate peroxidase activities during drought periods. The plants under higher N showed delayed senescence, increased GFD and lower grain yield reductions. The results of the study suggested that higher N nutrition contributed to drought tolerance in wheat by maintaining higher photosynthetic activities and antioxidative defense system during vegetative growth periods.

  3. Simulation of channeling and radiation of 855 MeV electrons and positrons in a small-amplitude short-period bent crystal

    Energy Technology Data Exchange (ETDEWEB)

    Korol, Andrei V., E-mail: korol@mbnexplorer.com [MBN Research Center, Altenhöferallee 3, 60438 Frankfurt am Main (Germany); Bezchastnov, Victor G. [A.F. Ioffe Physical-Technical Institute, Politechnicheskaya Str. 26, 194021 St. Petersburg (Russian Federation); Peter the Great St. Petersburg Polytechnic University, Politechnicheskaya 29, 195251 St. Petersburg (Russian Federation); Sushko, Gennady B.; Solov’yov, Andrey V. [MBN Research Center, Altenhöferallee 3, 60438 Frankfurt am Main (Germany)

    2016-11-15

    Channeling and radiation are studied for the relativistic electrons and positrons passing through a Si crystal periodically bent with a small amplitude and a short period. Comprehensive analysis of the channeling process for various bending amplitudes is presented on the grounds of numerical simulations. The features of the channeling are highlighted and elucidated within an analytically developed continuous potential approximation. The radiation spectra are computed and discussed.

  4. POSITION AND CHARACTER (Ɖ OR X) OF ENERGY STATES IN SHORT-PERIOD (GaAs)m(AlAs)n SUPERLATTICES

    OpenAIRE

    Nagle , J.; Garriga , M.; Stolz , W.; Isu , T.; Ploog , K.

    1987-01-01

    We have grown a series of (GaAs)m(AlAs)n short period superlattices by molecular beam epitaxy including samples with m=n and m≠n. Low temperature photoluminescence, excitation spectroscopy and ellipsometry measurements have been performed to determine the positions and origins of the different electronic states.

  5. Sediment-palaeosol successions in Calabria and Sardinia suggest spatially differentiated palaeo-vegetation patterns in southern Italy during the Last Glacial period

    Science.gov (United States)

    Sauer, Daniela; Zucca, Claudio; Al-Sharif, Riyad; Zwanzig, Lisa; Madrau, Salvatore; Andreucci, Stefano; Pascucci, Vincenzo; Kadereit, Annette; Scarciglia, Fabio; Brückner, Helmut

    2016-04-01

    Several lakes on the southern Italian peninsula provide valuable palaeoenvironmental archives of the Last Glacial period. These archives include, e.g., the long high-resolution record from varved lake sediments of Lago Grande di Monticchio, the bigger one of two maar lakes situated on top of Mt. Vulture. Its pollen record indicates (1) temperate deciduous forest during MIS5.2-MIS5.1 (St. Germain 2); (2) frequent vegetation fluctuations, then Artemisia steppe during MIS5.1-MIS4; (3) alternations between open steppe (stadials) and wooded steppe (interstadials) during MIS3; and (4) open steppe during MIS2 (Last Glacial Maximum). However, only few palaeosol records of this period have been reported from southern Italy in the literature so far. Such records would allow for gaining insight also into spatial patterns of the vegetation cover during this period that should have formed, e.g., according to relief, elevation, and continentality gradient (related to the much lower coastline during the last glacial period). So far, we have studied three sediment-palaeosol successions in southern Italy, two in the Calabria region, and one in north-western Sardinia. All of them have developed in alluvial fan deposits resting on littoral sediments of the Last Interglacial period (MIS 5). The southernmost succession studied is located near Lazzaro (south of Reggio di Calabria). It is exposed in an alluvial fan overlying the MIS5.5 terrace. Due to strong tectonic uplift (1.3 m ka-1) the alluvial fan has been dissected by the same creek which previously had built it up. Therefore, its internal structure is exposed, exhibiting a detailed sediment-palaeosol sequence. The palaeosols are mainly characterized by accumulation of soil organic matter (SOM), bioturbation and secondary carbonates. They represent Chernozem- and Phaeozem-like soils that most likely formed under steppe to forest steppe. SOM of the two uppermost Lazzaro palaeosols was 14C-dated to 26.8-28.8 ka cal BP and 28

  6. CHANGES IN THE MOISTURE CONTENT OF THE MIDDLE FEN SOILS IN THE ODRA RIVER VALLEY IN THE REGION OF BRZEG DOLNY IN THE VEGETATION PERIODS 2004–2009

    Directory of Open Access Journals (Sweden)

    Leszek Pływaczyk

    2014-10-01

    Full Text Available In soils, where the water table is deeply located and has a minor impact on the moisture content of the surface layer, we are dealing with the precipitation-and-water type of water management. If underground water level is close to the surface, the top stratum of the soil, apart from precipitation, is additionally fed by water absorption from underground waters. Then we are dealing with ground-and-water type of management. We consider such types of water management of soil in the area of the left-bank valley of the Odra river, above and below the dam in Brzeg Dolny. The dominant soil types here are middle fen soils, based on middle clay and heavy clay as well as loam, which, in conditions of either excess or deficiency of moisture, are difficult to cultivate. The work compares water management of two soil profiles in vegetation periods between 2004 and 2009. The formation of underground waters, meteorological conditions and the course of the water reserves in the strata 0–50 cm and 0–100 cm were estimated with various supplying conditions of the active stratum of the soil. The volume of the supply with percolated water from underground water of the layer 50–100 cm on approximately 75–90 mm was also estimated. This value was mainly dependent on the depth of the retention of the water table of the soil profile above the level in Brzeg Dolny.

  7. A novel approach of periodate oxidation coupled with HPLC-FLD for the quantitative determination of 3-chloro-1,2-propanediol in water and vegetable oil.

    Science.gov (United States)

    Hu, Zhixiong; Cheng, Peng; Guo, Mingli; Zhang, Weinong; Qi, Yutang

    2013-07-10

    A novel approach of periodate oxidation coupled with high-performance liquid chromatography (HPLC)-fluorescence detection (FLD) for the quantitative determination of 3-chloro-1,2-propanediol (3-MCPD) has been established. The essence of this approach lies in the production of chloroacetaldehyde by the oxidization cleavage of 3-MCPD with sodium periodate and the HPLC analysis of chloroacetaldehyde monitored by an FLD detector after fluorescence derivatization with adenine. The experimental parameters relating to the efficiency of the derivative reaction such as concentration of adenine, chloroacetaldehyde reaction temperature, and time were studied. Under the optimized conditions, the proposed method can provide high sensitivity, good linearity (r(2) = 0.999), and repeatability (percent relative standard deviations between 2.57% and 3.44%), the limits of detection and quantification were 0.36 and 1.20 ng/mL, respectively, and the recoveries obtained for water samples were in the range 93.39-97.39%. This method has been successfully applied to the analysis of real water samples. Also this method has been successfully used for the analysis of vegetable oil samples after pretreatment with liquid-liquid extraction; the recoveries obtained by a spiking experiment with soybean oil ranged from 96.27% to 102.42%. In comparison with gas chromatography or gas chromatography-mass spectrometry, the proposed method can provide the advantages of simple instrumental requirement, easy operation, low cost, and high efficiency, thus making this approach another good choice for the sensitive determination of 3-MCPD.

  8. The association between short periods of everyday life activities and affective states: a replication study using ambulatory assessment

    Directory of Open Access Journals (Sweden)

    Thomas eBossmann

    2013-04-01

    Full Text Available Regularly conducted exercise programs effectively influence affective states. Studies suggest that this is also true for short bouts of physical activity of ten minutes or less. Accordingly, everyday life activities of short duration might be used to regulate affective states. However, this association has rarely been studied in reference to unstructured activities in ongoing real-life situations. The current study examined the influence of various everyday life activities on three dimensions of mood (valence, calmness, energetic arousal in a predominantly inactive sample. Ambulatory Assessment (AA was used to investigate the association between actual physical activity (aPA and affective states during the course of one day. Seventy-seven students ages 19 - 30 participated in the study. aPA was assessed with accelerometers, and affective state assessments were conducted hourly using an e-diary with a six-item mood scale that was specially designed for AA. Multilevel analyses indicated that the mood dimensions energetic arousal (p = .001 and valence (p = .005 were positively influenced by the intensity of the activity carried out in the ten minutes prior to the assessment. As their activity increased, the participants’ positive feelings and energetic arousal increased. However, the students’ calmness was not affected by their activity levels. The findings highlight the importance of integrating short activity intervals of 10 minutes or less into everyday life routines to improve affective states.

  9. Interactions between climate and vegetation during the Lateglacial period as recorded by lake and mire sediment archives in Northern Italy and Southern Switzerland

    NARCIS (Netherlands)

    Vescovi, E.; Ravazzi, C.; Arpenti, E.; Finsinger, W.; Pini, R.; Valsecchi, V.; Wick, L.; Ammann, B.; Tinner, W.

    2007-01-01

    We reconstruct the vegetational history of the southern side of the Alps at 18,000–10,000 cal yr BP using previous and new AMS-dated stratigraphic records of pollen, stomata, and macrofossils. To address potential effects of climatic change on vegetation, we compare our results with independent

  10. The relative kicking frequency of infants born full-term and preterm during learning and short-term and long-term memory periods of the mobile paradigm.

    Science.gov (United States)

    Heathcock, Jill C; Bhat, Anjana N; Lobo, Michele A; Galloway, James C

    2005-01-01

    Infants born preterm differ in their spontaneous kicking, as well as their learning and memory abilities in the mobile paradigm, compared with infants born full-term. In the mobile paradigm, a supine infant's ankle is tethered to a mobile so that leg kicks cause a proportional amount of mobile movement. The purpose of this study was to investigate the relative kicking frequency of the tethered (right) and nontethered (left) legs in these 2 groups of infants. Ten infants born full-term and 10 infants born preterm (infants participated in the study. The relative kicking frequencies of the tethered and nontethered legs were analyzed during learning and short-term and long-term memory periods of the mobile paradigm. Infants born full-term showed an increase in the relative kicking frequency of the tethered leg during the learning period and the short-term memory period but not for the long-term memory period. Infants born preterm did not show a change in kicking pattern for learning or memory periods, and consistently kicked both legs in relatively equal amounts. Infants born full-term adapted their baseline kicking frequencies in a task-specific manner to move the mobile and then retained this adaptation for the short-term memory period. In contrast, infants born preterm showed no adaptation, suggesting a lack of purposeful leg control. This lack of control may reflect a general decrease in the ability of infants born preterm to use their limb movements to interact with their environment. As such, the mobile paradigm may be clinically useful in the early assessment and intervention of infants born preterm and at risk for future impairment.

  11. Response of Aspergillus niger Inoculated on Tomatoes Exposed to Vapor Phase Mustard Essential Oil for Short or Long Periods and Sensory Evaluation of Treated Tomatoes

    Directory of Open Access Journals (Sweden)

    Ana Elena Aguilar-González

    2017-01-01

    Full Text Available The inhibitory effect of mustard essential oil (EO in vapor phase against Aspergillus niger was evaluated in vitro and in vivo (in tomatoes. Mold response in tomatoes exposed for short or long periods to selected concentrations of mustard EO was also evaluated. Furthermore, a sensory evaluation was also performed among treated tomatoes and compared with nontreated ones. Minimum inhibitory concentration (MIC for the studied EO was determined by the inverted Petri dish method. MIC for the in vitro and in vivo tests for mustard EO was of 3.08 μL/Lair. In vitro and in vivo results demonstrate the effectiveness of vapors of mustard EO against A. niger. The studied EO contains highly volatile organic compounds with strong inhibitory effects, even when applied for short periods, and can consequently be considered a good alternative to traditional synthetic antimicrobials without detriment of selected sensory attributes.

  12. X-RAY AND EUV OBSERVATIONS OF SIMULTANEOUS SHORT AND LONG PERIOD OSCILLATIONS IN HOT CORONAL ARCADE LOOPS

    International Nuclear Information System (INIS)

    Kumar, Pankaj; Cho, Kyung-Suk; Nakariakov, Valery M.

    2015-01-01

    We report decaying quasi-periodic intensity oscillations in the X-ray (6–12 keV) and extreme-ultraviolet (EUV) channels (131, 94, 1600, 304 Å) observed by the Fermi Gamma-ray Burst Monitor and Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), respectively, during a C-class flare. The estimated periods of oscillation and decay time in the X-ray channel (6–12 keV) were about 202 and 154 s, respectively. A similar oscillation period was detected at the footpoint of the arcade loops in the AIA 1600 and 304 Å channels. Simultaneously, AIA hot channels (94 and 131 Å) reveal propagating EUV disturbances bouncing back and forth between the footpoints of the arcade loops. The period of the oscillation and decay time were about 409 and 1121 s, respectively. The characteristic phase speed of the wave is about 560 km s −1 for about 115 Mm of loop length, which is roughly consistent with the sound speed at the temperature about 10–16 MK (480–608 km s −1 ). These EUV oscillations are consistent with the Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation Doppler-shift oscillations interpreted as the global standing slow magnetoacoustic wave excited by a flare. The flare occurred at one of the footpoints of the arcade loops, where the magnetic topology was a 3D fan-spine with a null-point. Repetitive reconnection at this footpoint could have caused the periodic acceleration of non-thermal electrons that propagated to the opposite footpoint along the arcade and that are precipitating there, causing the observed 202 s periodicity. Other possible interpretations, e.g., the second harmonics of the slow mode, are also discussed

  13. X-RAY AND EUV OBSERVATIONS OF SIMULTANEOUS SHORT AND LONG PERIOD OSCILLATIONS IN HOT CORONAL ARCADE LOOPS

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pankaj; Cho, Kyung-Suk [Korea Astronomy and Space Science Institute (KASI), Daejeon, 305-348 (Korea, Republic of); Nakariakov, Valery M., E-mail: pankaj@kasi.re.kr [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, CV4 7AL (United Kingdom)

    2015-05-01

    We report decaying quasi-periodic intensity oscillations in the X-ray (6–12 keV) and extreme-ultraviolet (EUV) channels (131, 94, 1600, 304 Å) observed by the Fermi Gamma-ray Burst Monitor and Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), respectively, during a C-class flare. The estimated periods of oscillation and decay time in the X-ray channel (6–12 keV) were about 202 and 154 s, respectively. A similar oscillation period was detected at the footpoint of the arcade loops in the AIA 1600 and 304 Å channels. Simultaneously, AIA hot channels (94 and 131 Å) reveal propagating EUV disturbances bouncing back and forth between the footpoints of the arcade loops. The period of the oscillation and decay time were about 409 and 1121 s, respectively. The characteristic phase speed of the wave is about 560 km s{sup −1} for about 115 Mm of loop length, which is roughly consistent with the sound speed at the temperature about 10–16 MK (480–608 km s{sup −1}). These EUV oscillations are consistent with the Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation Doppler-shift oscillations interpreted as the global standing slow magnetoacoustic wave excited by a flare. The flare occurred at one of the footpoints of the arcade loops, where the magnetic topology was a 3D fan-spine with a null-point. Repetitive reconnection at this footpoint could have caused the periodic acceleration of non-thermal electrons that propagated to the opposite footpoint along the arcade and that are precipitating there, causing the observed 202 s periodicity. Other possible interpretations, e.g., the second harmonics of the slow mode, are also discussed.

  14. CSI 2264: Characterizing Young Stars In NGC 2264 With Short-Duration Periodic Flux Dips in Their Light Curves

    Science.gov (United States)

    2015-04-01

    excess presumably due to circumstellar Table 1 Basic Information for YSOs with Short Duration Flux Dips Mon IDa 2MASS ID CoRoTb CoRoTc SpTd Hα EWd FR4.5e...reported in Venuti et al. (2014); the JHKs data are from the on line 2MASS all-sky point source catalog; the IRAC data are from Sung et al. (2009), or...little additional reddening as inferred from their mean 2MASS photometry. One exception is Mon-6975, whose IR colors of H − Ks = 0.42, J −H = 0.90

  15. Short communication: Effect of heat stress on markers of autophagy in the mammary gland during the dry period.

    Science.gov (United States)

    Wohlgemuth, S E; Ramirez-Lee, Y; Tao, S; Monteiro, A P A; Ahmed, B M; Dahl, G E

    2016-06-01

    Heat stress (HT) during the dry period compromises mammary gland (MG) growth, thus negatively affecting subsequent milk yield. Cooling during the late dry period, when mammary tissue proliferates, is a common management practice. However, it neglects MG involution during the early dry period, a process that is accomplished by both apoptosis and autophagy. Our objective was to evaluate the effect of HT on MG autophagy during the early dry period. Holstein cows were dried off ~45d before expected calving and randomly assigned to 1 of 2 treatments: HT or cooling (CL). All cows were housed in the same free stall barn during the dry period, but only the stall area for CL cows was equipped with soakers and fans. Rectal temperature and respiration rate were measured daily during the dry period. Mammary gland biopsies were collected from each cow 3d before dry-off and on d 3, 7, 14, and 22±2 after dry-off. Autophagy in the MG was determined by measuring protein expression of 2 autophagic markers, autophagy-related protein 7 and microtubule-associated protein light chain 3 (LC3). The average temperature-humidity index during the dry period was 77.7, which indicated that HT and CL cows were exposed to significant heat stress. However, the cooling system effectively alleviated heat strain in CL cows by decreasing the rectal temperature (39.0 vs. 39.4°C) and respiration rate (47.3 vs. 71.2 breaths per minute) relative to HT cows. Protein expression of autophagy-related protein 7, a marker for early autophagosome formation, did not change within or between groups. In contrast, protein expression of LC3-II, a marker of autophagosomes, and its precursor LC3-I showed a dynamic expression pattern in MG from CL cows during the early dry period. Relative to HT cows, MG from CL cows displayed higher expression of LC3-I and LC3-II on d 7 and lower expression of LC3-II on d 14 and 22 after dry-off. Collectively, our data provide a possible mechanistic explanation for the impairment of

  16. RADIAL VELOCITY PLANETS DE-ALIASED: A NEW, SHORT PERIOD FOR SUPER-EARTH 55 Cnc e

    International Nuclear Information System (INIS)

    Dawson, Rebekah I.; Fabrycky, Daniel C.

    2010-01-01

    Radial velocity measurements of stellar reflex motion have revealed many extrasolar planets, but gaps in the observations produce aliases, spurious frequencies that are frequently confused with the planets' orbital frequencies. In the case of Gl 581 d, the distinction between an alias and the true frequency was the distinction between a frozen, dead planet and a planet possibly hospitable to life. To improve the characterization of planetary systems, we describe how aliases originate and present a new approach for distinguishing between orbital frequencies and their aliases. Our approach harnesses features in the spectral window function to compare the amplitude and phase of predicted aliases with peaks present in the data. We apply it to confirm prior alias distinctions for the planets GJ 876 d and HD 75898 b. We find that the true periods of Gl 581 d and HD 73526 b/c remain ambiguous. We revise the periods of HD 156668 b and 55 Cnc e, which were afflicted by daily aliases. For HD 156668 b, the correct period is 1.2699 days and the minimum mass is (3.1 ± 0.4) M + . For 55 Cnc e, the correct period is 0.7365 days-the shortest of any known planet-and the minimum mass is (8.3 ± 0.3) M + . This revision produces a significantly improved five-planet Keplerian fit for 55 Cnc, and a self-consistent dynamical fit describes the data just as well. As radial velocity techniques push to ever-smaller planets, often found in systems of multiple planets, distinguishing true periods from aliases will become increasingly important.

  17. Forecast demand and supply of energy in the short period. Its forecast and sensitivity analysis until the 2004 fiscal year

    International Nuclear Information System (INIS)

    Yamashita, Yukari; Suehiro, Shigeru; Yanagisawa, Akira; Imaeda, Toshiya; Komiyama, Ryouichi

    2004-01-01

    The object of this report is forecast demand and supply of energy in the 2003 and 2004 fiscal year, which correspond to a business recovery period. A macroeconomics model and an energy supply model are calculated by changing actual GNP, crude oil rate and the rerunning period of nuclear power plants. The calculation results are compared with the reference case. In the first chapter, forecast Japanese economy until the 2004 fiscal year is explained. In the second chapter, the results of energy demand and supply in the first chapter are investigated by the home supply and consumption of primary energy (the reference case) and each energy resources. The sensitivity analytical results of actual GNP, consumer price index, home supply of the primary energy, energy expenditure, sales account of electric power, city gas and fuel by five cases such as reference, increase and decrease of oil cost and increase and decrease of economic growth are investigated. The effects of fast rerunning period of nuclear power plant and atmosphere temperature on these above demands of energies are indicated in the third chapter. (S.Y.)

  18. THE ACS LCID PROJECT. I. SHORT-PERIOD VARIABLES IN THE ISOLATED DWARF SPHEROIDAL GALAXIES CETUS AND TUCANA

    International Nuclear Information System (INIS)

    Bernard, Edouard J.; Monelli, Matteo; Gallart, Carme

    2009-01-01

    We present the first study of the variable star populations in the isolated dwarf spheroidal galaxies (dSphs) Cetus and Tucana. Based on Hubble Space Telescope images obtained with the Advanced Camera for Surveys in the F475W and F814W bands, we identified 180 and 371 variables in Cetus and Tucana, respectively. The vast majority are RR Lyrae stars. In Cetus, we also found three anomalous Cepheids (ACs), four candidate binaries and one candidate long-period variable (LPV), while six ACs and seven LPV candidates were found in Tucana. Of the RR Lyrae stars, 147 were identified as fundamental mode (RRab) and only eight as first-overtone mode (RRc) in Cetus, with mean periods of 0.614 and 0.363 day, respectively. In Tucana, we found 216 RRab and 82 RRc giving mean periods of 0.604 and 0.353 day. These values place both galaxies in the so-called Oosterhoff Gap, as is generally the case for dSph. We calculated the distance modulus to both galaxies using different approaches based on the properties of RRab and RRc, namely, the luminosity-metallicity and period-luminosity-metallicity relations, and found values in excellent agreement with previous estimates using independent methods: (m - M) 0,Cet = 24.46 ± 0.12 and (m - M) 0,Tuc = 24.74 ± 0.12, corresponding to 780 ± 40 kpc and 890 ± 50 kpc. We also found numerous RR Lyrae variables pulsating in both modes simultaneously (RRd): 17 in Cetus and 60 in Tucana. Tucana is, after Fornax, the second dSph in which such a large fraction of RRd (∼17%) has been observed. We provide the photometry and pulsation parameters for all the variables, and compare the latter with values from the literature for well studied dSph of the Local Group and Galactic globular clusters. The parallel WFPC2 fields were also searched for variables, as they lie well within the tidal radius of Cetus, and at its limit in the case of Tucana. No variables were found in the latter, while 15 were discovered in the outer field of Cetus (11 RRab, three RRc

  19. Poliolefinas reforçadas com fibras vegetais curtas: sisal × curauá Polyolefins reinforced with short vegetal fibers: sisal vs. curauá

    Directory of Open Access Journals (Sweden)

    Márcia A. S. Spinacé

    2011-01-01

    Full Text Available É crescente o interesse nos compósitos poliméricos reforçados com fibras vegetais curtas em substituição às fibras de vidro, pois as fibras naturais provêm de fontes renováveis, não são abrasivas aos equipamentos de processamento, são biodegradáveis, e possuem baixa densidade comparada às fibras de vidro. Elas apresentam início de degradação em torno de 200 °C, sendo adequadas para reforçar poliolefinas que são processadas até essa temperatura ou termofíxos. Várias fibras vegetais vêm sendo usadas como reforço, dentre elas o curauá e o sisal; no entanto, há grande controvérsia na literatura sobre as propriedades finais dos compósitos. Neste trabalho comparamos as propriedades de compósitos de polietileno de alta densidade ou polipropileno com 20% em massa de fibras curtas de sisal ou de curauá com ou sem agentes de acoplagem. Todos foram processados por extrusão e moldados por injeção, exatamente nas mesmas condições, e os resultados foram comparados em termos das propriedades mecânicas. As fibras de curauá apresentam resistência à tração superior às fibras de sisal e os compósitos com fibras de curauá apresentaram resistência à tração e flexão ligeiramente superior aos compósitos com fibra de sisal. No caso da resistência ao impacto a situação se inverte. Como o sisal é mais frágil que o curauá, durante o processamento ocorre maior quebra da fibra provocando essa diferenciação nas propriedades mecânicas dos compósitos.There is growing interest in reinforced polymer composites using short vegetal fibers to replace glass fibers for several reasons. The composite fibers are produced from renewable resources, being biodegradable and less abrasive to the processing equipment, in addition to possessing a lower density than the glass fibers. Since their thermal degradation onset is at 200 °C, they can be used to reinforce thermoplastics processed below this temperature and thermosets

  20. A Conceptual Model for Calculating the Return of Costs Invested in the Creation of an Economic Security Service, During a Short-Term Period

    Directory of Open Access Journals (Sweden)

    Melikhova Tetiana O.

    2018-02-01

    Full Text Available The article is aimed at suggesting methods for calculating the short-term period of return of costs invested in creation of an economic security service. The article considers approaches to calculation of the period of return of costs, advanced at the level of enterprise, which build the methodical basis for definition of such period. At the level of structural subdivisions of enterprise, which do not produce products, it is suggested to use conditional money flow as a source of financing advanced costs. The calculation of the short-term return on investment at the enterprise level provides for: allocation of expenses for the permanent and the replacement parts during the year; determination of the production of money flow and the money flow accumulated during the year. Annual depreciation payments are the basis of fixed costs. Methods of determination of the gross, net, valid, and specified periods of return of costs, advanced during the year for introduction of an economic security service at enterprise, have been suggested.

  1. Exercise following a short immobilization period is detrimental to tendon properties and joint mechanics in a rat rotator cuff injury model.

    Science.gov (United States)

    Peltz, Cathryn D; Sarver, Joseph J; Dourte, Leann M; Würgler-Hauri, Carola C; Williams, Gerald R; Soslowsky, Louis J

    2010-07-01

    Rotator cuff tears are a common clinical problem that can result in pain and disability. Previous studies in a rat model showed enhanced tendon to bone healing with postoperative immobilization. The objective of this study was to determine the effect of postimmobilization activity level on insertion site properties and joint mechanics in a rat model. Our hypothesis was that exercise following a short period of immobilization will cause detrimental changes in insertion site properties compared to cage activity following the same period of immobilization, but that passive shoulder mechanics will not be affected. We detached and repaired the supraspinatus tendon of 22 Sprague-Dawley rats, and the injured shoulder was immobilized postoperatively for 2 weeks. Following immobilization, rats were prescribed cage activity or exercise for 12 weeks. Passive shoulder mechanics were determined, and following euthanasia, tendon cross-sectional area and mechanical properties were measured. Exercise following immobilization resulted in significant decreases compared to cage activity in range of motion, tendon stiffness, modulus, percent relaxation, and several parameters from both a structurally based elastic model and a quasi-linear viscoelastic model. Therefore, we conclude that after a short period of immobilization, increased activity is detrimental to both tendon mechanical properties and shoulder joint mechanics, presumably due to increased scar production. (c) 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc

  2. A non-accelerating foreshock sequence followed by a short period of quiescence for a large inland earthquake

    Science.gov (United States)

    Doi, I.; Kawakata, H.

    2012-12-01

    Laboratory experiments [e.g. Scholz, 1968; Lockner et al., 1992] and field observations [e.g. Dodge et al., 1996; Helmstetter and Sornette, 2003; Bouchon et al., 2011] have elucidated part of foreshock behavior and mechanism, but we cannot identify foreshocks while they are occurring. Recently, in Japan, a dense seismic network, Hi-net (High Sensitivity Seismograph Network), provides continuous waveform records for regional seismic events. The data from this network enable us to analyze small foreshocks which occur on long period time scales prior to a major event. We have an opportunity to grasp the more detailed pattern of foreshock generation. Using continuous waveforms recorded at a seismic station located in close proximity to the epicenter of the 2008 Iwate-Miyagi inland earthquake, we conducted a detailed investigation of its foreshocks. In addition to the two officially recognized foreshocks, calculation of cross-correlation coefficients between the continuous waveform record and one of the previously recognized foreshocks revealed that 20 micro foreshocks occurred within the same general area. Our analysis also shows that all of these foreshocks occurred within the same general area relative to the main event. Over the two week period leading up to the Iwate-Miyagi earthquake, such foreshocks only occurred during the last 45 minutes, specifically over a 35 minute period followed by a 10 minute period of quiescence just before the mainshock. We found no evidence of acceleration of this foreshock sequence. Rock fracturing experiments using a constant loading rate or creep tests have consistently shown that the occurrence rate of small fracturing events (acoustic emissions; AEs) increases before the main rupture [Scholz, 1968]. This accelerative pattern of preceding events was recognized in case of the 1999 Izmit earthquake [Bouchon et al., 2011]. Large earthquakes however need not be accompanied by acceleration of foreshocks if a given fault's host rock

  3. Task-irrelevant distractors in the delay period interfere selectively with visual short-term memory for spatial locations.

    Science.gov (United States)

    Marini, Francesco; Scott, Jerry; Aron, Adam R; Ester, Edward F

    2017-07-01

    Visual short-term memory (VSTM) enables the representation of information in a readily accessible state. VSTM is typically conceptualized as a form of "active" storage that is resistant to interference or disruption, yet several recent studies have shown that under some circumstances task-irrelevant distractors may indeed disrupt performance. Here, we investigated how task-irrelevant visual distractors affected VSTM by asking whether distractors induce a general loss of remembered information or selectively interfere with memory representations. In a VSTM task, participants recalled the spatial location of a target visual stimulus after a delay in which distractors were presented on 75% of trials. Notably, the distractor's eccentricity always matched the eccentricity of the target, while in the critical conditions the distractor's angular position was shifted either clockwise or counterclockwise relative to the target. We then computed estimates of recall error for both eccentricity and polar angle. A general interference model would predict an effect of distractors on both polar angle and eccentricity errors, while a selective interference model would predict effects of distractors on angle but not on eccentricity errors. Results showed that for stimulus angle there was an increase in the magnitude and variability of recall errors. However, distractors had no effect on estimates of stimulus eccentricity. Our results suggest that distractors selectively interfere with VSTM for spatial locations.

  4. Stress modulation of earthquakes: A study of long and short period stress perturbations and the crustal response

    Science.gov (United States)

    Johnson, Christopher W.

    laboratory to explore the causal relationship between low-amplitude stress changes and dynamically triggered events. Interestingly, observations of dynamically triggered M≥5.5 earthquakes are absent in the seismic records [Johnson et al., 2015; Parsons and Velasco, 2011], which invokes questions regarding whether or not large magnitude events can be dynamically triggered. Emerging results in the literature indicate undocumented M≥5.5 events at near to intermediate distances are dynamically triggered during the passage of surface waves but are undetected by automated networks [Fan and Shearer, 2016]. This raises new questions about the amplitude and duration of dynamic stressing for large magnitude events. I used 35-years of global seismicity and find that large event rate increases only occur following a delay from the transient load, suggesting aseismic processes are associated with large magnitude triggered events. To extend this finding I investigated three cases of large magnitude delayed dynamic triggering following the M8.6 2012 Indian Ocean earthquake [Pollitz et al., 2012] by producing microseismicity catalogs and modeling the transient stresses. The results indicate immediate triggering of microseismic events that hours later culminate into a large magnitude event and support the notion that large magnitude events are triggerable by transient loading, but seismic and aseismic processes (e.g. induced creep or fluid mobilization) are contributing to the nucleation process. Open questions remain concerning the source of a nucleation delay period following a stress perturbation that require both geodetic and seismic observations to constrain the source of delayed dynamic triggering and possibly provide insight into a precursory nucleation phase. Induced seismicity has gained much attention in the past 5 years as earthquake rates in regions of low tectonic strain accumulation accelerate to unprecedented levels [Ellsworth, 2013]. The source of the seismicity is

  5. Analisis Parameter Gap Dalam Tahapan Dekonvolusi Prediktif Guna Mereduksi Short Period Multiple dan Meningkatkan S/N Ratio pada Pengolahan Data Seismik Refleksi 2D Marine

    Directory of Open Access Journals (Sweden)

    Bella Chintia

    2017-05-01

    Full Text Available Penelitian ini bertujuan untuk menentukan nilai gap terbaik dari salah satu parameter gap yang digunakan untuk mereduksi short-period multiple dengan metode dekonvolusi prediktif. Variasi Nilai gap yang digunakan adalah 4, 8, 12, 16, 20, 24, 28, dan 64 ms. Berdasarkan hasil penelitian, diketahui bahwa gap 12 merupakan gap terbaik. Nilai gap 12 menghasilkan sp gather, penampang stack dan NTG (Near Trace Gather yang lebih tajam dibandingkan dengan gap lainnya. Selain itu, dari spectrum analysis didapatkan sp gather dan penampang stack yang menunjukkan bahwa frekuensi terletak pada rentang nilai 10 - 80 Hz, dan nilai spectrum amplitude seismik yang terkecil berkisar -21 s.d 0 dB.

  6. K2-111 b - a short period super-Earth transiting a metal poor, evolved old star

    Science.gov (United States)

    Fridlund, Malcolm; Gaidos, Eric; Barragán, Oscar; Persson, Carina M.; Gandolfi, Davide; Cabrera, Juan; Hirano, Teruyuki; Kuzuhara, Masayuki; Csizmadia, Sz.; Nowak, Grzegorz; Endl, Michael; Grziwa, Sascha; Korth, Judith; Pfaff, Jeremias; Bitsch, Bertram; Johansen, Anders; Mustill, Alexander J.; Davies, Melvyn B.; Deeg, Hans J.; Palle, Enric; Cochran, William D.; Eigmüller, Philipp; Erikson, Anders; Guenther, Eike; Hatzes, Artie P.; Kiilerich, Amanda; Kudo, Tomoyuki; MacQueen, Phillip; Narita, Norio; Nespral, David; Pätzold, Martin; Prieto-Arranz, Jorge; Rauer, Heike; Van Eylen, Vincent

    2017-07-01

    Context. From a light curve acquired through the K2 space mission, the star K2-111(EPIC 210894022) has been identified as possibly orbited by a transiting planet. Aims: Our aim is to confirm the planetary nature of the object and derive its fundamental parameters. Methods: We analyse the light curve variations during the planetary transit using packages developed specifically for exoplanetary transits. Reconnaissance spectroscopy and radial velocity observations have been obtained using three separate telescope and spectrograph combinations. The spectroscopic synthesis package SME has been used to derive the stellar photospheric parameters that were used as input to various stellar evolutionary tracks in order to derive the parameters of the system. The planetary transit was also validated to occur on the assumed host star through adaptive imaging and statistical analysis. Results: The star is found to be located in the background of the Hyades cluster at a distance at least 4 times further away from Earth than the cluster itself. The spectrum and the space velocities of K2-111 strongly suggest it to be a member of the thick disk population. The co-added high-resolution spectra show that that it is a metal poor ([Fe/H] = - 0.53 ± 0.05 dex) and α-rich somewhat evolved solar-like star of spectral type G3. We find Teff = 5730 ± 50 K, log g⋆ = 4.15 ± 0.1 cgs, and derive a radius of R⋆ = 1.3 ± 0.1 R⊙ and a mass of M⋆ = 0.88 ± 0.02 M⊙. The currently available radial velocity data confirms a super-Earth class planet with a mass of 8.6 ± 3.9 M⊕ and a radius of 1.9 ± 0.2 R⊕. A second more massive object with a period longer than about 120 days is indicated by a long-term radial velocity drift. Conclusions: The radial velocity detection together with the imaging confirms with a high level of significance that the transit signature is caused by a planet orbiting the star K2-111. This planet is also confirmed in the radial velocity data. A second more

  7. Influence of the interface on growth rates in AlN/GaN short period superlattices via metal organic vapor phase epitaxy

    Science.gov (United States)

    Rodak, L. E.; Korakakis, D.

    2011-11-01

    AlN/GaN short period superlattices are well suited for a number of applications including, but not limited to, digital alloys, intersubband devices, and emitters. In this work, AlN/GaN superlattices with periodicities ranging from 10 to 20 Å have been grown via metal organic vapor phase epitaxy in order to investigate the influence of the interface on the binary alloy growth rates. The GaN growth rate at the interface was observed to decrease with increasing GaN thickness while the AlN growth rate remained constant. This has been attributed to a decrease in the decomposition rate of GaN at the hetero-interface as seen in other III-V hetero-structures.

  8. Does urban vegetation mitigate air pollution in northern conditions?

    International Nuclear Information System (INIS)

    Setälä, Heikki; Viippola, Viljami; Rantalainen, Anna-Lea; Pennanen, Arto; Yli-Pelkonen, Vesa

    2013-01-01

    It is generally accepted that urban vegetation improves air quality and thereby enhances the well-being of citizens. However, empirical evidence on the potential of urban trees to mitigate air pollution is meager, particularly in northern climates with a short growing season. We studied the ability of urban park/forest vegetation to remove air pollutants (NO 2 , anthropogenic VOCs and particle deposition) using passive samplers in two Finnish cities. Concentrations of each pollutant in August (summer; leaf-period) and March (winter, leaf-free period) were slightly but often insignificantly lower under tree canopies than in adjacent open areas, suggesting that the role of foliage in removing air pollutants is insignificant. Furthermore, vegetation-related environmental variables (canopy closure, number and size of trees, density of understorey vegetation) did not explain the variation in pollution concentrations. Our results suggest that the ability of urban vegetation to remove air pollutants is minor in northern climates. -- Highlights: ► The ability of northern urban vegetation to remove air pollutants is minor. ► Vegetation-related environmental variables had no effect on air pollution levels. ► The ability of vegetation to clean air did not differ between summer and winter. ► Dry deposition passive samplers proved applicable in urban air pollution study. -- The ability of urban vegetation to remove air pollutants seems to be minor in northern climates

  9. Effects of feeding strategy during a short finishing period on performance, carcass and meat quality in previously-grazed young bulls.

    Science.gov (United States)

    Cerdeño, A; Vieira, C; Serrano, E; Lavín, P; Mantecón, A R

    2006-04-01

    Twenty-one Brown Swiss×Limousin young bulls reared on pasture were housed for a short finishing period (60 days). CA group (concentrate-ad libitum group) received concentrate and straw ad libitum for the whole finishing period. CR group (concentrate-restricted group) received 4kg of concentrate/animal per day and ad libitum alfalfa hay throughout the 60days. CRA group (concentrate-restricted/ad libitum group) received the same diet as CR group for the first 30days and the same diet as CA group for the last 30days. CA and CRA groups presented higher fatness values. Myoglobin concentration in muscle was highest in CA group (P0.05). It is concluded that, in this type of young animal, 4kg concentrate plus ad libitum alfalfa hay for a 60-day finishing period, despite lower fatness, provides carcasses and meat with acceptable quality characteristics, similar to those obtained from ad libitum fed animals for the same period.

  10. Effects of Pre - Season Short - Term Daily Undulating Periodized Training on Muscle Strength and Sprint Performance of Under - 20 Soccer Players

    Directory of Open Access Journals (Sweden)

    Charles Ricardo L OPES

    2015-06-01

    Full Text Available The aim of this study was to evaluate the effects of daily undulating training periodization designed for maximal lower limb muscle strength and sprint performance in under - 20 soccer players. Twenty - four male athletes (age = 19.1 ± 1.2 yr; mass = 71.1 ± 6. 8 kg; height = 178.0 ± 0.1 cm participated in four weeks of a daily undulating periodized (DUP training soccer program. During the pre - and post - training periods the subjects performed a one repetition maximum (1 RM half back squat test and a 15 - meter s print. Significant training - induced changes were observed in sprint times (pre = 2.38 ± 0.01 s; post = 2.31 ± 0.02 s and 1 RM tests (pre = 107.0 ± 2.0 kg; post = 128.0 ± 2.2 kg. These results indicate that a DUP program is efficient in promoting positive neuromuscular adaptations in soccer players, even with a short - term preseason training period.

  11. A dearth of short-period massive binaries in the young massive star forming region M 17. Evidence for a large orbital separation at birth?

    Science.gov (United States)

    Sana, H.; Ramírez-Tannus, M. C.; de Koter, A.; Kaper, L.; Tramper, F.; Bik, A.

    2017-03-01

    Aims: The formation of massive stars remains poorly understood and little is known about their birth multiplicity properties. Here, we aim to quantitatively investigate the strikingly low radial-velocity dispersion measured for a sample of 11 massive pre- and near-main-sequence stars (σ1D= 5.6 ± 0.2 km s-1) in the very young massive star forming region M 17, in order to obtain first constraints on the multiplicity properties of young massive stellar objects. Methods: We compute the radial-velocity dispersion of synthetic populations of massive stars for various multiplicity properties and we compare the obtained σ1D distributions to the observed value. We specifically investigate two scenarios: a low binary fraction and a dearth of short-period binary systems. Results: Simulated populations with low binary fractions () or with truncated period distributions (Pcutoff > 9 months) are able to reproduce the low σ1D observed within their 68%-confidence intervals. Furthermore, parent populations with fbin > 0.42 or Pcutoff < 47 d can be rejected at the 5%-significance level. Both constraints are in stark contrast with the high binary fraction and plethora of short-period systems in few Myr-old, well characterized OB-type populations. To explain the difference in the context of the first scenario would require a variation of the outcome of the massive star formation process. In the context of the second scenario, compact binaries must form later on, and the cut-off period may be related to physical length-scales representative of the bloated pre-main-sequence stellar radii or of their accretion disks. Conclusions: If the obtained constraints for the M 17's massive-star population are representative of the multiplicity properties of massive young stellar objects, our results may provide support to a massive star formation process in which binaries are initially formed at larger separations, then harden or migrate to produce the typical (untruncated) power-law period

  12. Retention of a 24-hour time memory in Syrian hamsters carrying the 20-hour short circadian period mutation in casein kinase-1ε (ck1εtau/tau).

    Science.gov (United States)

    Cain, Sean W; Yoon, Jeena; Shrestha, Tenjin C; Ralph, Martin R

    2014-10-01

    Circadian rhythmic expression of conditioned place avoidance (CPA) was produced in Syrian hamsters homozygous for the circadian short period mutation, tau. In constant dim red light neither the 20 h endogenous period, nor a 20 h place conditioning schedule eliminated the 24 h modulation of CPA behavior described previously for wild type (wt) hamsters and other species. Tau mutants exhibited a 20 h rhythm superimposed on the 24 h modulation. The 20 h component was removed selectively with lesions of the suprachiasmatic nucleus. Wt animals conditioned on a 20 h schedule did not produce a 20 h rhythm, but still expressed the 24 h modulation. The results show that the context entrainable oscillator (CEO) underlying memory for the timing of an unconditioned stimulus, retains a period of about 24 h regardless of clock gene background (tau mutation) and/or the conditioning schedule (24 vs 20 h). Therefore the CEO responsible for time memory is distinct from the biological clock controlling activity; the underlying circadian molecular mechanisms may differ from the ubiquitous transcription-translation feedback oscillator; and time memory itself is not classically conditioned. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. IUE spectrophotometry of the DA4 primary in the short-period white dwarf-red dwarf spectroscopic binary Case 1

    Science.gov (United States)

    Sion, E. M.; Guinan, E. F.; Wesemael, F.

    1984-01-01

    Low-resolution ultraviolet International Ultraviolet Explorer spectra of the DA white dwarf Case 1 are presented. The spectra show the presence of the 1400 A feature, already discovered in several other DA stars, and of a shallower trough in the 1550-1700 A range. A model atmosphere analysis of the ultraviolet energy distribution of the Ly-alpha red wing yields T(e) = 13,000 + or - 500 K. Possible interpretations of the 1400 A feature are reviewed. Case 1 is the coolest white dwarf found in a short-period, detached white dwarf-red dwarf binary, and its cooling time is consistent with estimates of the efficiency of angular momentum removal mechanisms in the phases subsequent to common envelope binary evolution.

  14. THE MAXIMUM AMOUNTS OF RAINFALL FALLEN IN SHORT PERIODS OF TIME IN THE HILLY AREA OF CLUJ COUNTY - GENESIS, DISTRIBUTION AND PROBABILITY OF OCCURRENCE

    Directory of Open Access Journals (Sweden)

    BLAGA IRINA

    2014-03-01

    Full Text Available The maximum amounts of rainfall are usually characterized by high intensity, and their effects on the substrate are revealed, at slope level, by the deepening of the existing forms of torrential erosion and also by the formation of new ones, and by landslide processes. For the 1971-2000 period, for the weather stations in the hilly area of Cluj County: Cluj- Napoca, Dej, Huedin and Turda the highest values of rainfall amounts fallen in 24, 48 and 72 hours were analyzed and extracted, based on which the variation and the spatial and temporal distribution of the precipitation were analyzed. The annual probability of exceedance of maximum rainfall amounts fallen in short time intervals (24, 48 and 72 hours, based on thresholds and class values was determined, using climatological practices and the Hyfran program facilities.

  15. Impact of streamflow data assimilation and length of the verification period on the quality of short-term ensemble hydrologic forecasts

    Science.gov (United States)

    Randrianasolo, A.; Thirel, G.; Ramos, M. H.; Martin, E.

    2014-11-01

    Data assimilation has gained wide recognition in hydrologic forecasting due mainly to its capacity to improve the quality of short-term forecasts. In this study, a comparative analysis is conducted to assess the impact of discharge data assimilation on the quality of streamflow forecasts issued by two different modeling conceptualizations of catchment response. The sensitivity of the performance metrics to the length of the verification period is also investigated. The hydrological modeling approaches are: the coupled physically-based hydro-meteorological model SAFRAN-ISBA-MODCOU, a distributed model with a data assimilation procedure that uses streamflow measurements to assess the initial state of soil water content that optimizes discharge simulations, and the lumped soil moisture-accounting type rainfall-runoff model GRP, which assimilates directly the last observed discharge to update the state of the routing store. The models are driven by the weather ensemble prediction system PEARP of Météo-France, which is based on the global spectral ARPEGE model zoomed over France. It runs 11 perturbed members for a forecast range of 60 h. Forecast and observed data are available for 86 catchments over a 17-month period (March 2005-July 2006) for both models and for 82 catchments over a 52-month period (April 2005-July 2009) for the GRP model. The first dataset is used to investigate the impact of streamflow data assimilation on forecast quality, while the second is used to evaluate the impact of the length of the verification period on the assessment of forecast quality. Forecasts are compared to daily observed discharges and scores are computed for lead times 24 h and 48 h. Results indicate an overall good performance of both hydrological models forced by the PEARP ensemble predictions when the models are run with their data assimilation procedures. In general, when data assimilation is performed, the quality of the forecasts increases: median differences between

  16. HATS-43b, HATS-44b, HATS-45b, and HATS-46b: Four Short-period Transiting Giant Planets in the Neptune–Jupiter Mass Range

    Science.gov (United States)

    Brahm, R.; Hartman, J. D.; Jordán, A.; Bakos, G. Á.; Espinoza, N.; Rabus, M.; Bhatti, W.; Penev, K.; Sarkis, P.; Suc, V.; Csubry, Z.; Bayliss, D.; Bento, J.; Zhou, G.; Mancini, L.; Henning, T.; Ciceri, S.; de Val-Borro, M.; Shectman, S.; Crane, J. D.; Arriagada, P.; Butler, P.; Teske, J.; Thompson, I.; Osip, D.; Díaz, M.; Schmidt, B.; Lázár, J.; Papp, I.; Sári, P.

    2018-03-01

    We report the discovery of four short-period extrasolar planets transiting moderately bright stars from photometric measurements of the HATSouth network coupled to additional spectroscopic and photometric follow-up observations. While the planet masses range from 0.26 to 0.90 {M}{{J}}, the radii are all approximately a Jupiter radii, resulting in a wide range of bulk densities. The orbital period of the planets ranges from 2.7 days to 4.7 days, with HATS-43b having an orbit that appears to be marginally non-circular (e = 0.173 ± 0.089). HATS-44 is notable for having a high metallicity ([{Fe}/{{H}}] = 0.320 ± 0.071). The host stars spectral types range from late F to early K, and all of them are moderately bright (13.3 Carnegie Institute is operated by PU in conjunction with PUC, the station at the High Energy Spectroscopic Survey (H.E.S.S.) site is operated in conjunction with MPIA, and the station at Siding Spring Observatory (SSO) is operated jointly with ANU. This paper includes data gathered with the MPG 2.2 m and ESO 3.6 m telescopes at the ESO Observatory in La Silla. This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile.

  17. Attenuation of short-period P, PcP, ScP, and pP waves in the earth's mantle

    International Nuclear Information System (INIS)

    Bock, G.; Clements, J.R.

    1982-01-01

    The parameter t* (ratio of body wave travel time to the average quality factor Q) was estimated under various assumptions of the nature of the earthquake sources for short-period P, PcP, and ScP phases originating from earthquakes in the Fiji-Tonga region and recorded at the Warramunga Seismic Array at Tennant Creek (Northern Territory, Australia). Spectral ratios were calculated for the amplitudes of PcP to P and of pP to P. The data reveal a laterally varying Q structure in the Fiji-Tonga region. The high-Q lithosphere descending beneath the Tonga Island arc is overlain above 350 km depth by a wedgelike zone of high attenuation with an average Q/sub α/ between 120 and 200 at short periods. The upper mantle farther to the west of the Tonga island arc is less attenuating, with Q/sub α/, between 370 and 560. Q/sub α/ is about 500 in the upper mantle on the oceanic side of the subduction zone. The t* estimates of this study are much smaller than estimates from the free oscillation model SL8. This can be partly explained by regional variations of Q in the upper mantle. If no lateral Q variations occur in the lower mantle, a frequency-dependent Q can make the PcP and ScP observations consistent with model SL8. Adopting the absorption band model to describe the frequency dependence of Q, the parameter tau 2 , the cut-off period of the high-frequency end of the absorption band, was determined. For different source models with finite corner frequencies, the average tau 2 for the mantle is between 0.01 and 0.10 s (corresponding to frequencies between 16 and 1.6 Hz) as derived from the PcP data, and between 0.06 and 0.12 s (2.7 and 1.3 Hz), as derived from the ScP data

  18. Riparian Vegetation Response to the March 2008 Short-Duration, High-Flow Experiment-Implications of Timing and Frequency of Flood Disturbance on Nonnative Plant Establishment Along the Colorado River Below Glen Canyon Dam

    Science.gov (United States)

    Ralston, Barbara E.

    2010-01-01

    years of sustained flooding. The results from the 2008 HFE suggest that riparian vegetation zones subject to intermittent disturbance and near the river under normal dam operations are more susceptible to nonnative species introductions following a disturbance. This study also finds that the timing of an HFE affects the types of species that can become established. For example, HFEs conducted in March are associated with reduced tamarisk seedling establishment compared to disturbances later in the season. Additionally, early season, short-duration flooding that results in vegetation burial may favor clonal species. Along the Colorado River many of these clonal species are native; these species include arrowweed (Pluchea sericea), coyote willow (Salix exigua), and rivercane (Phragmites australis).

  19. Climatic drivers of vegetation based on wavelet analysis

    Science.gov (United States)

    Claessen, Jeroen; Martens, Brecht; Verhoest, Niko E. C.; Molini, Annalisa; Miralles, Diego

    2017-04-01

    Vegetation dynamics are driven by climate, and at the same time they play a key role in forcing the different bio-geochemical cycles. As climate change leads to an increase in frequency and intensity of hydro-meteorological extremes, vegetation is expected to respond to these changes, and subsequently feed back on their occurrence. This response can be analysed using time series of different vegetation diagnostics observed from space, in the optical (e.g. Normalised Difference Vegetation Index (NDVI), Solar Induced Fluorescence (SIF)) and microwave (Vegetation Optical Depth (VOD)) domains. In this contribution, we compare the climatic drivers of different vegetation diagnostics, based on a monthly global data-cube of 24 years at a 0.25° resolution. To do so, we calculate the wavelet coherence between each vegetation-related observation and observations of air temperature, precipitation and incoming radiation. The use of wavelet coherence allows unveiling the scale-by-scale response and sensitivity of the diverse vegetation indices to their climatic drivers. Our preliminary results show that the wavelet-based statistics prove to be a suitable tool for extracting information from different vegetation indices. Going beyond traditional methods based on linear correlations, the application of wavelet coherence provides information about: (a) the specific periods at which the correspondence between climate and vegetation dynamics is larger, (b) the frequencies at which this correspondence occurs (e.g. monthly or seasonal scales), and (c) the time lag in the response of vegetation to their climate drivers, and vice versa. As expected, areas of high rainfall volumes are characterised by a strong control of radiation and temperature over vegetation. Furthermore, precipitation is the most important driver of vegetation variability over short terms in most regions of the world - which can be explained by the rapid response of leaf development towards available water content

  20. Bird Diversity and Composition in Even-Aged Loblolly Pine Stands Relative to Emergence of 13-year Periodical Cicadas and Vegetation Structure

    Science.gov (United States)

    Jennifer L. Hestir; Michael D. Cain

    1999-01-01

    In southern Arkansas, l3-year periodical cicadas (Magicicada spp.) were expected to emerge in late April and early May of 1998. Presence of a superabundant food source, such as periodical cicadas, may attract greater numbers of birds and more species of birds than is usually present in a particular area. Three even-aged loblolly pine (Pinus...

  1. [The effects of 16-weeks pilates mat program on anthropometric variables and body composition in active adult women after a short detraining period].

    Science.gov (United States)

    Vaquero-Cristóbal, Raquel; Alacid, Fernando; Esparza-Ros, Francisco; Muyor, José M; López-Miñarro, Pedro Ángel

    2015-04-01

    previous studies have analysed the effect of mat Pilates practice on anthropometric variables and body composition in sedentaries. To date no researchs have investigated the benefits of Pilates on these variables after a short detraining period. to determine the effect of a 16-week mat Pilates program on anthropometric variables, body composition and somatotype of women with previous practice experience after three weeks of detraining period. twenty-one women underwent a complete anthropometric assessment according with ISAK guidelines before and after a 16 week mat Pilates program (two days, one hour). All women had one to three years of mat Pilates experience and came to three weeks of detraining period (Christmas holiday). women showed significant decreases for body mass, BMI, upper limb (biceps and triceps) and trunk (subscapular, iliac crest, supraspinale and abdominal) individual skinfolds, 6 and 8 skinfold sums, endomorphy and fat mass; and a significant increases for muscle mass. The mean somatotype was classified as mesomorphic endomorph in the pre- (4.91, 4.01, 1.47) and post-test (4.68, 4.16, 1.69). Eight women changed their somatotype clasification after the intervention program. the practice of mat Pilates for 16 weeks caused changes associated with health state improvements on anthropometric variables, especially on skinfolds which significantly decreased, body composition (fat and muscle masses decreased and increased, respectively) and somatotype (there was a significantly decreased on the endomorph component in experienced women after three week of detraning. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  2. Joint analysis of short-period variations of ionospheric parameters in Siberia and the Far East and processes of the tropical cyclogenesis

    Science.gov (United States)

    Chernigovskaya, M. A.; Kurkin, V. I.; Orlov, I. I.; Sharkov, E. A.; Pokrovskaya, I. V.

    2009-04-01

    In this work a possibility of manifestation of strong meteorological disturbances in the Earth lower atmosphere in variations of ionospheric parameters in the zone remote from the disturbance source has been studied. The spectral analysis of short-period variations (about ten minutes, hours) in maximum observed frequencies (MOF) of one-skip signals of oblique sounding has been carried out. These variations were induced by changes in the upper atmosphere parameters along the Magadan-Irkutsk oblique-incidence sounding path on the background of diurnal variations in the parameter under study. Data on MOF measurements with off-duty factor approximately 5 min in equinoxes (September, March) of 2005-2007 were used. The analysis was made using the improved ISTP-developed technique of determining periodicities in time series. The increase of signal spectrum energy at certain frequencies is interpreted as manifestation of traveling ionospheric disturbances (TID) associated with propagation of internal gravity waves in the atmosphere. The analysis revealed TIDs of temporal scales under consideration. The question concerning localization of possible sources of revealed disturbances is discussed. Troposphere meteorological disturbances giant in their energy (tropical cyclones, typhoon) are considered as potential sources of observable TIDs. The needed information on tropical cyclones that occurred in the north area of the Indian Ocean, south-west and central areas of the Pacific Ocean in 2005-2007 is taken from the electron base of satellite data on the global tropical cyclogenesis "Global-TC" (ISR RAS). In order to effectively separate disturbances associated with the magnetospheric-ionospheric interaction and disturbances induced by the lower atmosphere influence on the upper atmosphere, we analyze the tropical cyclogenesis events that occurred in quiet helio-geomagnetic conditions. The study was supported by the Program of RAS Presidium N 16 (Part 3) and the RFBR Grant N 08-05-00658.

  3. Origin of short-period (30-300 s) Doppler frequency fluctuations of lower F region reflections in the equatorial electrojet region

    International Nuclear Information System (INIS)

    Sastri, J.H.; Ramesh, K.B.; Rao, J.V.S.V.; Somayajulu, V.V.

    1991-01-01

    Measurements of phase path P of lower F-region reflections at normal incidence at Kodaikanal revealed the ubiquitous presence of 30-300-s quasi-sinusoidal variations in the time rate of change of phase path, P (Doppler frequency shift) during day time. A study is made of the influence of the irregularities in the equatorial electrojet on the P fluctuations using simultaneous observations of F-region phase path at Kodaikanal and of equatorial electrojet with the VHF-backscatter radar at Thumba. It is shown that the spectral content of the Doppler fluctuations (quantified in terms of variance, sigma squared computed from P time series synthesized through FFT exp -1 (FFT) in the chosen period bands, 30-300 s/30-120 s of the FFT of original P times series) bears a significant positive linear relationship to the horizontal phase velocity of electrojet irregularities (3-m scale size) on a hourly basis. This result is in consonance with earlier findings (Sastri et al., 1990) of a significant linear relationship of sigma squared to the electrojet strength (estimated from H-field data) and a practical cessation of the P fluctuations at times of disappearance of Esq on ionograms (partial/complete counterelectrojet). The present work substantiates the interpretation that the short-period Doppler-frequency fluctuations are due to phase-path changes imposed on lower F region reflections by the refractive-index variations associated with the convective motions of plasma density irregularities (type I and II) in the daytime equatorial electrojet. 49 refs

  4. Quantum state engineering with ultra-short-period (AlN)m/(GaN)n superlattices for narrowband deep-ultraviolet detection.

    Science.gov (United States)

    Gao, Na; Lin, Wei; Chen, Xue; Huang, Kai; Li, Shuping; Li, Jinchai; Chen, Hangyang; Yang, Xu; Ji, Li; Yu, Edward T; Kang, Junyong

    2014-12-21

    Ultra-short-period (AlN)m/(GaN)n superlattices with tunable well and barrier atomic layer numbers were grown by metal-organic vapour phase epitaxy, and employed to demonstrate narrowband deep ultraviolet photodetection. High-resolution transmission electron microscopy and X-ray reciprocal space mapping confirm that superlattices containing well-defined, coherently strained GaN and AlN layers as thin as two atomic layers (∼ 0.5 nm) were grown. Theoretical and experimental results demonstrate that an optical absorption band as narrow as 9 nm (210 meV) at deep-ultraviolet wavelengths can be produced, and is attributable to interband transitions between quantum states along the [0001] direction in ultrathin GaN atomic layers isolated by AlN barriers. The absorption wavelength can be precisely engineered by adjusting the thickness of the GaN atomic layers because of the quantum confinement effect. These results represent a major advance towards the realization of wavelength selectable and narrowband photodetectors in the deep-ultraviolet region without any additional optical filters.

  5. A Bright Short Period M-M Eclipsing Binary from the KELT Survey: Magnetic Activity and the Mass-Radius Relationship for M Dwarfs

    Science.gov (United States)

    Lubin, Jack B.; Rodriguez, Joseph E.; Zhou, George; Conroy, Kyle E.; Stassun, Keivan G.; Collins, Karen; Stevens, Daniel J.; Labadie-Bartz, Jonathan; Stockdale, Christopher; Myers, Gordon; Colón, Knicole D.; Bento, Joao; Kehusmaa, Petri; Petrucci, Romina; Jofré, Emiliano; Quinn, Samuel N.; Lund, Michael B.; Kuhn, Rudolf B.; Siverd, Robert J.; Beatty, Thomas G.; Harlingten, Caisey; Pepper, Joshua; Gaudi, B. Scott; James, David; Jensen, Eric L. N.; Reichart, Daniel; Kedziora-Chudczer, Lucyna; Bailey, Jeremy; Melville, Graeme

    2017-08-01

    We report the discovery of KELT J041621-620046, a moderately bright (J ˜ 10.2) M-dwarf eclipsing binary system at a distance of 39 ± 3 pc. KELT J041621-620046 was first identified as an eclipsing binary using observations from the Kilodegree Extremely Little Telescope (KELT) survey. The system has a short orbital period of ˜1.11 days and consists of components with {M}1={0.447}+0.052-0.047 {M}⊙ and {M}2={0.399}+0.046-0.042 {M}⊙ in nearly circular orbits. The radii of the two stars are {R}1={0.540}+0.034-0.032 {R}⊙ and {\\text{}}{R}2=0.453+/- 0.017 {R}⊙ . Full system and orbital properties were determined (to ˜10% error) by conducting an EBOP (Eclipsing Binary Orbit Program) global modeling of the high precision photometric and spectroscopic observations obtained by the KELT Follow-up Network. Each star is larger by 17%-28% and cooler by 4%-10% than predicted by standard (non-magnetic) stellar models. Strong Hα emission indicates chromospheric activity in both stars. The observed radii and temperature discrepancies for both components are more consistent with those predicted by empirical relations that account for convective suppression due to magnetic activity.

  6. Cirugía ambulatoria y de corta hospitalización en el cáncer de mama Ambulatory breast cancer surgery with short hospitalization period

    Directory of Open Access Journals (Sweden)

    Alexis Cantero Ronquillo

    2007-06-01

    Full Text Available La cirugía mayor ambulatoria y de corta estadía constituye un método eficaz y seguro si se hace una selección adecuada de los enfermos y se utilizan técnicas quirúrgicas depuradas con la creación consecuente de la infraestructura para tales fines. Tradicionalmente, el cáncer de mama ha requerido ingreso hospitalario por el riesgo de hemorragia posoperatoria, la necesidad del control de los drenajes quirúrgicos, etc. Internacionalmente esto ha cambiado tras la introducción de nuevas técnicas quirúrgicas como la biopsia del ganglio centinela, la estandarización de las técnicas preservadoras de tejido mamario, así como la especialización de grupos de cirugía en afecciones de la mama. La creación de un grupo de mastología en nuestro centro permitió incursionar en esta modalidad y ya podamos contar 31 pacientes operadas entre enero de 2004 y junio de 2006. Fueron utilizadas diferentes técnicas quirúrgicas con cirugía de corta estadía, previo establecimiento de los criterios de selección. Pudimos concluir que el tratamiento ambulatorio del cáncer de mama en casos seleccionados es factible, dado que se garantiza la seguridad de la paciente, la calidad asistencial y la continuidad en la atención, que además facilita la recuperación psicológica de la enferma y su reinserción temprana en la familiaAmbulatory major surgery with short hospitalization period is an efficient and safe method if a proper selection of patients is made and refined surgical techniques are used, all supported on adequate infrastructure to this end. Traditionally, breast cancer has required admission at hospital due to postsurgical hemorrhage risk, need for surgical drainage control, etc. This has changed worlwide after the introduction of new surgical techniques as sentinel node biopsy, standardization of preserving techniques for breast tissue and specialization of surgeon teams in breast illnesses. The creation of a mastology group in our center

  7. Sociodemographic factors and attitudes toward food affordability and health are associated with fruit and vegetable consumption in a low-income French population.

    Science.gov (United States)

    Bihan, Hélène; Castetbon, Katia; Mejean, Caroline; Peneau, Sandrine; Pelabon, Laetitia; Jellouli, Fatima; Le Clesiau, Hervé; Hercberg, Serge

    2010-04-01

    Determinants of fruit and vegetable consumption, including affordability and attitudes, have been poorly investigated, especially in European deprived populations. Our objective was to analyze various determinants of low consumption of fruits and vegetables in disadvantaged participants. Our participants were randomized into 2 groups, 1 which received nutritional advice alone and 1 that also received vouchers that were exchangeable for fruits and vegetables during a 12-mo period. Socioeconomic characteristics, food insufficiency, affordability, and motivation for eating fruits and vegetables were assessed. A short FFQ was administered. Determinants of consumption of French population are numerous. The impact of financial difficulties is crucial, as is the perception of affordability of fruits and vegetables.

  8. Sublethal effects of the herbicide glufosinate ammonium on crops and wild plants: short-term effects compared to vegetative recovery and plant reproduction.

    Science.gov (United States)

    Carpenter, David; Boutin, Céline

    2010-10-01

    Current guidelines for phytotoxicity testing rely heavily on short-term testing of primarily crop species to predict the sensitivity of non-target, wild plants to herbicides. However, little is known on how plants recover following initial growth inhibitions in standard 14-28 day greenhouse tests conducted for pesticide assessment and registration. The objectives of this study were to assess the ability of plant species to recover (biomass and reproduction) when tested at the juvenile stage (routine regulatory testing), comparing crop and wild species and using the herbicide glufosinate ammonium. Ten crops and 10 wild species were tested with a one-time exposure to glufosinate ammonium in a greenhouse. Half the plants of each species (9 doses × 6 replicates) were harvested 3 weeks after being sprayed (short-term). The remaining plants were harvested several weeks later, coinciding with seed set or natural senescence (long-term). Total aboveground biomass and several endpoints related to crop production and plant reproduction were measured. Calculated IC50 values (dosage that results in a 50% decrease in the biomass of a plant as compared to the untreated controls) based solely on aboveground biomass, for species harvested in the long-term were generally higher than those obtained in the short-term (with two exceptions), indicating recovery over time. Crop species did not differ from wild species in terms of sensitivity. However, in seven out of 12 cases where reproduction was measurable, reproductive endpoints were more sensitive than either short or long-term biomass endpoints, indicating the importance of examining these parameters in phytotoxicity testing. Glufosinate ammonium was found to be phytotoxic at low doses (2.64-7.74% g ai/ha of the label rate).

  9. Effect of re-expansion after short-period lung collapse on pulmonary capillary permeability and pro-inflammatory cytokine gene expression in isolated rabbit lungs.

    Science.gov (United States)

    Funakoshi, T; Ishibe, Y; Okazaki, N; Miura, K; Liu, R; Nagai, S; Minami, Y

    2004-04-01

    Re-expansion pulmonary oedema is a rare complication caused by rapid re-expansion of a chronically collapsed lung. Several cases of pulmonary oedema associated with one-lung ventilation (OLV) have been reported recently. Elevated levels of pro-inflammatory cytokines in pulmonary oedema fluid are suggested to play important roles in its development. Activation of cytokines after re-expansion of collapsed lung during OLV has not been thoroughly investigated. Here we investigated the effects of re-expansion of the collapsed lung on pulmonary oedema formation and pro-inflammatory cytokine expression. Lungs isolated from female white Japanese rabbits were perfused and divided into a basal (BAS) group (n=7, baseline measurement alone), a control (CONT) group (n=9, ventilated without lung collapse for 120 min) and an atelectasis (ATEL) group (n=9, lung collapsed for 55 min followed by re-expansion and ventilation for 65 min). Pulmonary vascular resistance (PVR) and the coefficient of filtration (Kfc) were measured at baseline and 60 and 120 min. At the end of perfusion, bronchoalveolar lavage fluid/plasma protein ratio (B/P), wet/dry lung weight ratio (W/D) and mRNA expressions of tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta and myeloperoxidase (MPO) were determined. TNF-alpha and IL-1beta mRNA were significantly up-regulated in lungs of the ATEL group compared with BAS and CONT, though no significant differences were noted in PVR, Kfc, B/P and W/D within and between groups. MPO increased at 120 min in CONT and ATEL groups. Pro-inflammatory cytokines were up-regulated upon re-expansion and ventilation after short-period lung collapse, though no changes were noted in pulmonary capillary permeability.

  10. Short-period strain (0.1-105 s): Near-source strain field for an earthquake (M L 3.2) near San Juan Bautista, California

    Science.gov (United States)

    Johnston, M. J. S.; Borcherdt, R. D.; Linde, A. T.

    1986-10-01

    Measurements of dilational earth strain in the frequency band 25-10-5 Hz have been made on a deep borehole strainmeter installed near the San Andreas fault. These data are used to determine seismic radiation fields during nuclear explosions, teleseisms, local earthquakes, and ground noise during seismically quiet times. Strains of less than 10-10 on these instruments can be clearly resolved at short periods (< 10 s) and are recorded with wide dynamic range digital recorders. This permits measurement of the static and dynamic strain variations in the near field of local earthquakes. Noise spectra for earth strain referenced to 1 (strain)2/Hz show that strain resolution decreases at about 10 dB per decade of frequency from -150 dB at 10-4 Hz to -223 dB at 10 Hz. Exact expressions are derived to relate the volumetric strain and displacement field for a homogeneous P wave in a general viscoelastic solid as observed on colocated dilatometers and seismometers. A rare near-field recording of strain and seismic velocity was obtained on May 26, 1984, from an earthquake (ML 3.2) at a hypocentral distance of 3.2 km near the San Andreas fault at San Juan Bautista, California. While the data indicate no precursory strain release at the 5 × 10-11 strain level, a coseismic strain release of 1.86 nanostrain was observed. This change in strain is consistent with that calculated from a simple dislocation model of the event. Ground displacement spectra, determined from the downhole strain data and instrument-corrected surface seismic data, suggest that source parameters estimated from surface recordings may be contaminated by amplification effects in near-surface low-velocity materials.

  11. Short rotation willow coppice for renewable energy and improved environment. Proceedings of a joint Swedish - Estonian seminar on energy forestry and vegetation filters

    International Nuclear Information System (INIS)

    Perttu, K.; Koppel, A.

    1996-01-01

    The overall aim of the present seminar was to present and discuss results from the joint Swedish - Estonian energy forestry research activities during the period of 1993-1995 and to publish the papers in a technical report. The results is a publication, presenting interesting methods and results, and is meant partly to serve as the final report of the joint efforts during the period mentioned, partly to be used for future planning of new projects and for application of funding for a continued cooperation. Separate abstracts have been prepared for all of the 17 papers in the report

  12. Short vegetal-fiber reinforced HDPE—A study of electron-beam radiation treatment effects on mechanical and morphological properties

    International Nuclear Information System (INIS)

    Ferreira, Maiara S.; Sartori, Mariana N.; Oliveira, Rene R.; Guven, Olgun; Moura, Esperidiana A.B.

    2014-01-01

    Graphical abstract: - Highlights: • HDPE reinforced with short piassava fiber composites were prepared by melt-mixing processing. • Glycidyl methacrylate (GMA) was tested as a radiation cross-linking agent. • The materials were irradiated with 100 and 200 kGy using a 1.5 MeV electron beam accelerator, at room temperature in presence of air. • The better interfacial adhesion between fiber and HDPE matrix was observed for composites with GMA addition irradiated with radiation dose of 200 kGy. - Abstract: The effects of electron-beam radiation treatment on fiber-matrix adhesion and mechanical properties of short piassava fibers reinforced high density polyethylene (HDPE) matrix were studied. Glycidyl methacrylate (GMA) was added at 2.5% and 5.0% (on piassava fiber wt) as a cross-linking agent and the effects upon the properties of the resulting composites treated by electron-beam radiation were also examined. HDPE reinforced with short piassava fiber composites was prepared by melt-mixing processing, using a twin screw extruder machine. The materials were irradiated with 100 and 200 kGy using a 1.5 MeV electron beam accelerator, at room temperature in presence of air. Material samples were submitted to mechanical and thermo-mechanical tests and SEM analyses. Correlation between properties was discussed. The comparison of mechanical and thermo-mechanical properties of the composites showed that electron-beam radiation treatment produced a significant improvement in mechanical properties, when compared with the non-irradiated composite sample and neat HDPE. Scanning electron microscopy (SEM) studies of the composite failure surfaces indicated that there was an improved adhesion between fiber and matrix. Examination of the failure surfaces indicated dependence of the interfacial adhesion upon the radiation dose and GMA content. Better interfacial adhesion between fiber and HDPE matrix was observed for composites with 5.0% GMA addition and treated with electron

  13. Short vegetal-fiber reinforced HDPE—A study of electron-beam radiation treatment effects on mechanical and morphological properties

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Maiara S.; Sartori, Mariana N.; Oliveira, Rene R. [Nuclear and Energy Research Institute, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, zip code 05508-000 São Paulo, SP (Brazil); Guven, Olgun [Hacettepe University, Department of Chemistry, Polymer Chemistry Division, Beytepe, zip code 06800 Ankara (Turkey); Moura, Esperidiana A.B., E-mail: eabmoura@ipen.br [Nuclear and Energy Research Institute, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, zip code 05508-000 São Paulo, SP (Brazil)

    2014-08-15

    Graphical abstract: - Highlights: • HDPE reinforced with short piassava fiber composites were prepared by melt-mixing processing. • Glycidyl methacrylate (GMA) was tested as a radiation cross-linking agent. • The materials were irradiated with 100 and 200 kGy using a 1.5 MeV electron beam accelerator, at room temperature in presence of air. • The better interfacial adhesion between fiber and HDPE matrix was observed for composites with GMA addition irradiated with radiation dose of 200 kGy. - Abstract: The effects of electron-beam radiation treatment on fiber-matrix adhesion and mechanical properties of short piassava fibers reinforced high density polyethylene (HDPE) matrix were studied. Glycidyl methacrylate (GMA) was added at 2.5% and 5.0% (on piassava fiber wt) as a cross-linking agent and the effects upon the properties of the resulting composites treated by electron-beam radiation were also examined. HDPE reinforced with short piassava fiber composites was prepared by melt-mixing processing, using a twin screw extruder machine. The materials were irradiated with 100 and 200 kGy using a 1.5 MeV electron beam accelerator, at room temperature in presence of air. Material samples were submitted to mechanical and thermo-mechanical tests and SEM analyses. Correlation between properties was discussed. The comparison of mechanical and thermo-mechanical properties of the composites showed that electron-beam radiation treatment produced a significant improvement in mechanical properties, when compared with the non-irradiated composite sample and neat HDPE. Scanning electron microscopy (SEM) studies of the composite failure surfaces indicated that there was an improved adhesion between fiber and matrix. Examination of the failure surfaces indicated dependence of the interfacial adhesion upon the radiation dose and GMA content. Better interfacial adhesion between fiber and HDPE matrix was observed for composites with 5.0% GMA addition and treated with electron

  14. High-Precision Locations and the Stress Field from Instrumental Seismicity, Moment Tensors, and Short-Period Mechanisms through the Mina Deflection, Central Walker Lane

    Science.gov (United States)

    Ruhl, C. J.; Smith, K. D.

    2012-12-01

    well as available and developed short-period focal mechanisms are compiled to evaluate the stress field to assess mechanisms of slip accommodation. Based on the complex distribution of fault orientations, the stress field varies locally northward from the SWL throughout the MD; however, in many cases, fault plane alignments can be isolated from high-precision locations, providing better constraints on stress and slip orientations.

  15. Short period strain balanced gallium arsenide nitride/indium arsenide nitride superlattice lattice matched to indium phosphide for mid-infrared photovoltaics

    Science.gov (United States)

    Bhusal, Lekhnath

    Dilute nitrogen-containing III-V-N alloys have been intensively studied for their unusual electronic and optical behavior in the presence of a small amount of nitrogen. Those behaviors can further be manipulated, with a careful consideration of the strain and strain balancing, for example, in the context of a strain-balanced superlattice (SL) based on those alloys. In this work, the k.p approximation and the band anti-crossing model modified for the strain have been used to describe the electronic states of the strained bulk-like GaAs1-xNx and InAs 1-yNy ternaries in the vicinity of the center of the Brillouin zone (Gamma-point). Band-offsets between the conduction and valence bands of GaAs1-xNx and InAs1-yN y have also been evaluated, before implementing them into the SL structure. By minimizing the total mechanical energy of the stack of the alternating layers of GaAs1-xNx and InAs1-yNy in the SL, the ratio of the thicknesses of the epilayers is determined to make the structure lattice-matching on the InP(001), through the strain-balancing. Mini-band energies of the strain-balanced GaAs1-xNx/InAs 1-yNy short-period SL on InP(001) is then investigated using the transfer matrix formalism. This enabled identifying the evolution of the band edge transition energies of the superlattice structure for different nitrogen compositions. Results show the potential of the new proposed design to exceed the existing limits of bulk-like InGaAsN alloys and offer the applications for photon absorption/emission energies in the range of ~0.65-0.35eV at 300K for a typical nitrogen composition of ≤5%. The optical absorption coefficient of such a SL is then estimated under the anisotropic medium approximation, where the optical absorption of the bulk structure is modified according to the anisotropy imposed by the periodic potential in the growth direction. As an application, the developed SL structure is used to investigate the performance of double, triple and quadruple junction

  16. Temporal changes and factors influencing {sup 137}Cs concentration in vegetation colonizing an exposed lake bed over a three-year period

    Energy Technology Data Exchange (ETDEWEB)

    Hinton, T.G.; Bell, C.M. [Savannah River Ecology Laboratory, The University of Georgia, Aiken, SC (United States); Whicker, F.W. [Colorado State University, Fort Collins, CO (United States); Philippi, T. [Savannah River Ecology Laboratory, The University of Georgia, Aiken, SC (United States)

    1999-05-01

    Activity concentrations of {sup 137}Cs in sediments, as well as extractable sediment concentrations of K, Na, Mg, Ca, Mn, Zn and P, pH, percent organic matter and cation exchange capacity, were used as independent variables in an incomplete principal component analysis to identify factors affecting {sup 137}Cs activity concentrations in 12 species of native wetland and terrestrial plants invading a recently exposed lake bed. Sediments in the lake had been contaminated 35 years previously from discharges at a nuclear production reactor. {sup 137}Cs activity concentrations in plants were positively correlated with sediment concentrations of Na and {sup 137}Cs, and inversely correlated to K and pH. Significant decreases in concentrations of sediment constituents (from 3 to 77%), as well as a 42% decline in {sup 137}Cs activity concentrations in plants, occurred during the three-year period. Significant differences in {sup 137}Cs activity concentrations among plant species, driven by low concentrations in cattails (Typha latifolia), were observed. Terrestrial species had significantly lower activity concentrations of {sup 137}Cs than species classified as wetland (arithmetic mean{+-}S.E. of 1069{+-}151 and 2602{+-}394, respectively). Concentration ratios (Bq kg{sup -1} dry plant/Bq kg{sup -1} dry soil) were among the highest reported in the literature (arithmetic mean{+-}S.D.=12.5{+-}28.9; geometric mean=1.6, geometric S.D.=1.4) and were attributed to kaolinitic sediments of pH<5, organic matter <5%, K concentrations <15 ppm and cation exchange capacity <5 meq (100 g{sup -1}). Even though {sup 137}Cs was released into the system over 35 years ago, lowering of the water caused {sup 137}Cs in the newly formed terrestrial system to behave like a fresh, rather than aged, deposit (initial uptake rates by plants were high and subsequent reductions in bioavailability were rapid). Implications for management of contaminated reservoirs from a public risk perspective are

  17. Assessment the Effect of Drought on Vegetation in Desert Area using Landsat Data

    Directory of Open Access Journals (Sweden)

    H. Khosravi

    2017-04-01

    Full Text Available Drought phenomenon is one kind of a disaster that can significantly affect the density of vegetation in any area especially dry regions. This study tries to express the effect of drought on vegetation cover in Yazd-Ardakan plain, central Iran. At first, annual average for SPI index was calculated from 1996 to 2015, and then NDVI was calculated for May in 1998, 2000, 2009, 2010, 2011 and 2015. Afterwards, NDVI maps were classified into three groups including no vegetation, poor vegetation (pastures, and dense vegetation (farmlands and gardens. Based on the results the worst value of drought was −1.92 in year 1999. Besides, the annual SPI of 1996 with value of 2.4 was considered as the wettest year during study period (1996–2015. The highest percentage of dense vegetation and poor vegetation were related to 2010 and 1998 respectively, and the lowest percentage for both classes was related to 2000. There was correlation among the area of poor vegetation class in middle of spring and previous annual SPI at the significant level of 95%. In contract, no correlation was found between dense vegetation class areas in middle spring and previous amount of annual SPI. The study of the correlation between the SPI average and the percentage of vegetation classes indicated that pastures were highly sensitive to SPI changes; however, farming lands showed less sensitivity in short term due to using deep wells.

  18. ON THE POSSIBLE EXISTENCE OF SHORT-PERIOD g-MODE INSTABILITIES POWERED BY NUCLEAR-BURNING SHELLS IN POST-ASYMPTOTIC GIANT BRANCH H-DEFICIENT (PG1159-TYPE) STARS

    International Nuclear Information System (INIS)

    Corsico, A. H.; Althaus, L. G.; Miller Bertolami, M. M.; Gonzalez Perez, J. M.; Kepler, S. O.

    2009-01-01

    We present a pulsational stability analysis of hot post-asymptotic giant branch (AGB) H-deficient pre-white dwarf stars with active He-burning shells. The stellar models employed are state-of-the-art equilibrium structures representative of PG1159 stars derived from the complete evolution of the progenitor stars, through the thermally pulsing AGB phase and born-again episode. On the basis of fully nonadiabatic pulsation computations, we confirmed theoretical evidence for the existence of a separate PG1159 instability strip in the log T eff -log g diagram characterized by short-period g-modes excited by the ε-mechanism. This instability strip partially overlaps the already known GW Vir instability strip of intermediate/long-period g-modes destabilized by the classical κ-mechanism acting on the partial ionization of C and/or O in the envelope of PG1159 stars. We found that PG1159 stars characterized by thick He-rich envelopes and located inside this overlapping region could exhibit both short and intermediate/long periods simultaneously. As a natural application of our results, we study the particular case of VV 47, a pulsating planetary nebula nucleus (PG1159 type) that is particularly interesting because it has been reported to exhibit a rich and complex pulsation spectrum including a series of unusually short pulsation periods. We found that the long periods exhibited by VV 47 can be readily explained by the classical κ-mechanism, while the observed short-period branch below ∼300 s could correspond to modes triggered by the He-burning shell through the ε-mechanism, although more observational work is needed to confirm the reality of these short-period modes. Were the existence of short-period g-modes in this star convincingly confirmed by future observations, VV 47 could be the first known pulsating star in which both the κ-mechanism and the ε-mechanism of mode driving are simultaneously operating.

  19. Leaf-Like Sepals Induced by Ectopic Expression of a SHORT VEGETATIVE PHASE (SVP)-Like MADS-Box Gene from the Basal Eudicot Epimedium sagittatum

    Science.gov (United States)

    Li, Zhineng; Zeng, Shaohua; Li, Yanbang; Li, Mingyang; Souer, Erik

    2016-01-01

    Epimedium L. (Berberidaceae, Ranales), a perennial traditional Chinese medicinal herb, has become a new popular landscape plant for ground cover and pot culture in many countries based on its excellent ornamental characteristics and, distinctive and diverse floral morphology. However, little is known about the molecular genetics of flower development in Epimedium sagittatum. Here, we describe the characterization of EsSVP that encodes a protein sharing 68, 54, and 35% similarity with SVP, AGAMOUS-like 24 (AGL24) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) in Arabidopsis, respectively. Quantitative RT-PCR (qRT-PCR) indicated that EsSVP transcripts were principally found in petiole and leaf tissues, with little expression in roots and flowers and no in fruits. The highest EsSVP expression was observed in leaves. The flowering time of 35S::EsSVP in most Arabidopsis thaliana and in all petunia plants was not affected in both photoperiod conditions, but 35S::EsSVP 5# and 35S::EsSVP 1# Arabidopsis lines induced late and early flowering under long day (LD, 14 h light/10 h dark) and short day (SD, 10 h light/14 h dark) conditions, respectively. The 35S::EsSVP Arabidopsis produced extra secondary inflorescence or floral meristems in the axils of the leaf-like sepals with excrescent trichomes, and leaf-like sepals not able to enclose the inner three whorls completely. Moreover, almost all transgenic Arabidopsis plants showed persistent sepals around the completely matured fruits. Upon ectopic expression of 35S::EsSVP in Petunia W115, sepals were enlarged, sometimes to the size of leaves; corollas were greenish and did not fully open. These results suggest that EsSVP is involved in inflorescence meristem identity and flowering time regulation in some conditions. Although, the SVP homologs might have suffered functional diversification among diverse species between core and basal eudicots, the protein functions are conserved between Arabidopsis/Petunia and Epimedium

  20. Leaf-like sepals induced by ectopic expression of a SHORT VEGETATIVE PHASE (SVP-like MADS-box gene from the basal eudicot Epimedium sagittatum

    Directory of Open Access Journals (Sweden)

    Zhineng Li

    2016-09-01

    Full Text Available Epimedium L. (Berberidaceae, Ranales, a perennial traditional Chinese medicinal herb, has become a new popular landscape plant for ground cover and pot culture in many countries based on its excellent ornamental characteristics and, distinctive and diverse floral morphology. However, little is known about the molecular genetics of flower development in Epimedium sagittatum. Here, we describe the characterization of EsSVP that encodes a protein sharing 68%, 54% and 35% similarity with SVP, AGAMOUS-like 24 (AGL24 and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1 in Arabidopsis, respectively. Quantitative RT-PCR (qRT-PCR indicated that EsSVP transcripts were principally found in petiole and leaf tissues, with little expression in roots and flowers and no in fruits. The highest EsSVP expression was observed in leaves. The flowering time of 35S::EsSVP in most Arabidopsis thaliana and in all petunia plants was not affected in both photoperiod conditions, but 35S::EsSVP 5# and 35S::EsSVP 1# Arabidopsis lines induced late and early flowering under long day (LD, 14 hr light/10 hr dark and short day (SD, 10 hr light/14 hr dark conditions, respectively. The 35S::EsSVP Arabidopsis produced extra secondary inflorescence or floral meristems in the axils of the leaf-like sepals with excrescent trichomes, and leaf-like sepals not able to enclose the inner three whorls completely. Moreover, almost all transgenic Arabidopsis plants showed persistent sepals around the completely matured fruits. Upon ectopic expression of 35S::EsSVP in Petunia W115, sepals were enlarged, sometimes to the size of leaves; corollas were greenish and did not fully open. These results suggest that EsSVP is involved in inflorescence meristem identity and flowering time regulation in some conditions. Although the SVP homologs might have suffered functional diversification among diverse species between core and basal eudicots, the protein functions are conserved between Arabidopsis

  1. Short-term alpha-tocopherol treatment during neonatal period modulates pro-inflammatory response to endotoxin (LPS) challenge in the same calves several months later

    Science.gov (United States)

    Vitamin E, a major natural antioxidant, has been previously shown to attenuate pro-inflammatory response to immune challenge in cattle. Our objective was to evaluate the effect of short-term treatment with alpha-tocopherol in newborn calves on selected elements of the pro-inflamatory response to LPS...

  2. Student Teachers of Technology and Design: Can Short Periods of STEM-Related Industrial Placement Change Student Perceptions of Engineering and Technology?

    Science.gov (United States)

    Gibson, Ken S.

    2012-01-01

    This is a report, on a small-scale case study, of a programme of short industrial placements (5 day block) for student teachers of technology and design in Northern Ireland. Such placements increase student awareness and understanding of the nature of Engineering and Technology and therefore better prepare them to teach these subjects, as integral…

  3. Short-Term Impacts of Livestock Grazing on Vegetation and Track Formation in a High Mountain Environment: A Case Study from the Himalayan Miyar Valley (India

    Directory of Open Access Journals (Sweden)

    Michal Apollo

    2018-03-01

    Full Text Available Animals’ activities are a significant geomorphologic factor. An important reliefogenic role is played by animals introduced by man; that is, livestock. The activity of livestock on the earth’s surface can be direct (horizontal displacement of the soil, or indirect (preparation of ground for degradation. In this research the areas that livestock tread most often were put under examination, that is, places used for resting (e.g., during the night and paths used for moving (e.g., while passing to and from grazing spots. The experimental research areas were divided into two groups. During the two-week study period it was noted that (1 the number of plants and their stems had declined by 9.5% and 19% respectively, and the paths had widened by 6%; (2 the soil level had decreased, uncovering the measurement pins by 3.5 mm up to 24 mm, depending on the slope of the ground, while in the comparison (control areas the pins were uncovered only up to an average 1.8 mm. The results of the research show the scale of the phenomenon of zoogenic erosion caused by livestock. Based on the research the following formula has been elaborated y = ( − 0.005 x + 0.0526 T × N × S P 100 × 0.86 . This provided the opportunity to calculate the average (hypothetical data for soil loss (y, according to the slope degree (x, the number of animals (N, the time that those animals spend in the area (T, and the static pressure they caused on the ground (SP. The paper makes recommendations that could lead to a reduction in soil erosion caused by livestock.

  4. Kuchler Vegetation

    Data.gov (United States)

    California Natural Resource Agency — Digital version of potential natural plant communites as compiled and published on 'Map of the Natural Vegetation of California' by A. W. Kuchler, 1976. Source map...

  5. Wieslander Vegetation

    Data.gov (United States)

    California Natural Resource Agency — Digital version of the 1945 California Vegetation Type Maps by A. E. Wieslander of the U.S. Forest Service. Source scale of maps are 1:100,000. These compiled maps...

  6. Impact of vegetation variability on potential predictability and skill of EC-Earth simulations

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Martina; Hurk, Bart van den; Haarsma, Reindert; Hazeleger, Wilco [Royal Netherlands Meteorological Institute (KNMI), De Bilt (Netherlands)

    2012-12-15

    Climate models often use a simplified and static representation of vegetation characteristics to determine fluxes of energy, momentum and water vapour between surface and lower atmosphere. In order to analyse the impact of short term variability in vegetation phenology, we use remotely-sensed leaf area index and albedo products to examine the role of vegetation in the coupled land-atmosphere system. Perfect model experiments are carried out to determine the impact of realistic temporal variability of vegetation on potential predictability of evaporation and temperature, as well as model skill of EC-Earth simulations. The length of the simulation period is hereby limited by the availability of satellite products to 2000-2010. While a realistic representation of vegetation positively influences the simulation of evaporation and its potential predictability, a positive impact on 2 m temperature is of smaller magnitude, regionally confined and more pronounced in climatically extreme years. (orig.)

  7. The Upper Limit of the Periodic Table of Elements Points out to the "Long" Version of the Table, Instead of the "Short" One

    Directory of Open Access Journals (Sweden)

    Khazan A.

    2012-01-01

    Full Text Available Herein we present an analysis of the internal constitution of the “short” and “long” forms of the Periodic Table of Elements. As a result, we conclude that the second (long version is more correct. We also suggest a long version of the Table consisting of 8 periods and 18 groups, with the last (heaviest element being element No. 155, which closes the Table.

  8. Phenological characteristics of the main vegetation types on the Tibetan Plateau based on vegetation and water indices

    International Nuclear Information System (INIS)

    Peng, D L; Huang, W J; Zhou, B; Li, C J; Wu, Y P; Yang, X H

    2014-01-01

    Plant phenology is considered one of the most sensitive and easily observable natural indicators of climate change, though few studies have focused on the heterogeneities of phenology across the different vegetation types. In this study, we tried to find the phenological characteristics of the main vegetation types on the Tibetan Plateau. MCD12Q1 images over the Tibetan Plateau from 2001 to 2010 were used to extract the main vegetation types. The Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Land Surface Water Index (LSWI) were calculated using surface reflectance values from the blue, red, near-infrared, short-wave infrared (SWIR) 6 (for LSIW6), and SWIR7 (for LSIW7) bands derived from MOD09A1 and used to explore the phenological characteristics of the main vegetation types on the Tibetan Plateau. The results showed that there were eight constant vegetation types on the Tibetan Plateau from 2001 to 2010 demonstrating multiple phenological characteristics. Evergreen needleleaf forest, evergreen broadleaf forest, and permanent wetland had the minimum NDVI values during the summer season, while open shrubland and grassland had the maximum NDVI/EVI values during this period. NDVI and EVI of cropland/natural vegetation had two peaks for their seasonal variations. EVI showed a more significant correlation with LSWI6/LSWI7 than NDVI. Compared to LSWI7, larger EVI values occurred in evergreen needleleaf forest, evergreen broadleaf forest, mixed forest, and permanent wetland, while smaller values occurred in shrubland and barren or sparsely vegetated cover, and nearly equal values occurred in grassland and cropland

  9. RADIO FLARING FROM THE T6 DWARF WISEPC J112254.73+255021.5 WITH A POSSIBLE ULTRA-SHORT PERIODICITY

    Energy Technology Data Exchange (ETDEWEB)

    Route, Matthew; Wolszczan, Alexander, E-mail: mroute@purdue.edu, E-mail: alex@astro.psu.edu [Department of Astronomy and Astrophysics, the Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

    2016-04-20

    We present new results from a continuing 5 GHz search for flaring radio emission from a sample of L and T brown dwarfs, conducted with the 305 m Arecibo radio telescope. In addition to the previously reported flaring from the T6.5 dwarf 2MASS J10475385+212423, we have detected and confirmed circularly polarized flares from another T6 dwarf, WISEPC J112254.73+255021.5. Although the flares are sporadic, they appear to occur at a stable period of 0.288 hr. Given the current constraints, periods equal to its second and third subharmonic cannot be ruled out. The stability of this period over the eight-month timespan of observations indicates that, if real, it likely reflects the star’s rapid rotation. If confirmed, any of the three inferred periodicities would be much shorter than the shortest, 1.41 hr, rotation period of a brown dwarf measured so far. This finding would place a new observational constraint on the angular momentum evolution and rotational stability of substellar objects. The detection of radio emission from the sixth ∼1000 K dwarf further demonstrates that the coolest brown dwarfs and, possibly, young giant planets, can be efficiently investigated using radio observations at centimeter wavelengths as a tool.

  10. Sequential Injection Chromatography with an Ultra-short Monolithic Column for the Low-Pressure Separation of α-Tocopherol and γ-Oryzanol in Vegetable Oils and Nutrition Supplements.

    Science.gov (United States)

    Thaithet, Sujitra; Kradtap Hartwell, Supaporn; Lapanantnoppakhun, Somchai

    2017-01-01

    A low-pressure separation procedure of α-tocopherol and γ-oryzanol was developed based on a sequential injection chromatography (SIC) system coupled with an ultra-short (5 mm) C-18 monolithic column, as a lower cost and more compact alternative to the HPLC system. A green sample preparation, dilution with a small amount of hexane followed by liquid-liquid extraction with 80% ethanol, was proposed. Very good separation resolution (R s = 3.26), a satisfactory separation time (10 min) and a total run time including column equilibration (16 min) were achieved. The linear working range was found to be 0.4 - 40 μg with R 2 being more than 0.99. The detection limits of both analytes were 0.28 μg with the repeatability within 5% RSD (n = 7). Quantitative analyses of the two analytes in vegetable oil and nutrition supplement samples, using the proposed SIC method, agree well with the results from HPLC.

  11. Short communication

    DEFF Research Database (Denmark)

    Vargas-Bello-Pérez, E.; Fehrmann-Cartes, K.; Íiguez-González, G.

    2015-01-01

    with soybean (SO) and hydrogenated vegetable (HVO) oils on chemical and FA composition of milk and cheese and sensory characteristics of cheese. Nine multiparous Holstein cows averaging 169 ± 24. d in milk at the beginning of the study were used in a replicated (n = 3) 3 × 3 Latin square design that included 3...... periods of 21. d. All cows received a basal diet formulated with a 56:44 forage:concentrate ratio. Dietary treatments consisted of the basal diet (control; no fat supplement), and the basal diet supplemented with SO (unrefined oil; 500. g/d per cow) and HVO (manufactured from palm oil; 500. g/d per cow...

  12. Consequences of dietary energy source and energy level on energy balance, lactogenic hormones, and lactation curve characteristics of cows after a short or omitted dry period

    NARCIS (Netherlands)

    van Hoeij, R J; Dijkstra, J; Bruckmaier, R.M.; Gross, James J; Lam, T J G M; Remmelink, G J; Kemp, B.; Knegsel, A.T.M.

    2017-01-01

    Omitting the dry period (DP) generally reduces milk production in the subsequent lactation. The aim of this study was to evaluate the effect of dietary energy source-glucogenic (G) or lipogenic (L)-and energy level-standard (std) or low-on milk production; energy balance (EB); lactogenic hormones

  13. Udder health of dairy cows fed different dietary energy levels after a short or no dry period without use of dry cow antibiotics

    NARCIS (Netherlands)

    Hoeij, van R.J.; Lam, T.J.G.M.; Bruckmaier, R.M.; Dijkstra, J.; Remmelink, G.J.; Kemp, B.; Knegsel, van A.T.M.

    2018-01-01

    Reports on the effects of length of dry period (DP) on udder health of cows that were not treated with dry cow antibiotics are scarce. Additionally, the effects of a reduced dietary energy level for cows with a 0-d DP on udder health have not yet been studied. The aims of this study were (1) to

  14. Consequences of dietary energy source and energy level on energy balance, lactogenic hormones, and lactation curve characteristics of cows after a short or omitted dry period

    NARCIS (Netherlands)

    Hoeij, van R.J.; Dijkstra, J.; Bruckmaier, R.M.; Gross, J.J.; Lam, Theo J.G.M.; Remmelink, G.J.; Kemp, B.; Knegsel, van A.T.M.

    2017-01-01

    Omitting the dry period (DP) generally reduces milk production in the subsequent lactation. The aim of this study was to evaluate the effect of dietary energy source—glucogenic (G) or lipogenic (L)—and energy level—standard (std) or low—on milk production; energy balance (EB); lactogenic hormones

  15. Influence of winds on temporally varying short and long period gravity waves in the near shore regions of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Glejin, J.; SanilKumar, V.; Nair, T.M.B.; Singh, J.

    pro- vided by the NOAA-CIRES (Cooperative Institute for Re- search in the Environmental Sciences) Climate Diagnostics Center in Boulder, Colorado (http://www.cdc.noaa.gov/). To determine the sea/land breeze system at Ratnagiri during the study period...

  16. Ultra-short-period W/B4C multilayers for x-ray optics-microstructure limits on reflectivity

    Energy Technology Data Exchange (ETDEWEB)

    Walton, Christopher Charles [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

    1997-12-01

    Multilayer thin films are used as Bragg reflectors for soft x-rays in the energy range 50eV < E < 1000eV in many x-ray optics applications such as x-ray microscopes and telescopes, reducing optics for extreme ultraviolet (EUV) lithography, and x-ray polarizers and phase retarders. Applications often depend critically on reflectivity, which has not been systematically characterized for multilayer periods below 20Å. For this study, W/B4C multilayers were fabricated by magnetron sputtering on Si(111), with periods from 48Å to as little as 4.7Å. The x-ray reflectivity measured at λ = 1.54Å and at 45° incidence (289 eV < E < 860 eV) was found to decrease sharply for multilayer periods less than 15-20Å. Examination by high-resolution transmission electron microscopy (HRTEM) showed an expansion of the thickness of the W-rich layers of 30-40% from the nominal values, consistent with intermixture of the two materials during sputter growth, and discontinuous W-rich layers for multilayer periods below about 15Å. The experimental data for the specular reflectivity in the hard and soft x-ray regimes and the diffuse scattering fit well to a model of multilayer roughness. The model is expressed as a power-law dependence of roughness on spatial frequency. Analysis of small-angle scattering in transmission from multilayers grown on freestanding Si3N4 membranes confirms the onset of discontinuity at periods between 14Å and 22Å. Spectroscopy studies by x-ray absorption (NEXAFS) and electron energy loss (EELS) at the boron K-edge (188eV) are consistent with changes in the average boron bonding environment, as the multilayer period decreases and the W-rich layers are increasingly thin and dispersed. A discrete W-rich phase is present for periods at least as small as 6.3Å.

  17. VEGETATION MAPPING IN WETLANDS

    Directory of Open Access Journals (Sweden)

    F. PEDROTTI

    2004-01-01

    Full Text Available The current work examines the main aspects of wetland vegetation mapping, which can be summarized as analysis of the ecological-vegetational (ecotone gradients; vegetation complexes; relationships between vegetation distribution and geomorphology; vegetation of the hydrographic basin lo which the wetland in question belongs; vegetation monitoring with help of four vegetation maps: phytosociological map of the real and potential vegetation, map of vegetation dynamical tendencies, map of vegetation series.

  18. The effects of short work vs. longer work periods within intermittent exercise on V̇o2p kinetics, muscle deoxygenation, and energy system contribution.

    Science.gov (United States)

    McCrudden, Michael C; Keir, Daniel A; Belfry, Glen R

    2017-06-01

    We examined the effects of inserting 3-s recovery periods during high-intensity cycling exercise at 25-s and 10-s intervals on pulmonary oxygen uptake (V̇o 2p ), muscle deoxygenation [deoxyhemoglobin (HHb)], their associated kinetics (τ), and energy system contributions. Eleven men (24 ± 3 yr) completed two trials of three cycling protocols: an 8-min continuous protocol (CONT) and two 8-min intermittent exercise protocols with work-to-rest periods of 25 s to 3 s (25INT) and 10 s to 3 s (10INT). Each protocol began with a step-transition from a 20-W baseline to a power output (PO) of 60% between lactate threshold and maximal V̇o 2p (Δ60). This PO was maintained for 8 min in CONT, whereas 3-s periods of 20-W cycling were inserted every 10 s and 25 s after the transition to Δ60 in 10INT and 25INT, respectively. Breath-by-breath gas exchange measured by mass spectrometry and turbine and vastus lateralis [HHb] measured by near-infrared spectroscopy were recorded throughout. Arterialized-capillary lactate concentration ([Lac - ]) was obtained before and 2 min postexercise. The τV̇o 2p was lowest ( P 0.05) between conditions. Postexercise [Lac - ] was lowest ( P exercise speeded V̇o 2p kinetics and reduced overall V̇o 2p , suggesting an increased reliance on PCr-derived phosphorylation during the work period of INT compared with an identical PO performed continuously. NEW & NOTEWORTHY We report novel observations on the effects of differing heavy-intensity work durations between 3-s recovery periods on pulmonary oxygen uptake (V̇o 2p ) kinetics, muscle deoxygenation, and energy system contributions. Relative to continuous exercise, V̇o 2p kinetics are faster in intermittent exercise, and increased frequency of 3-s recovery periods improves microvascular O 2 delivery and reduces V̇o 2p and arterialized-capillary lactate concentration. The metabolic burden of identical intensity work is altered when performed intermittently vs. continuously. Copyright

  19. Early feeding of carnivorous rainbow trout (Oncorhynchus mykiss) with a hyperglucidic diet during a short period: effect on dietary glucose utilization in juveniles.

    Science.gov (United States)

    Geurden, I; Aramendi, M; Zambonino-Infante, J; Panserat, S

    2007-06-01

    Based on the concept of nutritional programming in higher vertebrates, we tested whether an acute hyperglucidic stimulus during early life could induce a long-lasting effect on carbohydrate utilization in carnivorous rainbow trout. The trout were fed a hyperglucidic diet (60% dextrin) at two early stages of development: either at first feeding (3 days, stimulus 1) or after yolk absorption (5 days, stimulus 2). Before and after the hyperglucidic stimulus, they received a commercial diet until juvenile stage (>10 g). Fish that did not experience the hyperglucidic stimuli served as controls. The short- and long-term effects of the stimuli were evaluated by measuring the expression of five key genes involved in carbohydrate utilization: alpha-amylase, maltase (digestion), sodium-dependent glucose cotransporter (SGLT1; intestinal glucose transport), and glucokinase and glucose-6-phosphatase, involved in the utilization and production of glucose, respectively. The hyperglucidic diet rapidly increased expressions of maltase, alpha-amylase, and glucokinase in stimulus 1 fish and only of maltase in stimulus 2 fish, probably because of a lower plasticity at this later stage of development. In the final challenge test with juveniles fed a 25% dextrin diet, both digestive enzymes were upregulated in fish that had experienced the hyperglucidic stimulus at first feeding, confirming the possibility of modification of some long-term physiological functions in rainbow trout. In contrast, no persistent molecular adaptations were found for the genes involved in glucose transport or metabolism. In addition, growth and postprandial glycemia were unaffected by the stimuli. In summary, our data show that a short hyperglucidic stimulus during early trout life may permanently influence carbohydrate digestion.

  20. Studies of self focusing and filamentation instabilities in short wavelength laser fusion: Final technical report for the period 29 May 1986-28 April 1988

    International Nuclear Information System (INIS)

    Joshi, Chan.

    1988-04-01

    Azimuthal periodic breakup of a radially modulated 0.35 μm laser beam has been inferred in plasmas produced from solid targets. The breakup is more severe in gold plasmas compared to glass or aluminum plasmas and occurs at rather modest laser intensities of /approximately/5 /times/ 10 12 Wcm 2 . Thermal filamentation is suggested as the mechanism for the observed beam breakup

  1. Absorption of some mineral salts by root system of different woody species and accumulation over a whole vegetative cycle (1963)

    International Nuclear Information System (INIS)

    Gagnaire, J.; Gerard, J.M.

    1963-01-01

    The concentration power of plant tissues and the translocation speed of mineral salts are considerably varying with the absorbed salt, the botanical species, the considered tissue and the part of the vegetative cycle. In Grenoble, with Picea excelsa, the 'true dormancy' is short (half-november, end of december). It is accompanied by a pre-dormancy period (October, half-november) and a post dormancy period (January, february, march). In vegetative period, Picea excelsa leaves are less concentrating mineral salt than Acer campestris leaves (coefficient 2 for calcium - 3 for phosphates) and Populus nigra leaves (coefficient 3 for calcium, coefficient 5 for phosphates). (author) [fr

  2. Short- and long-term effects of forage supplementation of calves during the preweaning period on performance, reproduction, and milk yield at first lactation.

    Science.gov (United States)

    Castells, Ll; Bach, A; Terré, M

    2015-07-01

    Sixty female Holstein calves [body weight (BW)=39.5±3.76kg] were fed a ground starter concentrate [19% crude protein, 19% neutral detergent fiber (NDF)] during the preweaning period. Furthermore, oats hay (68% NDF) was supplemented only during the postweaning period (CON) or during both pre- and postweaning periods (OH) to evaluate performance until first breeding, diet digestibility after weaning, reproductive performance, and milk yield at first lactation. Calves were individually housed and bedded with wood shavings. All calves were offered 6 L/d of milk replacer (MR) at 12% dry matter (DM) in 2 feedings until 28d of age, 3 L/d of MR at 12% DM in 2 feedings from 29 to 44d of age calves, and 1.5 L of MR at 12% DM in 1 feeding from 45 to 51d of age. Animals were weaned at 52d of age. Starter concentrate and forage intake were recorded daily and BW weekly until 65d of age. Two weeks after weaning, total-tract apparent digestibility was determined in 6 calves per treatment. Heifer BW was recorded at 10 mo of age. Breeding and milk yield at first lactation were also recorded. Starter concentrate intake was greater in OH compared with CON animals during the preweaning period. As a result, calves in the OH treatment had greater average daily gain (ADG) than CON animals during the preweaning period. After weaning, OH calves consumed more forage than CON animals, but we found no differences between treatments in ADG and starter concentrate intake. Similarly, total-tract apparent digestibility did not differ between treatments, and BW and ADG from 2wk after weaning to 10mo of age did not differ between treatments. Moreover, no differences in reproductive performance [age at first artificial insemination (AI), age at fertile insemination, conception rate at first AI, and number of AI] or milk yield at first lactation were observed between treatments, although a positive relationship between growth rate early in life and future energy-corrected milk yield was found. We

  3. Vegetation anomalies caused by antecedent precipitation in most of the world

    Science.gov (United States)

    Papagiannopoulou, C.; Miralles, D. G.; Dorigo, W. A.; Verhoest, N. E. C.; Depoorter, M.; Waegeman, W.

    2017-07-01

    Quantifying environmental controls on vegetation is critical to predict the net effect of climate change on global ecosystems and the subsequent feedback on climate. Following a non-linear Granger causality framework based on a random forest predictive model, we exploit the current wealth of multi-decadal satellite data records to uncover the main drivers of monthly vegetation variability at the global scale. Results indicate that water availability is the most dominant factor driving vegetation globally: about 61% of the vegetated surface was primarily water-limited during 1981-2010. This included semiarid climates but also transitional ecoregions. Intra-annually, temperature controls Northern Hemisphere deciduous forests during the growing season, while antecedent precipitation largely dominates vegetation dynamics during the senescence period. The uncovered dependency of global vegetation on water availability is substantially larger than previously reported. This is owed to the ability of the framework to (1) disentangle the co-linearities between radiation/temperature and precipitation, and (2) quantify non-linear impacts of climate on vegetation. Our results reveal a prolonged effect of precipitation anomalies in dry regions: due to the long memory of soil moisture and the cumulative, non-linear, response of vegetation, water-limited regions show sensitivity to the values of precipitation occurring three months earlier. Meanwhile, the impacts of temperature and radiation anomalies are more immediate and dissipate shortly, pointing to a higher resilience of vegetation to these anomalies. Despite being infrequent by definition, hydro-climatic extremes are responsible for up to 10% of the vegetation variability during the 1981-2010 period in certain areas, particularly in water-limited ecosystems. Our approach is a first step towards a quantitative comparison of the resistance and resilience signature of different ecosystems, and can be used to benchmark Earth

  4. Vegetative regeneration

    Science.gov (United States)

    George A. Schier; John R. Jones; Robert P. Winokur

    1985-01-01

    Aspen is noted for its ability to regenerate vegetatively by adventitious shoots or suckers that arise on its long lateral roots. It also produces sprouts from stumps and root collars; but they are not common. In a survey of regeneration after clearcutting mature aspen in Utah. Baker (1918b) found that 92% of the shoots originated from roots, 7% from root collars, and...

  5. Understory vegetation

    Science.gov (United States)

    Steve Sutherland; Todd F. Hutchinson; Jennifer L. Windus

    2003-01-01

    This chapter documents patterns of species composition and diversity within the understory vegetation layer and provides a species list for the four study areas in southern Ohio. Within each of 108 plots, we recorded the frequency of all vascular plant species in sixteen 2-m² quadrats. We recorded 297 species, including 187 forbs (176 perennials, 9 annuals, 2...

  6. Short periods of high temperature during meiosis prevent normal meiotic progression and reduce grain number in hexaploid wheat (Triticum aestivum L.).

    Science.gov (United States)

    Draeger, Tracie; Moore, Graham

    2017-09-01

    Exposure of wheat to high temperatures during male meiosis prevents normal meiotic progression and reduces grain number. We define a temperature-sensitive period and link heat tolerance to chromosome 5D. This study assesses the effects of heat on meiotic progression and grain number in hexaploid wheat (Triticum aestivum L. var. Chinese Spring), defines a heat-sensitive stage and evaluates the role of chromosome 5D in heat tolerance. Plants were exposed to high temperatures (30 or 35 °C) in a controlled environment room for 20-h periods during meiosis and the premeiotic interphase just prior to meiosis. Examination of pollen mother cells (PMCs) from immature anthers immediately before and after heat treatment enabled precise identification of the developmental phases being exposed to heat. A temperature-sensitive period was defined, lasting from premeiotic interphase to late leptotene, during which heat can prevent PMCs from progressing through meiosis. PMCs exposed to 35 °C were less likely to progress than those exposed to 30 °C. Grain number per spike was reduced at 30 °C, and reduced even further at 35 °C. Chinese Spring nullisomic 5D-tetrasomic 5B (N5DT5B) plants, which lack chromosome 5D, were more susceptible to heat during premeiosis-leptotene than Chinese Spring plants with the normal (euploid) chromosome complement. The proportion of plants with PMCs progressing through meiosis after heat treatment was lower for N5DT5B plants than for euploids, but the difference was not significant. However, following exposure to 30 °C, in euploid plants grain number was reduced (though not significantly), whereas in N5DT5B plants the reduction was highly significant. After exposure to 35 °C, the reduction in grain number was highly significant for both genotypes. Implications of these findings for the breeding of thermotolerant wheat are discussed.

  7. Surface hardness evaluation of different composite resin materials: influence of sports and energy drinks immersion after a short-term period

    Directory of Open Access Journals (Sweden)

    Ugur Erdemir

    2013-04-01

    Full Text Available Objectives: This study evaluated the effect of sports and energy drinks on the surface hardness of different composite resin restorative materials over a 1-month period. Material and Methods: A total of 168 specimens: Compoglass F, Filtek Z250, Filtek Supreme, and Premise were prepared using a customized cylindrical metal mould and they were divided into six groups (N=42; n=7 per group. For the control groups, the specimens were stored in distilled water for 24 hours at 37°C and the water was renewed daily. For the experimental groups, the specimens were immersed in 5 mL of one of the following test solutions: Powerade, Gatorade, X-IR, Burn, and Red Bull, for two minutes daily for up to a 1-month test period and all the solutions were refreshed daily. Surface hardness was measured using a Vickers hardness measuring instrument at baseline, after 1-week and 1-month. Data were statistically analyzed using Multivariate repeated measure ANOVA and Bonferroni's multiple comparison tests (α=0.05. Results: Multivariate repeated measures ANOVA revealed that there were statistically significant differences in the hardness of the restorative materials in different immersion times (p<0.001 in different solutions (p<0.001. The effect of different solutions on the surface hardness values of the restorative materials was tested using Bonferroni's multiple comparison tests, and it was observed that specimens stored in distilled water demonstrated statistically significant lower mean surface hardness reductions when compared to the specimens immersed in sports and energy drinks after a 1-month evaluation period (p<0.001. The compomer was the most affected by an acidic environment, whereas the composite resin materials were the least affected materials. Conclusions: The effect of sports and energy drinks on the surface hardness of a restorative material depends on the duration of exposure time, and the composition of the material.

  8. Study of niobium isotopes having excess neutrons and a short half-life; Etude des isotopes du niobium excedentaires en neutrons et de courte periode

    Energy Technology Data Exchange (ETDEWEB)

    Huebenthal, K [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1968-02-01

    By irradiating Mo with 14 MeV neutrons isomers have been found for {sup 98}Nb (2.8 s half-life) {sup 99}Nb (9 s) and {sup 100}Nb (2.4 s). No isomer of this type seems to exist for {sup 96}Nb. Rapid separation methods are developed for isolating {sup 98}Zr from fission products, and for separating Zr and Nb. The half-life of {sup 98}Zr is measured (31 s) and the formation of {sup 98}Nb (2.8 s) from {sup 98}Zr (31 s) is shown by milking. Rough {beta} and {gamma} measurements of these nuclei are described. The {gamma} spectrum of {sup 98}Nb (51 mn) is studied with a high-resolution Ge/Li - detector. (authors) [French] Des irradiations des isotopes de molybdene avec des neutrons de 14 MeV ont mis en evidence l'existence des isomeres de {sup 98}Nb (periode 2.8 s) {sup 99}Nb (9 s) et {sup 100}Nb (2.4 s). Pour le {sup 96}Nb un isomere de ce type ne semble pas exister. Des methodes rapides de separation sont mises au point pour isoler le zirconium 98 des produits de fission, et pour separer ensuite le niobium du zirconium. La periode du {sup 98}Zr est de 3l s, et on demontre la formation du {sup 98}Nb (2.8 s) a partir du Zr (31 s). Ces corps sont etudies sommairement en spectroscopie {beta} et {gamma}. Le spectre gamma de {sup 98}Nb (periode 51 mn) est etudie avec un detecteur Ge/Li de haute resolution. (auteurs)

  9. Characterization by Raman scattering, x-ray diffraction, and transmission electron microscopy of (AlAs)m(InAs)m short period superlattices grown by migration enhanced epitaxy

    DEFF Research Database (Denmark)

    Bradshaw, J.; Song, X.J.; Shealy, J.R.

    1992-01-01

    We report growth of (InAs)1(AlAs)1 and (InAs)2(AlAs)2 strained layer superlattices by migration enhanced epitaxy. The samples were grown on InP (001) substrates and characterized by Raman spectroscopy, x-ray diffraction, and transmission electron microscopy. Satellite peaks in the x-ray data...... confirm the intended periodicity and indicate the presence of some disorder in the monolayer sample. The energies of the zone folded and quantum confined optic phonons are in reasonable agreement with calculations based on one-dimensional elastic continuum and linear chain models. Journal of Applied...

  10. Short communication: concentrations of nonesterified fatty acids and β-hydroxybutyrate in dairy cows are not well correlated during the transition period.

    Science.gov (United States)

    McCarthy, M M; Mann, S; Nydam, D V; Overton, T R; McArt, J A A

    2015-09-01

    The objective was to use longitudinal data of blood nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA) concentrations to describe the relationship between NEFA and BHBA in dairy cows during the periparturient period. Blood NEFA and BHBA concentration data collected from d 21 prepartum to 21 postpartum for 269 multiparous Holstein cows were selected from 4 different studies carried out within our research groups. Overall, NEFA concentrations were increased beginning near parturition with a relatively steady elevation of NEFA through d 9, after which concentrations gradually decreased. Prepartum BHBA concentrations began to increase beginning several days before parturition, continued to increase during the first week after parturition, and remained elevated through d 21 postpartum. Of the 269 cows included in the data set, 117 cows (43.5%) had at least one postpartum hyperketonemic event (BHBA ≥1.2mmol/L), and 202 cows (75.1%) had at least one event of elevated postpartum NEFA concentrations (≥0.70mmol/L) between 3 and 21 d in milk. Area under the curve (AUC) was used to investigate relationships between metabolites over time. Overall, the correlations between transition period NEFA and BHBA AUC were weak. We detected a negative correlation between prepartum BHBA AUC and postpartum NEFA AUC (r=-0.26). A positive correlation existed between postpartum NEFA AUC and postpartum BHBA AUC; however, the correlation coefficient was low (r=0.26). Large variation was found between the day of maximum NEFA concentration within the first 21 d in milk and day of maximum BHBA concentration for the same period. The mean and median times of maximum NEFA concentration were 6.8 and 6 d, respectively, whereas the mean and median times of maximum BHBA were 9.6 and 8 d, respectively; however, the range in days for both the mean and median day of maximum concentrations was very large. Overall, our data set indicates a weak relationship between blood concentrations of NEFA

  11. Short-wavelength multiline erbium-doped fiber ring laser by a broadband long-period fiber grating inscribed in a taper transition

    International Nuclear Information System (INIS)

    Anzueto-Sánchez, G; Martínez-Rios, A

    2014-01-01

    A stable multiwavelength all-fiber erbium-doped fiber ring laser (EDFRL) based on a broadband long-period fiber grating (LPFG) inscribed in a fiber taper transition is presented. The LPFG’s characteristics were engineered to provide a higher loss at the natural lasing wavelength of the laser cavity. The LPFG inscribed on a taper transition provided a depth greater than 25 dB, and posterior chemical etching provided a broad notch band to inhibit laser generation on the long-wavelength side of the EDF gain. Up to four simultaneous laser wavelengths are generated in the range of 1530–1535 nm. (paper)

  12. Shannon Entropy in a European Seabass (Dicentrarchus labrax System during the Initial Recovery Period after a Short-Term Exposure to Methylmercury

    Directory of Open Access Journals (Sweden)

    Harkaitz Eguiraun

    2016-05-01

    Full Text Available Methylmercury (MeHg is an environmental contaminant of increasing relevance as a seafood safety hazard that affects the health and welfare of fish. Non-invasive, on-line methodologies to monitor and evaluate the behavior of a fish system in aquaculture may make the identification of altered systems feasible—for example, due to the presence of agents that compromise their welfare and wholesomeness—and find a place in the implementation of Hazard Analysis and Critical Control Points and Fish Welfare Assurance Systems. The Shannon entropy (SE of a European seabass (Dicentrarchus labrax system has been shown to differentiate MeHg-treated from non-treated fish, the former displaying a lower SE value than the latter. However, little is known about the initial evolution of the system after removal of the toxicant. To help to cover this gap, the present work aims at providing information about the evolution of the SE of a European seabass system during a recuperation period of 11 days following a two-week treatment with 4 µg·MeHg/L. The results indicate that the SE of the system did not show a recovery trend during the examined period, displaying erratic responses with daily fluctuations and lacking a tendency to reach the initial SE values.

  13. An Ultra-short Period Rocky Super-Earth with a Secondary Eclipse and a Neptune-like Companion around K2-141

    DEFF Research Database (Denmark)

    Malavolta, Luca; Mayo, Andrew W.; Louden, Tom

    2018-01-01

    of USP planets, and it is therefore extremely important to increase the still limited sample of USP planets with precise and accurate mass and density measurements. We report here the characterization of a USP planet with a period of 0.28 days around K2-141 (EPIC 246393474), and the validation...... of an outer planet with a period of 7.7 days in a grazing transit configuration. We derived the radii of the planets from the K2 light curve and used high-precision radial velocities gathered with the HARPS-N spectrograph for mass measurements. For K2-141b, we thus inferred a radius of 1.51 ± 0.05 R......⊕ and a mass of 5.08 ± 0.41 M ⊕, consistent with a rocky composition and lack of a thick atmosphere. K2-141c is likely a Neptune-like planet, although due to the grazing transits and the non-detection in the RV data set, we were not able to put a strong constraint on its density. We also report the detection...

  14. Mechanisms controlling primary and new production in a global ecosystem model – Part II: The role of the upper ocean short-term periodic and episodic mixing events

    Directory of Open Access Journals (Sweden)

    E. E. Popova

    2006-01-01

    Full Text Available The use of 6 h, daily, weekly and monthly atmospheric forcing resulted in dramatically different predictions of plankton productivity in a global 3-D coupled physical-biogeochemical model. Resolving the diurnal cycle of atmospheric variability by use of 6 h forcing, and hence also diurnal variability in UML depth, produced the largest difference, reducing predicted global primary and new production by 25% and 10% respectively relative to that predicted with daily and weekly forcing. This decrease varied regionally, being a 30% reduction in equatorial areas primarily because of increased light limitation resulting from deepening of the mixed layer overnight as well as enhanced storm activity, and 25% at moderate and high latitudes primarily due to increased grazing pressure resulting from late winter stratification events. Mini-blooms of phytoplankton and zooplankton occur in the model during these events, leading to zooplankton populations being sufficiently well developed to suppress the progress of phytoplankton blooms. A 10% increase in primary production was predicted in the peripheries of the oligotrophic gyres due to increased storm-induced nutrient supply end enhanced winter production during the short term stratification events that are resolved in the run forced by 6 h meteorological fields. By resolving the diurnal cycle, model performance was significantly improved with respect to several common problems: underestimated primary production in the oligotrophic gyres; overestimated primary production in the Southern Ocean; overestimated magnitude of the spring bloom in the subarctic Pacific Ocean, and overestimated primary production in equatorial areas. The result of using 6 h forcing on predicted ecosystem dynamics was profound, the effects persisting far beyond the hourly timescale, and having major consequences for predicted global and new production on an annual basis.

  15. Energy compensation in the real world: good compensation for small portions of chocolate and biscuits over short time periods in complicit consumers using commercially available foods.

    Science.gov (United States)

    Appleton, Katherine M; McKeown, Pascal P; Woodside, Jayne V

    2015-02-01

    While investigations using covert food manipulations tend to suggest that individuals are poor at adjusting for previous energy intake, in the real world adults rarely consume foods of which they are ill-informed. This study investigated the impact in fully complicit consumers of consuming commercially available dark chocolate, milk chocolate, sweet biscuits and fruit bars on subsequent appetite. Using a repeated measures design, participants received four small portions (4 × 10-11 g) of either dark chocolate, milk chocolate, sweet biscuits, fruit bars or no food throughout five separate study days (counterbalanced in order), and test meal intake, hunger, liking and acceptability were measured. Participants consumed significantly less at lunch following dark chocolate, milk chocolate and sweet biscuits compared to no food (smallest t(19) = 2.47, p = 0.02), demonstrating very good energy compensation (269-334%). No effects were found for fruit bars (t(19) = 1.76, p = 0.09), in evening meal intakes (F(4,72) = 0.62, p = 0.65) or in total intake (lunch + evening meal + food portions) (F(4,72) = 0.40, p = 0.69). No differences between conditions were found in measures of hunger (largest F(4,76) = 1.26, p = 0.29), but fruit bars were significantly less familiar than all other foods (smallest t(19) = 3.14, p = 0.01). These findings demonstrate good compensation over the short term for small portions of familiar foods in complicit consumers. Findings are most plausibly explained as a result of participant awareness and cognitions, although the nature of these cognitions cannot be discerned from this study. These findings however, also suggest that covert manipulations may have limited transfer to real world scenarios. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. componente vegetal

    Directory of Open Access Journals (Sweden)

    Fabio Moscovich

    2005-01-01

    Full Text Available In order to determine environmental impact, indicators based on vegetation characteristics that would generate the forestry monoculture with the adjacent native forest, 32 sample unit were installed in an area of LIPSIA private enterprise, Esperanza Department, Misiones with those characteristics. The plots of 100 m2 were distributed systematically every 25 meters. The vegetation was divided in stratum: superior (DBH ≥ 10 cm, middle (1,6 cm ≤ DBH > 10 cm and inferior (DBH< cm. There were installed 10 plots in a logged native forest, 10 plots in a 18 years old Pinus elliottii Engelm. with approximately 400 trees/ha., 6 plots in a 10 – 25 years old Araucaria angustifolia (Bertd. Kuntze limiting area with approximately 900 trees/ha., and 6 plots located in this plantation. In the studied area were identified 150 vegetation species. In the inferior stratum there were found differences as function of various floristic diversity indexes. In all the cases the native forest showed larger diversity than plantations, followed by Pinus elliottii, Araucaria plantation and Araucaria limiting area. All the studied forest fitted to a logarithmical series of species distributions, that would indicate the incidence of a environmental factor in this distribution.

  17. FORECASTING ENERGY CONSUMPTION IN SHORT-TERM AND LONG-TERM PERIOD BY USING ARIMAX MODEL IN THE CONSTRUCTION AND MATERIALS SECTOR IN THAILAND

    Directory of Open Access Journals (Sweden)

    Pruethsan Sutthichaimethee

    2017-07-01

    Full Text Available This study aims to analyze the forecasting of energy consumption in the Construction and Materials sectors. The scope of the study covers the forecasting periods of energy consumption for the next 10 years, 2017-2026, 20 years, 2017-2036, and 30 years, 2017-2046, by using ARIMAX Model. The prediction results show that these models are effective in the forecast measured by RMSE, MAE, and MAPE. The results show that from the first model (2,1,1, which predicted the duration of 10 years, 2017-2026, indicates that Thailand has increased an energy consumption rate with the average of 18.09%, while the second model (2,1,2 with the prediction of 20 years, 2017-2036, Thailand arises its energy consumption up to 37.32%. In addition, the third model (2,1,3 predicted the duration of 30 years from 2017 to 2046, and it has found that Thailand increases its energy consumption up to 49.72%.

  18. Probability Estimates of Solar Particle Event Doses During a Period of Low Sunspot Number for Thinly-Shielded Spacecraft and Short Duration Missions

    Science.gov (United States)

    Atwell, William; Tylka, Allan J.; Dietrich, William; Rojdev, Kristina; Matzkind, Courtney

    2016-01-01

    In an earlier paper (Atwell, et al., 2015), we investigated solar particle event (SPE) radiation exposures (absorbed dose) to small, thinly-shielded spacecraft during a period when the sunspot number (SSN) was less than 30. These SPEs contain Ground Level Events (GLE), sub-GLEs, and sub-sub-GLEs (Tylka and Dietrich, 2009, Tylka and Dietrich, 2008, and Atwell, et al., 2008). GLEs are extremely energetic solar particle events having proton energies extending into the several GeV range and producing secondary particles in the atmosphere, mostly neutrons, observed with ground station neutron monitors. Sub-GLE events are less energetic, extending into the several hundred MeV range, but do not produce secondary atmospheric particles. Sub-sub GLEs are even less energetic with an observable increase in protons at energies greater than 30 MeV, but no observable proton flux above 300 MeV. In this paper, we consider those SPEs that occurred during 1973-2010 when the SSN was greater than 30 but less than 50. In addition, we provide probability estimates of absorbed dose based on mission duration with a 95% confidence level (CL). We also discuss the implications of these data and provide some recommendations that may be useful to spacecraft designers of these smaller spacecraft.

  19. Cumhuriyet Tarihi Üzerine Kısa Bir Dönemlendirme Denemesi / A Short Essay on Periodization of History of Republic

    Directory of Open Access Journals (Sweden)

    Cengiz SUNAY

    2016-01-01

    Full Text Available Türkiye Cumhuriyeti tarihi, bir asra yaklaşan geçmişiyle oldukça keskin dönüşümlerin gözlendiği bir süreci ifade ediyor. Bu dönüşümlerin içeride ve dışarıdaki hangi değişimler ekseninde meydana geldiği konusunda, nesnel araştırmaların yapıldığı bilinmekle birlikte; son tahlilde, cumhuriyet tarihinde olan bitenleri ileri-geri; devrimci-karşı devrimci şeklindeki öznel değerlendirmelerin belirlediği de söylenebilir. Geçmişte, nelerin olup bittiğine dair çoğu anlatımın, örtülü de olsa bu zaafla malul olduğu söylenebilir; bu çerçevede, tarihin bilimden ziyade, ideoloji olduğuna ilişkin tezler üzerinde düşünmek gerekiyor. Tarihin bilim olduğu kabul edilse bile, güçlünün kaleminden okunduğu, bu nedenle bilimlerin en Darwinist’i olduğu tezi, ihmal edilebilir gibi gözükmüyor. Bu çalışmada, Türkiye Cumhuriyeti tarihinin ana hatları üzerinden kuşbakışı bir gözlem deneniyor; ek okumalar öneriliyor. Son doksan beş yılda nelerin olup, nelerin bittiğine ilişkin kimi zaman alternatif bir perspektiften bakılmaya çalışılıyor. / History of the Turkish Republic expresses a period with considerably sharp transformations with its past which almost reaches one century. It is known that objective studies have been made on the axises on which these transformations took place at home and abroad; nevertheless, in the last analysis, it can be claimed that the occurrences in republican history are determined by subjective evaluations such as forward-backward, revolutionary-counter revolutionary etc. It can be said that most narrations as to what happened in the past suffer from this weakness albeit implicitly; within this framework, the thesis that history is more an ideology than a science should be contemplated. Even if it is accepted that history is science, it is hardly negligible that it is read from the pen of the mighty, for which reason it is the most Darwinist of all sciences

  20. Consequences of dietary energy source and energy level on energy balance, lactogenic hormones, and lactation curve characteristics of cows after a short or omitted dry period.

    Science.gov (United States)

    van Hoeij, R J; Dijkstra, J; Bruckmaier, R M; Gross, J J; Lam, T J G M; Remmelink, G J; Kemp, B; van Knegsel, A T M

    2017-10-01

    Omitting the dry period (DP) generally reduces milk production in the subsequent lactation. The aim of this study was to evaluate the effect of dietary energy source-glucogenic (G) or lipogenic (L)-and energy level-standard (std) or low-on milk production; energy balance (EB); lactogenic hormones insulin, insulin-like growth factor 1 (IGF-1), and growth hormone (GH); and lactation curve characteristics between wk 1 and 44 postpartum in cows after a 0-d or 30-d DP. Cows (n = 110) were assigned randomly to 3 transition treatments: a 30-d DP with a standard energy level required for expected milk yield [30-d DP(std)], a 0-d DP with the same energy level as cows with a 30-d DP [0-d DP(std)], and a 0-d DP with a low energy level [0-d DP(low)]. In wk 1 to 7, cows were fed the same basal ration but the level of concentrate increased to 6.7 kg/d for cows fed the low energy level and to 8.5 kg/d for cows fed the standard energy level in wk 4. From wk 8 postpartum onward, cows received a G ration (mainly consisting of corn silage and grass silage) or an L ration (mainly consisting of grass silage and sugar beet pulp) with the same energy level contrast (low or std) as in early lactation. Cows fed the G ration had greater milk, lactose, and protein yields, lower milk fat percentage, greater dry matter and energy intakes, and greater plasma IGF-1 concentration compared with cows fed the L ration. Dietary energy source did not affect EB or lactation curve characteristics. In cows with a 0-d DP, the reduced energy level decreased energy intake, EB, and weekly body weight gain, but did not affect milk production or lactation curve characteristics. A 30-d DP resulted in a greater total predicted lactation yield, initial milk yield after calving, peak milk yield, energy intake, energy output in milk, days to conception [only when compared with 0-d DP(low)], plasma GH concentration [only when compared with 0-d DP(std)], and decreased weekly body weight gain compared with a 0-d DP. A

  1. Analysis of vegetation from satellite images correlated to the bird species presence and the state of health of the ecosystems of Bucharest during the period from 1991 to 2006

    Directory of Open Access Journals (Sweden)

    Dragoș Mirela

    2017-01-01

    Full Text Available The urban vegetation needs adequate monitoring and conservation, being a critical resource of urban landscape. To its deeply esthetic values, the practical values and, respectively, ecosystem services delivered by the urban biodiversity are added (amelioration of the environment and urban microclimate, flood control, diminishing of the environmental pollution, increasing of biodiversity and habitats etc.. Accurate remote sensing techniques have been used widely in locating and mapping urban vegetation (Light Detection And Ranging-LiDAR, satellite images. The purpose of this study is to point out the vegetation status in correlation with the number of the bird species (as indicator of the ecosystem's health, using remote sensing techniques (Landsat satellite images, between 1991-2006 in Bucharest, Romania's capital. Rapid urban evolution of Bucharest led to important changes within the structure of the city, underlined by the increasing of the built area to the detriment of the green one. The intensity of the urbanization rate also led to the decreasing of the number of the bird species. The results obtained through analysis of satellite images indicate the necessity to acquire the up-to-date information related to the vegetation status in order to establish in the future, through urban landscape projects, protection measures for the vegetation cover and for the bird habitats in Bucharest Municipality.

  2. Assessment of human impacts on landuse and vegetation cover ...

    African Journals Online (AJOL)

    This paper is an assessment of the impact of man's activities on the landuse and vegetation cover of Mubi region. Landsat MSS Landuse/vegetation image of 1978 and Spot XS landuse/vegetation image of 1995 were used to study the landuse/vegetation cover changes of the region between 1978 and 1995 – a period of 17 ...

  3. Effectiveness of flavour nutrient learning and mere exposure as mechanisms to increase toddler's intake and preference for green vegetables.

    Science.gov (United States)

    de Wild, Victoire W T; de Graaf, Cees; Jager, Gerry

    2013-05-01

    Children's consumption of vegetables is still below recommendations. Since preference is the most important predictor of children's intake and most children dislike vegetables, new strategies are needed to increase their preferences for vegetables. Flavour nutrient learning (FNL) could be an effective mechanism to change preferences. Forty healthy toddlers were included in a randomized intervention study. During an intervention period of 7weeks, they consumed vegetable soups (endive and spinach) twice per week. Half of the group received a high-energy variant of one soup (e.g. HE spinach) and a low energy variant of the other (LE endive), whereas for the other half the order was reversed (HE endive, LE spinach). Primary outcome measures were preference and ad libitum consumption (with a maximum of 200g) of both vegetable products (LE), measured before, shortly after the intervention period, and 2 and 6months following conditioning to assess longer-term effects. After completion of the intervention period, 28 children (14 girls and 14 boys, age 35months; SD±8.3) met criteria for FNL to occur, and were included in further data analysis. Results showed a significant increase (~58g) in ad libitum intake for both vegetable soups (stable over time), but irrespective of the energy content. This indicates a robust effect of mere exposure on intake, but no FNL. For preference, however, results showed a significant shift in liking for the vegetable soup consistently paired with high energy, supporting FNL. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Localization of Short Duration Periodic Signals

    Science.gov (United States)

    2013-09-30

    TDOA m, referenced to the hydrophone that is common between TDOA l and m. This measure is effectively a count of the number of matching click times...the localization of multiple interfering sperm whales using multi- sensor time difference of arrival”, 130 Journal of the Acoustical Society of

  5. SPINIFICI-SCAEVOLETEA SERICEAE, A NEW VEGETATION CLASS FOR PSAMMOPHYTIC DUNE VEGETATION IN THAILAND

    Directory of Open Access Journals (Sweden)

    S. PIGNATII

    1996-04-01

    Full Text Available This is a short account on the coastal dune vegetation of the Gulf of Siam in Thailand. Vegetation is mainly composed by succulent creeping plants with herbaceous habit as to Canavalia maritima (Papilionaceae and Iponwea pes-caprae (Convolvulaceae and the robust stoloniferous grass Spinijex littoreus, the last having an important function for the fonnation of coastal dunes.

  6. SPINIFICI-SCAEVOLETEA SERICEAE, A NEW VEGETATION CLASS FOR PSAMMOPHYTIC DUNE VEGETATION IN THAILAND

    Directory of Open Access Journals (Sweden)

    S. PIGNATII

    1996-01-01

    Full Text Available This is a short account on the coastal dune vegetation of the Gulf of Siam in Thailand. Vegetation is mainly composed by succulent creeping plants with herbaceous habit as to Canavalia maritima (Papilionaceae and Iponwea pes-caprae (Convolvulaceae and the robust stoloniferous grass Spinijex littoreus, the last having an important function for the fonnation of coastal dunes.

  7. Temporal reflectance changes in vegetables

    DEFF Research Database (Denmark)

    Dissing, Bjørn Skovlund; Clemmensen, Line Katrine Harder; Ersbøll, Bjarne Kjær

    2009-01-01

    Quality control in the food industry is often performed by measuring various chemical compounds of the food involved. We propose an imaging concept for acquiring high quality multispectral images to evaluate changes of carrots and celeriac over a period of 14 days. Properties originating...... in the surface chemistry of vegetables may be captured in an integrating sphere illumination which enables the creation of detailed surface chemistry maps with a good combination of spectral and spatial resolutions. Prior to multispectral image recording, the vegetables were prefried and frozen at -30Â......°C for four months. During the 14 days of image recording, the vegetables were kept at +5°C in refrigeration. In this period, surface changes and thereby reflectance properties were very subtle. To describe this small variation we employed advanced statistical techniques to search a large featurespace...

  8. Lake Bathymetric Aquatic Vegetation

    Data.gov (United States)

    Minnesota Department of Natural Resources — Aquatic vegetation represented as polygon features, coded with vegetation type (emergent, submergent, etc.) and field survey date. Polygons were digitized from...

  9. Spatial-temporal development of the mangrove vegetation cover on a hydraulic landfill (Via Expressa Sul, Florianópolis, SC): mapping and interpretation of digital aerophotographs, and quantitative analysis

    OpenAIRE

    Anderson Tavares de Melo; Eduardo Juan Soriano-Sierra; Luiz Antônio Paulino

    2011-01-01

    The implementation of a hydraulic landfill along the southern expressway (Via Expressa Sul), in the central-south region of Santa Catarina Island, started in 1995 and was completed in 1997. The landfill provided the mangrove vegetation a new environment to colonize, which has developed rapidly during this short period of time. This study mapped the vegetation cover of this region using aerial photographs from five years (1994, 1997, 2002, 2004 and 2007), which demonstrated the spatial-tempora...

  10. Abrupt vegetation transitions characterise long-term Amazonian peatland development

    Science.gov (United States)

    Roucoux, K. H.; Baker, T. R.; Gosling, W. D.; Honorio Coronado, E.; Jones, T. D.; Lahteenoja, O.; Lawson, I. T.

    2012-04-01

    Recent investigations of wetlands in western Amazonia have revealed the presence of extensive peatlands with peat deposits of up to 8 m-thick developing under a variety of vegetation types (Lähteenoja et al. 2012). Estimated to cover 150,000 km2 (Schulman et al. 1999), these peatlands make a valuable contribution to landscape and biological diversity and represent globally important carbon stores. In order to understand the processes leading to peat formation, and the sensitivity of these environments to future climatic change, it is necessary to understand their long-term history. The extent to which peatland vegetation changes over time, the stability of particular communities, the controls on transitions between vegetation types and how these factors relate to the accumulation of organic matter are not yet known. We report the first attempt to establish the long-term (millennial scale) vegetation history of a recently-described peatland site: Quistococha, a palm swamp, or aguajal, close to Iquitos in northern Peru. The vegetation is dominated by Mauritia flexuosa and Mauritiella armata and occupies a basin which is thought to be an abandoned channel of the River Amazon. We obtained a 4 m-long peat sequence from the deepest part of the basin. AMS-radiocarbon dating yielded a maximum age of 2,212 cal yr BP for the base of the peat, giving an average accumulation rate of 18 cm per century. Below the peat are 2 m of uniform, largely inorganic pale grey clays of lacustrine origin, which are underlain by an unknown thickness of inorganic sandy-silty clay of fluvial origin. Pollen analysis, carried out at c. 88-year intervals, shows the last 2,212 years to be characterised by the development of at least four distinct vegetation communities, with peat accumulating throughout. The main phases were: (1) Formation of Cyperaceae (sedge) fen coincident with peat initiation; (2) A short-lived phase of local Mauritia/Mauritiella development; (3) Development of mixed wet

  11. VERY-LOW-MASS STELLAR AND SUBSTELLAR COMPANIONS TO SOLAR-LIKE STARS FROM MARVELS. III. A SHORT-PERIOD BROWN DWARF CANDIDATE AROUND AN ACTIVE G0IV SUBGIANT

    Energy Technology Data Exchange (ETDEWEB)

    Ma Bo; Ge Jian; De Lee, Nathan; Fleming, Scott W.; Lee, Brian L.; Wang Ji [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States); Barnes, Rory; Agol, Eric [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States); Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Dutra-Ferreira, Leticia; Porto de Mello, G. F. [Observatorio do Valongo, Universidade Federal do Rio de Janeiro, Ladeira do Pedro Antonio, 43, CEP: 20080-090, Rio de Janeiro, RJ (Brazil); Esposito, Massimiliano; Femenia, Bruno; Gonzalez Hernandez, Jonay I. [Instituto de Astrofisica de Canarias, C/Via Lctea S/N, E-38200 La Laguna (Spain); Gaudi, B. Scott [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Ghezzi, Luan [Laboratorio Interinstitucional de e-Astronomia (LIneA), Rio de Janeiro, RJ 20921-400 (Brazil); Hebb, Leslie; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Wisniewski, John P. [Homer L Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W Brooks St, Norman, OK 73019 (United States); Bizyaev, Dmitry, E-mail: boma@astro.ufl.edu [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349-0059 (United States); and others

    2013-01-01

    We present an eccentric, short-period brown dwarf candidate orbiting the active, slightly evolved subgiant star TYC 2087-00255-1, which has effective temperature T{sub eff} = 5903 {+-} 42 K, surface gravity log (g) = 4.07 {+-} 0.16 (cgs), and metallicity [Fe/H] = -0.23 {+-} 0.07. This candidate was discovered using data from the first two years of the Multi-object APO Radial Velocity Exoplanets Large-area Survey, which is part of the third phase of Sloan Digital Sky Survey. From our 38 radial velocity measurements spread over a two-year time baseline, we derive a Keplerian orbital fit with semi-amplitude K = 3.571 {+-} 0.041 km s{sup -1}, period P = 9.0090 {+-} 0.0004 days, and eccentricity e = 0.226 {+-} 0.011. Adopting a mass of 1.16 {+-} 0.11 M{sub Sun} for the subgiant host star, we infer that the companion has a minimum mass of 40.0 {+-} 2.5 M{sub Jup}. Assuming an edge-on orbit, the semimajor axis is 0.090 {+-} 0.003 AU. The host star is photometrically variable at the {approx}1% level with a period of {approx}13.16 {+-} 0.01 days, indicating that the host star spin and companion orbit are not synchronized. Through adaptive optics imaging we also found a point source 643 {+-} 10 mas away from TYC 2087-00255-1, which would have a mass of 0.13 M{sub Sun} if it is physically associated with TYC 2087-00255-1 and has the same age. Future proper motion observation should be able to resolve if this tertiary object is physically associated with TYC 2087-00255-1 and make TYC 2087-00255-1 a triple body system. Core Ca II H and K line emission indicate that the host is chromospherically active, at a level that is consistent with the inferred spin period and measured v{sub rot}sin i, but unusual for a subgiant of this T{sub eff}. This activity could be explained by ongoing tidal spin-up of the host star by the companion.

  12. Design and measured performance of a porous evaporative cooler for preservation of fruits and vegetables

    International Nuclear Information System (INIS)

    Anyanwu, E.E.

    2004-01-01

    The design, construction and measured performance of a porous evaporative cooler for preservation of fruits and vegetables are reported. The experimental cooler, with a total storage space of 0.014 m 3 , consists of a cuboid shaped porous clay container located inside another clay container. The gap between them is filled with coconut fibre. A water reservoir linked to the cooler at the top through a flexible pipe supplied water to fill the gap, thus keeping the coconut fibre continuously wet. Results of the transient performance tests revealed that the cooler storage chamber temperature depression from ambient air temperature varied over 0.1-12 deg. C. Ambient air temperatures during the test periods ranged over 22-38 deg. C. The results also illustrate superior performance of the cooler over open air preservation of vegetables soon after harvest during the diurnal operations. Thus, the evaporative cooler has prospects for use for short term preservation of vegetables and fruits soon after harvest

  13. Growth kinetics and structural perfection of (InN){sub 1}/(GaN){sub 1–20} short-period superlattices on +c-GaN template in dynamic atomic layer epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Kusakabe, Kazuhide; Hashimoto, Naoki; Wang, Ke; Imai, Daichi [Center for SMART Green Innovation Research, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Itoi, Takaomi [Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Yoshikawa, Akihiko, E-mail: yoshi@faculty.chiba-u.jp [Center for SMART Green Innovation Research, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Graduate School of Engineering, Kogakuin University, Hachioji, Tokyo 192-0015 (Japan)

    2016-04-11

    The growth kinetics and structural perfection of (InN){sub 1}/(GaN){sub 1–20} short-period superlattices (SPSs) were investigated with their application to ordered alloys in mind. The SPSs were grown on +c-GaN template at 650 °C by dynamic atomic layer epitaxy in conventional plasma-assisted molecular beam epitaxy. It was found that coherent structured InN/GaN SPSs could be fabricated when the thickness of the GaN barrier was 4 ML or above. Below 3 ML, the formation of SPSs was quite difficult owing to the increased strain in the SPS structure caused by the use of GaN as a template. The effective or average In composition of the (InN){sub 1}/(GaN){sub 4} SPSs was around 10%, and the corresponding InN coverage in the ∼1 ML-thick InN wells was 50%. It was found that the effective InN coverage in ∼1 ML-thick InN wells could be varied with the growth conditions. In fact, the effective In composition could be increased up to 13.5%, i.e., the corresponding effective InN coverage was about 68%, by improving the capping/freezing speed by increasing the growth rate of the GaN barrier layer.

  14. Growth kinetics and structural perfection of (InN)_1/(GaN)_1_–_2_0 short-period superlattices on +c-GaN template in dynamic atomic layer epitaxy

    International Nuclear Information System (INIS)

    Kusakabe, Kazuhide; Hashimoto, Naoki; Wang, Ke; Imai, Daichi; Itoi, Takaomi; Yoshikawa, Akihiko

    2016-01-01

    The growth kinetics and structural perfection of (InN)_1/(GaN)_1_–_2_0 short-period superlattices (SPSs) were investigated with their application to ordered alloys in mind. The SPSs were grown on +c-GaN template at 650 °C by dynamic atomic layer epitaxy in conventional plasma-assisted molecular beam epitaxy. It was found that coherent structured InN/GaN SPSs could be fabricated when the thickness of the GaN barrier was 4 ML or above. Below 3 ML, the formation of SPSs was quite difficult owing to the increased strain in the SPS structure caused by the use of GaN as a template. The effective or average In composition of the (InN)_1/(GaN)_4 SPSs was around 10%, and the corresponding InN coverage in the ∼1 ML-thick InN wells was 50%. It was found that the effective InN coverage in ∼1 ML-thick InN wells could be varied with the growth conditions. In fact, the effective In composition could be increased up to 13.5%, i.e., the corresponding effective InN coverage was about 68%, by improving the capping/freezing speed by increasing the growth rate of the GaN barrier layer.

  15. Estimation of Soil Moisture Under Vegetation Cover at Multiple Frequencies

    Science.gov (United States)

    Jadghuber, Thomas; Hajnsek, Irena; Weiß, Thomas; Papathanassiou, Konstantinos P.

    2015-04-01

    Soil moisture under vegetation cover was estimated by a polarimetric, iterative, generalized, hybrid decomposition and inversion approach at multiple frequencies (X-, C- and L-band). Therefore the algorithm, originally designed for longer wavelength (L-band), was adapted to deal with the short wavelength scattering scenarios of X- and C-band. The Integral Equation Method (IEM) was incorporated together with a pedo-transfer function of Dobson et al. to account for the peculiarities of short wavelength scattering at X- and C-band. DLR's F-SAR system acquired fully polarimetric SAR data in X-, C- and L-band over the Wallerfing test site in Lower Bavaria, Germany in 2014. Simultaneously, soil and vegetation measurements were conducted on different agricultural test fields. The results indicate a spatially continuous inversion of soil moisture in all three frequencies (inversion rates >92%), mainly due to the careful adaption of the vegetation volume removal including a physical constraining of the decomposition algorithm. However, for X- and C-band the inversion results reveal moisture pattern inconsistencies and in some cases an incorrectly high inversion of soil moisture at X-band. The validation with in situ measurements states a stable performance of 2.1- 7.6vol.% at L-band for the entire growing period. At C- and X-band a reliable performance of 3.7-13.4vol.% in RMSE can only be achieved after distinct filtering (X- band) leading to a loss of almost 60% in spatial inversion rate. Hence, a robust inversion for soil moisture estimation under vegetation cover can only be conducted at L-band due to a constant availability of the soil signal in contrast to higher frequencies (X- and C-band).

  16. East African Cenozoic vegetation history.

    Science.gov (United States)

    Linder, Hans Peter

    2017-11-01

    The modern vegetation of East Africa is a complex mosaic of rainforest patches; small islands of tropic-alpine vegetation; extensive savannas, ranging from almost pure grassland to wooded savannas; thickets; and montane grassland and forest. Here I trace the evolution of these vegetation types through the Cenozoic. Paleogene East Africa was most likely geomorphologically subdued and, as the few Eocene fossil sites suggest, a woodland in a seasonal climate. Woodland rather than rainforest may well have been the regional vegetation. Mountain building started with the Oligocene trap lava flows in Ethiopia, on which rainforest developed, with little evidence of grass and none of montane forests. The uplift of the East African Plateau took place during the middle Miocene. Fossil sites indicate the presence of rainforest, montane forest and thicket, and wooded grassland, often in close juxtaposition, from 17 to 10 Ma. By 10 Ma, marine deposits indicate extensive grassland in the region and isotope analysis indicates that this was a C 3 grassland. In the later Miocene rifting, first of the western Albertine Rift and then of the eastern Gregory Rift, added to the complexity of the environment. The building of the high strato-volcanos during the later Mio-Pliocene added environments suitable for tropic-alpine vegetation. During this time, the C 3 grassland was replaced by C 4 savannas, although overall the extent of grassland was reduced from the mid-Miocene high to the current low level. Lake-level fluctuations during the Quaternary indicate substantial variation in rainfall, presumably as a result of movements in the intertropical convergence zone and the Congo air boundary, but the impact of these fluctuations on the vegetation is still speculative. I argue that, overall, there was an increase in the complexity of East African vegetation complexity during the Neogene, largely as a result of orogeny. The impact of Quaternary climatic fluctuation is still poorly understood

  17. Sensitivity of vegetation indices and gross primary production of tallgrass prairie to severe drought

    Energy Technology Data Exchange (ETDEWEB)

    Wagle, Pradeep; Xiao, Xiangming; Torn, Margaret S.; Cook, David R.; Matamala, Roser; Fischer, Marc L.; Jin, Cui; Dong, Jinwei; Biradar, Chandrashekhar

    2014-09-01

    Drought affects vegetation photosynthesis and growth.Many studies have used the normalized difference vegetation index (NDVI), which is calculated as the normalized ratio between near infrared and red spectral bands in satellite images, to evaluate the response of vegetation to drought. In this study, we examined the impacts of drought on three vegetation indices (NDVI, enhanced vegetation index, EVI, and land surface water index, LSWI) and CO2 flux from three tallgrass prairie eddy flux tower sites in the U.S. Gross primary production (GPP) was also modeled using a satellite-based Vegetation Photosynthesis Model (VPM), and the modeled GPP (GPPVPM) was compared with the GPP (GPPEC) derived from eddy covariance measurements. Precipitation at two sites in Oklahoma was 30% below the historical mean in both years of the study period (2005–2006), while the site in Illinois did not experience drought in the 2005–2007 study period. The EVI explained the seasonal dynamics of GPP better than did NDVI. The LSWI dropped below zero during severe droughts in the growing season, showing its potential to track drought. The result shows that GPP was more sensitive to drought than were vegetation indices, and EVI and LSWI were more sensitive than NDVI. We developed a modified function (Wscalar), calculated as a function of LSWI, to account for the effect of severe droughts on GPP in VPM. The GPPVPM from the modified VPM accounted for the rapid reduction in GPP during severe droughts and the seasonal dynamics of GPPVPM agreed reasonably well with GPPEC. Our analysis shows that 8-day averaged values (temperature, vapor-pressure deficit) do not reflect the short-term extreme climate events well, suggesting that satellite based models may need to be run at daily or hourly scales, especially under unfavorable climatic conditions.

  18. Vegetation dynamics and dynamic vegetation science

    NARCIS (Netherlands)

    Van der Maarel, E

    1996-01-01

    his contribution presents a review of the development of the study of vegetation dynamics since 1979, in the framework of a jubilee meeting on progress in the study of vegetation. However, an exhaustive review is both impossible and unnecessary. It is impossible within the few pages available

  19. The Impact of Observed Vegetation Changes on Land–Atmosphere Feedbacks During Drought

    KAUST Repository

    Meng, X. H.

    2014-04-01

    Moderate Resolution Imaging Spectroradiometer (MODIS)-derived vegetation fraction data were used to update the boundary conditions of the advanced research Weather Research and Forecasting (WRF) Model to assess the influence of realistic vegetation cover on climate simulations in southeast Australia for the period 2000–08. Results show that modeled air temperature was improved when MODIS data were incorporated, while precipitation changes little with only a small decrease in the bias. Air temperature changes in different seasons reflect the variability of vegetation cover well, while precipitation changes have a more complicated relationship to changes in vegetation fraction. Both MODIS and climatology-based simulation experiments capture the overall precipitation changes, indicating that precipitation is dominated by the large-scale circulation, with local vegetation changes contributing variations around these. Simulated feedbacks between vegetation fraction, soil moisture, and drought over southeast Australia were also investigated. Results indicate that vegetation fraction changes lag precipitation reductions by 6–8 months in nonarid regions. With the onset of the 2002 drought, a potential fast physical mechanism was found to play a positive role in the soil moisture–precipitation feedback, while a slow biological mechanism provides a negative feedback in the soil moisture–precipitation interaction on a longer time scale. That is, in the short term, a reduction in soil moisture leads to a reduction in the convective potential and, hence, precipitation, further reducing the soil moisture. If low levels of soil moisture persist long enough, reductions in vegetation cover and vigor occur, reducing the evapotranspiration and thus reducing the soil moisture decreases and dampening the fast physical feedback. Importantly, it was observed that these feedbacks are both space and time dependent.

  20. Vegetation and climate history during the last millennium derived from Anggertu Lake, Tengger Desert

    Science.gov (United States)

    Duan, F.; An, C.; Zhao, Y.; Wang, W.; Cao, Z.

    2017-12-01

    Studying the climate changes during the last millennium can help us to understand current relationship between human-social activities and natural environment changes, and improve projections of future climate. Pollen assemblages, loss-on-ignition (LOIorg at 550 °C) and grain size data collected from sediment core (AGE15A) from the center of Anggertu lake (eastern Tengger Desert, Inner Mongolia) are presented to reconstruct regional vegetation and climate history during the last millennium. Results show that: 1) desert or desert steppe dominated by Artemisia and Amaranthaceae expanded around this region during the period of 988 1437 A.D., indicating a generally dry climate condition with two short humid periods (1003 1082 A.D. and 1388 1437 A.D). These two wet periods are characterized by relatively high vegetation cover and bio-productivity, reflected by high pollen concentrations and LOIorg. Increase in the steppe or meadow vegetation communities (Poaceae, Cyperaceae) and vegetation cover during the period of 1437 2015 A.D. suggest a wetting trend, as also indicated by gradually finer grain size. The relatively high LOI indicate a high bio-productivity during this interval. And then unstable lacustrine environment was found with frequent fluctuations in pollen concentration and grain size since 1842 A.D.. 2) This study recorded a relatively dry Medieval Warm Period (MWP; 1082 1388 A.D.) and a wet Little Ice Age (LIA; 1437 1842 A.D.), which is generally consistent with climate characteristics in arid central Asia (ACA). 3) Increased Amaranthaceae and high abundance of Poaceae were related to overgrazing and agricultural activities at that time to some extent. Thus vegetation evolution of the lake region was influenced by human activities and climate changes.

  1. Short philtrum

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003302.htm Short philtrum To use the sharing features on this page, please enable JavaScript. A short philtrum is a shorter than normal distance between ...

  2. Fruits and vegetables (image)

    Science.gov (United States)

    A healthy diet includes adding vegetables and fruit every day. Vegetables like broccoli, green beans, leafy greens, zucchini, cauliflower, cabbage, carrots, and tomatoes are low in calories and high in fiber, vitamins, and minerals. ...

  3. Vegetable Production System (Veggie)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Vegetable Production System (Veggie) was developed to be a simple, easily stowed, high growth volume, low resource facility capable of producing fresh vegetables...

  4. European Vegetation Archive (EVA)

    NARCIS (Netherlands)

    Chytrý, Milan; Hennekens, S.M.; Jiménez-Alfaro, Borja; Schaminée, J.H.J.; Haveman, Rense; Janssen, J.A.M.

    2016-01-01

    The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and

  5. Post Fire Vegetation Recovery in Portugal

    Science.gov (United States)

    Gouveia, Celia; Bastos, Ana; DaCamara, Carlos; Trigo, Ricardo M.

    2011-01-01

    Fires in Portugal, as in the Mediterranean ecosystems, have a complex effect on vegetation regeneration due to the different responses of vegetation to the variety of fire regimes and to the complexity of landscape structures. A thorough evaluation of vegetation recovery after fire events becomes therefore crucial in land management. In 2005, Portugal suffered a strong damage from forest fires that damaged an area of 300 000 ha of forest and shrub. This year are particularly interesting because it is associated the severe drought of 2005. The aim of the present study is to identify large burnt scars in Portugal during the 2005 fire seasons and monitoring vegetation behaviour throughout the pre and the post fire periods. The mono-parametric model developed by Gouveia et al. (2010), based on monthly values of NDVI, at the 1km×1km spatial scale, as obtained from the VEGETATION-SPOT5 instrument, from 1999 to 2009, was used.

  6. Índice de cobertura vegetal pela cultura do milho no período de chuvas intensas no sul de Minas Gerais Plant cover index in the period of intensive rainfall for corn crop at south of Minas Gerais state, Brazil

    Directory of Open Access Journals (Sweden)

    Fabiana Silva de Souza

    2010-04-01

    Full Text Available A cobertura vegetal é a defesa natural do solo contra a erosão hídrica. Nos modelos de estimativas de perdas de solo, o efeito da cobertura vegetal na interceptação da energia cinética da chuva é a variável chave na modelagem do processo erosivo. Assim sendo, objetivou-se avaliar a eficiência da cobertura vegetal, proporcionada pela cultura do milho, e suas relações com os atributos fitotécnicos desta cultura para alguns híbridos. O estudo foi realizado no campo demonstrativo de híbridos de milho da Universidade Federal de Lavras, localizada no município de Lavras, MG. Para determinação da cobertura vegetal utilizou-se um aparato que consiste em uma estrutura horizontal, contendo orifícios para visualização dos pontos com cobertura e sem cobertura vegetal, sendo as leituras feitas de forma aleatória e transversalmente às linhas da cultura. Os atributos fitotécnicos avaliados foram altura da planta, estande, matéria seca e produção de grãos. Diante dos resultados pode-se concluir que o maior índice de cobertura vegetal foi observado para os híbridos de milho P 30F33, P 30F90, P 3021, STRIKE, FORT, VALENT, UFLA 2001, UFLA 2004, CO 32, D 8480, D 8420 DKB 333B, DKB 440, evidenciando boa qualidade como planta protetora do solo. No período de maior ocorrência de chuvas, na região sul de Minas Gerais, a cultura do milho pode minimizar o efeito do processo erosivo. A produção de matéria seca relacionou-se bem com o índice de cobertura vegetal, podendo ser um indicativo quanto à proteção do solo.The plant cover is a natural protection of soil against water erosion. In estimative models of soil loss, the effect of plant cover in the interception of rainfall kinetic energy is the key variable in the modeling of the erosive process. Thus, the aim of this work is to evaluate the efficiency of the plant cover provided by the corn crop and their relations with the phytotechnical attributes of this crop for its respective

  7. Impedance deduction for vegetated roof surfaces : multiple geometry strategy

    NARCIS (Netherlands)

    Liu, C.; Hornikx, M.

    2016-01-01

    The transfer function method is an efficient procedure to deduce the ground surface impedance from short-range propagation measurements using one point source. It is able to provide a reasonable prediction of the surface impedance of a vegetated roof as well, and the characteristics of the vegetated

  8. Co-composting of vegetable wastes and carton: Effect of carton composition and parameter variations.

    Science.gov (United States)

    Rawoteea, Soonita Anjeena; Mudhoo, Ackmez; Kumar, Sunil

    2017-03-01

    The aim of the study was to investigate the effects of carton in the composting process of mixed vegetable wastes using an experimental composter of capacity 80L. Three different mixes were set-up (Mixes 1, 2 and 3) which consisted of vegetable wastes, 2.0kg paper and bulking agents, vegetable wastes, 1.5kg carton and bulking agents, vegetable wastes, 4.5kg carton and bulking agents, respectively. Temperature evolution, pH trends, moisture levels, respiration rates, percentage volatile solids and electrical conductivity were monitored for a period of 50days. The system remained under thermophilic conditions for a very short period due to the small size of the reactor. The three mixes did not exceed a temperature of 55°C, where sanitization takes place by the destruction of pathogens. The highest peak of CO 2 evolution was observed in Mix 2 indicating that maximum microbial degradation took place in that mix. Copyright © 2016. Published by Elsevier Ltd.

  9. Post-fire vegetation behaviour in large burnt scars from 2005 fire season in Spain

    Science.gov (United States)

    Bastos, A.; Gouveia, C. M.; DaCamara, C. C.; Trigo, R. M.

    2012-04-01

    Wildfires have a wide diversity of impacts on landscape which, in turn, depend on the interaction of fire regimes (e.g. intensity, extent, frequency) and the response of vegetation to them in short and long-terms. The increase in erosion rates and the loss of nutrients by runoff in the first months following the fire are among the major impacts of wildfires. A minimum of 30% of vegetation cover is enough to protect soils against erosion but vegetation may require a long period to reach this threshold after severe fires. Since erosion risk is strongly linked to vegetation recovery rates, post-fire vegetation monitoring becomes crucial in land management. Fire regimes in the Mediterranean have been changing in the past decades due to modifications in both socio-economic and climate patterns. Although many vegetation species in Mediterranean ecosystems are adapted to wildfires, changes in fire regime characteristics affect the ability of ecosystems to recover to their previous state. In Spain, fire is an important driver of changes in landscape composition, leading to dominance of shrubland following fire and to a major decrease of pine woodlands (Viedma et al., 2006). Remote sensing is a powerful tool in land management, allowing vegetation monitoring on large spatial scales for relatively long periods of time. In order to assess vegetation dynamics, monthly NDVI data from 1998-2009 from SPOT/VEGETATION at 1km spatial resolution over the Iberian Peninsula were used. This work focuses on 2005 fire season in Spain, which registered the highest amount of burnt area since 1994, with more than 188000 ha burnt. Burnt scars in this fire season were identified by cluster analysis. Post-fire vegetation recovery was assessed based on the monoparametric model developed by Gouveia et al. (2010) that was applied to four large scars located in different geographical settings with different land cover characteristics. While the two northern regions presented fast recovery, in the

  10. Compositional Changes in Selected Minimally Processed Vegetables

    OpenAIRE

    O'Reilly, Emer, (Thesis)

    2000-01-01

    Compositional, physiological and microbiological changes in selected minimally processed vegetables packaged under a modified atmosphere of 2% oxygen and 5% carbon dioxide were monitored over a ten day storage period at 40 C and 80 C. The analysis targeted specific changes in the nutritional, chemical and physiological make up of the vegetables as well as the changes in the microbial levels. In addition the changes in the gas atmospheres within the packs were monitored. It has been widely acc...

  11. Contribution to the experimental survey of the nuclear isomerism. Application of the deferred coincidences method to research and to the survey of metastable states of short period; Contribution a l'etude experimentale de l'isomerie nucleaire. Application de la methode des coincidences differees a la recherche et a l'etude d'etats metastables de periode courte

    Energy Technology Data Exchange (ETDEWEB)

    Ballini, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1953-06-15

    Various methods of the physics brought many informations on the nuclear elements which one can arrange some ponderable quantities, what is the case of the steady elements and some, unsteady elements, as most of natural radioelements. On the other hand, elements of shorter life duration, and notably those that are carried to an excited state, are more badly known, and one can get information to their consideration that by the mediator of the properties of the transitions that they undergo, when they give birth has best-known nuclear cash: among these transitions represent the isomeric transitions. The goal of this work is the survey of the isomeric transitions from metastable states of short period, included in the domain of the microsecond to some milliseconds. The method of the deferred coincidences has been put to the point and applied in this goal while using the advantages of the selectors to several channels, under two main aspects where the device to several channels was either a selector of time, either a selector of amplitudes. This method served to study the working of Geiger-Muller counter and to measure with precision the period of {sup 181}Ta{sup *} in of the varied experimental conditions. The adopted value is 17,2 {+-}0,2 {mu}s. This work also found an immediate practical application to the setting in evidence of very weak quantities of hafnium in zirconium, of which it constitutes a tenacious and difficult impurity to analyze by the ordinary ways. (M.B.) [French] Les diverses methodes de la physique ont apporte de nombreux renseignements sur les especes nucleaires dont on peut disposer en quantites ponderables, ce qui est le cas des especes stables et de certaines especes instables, comme la plupart des radioelements naturels. Par contre, les noyaux de duree de vie plus courte, et notamment ceux qui sont portes a un etat excite, sont plus mal connus, et on ne peut obtenir de renseignements a leur egard que par l'intermediaire des proprietes des

  12. Problem Periods

    Science.gov (United States)

    ... ovary syndrome. Read our information on PCOS for teens , and see your doctor if you think you may have PCOS. Major weight loss. Girls who have anorexia will often stop having periods. When to see ...

  13. Elephant movement closely tracks precipitation-driven vegetation dynamics in a Kenyan forest-savanna landscape.

    Science.gov (United States)

    Bohrer, Gil; Beck, Pieter Sa; Ngene, Shadrack M; Skidmore, Andrew K; Douglas-Hamilton, Ian

    2014-01-01

    This study investigates the ranging behavior of elephants in relation to precipitation-driven dynamics of vegetation. Movement data were acquired for five bachelors and five female family herds during three years in the Marsabit protected area in Kenya and changes in vegetation were mapped using MODIS normalized difference vegetation index time series (NDVI). In the study area, elevations of 650 to 1100 m.a.s.l experience two growth periods per year, while above 1100 m.a.s.l. growth periods last a year or longer. We find that elephants respond quickly to changes in forage and water availability, making migrations in response to both large and small rainfall events. The elevational migration of individual elephants closely matched the patterns of greening and senescing of vegetation in their home range. Elephants occupied lower elevations when vegetation activity was high, whereas they retreated to the evergreen forest at higher elevations while vegetation senesced. Elephant home ranges decreased in size, and overlapped less with increasing elevation. A recent hypothesis that ungulate migrations in savannas result from countervailing seasonally driven rainfall and fertility gradients is demonstrated, and extended to shorter-distance migrations. In other words, the trade-off between the poor forage quality and accessibility in the forest with its year-round water sources on the one hand and the higher quality forage in the low-elevation scrubland with its seasonal availability of water on the other hand, drives the relatively short migrations (the two main corridors are 20 and 90 km) of the elephants. In addition, increased intra-specific competition appears to influence the animals' habitat use during the dry season indicating that the human encroachment on the forest is affecting the elephant population.

  14. Consumer Acceptance Comparison Between Seasoned and Unseasoned Vegetables.

    Science.gov (United States)

    Feng, Yiming; Albiol Tapia, Marta; Okada, Kyle; Castaneda Lazo, Nuria Blanca; Chapman-Novakofski, Karen; Phillips, Carter; Lee, Soo-Yeun

    2018-02-01

    Recent findings show that approximately 87% of the U.S. population fail to meet the vegetable intake recommendations, with unpleasant taste of vegetables being listed as the primary reason for this shortfall. In this study, spice and herb seasoning was used to enhance palatability of vegetables, in order to increase consumer acceptance. In total, 749 panelists were screened and recruited as specific vegetable likers of the vegetable being tested or general vegetable likers. Four sessions were designed to evaluate the effect of seasoning within each type of vegetable, including broccoli, cauliflower, carrot, and green bean. Each panelist was only allowed to participate in one test session to evaluate only one vegetable type, so as to mitigate potential learning effect. Overall, the results showed that seasoned vegetables were significantly preferred over unseasoned vegetables (P trend of seasoned vegetable being preferred remained. The findings from this study demonstrate the effect of seasoning in enhancing consumer liking of vegetables, which may lead to increased consumption to be assessed in future studies. To improve the sensory properties of vegetables, masking the bitter taste of vegetables using spice and herb seasoning are gaining increasing attention. Our findings suggest that the overall liking of vegetables could be improved by incorporating spice and herb seasonings that are specifically formulated for each vegetable. Ultimately, developing and commercializing spice and herb seasonings may aid to increase vegetable consumption, as well as expanding the vegetable seasoning market. © 2018 The Authors Journal of Food Science published by Wiley Periodicals, Inc. on behalf of Institute of Food Technologists.

  15. Clearing and vegetation management issues

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Clearing and continued management of incompatible plant species is critical to maintaining safe and reliable transmission and distribution lines at British Columbia Hydro. As part of a general review of policies regarding rights-of-way, the clearing of BC Hydro rights-of-way was studied by a task team in order to formulate a set of recommended policies and procedures to guide employees in all rights-of-way decisions, and to provide clear direction for resolution of all rights-of-way issues in a cost-effective manner. Issues reviewed were: clearing standards and line security standardization for transmission circuits; clearing rights for removal of trees or management of vegetation beyond the statutory right-of-way; clearing and vegetation management procedures; tree replacement; arboricultural techniques; periodic reviewing of clearing practices; compensation for tree removal; herbicide use; and heritage and wildlife trees. Justification for the recommendation is provided along with alternate options and costs of compliance

  16. Irradiation of dehydrated vegetables

    International Nuclear Information System (INIS)

    Esterhuyse, A; Esterhuizen, T.

    1985-01-01

    The reason for radurization was to decreased the microbial count of dehydrated vegetables. The average absorbed irradiation dose range between 2kGy and 15kGy. The product catagories include a) Green vegetables b) White vegetables c) Powders of a) and b). The microbiological aspects were: Declining curves for the different products of T.P.C., Coliforms, E. Coli, Stap. areus, Yeast + Mold at different doses. The organoleptical aspects were: change in taste, flavour, texture, colour and moisture. The aim is the marketing of irradiated dehydrated vegetables national and international basis

  17. Vegetation recovery assessment following large wildfires in the Mediterranean Basin

    Science.gov (United States)

    Bastos, A.; Gouveia, C. M.; Trigo, R. M.; DaCamara, C. C.

    2012-04-01

    Mediterranean ecosystems have evolved along with fire, adapting to quick recovering following wildfire events. However, vegetation species respond differently to the changes in fire regimes that have been observed in the past decades in the Mediterranean. These changes, which occurred mainly due to socio-economic and climatic changes, led to dramatic modifications of landscape composition and structure (Malkinson et al., 2011). Post-fire vegetation recovery depends on environmental factors such as landscape features and climatic variables and on specific plant traits; however it also depends on the differentiated response of each species to the characteristics of fire regimes, such as recurrence, severity and extent. The complexity of the interactions between these factors emphasizes the importance of assessing quantitatively post-fire recovery as well as the role of driving factors of regeneration over different regions in the Mediterranean. In 2006, Spain experienced the fire season with larger fires, restricted to a relatively small region of the province of Galicia, that represents more than 60% of total burned area of this fire season (92000ha out of 148827 ha). The 2007 fire season in Greece was remarkably severe, registering the highest value of burnt area (225734 ha) since 1980. Finally, in 2010 a very large wildfire of about 5000 ha occurred in Mount Carmel, Israel, with major social and environmental impacts. The work relies on monthly NDVI data from SPOT/VEGETATION at 1km spatial resolution over the period from September 1998 - August 2011 for Spain, Greece and Israel. Here we have applied the same sequential methodology developed at our laboratory, starting by the identification of very large burnt scars by means of a spatial cluster analysis followed by the application of the monoparametric model (Gouveia et al., 2010; Bastos et al., 2011) in order to study post-fire vegetation dynamics. Post-fire recovery times were estimated for burnt scars from each

  18. Short communication

    African Journals Online (AJOL)

    abp

    2017-09-04

    Sep 4, 2017 ... Face-to-face interviews were conducted using a standardized ... Short communication. Open Access ... clinic during the time of the study and were invited to participate in the study. .... consume them. This is another ...

  19. SHORT COMMUNICATION

    African Journals Online (AJOL)

    PROF P.T. KAYE

    . SHORT COMMUNICATION. Formation and Structural Analysis of Novel Dibornyl Ethers. Perry T. Kaye*, Andrew R. Duggan, Joseph M. Matjila, Warner E. Molema, and. Swarnam S. Ravindran. Department of Chemistry, Rhodes University, Grahamstown, ...

  20. Multispectral Imaging of Wok-Fried Vegetables

    DEFF Research Database (Denmark)

    Clemmensen, Line Katrine Harder; Dissing, Bjørn Skovlund; Hyldig, Grethe

    2012-01-01

    Quality control in the food industry is often performed by measuring various chemical compounds in the food involved. The authors propose an imaging concept for acquiring high-quality multispectral images to evaluate optical reflection changes in carrots and celeriac over a period of 14 days....... For comparison, sensory analysis was performed on the same samples. Prior to multispectral image recording, the vegetables were prefried and frozen at -30 °C for 4 months. During the 14 days of image recording, the vegetables were kept at +5 °C. In this period, surface changes and thereby reflectance properties...

  1. Calibration of transfer functions between phytolith, vegetation and climate for integration of grassland dynamics in vegetation models. Application to a 50,000 yr crater lake core in Tanzania.

    Science.gov (United States)

    Bremond, L.; Alexandre, A.; Hely, C.; Vincens, A.; Williamson, D.; Guiot, J.

    2004-12-01

    Global vegetation models provide a way to translate the outputs from climate models into maps of potential vegetation distribution for present, past and future. Validation of these models goes through the comparison between model outputs and vegetation proxies for well constrained past climatic periods. Grass-dominated biomes are widespread and numerous. This diversity is hardly mirrored by common proxies such as pollen, charcoal or carbon isotopes. Phytoliths are amorphous silica that precipitate in and/or between living plant cells. They are commonly used to trace grasslands dynamics. However, calibration between phytolith assemblages, vegetation, and climate parameters are scarce. This work introduces transfer functions between phytolith indices, inter-tropical grassland physiognomy, and bio-climatic data that will be available for model/data comparisons. The Iph phytolith index discriminates tall from short grass savannas in West Africa. A transfer function allows to estimate evapo-transpiration AET/PET. The Ic phytolith index accurately estimates the proportion of Pooideae and Panicoideae grass sub-families, and potentially the C4/C3 grass dominance on East African mountains. The D/P index appears as a good proxy of Leaf Area Index (LAI) in tropical areas. These environmental parameters are commonly used as vegetation model outputs, but have been, up to now, hardly estimated by vegetation proxies. These transfer functions are applied to a 50,000 yr phytolith sequence from a crater lake (9°S; 33°E Tanzania). The record is compared to the pollen vegetation reconstruction and confronted to simulations of the LPJ-GUESS vegetation model (Stitch et. al, 2003).

  2. Balkan Vegetation Database

    NARCIS (Netherlands)

    Vassilev, Kiril; Pedashenko, Hristo; Alexandrova, Alexandra; Tashev, Alexandar; Ganeva, Anna; Gavrilova, Anna; Gradevska, Asya; Assenov, Assen; Vitkova, Antonina; Grigorov, Borislav; Gussev, Chavdar; Filipova, Eva; Aneva, Ina; Knollová, Ilona; Nikolov, Ivaylo; Georgiev, Georgi; Gogushev, Georgi; Tinchev, Georgi; Pachedjieva, Kalina; Koev, Koycho; Lyubenova, Mariyana; Dimitrov, Marius; Apostolova-Stoyanova, Nadezhda; Velev, Nikolay; Zhelev, Petar; Glogov, Plamen; Natcheva, Rayna; Tzonev, Rossen; Boch, Steffen; Hennekens, Stephan M.; Georgiev, Stoyan; Stoyanov, Stoyan; Karakiev, Todor; Kalníková, Veronika; Shivarov, Veselin; Russakova, Veska; Vulchev, Vladimir

    2016-01-01

    The Balkan Vegetation Database (BVD; GIVD ID: EU-00-019; http://www.givd.info/ID/EU-00- 019) is a regional database that consists of phytosociological relevés from different vegetation types from six countries on the Balkan Peninsula (Albania, Bosnia and Herzegovina, Bulgaria, Kosovo, Montenegro

  3. Soil and vegetation surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, E.J.

    1995-06-01

    Soil sampling and analysis evaluates long-term contamination trends and monitors environmental radionuclide inventories. This section of the 1994 Hanford Site Environmental Report summarizes the soil and vegetation surveillance programs which were conducted during 1994. Vegetation surveillance is conducted offsite to monitor atmospheric deposition of radioactive materials in areas not under cultivation and onsite at locations adjacent to potential sources of radioactivity.

  4. Creating action plans in a serious video game increases and maintains child fruit-vegetable intake: a randomized controlled trial.

    Science.gov (United States)

    Thompson, Debbe; Bhatt, Riddhi; Vazquez, Isabel; Cullen, Karen W; Baranowski, Janice; Baranowski, Tom; Liu, Yan

    2015-03-18

    Child fruit and vegetable intake is below recommended levels, increasing risk for chronic disease. Interventions to influence fruit and vegetable intake among youth have had mixed effects. Innovative, theory-driven interventions are needed. Goal setting, enhanced by implementation intentions (i.e., plans tightly connected to a behavioral goal), may offer a solution. Action plans state "how" a goal will be achieved, while coping plans identify a potential barrier and corresponding solution. The research reported here evaluated the short- and long-term effects of goal setting enhanced with implementation intentions on child fruit and vegetable intake in a 10-episode, theoretically-grounded serious videogame promoting fruit and vegetables. This is one of the first studies to test the efficacy of implementation intentions on the dietary intake of healthy children. A four-group randomized design with three data collection periods (baseline, immediate post-intervention, 3 months post-intervention) was employed. Groups varied on whether children created an implementation intention (none, action, coping, both) as part of goal setting. Participants were 4th and 5th grade children (~9-11 years old) and one parent. An a priori power analysis indicated this would provide >80% power to detect a small effect (Cohen's d = 0.17). Children played a 10-episode online videogame; parents received 10 electronic newsletters and access to a parent-only website. The primary outcome was child fruit and vegetable intake, assessed via three, dietitian-assisted telephone recalls at each data collection period. The primary analysis was conducted using a repeated measures analysis of covariance with a mixed model procedure. Secondary analyses examined intervention effects on fruit and vegetables separately. Four hundred parent/child dyads were recruited. A significant group-by-time interaction for fruit and vegetable intake (p adolescent children. Videogames promoting healthy diets offer

  5. The role of natural vegetative disturbance in determining stream reach characteristics in central Idaho and western Montana

    Science.gov (United States)

    Roper, B.B.; Jarvis, B.; Kershner, J.L.

    2007-01-01

    We evaluated the relationship between natural vegetative disturbance and changes in stream habitat and macroinvertebrate metrics within 33 randomly selected minimally managed watersheds in central Idaho and western Montana. Changes in stream reach conditions were related to vegetative disturbance for the time periods from 1985 to 1993 and 1993 to 2000, respectively, at the following three spatial scales; within the stream buffer and less than 1 km from the evaluated reach, within the watershed and within 1 km of the stream reach, and within the watershed. Data for stream reaches were based on field surveys and vegetative disturbance was generated for the watershed above the sampled reach using remotely sensed data and geographical information systems. Large scale (>100 ha) vegetative disturbance was common within the study area. Even though natural vegetative disturbance rates were high, we found that few of the measured attributes were related to the magnitude of vegetative disturbance. The three physical habitat attributes that changed significantly were sinuosity, median particle size, and percentage of undercut bank; each was related to the disturbance in the earlier (1985-1993) time frame. There was a significant relationship between changes in two macroinvertebrate metrics, abundance and percent collectors/filterers, and the magnitude of disturbance during the more recent time period (1993-2000). We did not find a consistent relationship between the location of the disturbance within the watershed and changes in stream conditions. Our findings suggest that natural vegetative disturbance within the northern Rocky Mountains is complex but likely does not result in substantial short-term changes in the characteristics of most stream reaches. ?? 2007 by the Northwest Scientific Association. All rights reserved.

  6. Method of producing vegetable puree

    DEFF Research Database (Denmark)

    2004-01-01

    A process for producing a vegetable puree, comprising the sequential steps of: a)crushing, chopping or slicing the vegetable into pieces of 1 to 30 mm; b) blanching the vegetable pieces at a temperature of 60 to 90°C; c) contacted the blanched vegetable pieces with a macerating enzyme activity; d......) blending the macerated vegetable pieces and obtaining a puree....

  7. Vegetation survey: a new focus for Applied Vegetation Science

    NARCIS (Netherlands)

    Chytry, M.; Schaminee, J.H.J.; Schwabe, A.

    2011-01-01

    Vegetation survey is an important research agenda in vegetation science. It defines vegetation types and helps understand differences among them, which is essential for both basic ecological research and applications in biodiversity conservation and environmental monitoring. In this editorial, we

  8. Waste vegetable oil survey report

    Energy Technology Data Exchange (ETDEWEB)

    MacLeod, R. [Science enterprise Algoma seA, Sault Ste. Marie, ON (Canada)

    2009-02-06

    This study was conducted to estimate potential sources of feedstock waste oils for biodiesel production in the Sault Ste. Marie region of Ontario. Two feedstocks were investigated over a period of several months, notably cooking oil and waste vegetable oil. The study was conducted to examine oil throughput, collection practices, and to gauge interest in local initiatives. A distribution list of commercial restaurant listings was developed, and surveys were conducted with members of private enterprises, city government, and non-profit stakeholders in the region. Average volumes of waste vegetable oil were presented for different types of restaurants. The various types of oil used in the restaurants were also quantified. Results of the study showed a positive public response to the idea of a local biodiesel initiative. Steak house, fast food, and Italian establishments generated the largest portion of waste vegetable oil amongst survey respondents. However, the highest response rates came from establishments with little or no oil consumption. Many franchise fast food restaurants are already in contracts with waste oil removal companies. 3 tabs., 3 figs.

  9. Short Stature

    DEFF Research Database (Denmark)

    Christesen, Henrik Boye Thybo; Pedersen, Birgitte Tønnes; Pournara, Effie

    2016-01-01

    -scale, non-interventional, multinational study. The patient cohort consisted of 5996 short pediatric patients diagnosed with growth hormone deficiency (GHD), Turner syndrome (TS) or born small for gestational age (SGA). The proportions of children with baseline height standard deviation score (SDS) below......The use of appropriate growth standards/references is of significant clinical importance in assessing the height of children with short stature as it may determine eligibility for appropriate therapy. The aim of this study was to determine the impact of using World Health Organization (WHO) instead...... of national growth standards/references on height assessment in short children. Data were collected from routine clinical practice (1998-2014) from nine European countries that have available national growth references and were enrolled in NordiNet® International Outcome Study (IOS) (NCT00960128), a large...

  10. Post-fire vegetation recovery in Portugal based ewline on spot/vegetation data

    Directory of Open Access Journals (Sweden)

    C. Gouveia

    2010-04-01

    Full Text Available A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI, with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation

  11. Post-fire vegetation recovery in Portugal based on spot/vegetation data

    Science.gov (United States)

    Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

    2010-04-01

    A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI), with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation indices.

  12. The use of a commercial vegetable juice as a practical means to increase vegetable intake: a randomized controlled trial.

    Science.gov (United States)

    Shenoy, Sonia F; Kazaks, Alexandra G; Holt, Roberta R; Chen, Hsin Ju; Winters, Barbara L; Khoo, Chor San; Poston, Walker S C; Haddock, C Keith; Reeves, Rebecca S; Foreyt, John P; Gershwin, M Eric; Keen, Carl L

    2010-09-17

    Recommendations for daily dietary vegetable intake were increased in the 2005 USDA Dietary Guidelines as consumption of a diet rich in vegetables has been associated with lower risk of certain chronic health disorders including cardiovascular disease. However, vegetable consumption in the United States has declined over the past decade; consequently, the gap between dietary recommendations and vegetable intake is widening. The primary aim of this study is to determine if drinking vegetable juice is a practical way to help meet daily dietary recommendations for vegetable intake consistent with the 2005 Dietary Guidelines and the Dietary Approaches to Stop Hypertension (DASH) diet. The secondary aim is to assess the effect of a vegetable juice on measures of cardiovascular health. We conducted a 12-week, randomized, controlled, parallel-arm study consisting of 3 groups of free-living, healthy volunteers who participated in study visits at the Ragle Human Nutrition Research Center at the University of California, Davis. All subjects received education on the DASH diet and 0, 8 or 16 fluid ounces of vegetable juice daily. Assessments were completed of daily vegetable servings before and after incorporation of vegetable juice and cardiovascular health parameters including blood pressure. Without the juice, vegetable intake in all groups was lower than the 2005 Dietary Guidelines and DASH diet recommendations. The consumption of the vegetable juice helped participants reach recommended intake. In general, parameters associated with cardiovascular health did not change over time. However, in the vegetable juice intervention groups, subjects who were pre-hypertensive at the start of the study showed a significant decrease in blood pressure during the 12-week intervention period. Including 1-2 cups of vegetable juice daily was an effective and acceptable way for healthy adults to close the dietary vegetable gap. Increase in daily vegetable intake was associated with a

  13. The need of data harmonization to derive robust empirical relationships between soil conditions and vegetation.

    NARCIS (Netherlands)

    Bartholomeus, R.P.; Witte, J.P.M.; van Bodegom, P.M.; Aerts, R.

    2008-01-01

    Question: Is it possible to improve the general applicability and significance of empirical relationships between abiotic conditions and vegetation by harmonization of temporal data? Location: The Netherlands. Methods: Three datasets of vegetation, recorded after periods with different

  14. Trends in landscape and vegetation change and implications for the Santa Cruz Watershed

    Science.gov (United States)

    Villarreal, Miguel; Norman, Laura M.; Webb, Robert H.; Turner, Raymond M.

    2013-01-01

    Monitoring and characterizing the interactive effects of land use and climate on land surface processes is a primary focus of land change science, and of particular concern in arid Wells Distribution in Shallow Groundwater Areas Pumping Trends Increase Streamflow Extent Declines 27 environments where both landscapes and livelihoods can be impacted by short-term climate variability. Using a multi-observational approach to land-change analysis that included landownership data as a proxy for land-use practices, multitemporal land-cover maps, and repeat photography dating to the late 19th century, we examine changing spatial and temporal distributions of two vegetation types with high conservation value in the southwestern United States: grasslands and riparian vegetation. Our study area is the bi-national Santa Cruz Watershed, a topographically complex watershed that straddles the Sonoran Desert and the Madrean Archipelago Ecoregions. In this presentation we focus on historical changes in vegetation and land use in grasslands and riparian areas of the Madrean Ecoregion (San Raphael Valley, Cienega Creek, Sonoita), and compare changes in these areas to changes in the warmer and drier Sonoran Ecoregion. Analysis of historical photography confirms major 20th century vegetation shifts documented in other research: woody plant encroachment, desertification of grasslands, and changing riparian and xeroriparian vegetation occurred in both ecoregions following human settlement. However, vegetation changes over the past decade appear to be more subtle and some of the past trajectories appear to be reversing; most notable are recent mesquite declines in xeroriparian and upland areas, and changes from shrubland to grassland area in the Madrean ecoregion. Land cover changes were temporally variable, reflecting broad climate changes. The most dynamic cover changes occurred during the period from 1989 to 1999, a period with two intense droughts. The degree of vegetation change

  15. Short Review

    DEFF Research Database (Denmark)

    Lynnerup, Niels; Rühli, Frank

    2015-01-01

    modality in ancient mummy research. The aim of this short review is to address the advantages and pitfalls of this particular technique for such unique samples. We recommend that when results of X-ray examination of mummies are presented, the specific recording data should be listed, and any given finds...

  16. Short fusion

    CERN Multimedia

    2002-01-01

    French and UK researchers are perfecting a particle accelerator technique that could aid the quest for fusion energy or make X-rays that are safer and produce higher-resolution images. Led by Dr Victor Malka from the Ecole Nationale Superieure des Techniques Avancees in Paris, the team has developed a better way of accelerating electrons over short distances (1 page).

  17. Short communication

    African Journals Online (AJOL)

    UPuser

    Short communication. Polymorphisms of the CAST gene in the Meishan and five other pig populations in China. Q.S. Wang. 1. , Y.C. Pan. 1#. , L.B. Sun. 2 and H. Meng. 1. 1 Department of Animal Science, School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai. 201101, P.R. China. 2 Shanghai Institute of ...

  18. SHORT COMMUNICATION

    African Journals Online (AJOL)

    a

    ______. *Corresponding author. E-mail: vani_chem@yahoo.com. SHORT COMMUNICATION. OXIDATION OF L-CYSTINE BY CHROMIUM(VI) - A KINETIC STUDY. Kalyan Kumar Adari, Annapurna Nowduri and Vani Parvataneni*. Department of Inorganic and Analytical Chemistry, School of Chemistry, Andhra University,.

  19. Short communication

    NARCIS (Netherlands)

    Pantophlet, Andre J.; Gilbert, M.S.; Gerrits, W.J.J.; Vonk, R.J.

    2017-01-01

    Heavy veal calves (4-6 mo old) often develop problems with insulin sensitivity. This could lead to metabolic disorders and impaired animal growth performance. Studies in various animal species have shown that the supplementation of short-chain fructo-oligosaccharides (scFOS) can improve insulin

  20. The language used in describing autobiographical memories prompted by life period visually presented verbal cues, event-specific visually presented verbal cues and short musical clips of popular music.

    Science.gov (United States)

    Zator, Krysten; Katz, Albert N

    2017-07-01

    Here, we examined linguistic differences in the reports of memories produced by three cueing methods. Two groups of young adults were cued visually either by words representing events or popular cultural phenomena that took place when they were 5, 10, or 16 years of age, or by words referencing a general lifetime period word cue directing them to that period in their life. A third group heard 30-second long musical clips of songs popular during the same three time periods. In each condition, participants typed a specific event memory evoked by the cue and these typed memories were subjected to analysis by the Linguistic Inquiry and Word Count (LIWC) program. Differences in the reports produced indicated that listening to music evoked memories embodied in motor-perceptual systems more so than memories evoked by our word-cueing conditions. Additionally, relative to music cues, lifetime period word cues produced memories with reliably more uses of personal pronouns, past tense terms, and negative emotions. The findings provide evidence for the embodiment of autobiographical memories, and how those differ when the cues emphasise different aspects of the encoded events.

  1. Vegetation Identification With LIDAR

    National Research Council Canada - National Science Library

    Helt, Michael F

    2005-01-01

    .... The specific terrain element of interest is vegetation, and in particular, tree type. Data taken on April 12th, 2005, were taken over a 10 km 20 km region which is mixed use agriculture and wetlands...

  2. The influence of short-time period of an adaptation to decreased ambient temperature on interleukin-6 and corticosterone levels in female Wistar strain rats in the proestrous phase of the reproductive cycle.

    Directory of Open Access Journals (Sweden)

    Grazyna Wójcik

    2008-04-01

    Full Text Available To date, there has been little research examining whether short-time changes of external environmental conditions exert any effects on immune responses. The activation of metabolic changes, release of hormones responsive for immunomodulation and the action of interleukins play an important role in interaction with hormones of an anterior pituitary gland in the proestrous phase of the reproductive cycle. The aim of our study was to determine the effects of a short-time change of ambient temperature (30 minutes on interleukin-6 (IL-6 and corticosterone plasma concentration of female rats in the proestrous phase of the reproductive cycle. The climatic chamber with automatically adjustable and monitored internal environmental parameters (temperature, oxygenation, humidity was used during the experiment. The estimation of the vaginal lavage using a microscope was done to determine the estrous cycle. On the day of the experiment, animals were divided into 2 groups: the control group (ambient temperature 21 degrees C +/- 1 degrees C; normoxia 21% O2 and the test group (ambient temperature 10 degrees C +/- 1 degrees C; normoxia 21% O2 stayed in the climatic chamber for 30 minutes. The blood samples were collected before the experiment and after 30, 60, 90, 150 and 210 minutes from the beginning of the experiment. The concentrations of IL-6 and corticosterone were measured in blood plasma samples using ELISA method. There was a significant elevation of IL-6 levels after staying in 10 degrees C during the first 150 minutes from the beginning of the experiment, with the highest value occurring after 60 minutes (426.6 pg/ml; SE - 146.1 with comparison to the value at first sampling (108.5 pg/ml; SE - 29.5; p<0.05 and with comparison to the control group at the same time from the beginning of the experiment (87.6 pg/ml; SE - 2.3; p<0.05. The changed level of corticosterone in the test group in comparison to control group was observed but the differences were

  3. Vegetation and soils

    Science.gov (United States)

    Burke, M.K.; King, S.L.; Eisenbies, M.H.; Gartner, D.

    2000-01-01

    Intro paragraph: Characterization of bottomland hardwood vegetation in relatively undisturbed forests can provide critical information for developing effective wetland creation and restoration techniques and for assessing the impacts of management and development. Classification is a useful technique in characterizing vegetation because it summarizes complex data sets, assists in hypothesis generation about factors influencing community variation, and helps refine models of community structure. Hierarchical classification of communities is particularly useful for showing relationships among samples (Gauche 1982).

  4. Spatial-temporal development of the mangrove vegetation cover on a hydraulic landfill (Via Expressa Sul, Florianópolis, SC: mapping and interpretation of digital aerophotographs, and quantitative analysis

    Directory of Open Access Journals (Sweden)

    Anderson Tavares de Melo

    2011-12-01

    Full Text Available The implementation of a hydraulic landfill along the southern expressway (Via Expressa Sul, in the central-south region of Santa Catarina Island, started in 1995 and was completed in 1997. The landfill provided the mangrove vegetation a new environment to colonize, which has developed rapidly during this short period of time. This study mapped the vegetation cover of this region using aerial photographs from five years (1994, 1997, 2002, 2004 and 2007, which demonstrated the spatial-temporal evolution of the vegetation since the year before the implementation of the landfill (1994 to its recent state (2007. The data from this study allowed changes in the surface of three bands of vegetation, a band of trees (Laguncularia racemosa and Avicennia schaueriana, a band of the seagrass praturá (Spartina alterniflora and a transition band (companions of mangrove species and restinga plants, to be quantified.

  5. Short Communication

    African Journals Online (AJOL)

    huis

    Short Communication. QTL analysis of production traits on SSC3 in a Large White×Meishan pig resource family. B. Zuo. 1. , Y.Z. Xiong. 1#. , Y.H. Su. 2. , C.Y. Deng. 1. , M.G. Lei. 1. , F.E. Li. 1. , R. Zheng. 1 and S.W. Jiang. 1. 1 Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture & Key Lab of Agricultural ...

  6. 'Just a pinch of salt'. An experimental comparison of the effect of repeated exposure and flavor-flavor learning with salt or spice on vegetable acceptance in toddlers.

    Science.gov (United States)

    Bouhlal, Sofia; Issanchou, Sylvie; Chabanet, Claire; Nicklaus, Sophie

    2014-12-01

    Children's vegetable intake is below the recommended amounts. No studies to date have tested the relevance of using salt or spices to increase children's vegetable acceptance. Our objective was to compare the effect of repeated exposure (RE) and of flavor-flavor learning (FFL) on toddlers' acceptance of a non-familiar vegetable. Two unconditioned stimuli were used: salt and a salt-associated spice. Toddlers attending six nurseries were assigned to 3 groups in a between subject design. Groups were exposed 8 times to a basic salsify puree (0.2% salt w/w; RE group; n = 47), a salty salsify puree (0.5% salt w/w; FFL-Salt group; n = 54) or a spiced salsify puree (0.2% salt and 0.02% nutmeg w/w; FFL-Nutmeg group; n = 50). Acceptance (intake and liking) of the target vegetable (basic salsify puree) and of a control vegetable (carrot puree) was evaluated at pre-exposure, at each exposure of the learning period, at post-exposure, and at 1, 3 and 6 months after exposure. In all groups, intake of the target vegetable increased from pre- to post-exposure. This increase was significantly higher in the RE group (64 ± 11 g) than in the FFL-Salt group (23 ± 11 g) and marginally higher than in the FFL-Nutmeg group (36 ± 11 g). No difference between groups was observed on the increase in liking of the target vegetable from pre- to post-exposure. The increase of the target vegetable intake was still observed after 6 months for all groups. Thus, repeated exposure appears to be the simplest choice to increase vegetable intake on the short and long term in toddlers. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. CONSIDERATIONS ON ROMANIA’S VEGETABLE MARKET

    Directory of Open Access Journals (Sweden)

    Agatha POPESCU

    2013-12-01

    Full Text Available The paper aimed to present the situation of Romania’s vegetable market in the period 2007-2011 based on the statistical data regarding the main vegetables: tomatoes, onion, garlic, cabbage, green peppers and melons. The vegetable production increased by 33.99 from 3,166.8 tons in 2007 to 4,176.3 tons in 2011.This was due to the yield gain as follows: 58.55 % for melons, 27.62 % for green peppers, 27.05 % for tomatoes, 25.99 % for dry garlic, 24.96 % for dry onion, 12.61 % for white cabbage. In 2011, the contribution of various categories of vegetables to production was: 24.55 % white cabbage, 21.81 % tomatoes, 15.45 % melons, 9.44 % onion, 6.06 % green pepper, 1.59 % garlic and 21.1 % other vegetables. The contribution of the micro regions to vegetable production in 2011 was: 19.46 % South Muntenia, 18.95 % South East Romania, 17.30 % South West Oltenia, 15.92 % North East Romania, 10.43 % West Romania, 8.47 % North West Romania, 6.54 % Central Romania, 2.93 % Bucharest Ilfov. Vegetable production per inhabitant is higher in Romania compared to the average production per capita in the EU. The average consumption increased as a postive aspect reflecting the obtained production and import. Vegetable production should increase in order to cover much better the doestic market needs and support export to the EU market.

  8. Congenital Short QT Syndrome

    Directory of Open Access Journals (Sweden)

    Lia Crotti

    2010-02-01

    Full Text Available The Short QT Syndrome is a recently described new genetic disorder, characterized by abnormally short QT interval, paroxysmal atrial fibrillation and life threatening ventricular arrhythmias. This autosomal dominant syndrome can afflict infants, children, or young adults; often a remarkable family background of cardiac sudden death is elucidated. At electrophysiological study, short atrial and ventricular refractory periods are found, with atrial fibrillation and polymorphic ventricular tachycardia easily induced by programmed electrical stimulation. Gain of function mutations in three genes encoding K+ channels have been identified, explaining the abbreviated repolarization seen in this condition: KCNH2 for Ikr (SQT1, KCNQ1 for Iks (SQT2 and KCNJ2 for Ik1 (SQT3. The currently suggested therapeutic strategy is an ICD implantation, although many concerns exist for asymptomatic patients, especially in pediatric age. Pharmacological treatment is still under evaluation; quinidine has shown to prolong QT and reduce the inducibility of ventricular arrhythmias, but awaits additional confirmatory clinical data.

  9. Is adolescence a critical period for learning formal thinking skills? A case study investigating the development of formal thinking skills in a short-term inquiry-based intervention program

    Science.gov (United States)

    Towne, Forrest S.

    Current domestic and international comparative studies of student achievement in science are demonstrating that the U.S. needs to improve science education if it wants to remain competitive in the global economy. One of the causes of the poor performance of U.S. science education is the lack of students who have developed the formal thinking skills that are necessary to obtain scientific literacy. Previous studies have demonstrated that formal thinking skills can be taught to adolescents, however only 25% of incoming college freshman have these necessary skills. There is some evidence that adolescence (girls aged 11-13, boys aged 12-14) is a critical period where students must learn formal thinking skills, similar to the critical period that exists for young children learning languages. It is not known whether it is more difficult for students to learn formal thinking skills either prior to or following adolescence. The purpose of this quantitative case study is to determine whether adolescence is a critical period for students to learn formal thinking skills. The study also investigates whether a formal thinking skills focused program can improve students' intelligence. In this study 32 students who had not developed any formal thinking skills, ranging in age from 10-16, underwent an intensive four-week, inquiry-based, formal thinking skill intervention program that focused on two formal thinking skills: (1) the ability to control and exclude variables; and (2) the ability to manipulate ratios and proportionalities. The students undergoing the training were matched with control students by age, gender, formal thinking skill ability, and intelligence. The control group attended their traditional science course during the intervention periods. The results of the study showed that the intervention program was successful in developing students' formal thinking skills. The pre-adolescents (males, age 10-11, females, age 10) were unable to learn formal thinking skills

  10. Detection of viruses in seeds of some vegetables by reverse ...

    African Journals Online (AJOL)

    my mord

    samples for each vegetable obtained from various foundations and farmers were tested ... 3892 Afr. J. Biotechnol. ... reduction in yield and germination, changes in shape and ... incubated for 4 h at 37°C. After this period, plates were washed.

  11. Radionuclide accumulation peculiarities demonstrated by vegetable varieties

    International Nuclear Information System (INIS)

    Kruk, A.V.; Goncharenko, G.G.; Kilchevsky, A.V.

    2004-01-01

    This study focused on ecological and genetic aspects of radionuclide accumulation demonstrated by a number of vegetable varieties. The researches resulted in determining the cabbage varieties which were characterised by the minimal level of radionuclide accumulation. It was shown that the above varieties manifested the relation between radionuclide accumulation and morphobiological characteristics such as vegetation period duration and yield criteria. The study specified the genotypes with high ecological stability as regards to radionuclide accumulation: 'Beloruskaya 85' cabbage and 'Dokhodny' tomato showed the best response to Cs 137, while 'Beloruskaya 85', 'Rusinovka', 'Amager 611' cabbage varieties and 'Sprint' tomato showed the minimal level of Sr 90 accumulation. (authors)

  12. Investigation on the Patterns of Global Vegetation Change Using a Satellite-Sensed Vegetation Index

    Directory of Open Access Journals (Sweden)

    Ainong Li

    2010-06-01

    Full Text Available The pattern of vegetation change in response to global change still remains a controversial issue. A Normalized Difference Vegetation Index (NDVI dataset compiled by the Global Inventory Modeling and Mapping Studies (GIMMS was used for analysis. For the period 1982–2006, GIMMS-NDVI analysis indicated that monthly NDVI changes show homogenous trends in middle and high latitude areas in the northern hemisphere and within, or near, the Tropic of Cancer and Capricorn; with obvious spatio-temporal heterogeneity on a global scale over the past two decades. The former areas featured increasing vegetation activity during growth seasons, and the latter areas experienced an even greater amplitude in places where precipitation is adequate. The discussion suggests that one should be cautious of using the NDVI time-series to analyze local vegetation dynamics because of its coarse resolution and uncertainties.

  13. Precision radiocarbon dating of a Late Holocene vegetation history

    International Nuclear Information System (INIS)

    Prior, C.A.; Chester, P.I.

    2001-01-01

    The purpose of this research is to precisely date vegetation changes associated with early human presence in the Hawkes Bay region. A sequence of AMS radiocarbon ages was obtained using a new technique developed at Rafter Radiocarbon Laboratory. A density separation method was used to concentrate pollen and spores extracted from unconsolidated lake sediments from a small-enclosed lake in coastal foothills of southern Hawkes Bay. Radiocarbon measurements were made on fractions of concentrated pollen, separated from associated organic debris. These ages directly date vegetation communities used to reconstruct the vegetation history of the region. This technique results in more accurate dating of Late Holocene vegetation changes interpreted from palynological analyses than techniques formerly used. Precision dating of palynological studies of New Zealand prehistory and history is necessary for correlation of vegetation changes to cultural changes because of the short time span of human occupation of New Zealand. (author). 35 refs., 3 figs., 1 tab

  14. The Vegetables Turned:

    DEFF Research Database (Denmark)

    Carter, Dale

    2009-01-01

    in the relationship between creative artists and the Anglo-American popular music industry in the mid-1960s. Finally, and in retrospect, the figure of the vegetable cast into relief the counter-culture's utopian and dystopian dynamics as manifested in these song-writers' personal lives, now rendered as contemporary...... lyricist Van Dyke Parks, the incongruous, semantically complex figure of the vegetable came to illuminate aspects of psychedelic consciousness and - part by design, part by accident - the link between LSD and Anglo-American popular music. It threw light, too, on the scope and limits of changes...

  15. leafy vegetable, Gnetum africanum

    African Journals Online (AJOL)

    A prerequisite for successful in vitro culture is the establishment of an aseptic technique, thus the experiment was to investigate suitable sterilization regimes for the leaf explants of Gnetum africanum, an endangered green leafy vegetable. Three sterilization regimes were tested to establish the best regime using three to four ...

  16. Analysis of agricultural drought using vegetation temperature condition index (VTCI) from Terra/MODIS satellite data.

    Science.gov (United States)

    Patel, N R; Parida, B R; Venus, V; Saha, S K; Dadhwal, V K

    2012-12-01

    The most commonly used normalized difference vegetation index (NDVI) from remote sensing often fall short in real-time drought monitoring due to a lagged vegetation response to drought. Therefore, research recently emphasized on the use of combination of surface temperature and NDVI which provides vegetation and moisture conditions simultaneously. Since drought stress effects on agriculture are closely linked to actual evapotranspiration, we used a vegetation temperature condition index (VTCI) which is more closely related to crop water status and holds a key place in real-time drought monitoring and assessment. In this study, NDVI and land surface temperature (T (s)) from MODIS 8-day composite data during cloud-free period (September-October) were adopted to construct an NDVI-T (s) space, from which the VTCI was computed. The crop moisture index (based on estimates of potential evapotranspiration and soil moisture depletion) was calculated to represent soil moisture stress on weekly basis for 20 weather monitoring stations. Correlation and regression analysis were attempted to relate VTCI with crop moisture status and crop performance. VTCI was found to accurately access the degree and spatial extent of drought stress in all years (2000, 2002, and 2004). The temporal variation of VTCI also provides drought pattern changes over space and time. Results showed significant and positive relations between CMI (crop moisture index) and VTCI observed particularly during prominent drought periods which proved VTCI as an ideal index to monitor terminal drought at regional scale. VTCI had significant positive relationship with yield but weakly related to crop anomalies. Duration of terminal drought stress derived from VTCI has a significant negative relationship with yields of major grain and oilseeds crops, particularly, groundnut.

  17. Monitoring vegetation recovery in fire-affected areas using temporal profiles of spectral signal from time series MODIS and LANDSAT satellite images

    Science.gov (United States)

    Georgopoulou, Danai; Koutsias, Nikos

    2015-04-01

    Vegetation phenology is an important element of vegetation characteristics that can be useful in vegetation monitoring especially when satellite remote sensing observations are used. In that sense temporal profiles extracted from spectral signal of time series MODIS and LANDSAT satellite images can be used to characterize vegetation phenology and thus to be helpful for monitoring vegetation recovery in fire-affected areas. The aim of this study is to explore the vegetation recovery pattern of the catastrophic wildfires that occurred in Peloponnisos, southern Greece, in 2007. These fires caused the loss of 67 lives and were recognized as the most extreme natural disaster in the country's recent history. Satellite remote sensing data from MODIS and LANDSAT satellites in the period from 2000 to 2014 were acquired and processed to extract the temporal profiles of the spectral signal for selected areas within the fire-affected areas. This dataset and time period analyzed together with the time that these fires occurred gave the opportunity to create temporal profiles seven years before and seven years after the fire. The different scale of the data used gave us the chance to understand how vegetation phenology and therefore the recovery patterns are influenced by the spatial resolution of the satellite data used. Different metrics linked to key phenological events have been created and used to assess vegetation recovery in the fire-affected areas. Our analysis was focused in the main land cover types that were mostly affected by the 2007 wildland fires. Based on CORINE land-cover maps these were agricultural lands highly interspersed with large areas of natural vegetation followed by sclerophyllous vegetation, transitional woodland shrubs, complex cultivation patterns and olive groves. Apart of the use of the original spectral data we estimated and used vegetation indices commonly found in vegetation studies as well as in burned area mapping studies. In this study we

  18. A reconnaissance survey of the vegetation of the North Luangwa National Park, Zambia

    Directory of Open Access Journals (Sweden)

    P. P. Smith

    1998-10-01

    Full Text Available A comprehensive survey of the vegetation of the North Luangwa National Park (NLNP was carried out over a period of two years. The main aims of the survey were to describe the major vegetation communities in the park and to produce a vegetation map of the NLNP Initial differentiation of vegetation units was established by the appearance of the vegetation on aerial photographs Further information was derived from 353 ground plots in which > 20 000 woody plants were identified and measured Thirteen broad vegetation types were recognised in the NLNP Details of their physiognomy, species composition, distribution, topography and edaphic associations are given.

  19. Canopy Modeling of Aquatic Vegetation: Construction of Submerged Vegetation Index

    Science.gov (United States)

    Ma, Z.; Zhou, G.

    2018-04-01

    The unique spectral characteristics of submerged vegetation in wetlands determine that the conventional terrestrial vegetation index cannot be directly employed to species identification and parameter inversion of submerged vegetation. Based on the Aquatic Vegetation Radiative Transfer model (AVRT), this paper attempts to construct an index suitable for submerged vegetation, the model simulated data and a scene of Sentinel-2A image in Taihu Lake, China are utilized for assessing the performance of the newly constructed indices and the existent vegetation indices. The results show that the angle index composed by 525 nm, 555 nm and 670 nm can resist the effects of water columns and is more sensitive to vegetation parameters such as LAI. Furthermore, it makes a well discrimination between submerged vegetation and water bodies in the satellite data. We hope that the new index will provide a theoretical basis for future research.

  20. Willow vegetation filters: Principles, results and economy

    International Nuclear Information System (INIS)

    Perttu, K.

    1996-01-01

    During recent years, it has become obvious that it is both environmentally and economically appropriate to use vegetation filters of different short rotation willows (Salix spp.) to purify water and soil. Swedish experiences of vegetation filter efficiencies have been demonstrated in several laboratory, field lysimeter, and full-scale experiments. However, there are still many questions to be answered, for example, how the uptake and allocation mechanisms of heavy metals and recalcitrant organic constituents function, or which maximum doses are possible in a particular situation without any risk of leachate losses. As far as plant nutrition is concerned, the past two decades of integrated research in Sweden have demonstrated that the willows have capacity for efficient uptake both of macro and micro nutrients, which is reflected in their high productivity. The purpose of this paper is to present some results on how vegetation filter stands of willow, irrigated with municipal wastewater, can function as purification plants, while at the same time producing fuelwood. This twofold utilization benefits both the environment and the economy. Treatment plants for wastewater purification using various types of vegetation filters have been tried in Sweden. The experiences consider both the nutrient and heavy metal uptake, and the whole process chain from establishment, cultivation and harvesting of the wastewater irrigated willow stands, to the utilization of the wood in heating plants. 33 refs, 5 tabs

  1. Review of Vegetable Market Development in China

    Institute of Scientific and Technical Information of China (English)

    Chaoping; LUO; Yuandong; NI; Qiong; ZHAI

    2013-01-01

    This paper has reviewed vegetable market development from vegetable circulation system, the develop history of the liberalize vegetable market and the growth of the vegetable wholesale market in China. From the development of vegetables market in China and its characteristics: the development of vegetable market in China is related to vegetable market system, the change of institution, some technology development and infrastructure. this paper has put forward some related measures to perfect the vegetable market and improve the vegetable circulation efficiency in China.

  2. Using NDVI to assess vegetative land cover change in central Puget Sound.

    Science.gov (United States)

    Morawitz, Dana F; Blewett, Tina M; Cohen, Alex; Alberti, Marina

    2006-03-01

    We used the Normalized Difference Vegetation Index (NDVI) in the rapidly growing Puget Sound region over three 5-year time blocks between 1986-1999 at three spatial scales in 42 Watershed Administrative Units (WAUs) to assess changes in the amounts and patterns of green vegetation. On average, approximately 20% of the area in each WAU experienced significant NDVI change over each 5-year time block. Cumulative NDVI change over 15 years (summing change over each 5-year time block) was an average of approximately 60% of each WAU, but was as high as 100% in some. At the regional scale, seasonal weather patterns and green-up from logging were the primary drivers of observed increases in NDVI values. At the WAU scale, anthropogenic factors were important drivers of both positive and negative NDVI change. For example, population density was highly correlated with negative NDVI change over 15 years (r = 0.66, P < 0.01), as was road density (r = 0.71, P < 0.01). At the smallest scale (within 3 case study WAUs) land use differences such as preserving versus harvesting forest lands drove vegetation change. We conclude that large areas within most watersheds are continually and heavily impacted by the high levels of human use and development over short time periods. Our results indicate that varying patterns and processes can be detected at multiple scales using changes in NDVIa values.

  3. Cruciferous Vegetables and Cancer Prevention

    Science.gov (United States)

    ... case-control studies have found that people who ate greater amounts of cruciferous vegetables had a lower ... Professionals’ Follow-up Study—showed that women who ate more than 5 servings of cruciferous vegetables per ...

  4. Ecogeomorphology of Sand Dunes Shaped by Vegetation

    Science.gov (United States)

    Tsoar, H.

    2014-12-01

    Two dune types associated with vegetation are known: Parabolic and Vegetated Linear Dunes (VLDs), the latters are the dominant dune type in the world deserts. Parabolic dunes are formed in humid, sub-humid and semi-arid environments (rather than arid) where vegetation is nearby. VLDs are known today in semiarid and arid lands where the average yearly rainfall is ≥100 mm, enough to support sparse cover of vegetation. These two dune types are formed by unidirectional winds although they demonstrate a different form and have a distinct dynamics. Conceptual and mathematical models of dunes mobility and stability, based on three control parameters: wind power (DP), average annual precipitation (p), and the human impact parameter (μ) show that where human impact is negligible the effect of wind power (DP) on vegetative cover is substantial. The average yearly rainfall of 60-80 mm is the threshold of annual average rainfall for vegetation growth on dune sand. The model is shown to follow a hysteresis path, which explains the bistability of active and stabilized dunes under the same climatic conditions with respect to wind power. We have discerned formation of parabolic dunes from barchans and transverse dunes in the coastal plain of Israel where a decrease in human activity during the second half of the 20th century caused establishment of vegetation on the crest of the dunes, a process that changed the dynamics of these barchans and transverse dunes and led to a change in the shape of the windward slope from convex to concave. These dunes gradually became parabolic. It seems that VLDs in Australia or the Kalahari have always been vegetated to some degree, though the shrubs were sparser in colder periods when the aeolian erosion was sizeable. Those ancient conditions are characterized by higher wind power and lower rainfall that can reduce, but not completely destroy, the vegetation cover, leading to the formation of lee (shadow) dunes behind each shrub. Formation of

  5. Comparison of vegetation roughness descriptions

    NARCIS (Netherlands)

    Augustijn, Dionysius C.M.; Huthoff, Freek; van Velzen, E.H.; Altinakar, M.S.; Kokpinar, M.A.; Aydin, I.; Cokgor, S.; Kirkgoz, S.

    2008-01-01

    Vegetation roughness is an important parameter in describing flow through river systems. Vegetation impedes the flow, which affects the stage-discharge curve and may increase flood risks. Roughness is often used as a calibration parameter in river models, however when vegetation is allowed to

  6. The vegetation of Yucca Mountain: Description and ecology

    International Nuclear Information System (INIS)

    1996-01-01

    Vegetation at Yucca Mountain, Nevada, was monitored over a six-year period, from 1989 through 1994. Yucca Mountain is located at the northern limit of the Mojave Desert and is the only location being studied as a potential repository for high-level nuclear waste. Site characterization consists of a series of multidisciplinary, scientific investigations designed to provide detailed information necessary to assess the suitability of the Yucca Mountain Site as a repository. This vegetation description establishes a baseline for determining the ecological impact of site characterization activities; it porvides input for site characterization research and modeling; and it clarifies vegetation community dynamics and relationships to the physical environment. A companion study will describe the impact of site characterization of vegetation. Cover, density, production, and species composition of vascular plants were monitored at 48 Ecological Study Plots (ESPs) stratified in four vegetation associations. Precipitation, soil moisture, and maximum and minimum temperatures also were measured at each study plot

  7. The vegetation of Yucca Mountain: Description and ecology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-29

    Vegetation at Yucca Mountain, Nevada, was monitored over a six-year period, from 1989 through 1994. Yucca Mountain is located at the northern limit of the Mojave Desert and is the only location being studied as a potential repository for high-level nuclear waste. Site characterization consists of a series of multidisciplinary, scientific investigations designed to provide detailed information necessary to assess the suitability of the Yucca Mountain Site as a repository. This vegetation description establishes a baseline for determining the ecological impact of site characterization activities; it porvides input for site characterization research and modeling; and it clarifies vegetation community dynamics and relationships to the physical environment. A companion study will describe the impact of site characterization of vegetation. Cover, density, production, and species composition of vascular plants were monitored at 48 Ecological Study Plots (ESPs) stratified in four vegetation associations. Precipitation, soil moisture, and maximum and minimum temperatures also were measured at each study plot.

  8. A seasonal comparison of deposition velocities and retention half-times for Cs-134 and Ce-141 on cool desert vegetation

    International Nuclear Information System (INIS)

    Millard, Gloria C.; Fraley, Leslie Jr.; Markham, O.D.

    1978-01-01

    Due to a scarcity of reliable deposition velocity estimates for radionuclides (particularly those in the submicron range) pooled estimates have been used to predict population doses resulting from atmospheric releases of radioactive particulates. The use of these estimates has led to large uncertainties in whole body dose estimates. Deposition velocities and retention half-times were therefore determined for submicron aerosols of 141 Ce (biologically inactive) and 134 Cs (biologically active) on sagebrush dominated desert vegetation in SE Idaho. Approximately 250 mCi (9.3 GBq) of each radionuclide were released over stands of Artemisia tridentata (big sagebrush) and bottlebrush grass (Sitanion hystrix) during three stages of plant development - spring vegetative growth, seed development, and plant dormancy. Air filters and vegetation samples were collected immediately following each release for use in deposition velocity calculations. Vegetation sampling was continued for a period of three months to obtain retention data. Deposition velocity values were 0.20 cm/s for sagebrush and 0.025 cm/s for grass. The loss of activity on the vegetation seemed to best fit a two component exponential loss function. Short component half-times were 1 to 2 days for both species. Long component half-times were two to three weeks for the shrub species and one to two weeks for the grass species. No significant difference was observed between nuclides. (author)

  9. Progress in short period multilayer coatings for water window applications

    International Nuclear Information System (INIS)

    Gullikson, E.M.; Salmassi, F.; Aquila, A.L.; Dollar, F.

    2006-01-01

    Absolute photoionization cross-section measurements for a mixture of ground and metastable states of Xe4+, Xe5+, and Xe6+ are reported in the photon energy range of 4d-nf transitions, which occur within or adjacent to the 13.5 nm window for extreme ultraviolet lithography light source development. The reported values allow the quantification of opacity effects in xenon plasmas due to these 4d-4f autoionizing states. The oscillator strengths for the 4d-4f and 4d-5f transitions in Xeq+ (q=1-6) ions are calculated using nonrelativistic Hartree-Fock and random phase approximations. These are compared with published experimental values for Xe+ to Xe3+ and with the values obtained from the present experimental cross-section measurements for Xe4+ to Xe6+. The calculations assisted in the determination of the metastable content in the ion beams for Xe5+T and Xe6+. The experiments were performed by merging a synchrotron photon beam generated by an undulator beamline of the Advanced Light Source with an ion beam produced by an electron cyclotron resonance ion source

  10. Fire and biodiversity: studies of vegetation and arthropods

    Science.gov (United States)

    S.M. Hermann; T. Van Hook; R.W. Flowers; [and others

    1998-01-01

    The authors summarize and update the state of knowledge for some components of prescribed fire in the southeastern Coastal Plain, with a primary focus on effects of season of burn on plants and arthropods. Specifically, the authors: 1) briefly explain season of fire terminology; 2) present a short synopsis of how fire regimes affect trees and groundcover vegetation in...

  11. Analytical studies by activation. Part A and B: Counting of short half-life radio-nuclides. Part C: Analytical programs for decay curves; Etudes d'analyse par activation. Parties A et B: le comptage des radio-nucleides de periodes courtes. Partie C: programme de depouillement des courbes de decroissance

    Energy Technology Data Exchange (ETDEWEB)

    Junod, E [Commissariat a l' Energie Atomique Grenoble (France). Centre d' Etudes Nucleaires

    1966-03-01

    Part A and B: Since a radio-nuclide of short half-life is characterized essentially by the decrease in its activity even while it is being measured, the report begins by recalling the basic relationships linking the half-life the counting time, the counting rate and the number of particles recorded. The second part is devoted to the problem of corrections for counting losses due to the idle period of multichannel analyzers. Exact correction formulae have been drawn up for the case where the short half-life radionuclide is pure or contains only a long half-life radio-nuclide. By comparison, charts have been drawn up showing the approximations given by the so-called 'active time' counting and by the counting involving the real time associated with a measurement of the overall idle period, this latter method proving to be more valid than the former. A method is given for reducing the case of a complex mixture to that of a two-component mixture. Part C: The problems connected with the qualitative and quantitative analysis of the decay curves of a mixture of radioactive sources of which one at least has a short half-life are presented. A mathematical description is given of six basic processes for which some elements of Fortran programs are proposed. Two supplementary programs are drawn up for giving an overall treatment of problems of dosage in activation analysis: one on the basis of a simultaneous irradiation of the sample and of one or several known samples, the other with separate irradiation of the unknown and known samples, a dosimeter (activation, or external) being used for normalizing the irradiation flux conditions. (author) [French] Parties A et B: Un radionucleide de periode courte etant defini specialement par la decroissance de son activite pendant la duree meme du comptage, on rappelle en premiere partie de ce rapport les relations fondamentales qui lient periode, temps de comptage, taux de comptage et nombre d'impulsions enregistrees. La seconde partie

  12. The importance of coprophagous macrodetritivores for the maintenance of vegetation heterogeneity in an African savannah

    NARCIS (Netherlands)

    Howison, Ruth A.; Berg, Matty P.; Smit, Christian; van Dijk, Kaylee; Olff, Han

    Grazing ecosystems are often characterized by dynamic vegetation structure mosaics of short grazing lawns and tall grass vegetation that are important for the biodiversity and functioning of these ecosystems. Grazing-induced trampling, causing soil compaction and reduced water infiltration, has been

  13. The Importance of Coprophagous Macrodetritivores for the Maintenance of Vegetation Heterogeneity in an African Savannah

    NARCIS (Netherlands)

    Howison, R.A.; Berg, M.P.; Smit, C.; van Dijk, Kaylee

    2016-01-01

    Grazing ecosystems are often characterized by dynamic vegetation structure mosaics of short grazing lawns and tall grass vegetation that are important for the biodiversity and functioning of these ecosystems. Grazing-induced trampling, causing soil compaction and reduced water infiltration, has been

  14. Response of Competing Vegetation to Site Preparation on West Gulf Coastal Plain Commercial Forest Land

    Science.gov (United States)

    Gale L. Wolters; Henry A. Pearson; Ronald E. Thill; V. Clark Baldwin; Alton Martin

    1995-01-01

    The response of woody and herbaceous vegetation to site preparation, subsoil texture, and fertilization was measured on the West Gulf Coastal Plain. The influences of these treatments on competing vegetation were short-term. Drastic soil disturbance and fertilization briefly increased herbage production. Shear-windrow and shear-disk were generally the most effective...

  15. THE USE OF GENETIC RESOURCES IN BREEDING OF VEGETABLE AND MELON CROPS

    Directory of Open Access Journals (Sweden)

    V. I. Burenin

    2013-01-01

    Full Text Available The analysis of the modern homeland assortment of vegetable crops is given. The donors of the most important traits and the accessions  of vegetable and melon crops perspective for breeding from the VIR collection are shown. The short characteristic of the varieties is given.

  16. Medicare Program: Hospital Outpatient Prospective Payment and Ambulatory Surgical Center Payment Systems and Quality Reporting Programs; Short Inpatient Hospital Stays; Transition for Certain Medicare-Dependent, Small Rural Hospitals Under the Hospital Inpatient Prospective Payment System; Provider Administrative Appeals and Judicial Review. Final rule with comment period; final rule.

    Science.gov (United States)

    2015-11-13

    This final rule with comment period revises the Medicare hospital outpatient prospective payment system (OPPS) and the Medicare ambulatory surgical center (ASC) payment system for CY 2016 to implement applicable statutory requirements and changes arising from our continuing experience with these systems. In this final rule with comment period, we describe the changes to the amounts and factors used to determine the payment rates for Medicare services paid under the OPPS and those paid under the ASC payment system. In addition, this final rule with comment period updates and refines the requirements for the Hospital Outpatient Quality Reporting (OQR) Program and the ASC Quality Reporting (ASCQR) Program. Further, this document includes certain finalized policies relating to the hospital inpatient prospective payment system: Changes to the 2-midnight rule under the short inpatient hospital stay policy; and a payment transition for hospitals that lost their status as a Medicare-dependent, small rural hospital (MDH) because they are no longer in a rural area due to the implementation of the new Office of Management and Budget delineations in FY 2015 and have not reclassified from urban to rural before January 1, 2016. In addition, this document contains a final rule that finalizes certain 2015 proposals, and addresses public comments received, relating to the changes in the Medicare regulations governing provider administrative appeals and judicial review relating to appropriate claims in provider cost reports.

  17. An analysis on vegetation pattern of ecotone in North China

    Energy Technology Data Exchange (ETDEWEB)

    Jia, J.C.; Zhang, H.Y. [North China Electric Power Univ., Beijing (China). Energy and Environmental Research Center

    2008-07-01

    Vegetation pattern is influenced by several natural factors, including climatic elements, elevation factors and soil conditions. Since soil formation and soil types are influenced by water-temperature conditions, much can be learned about vegetation distribution patterns by studying the relationship between water-temperature conditions and vegetation distribution. This paper presented the results of a study whose purpose was to provide scientific evidence for exploiting natural resources, planting trees, and restoring grassland from cropland. A warmth index (WI ) and humidity index (HI) were used to examine the relation between the distribution of vegetation and the water-temperature condition in North China's ecotone, the transition area between two adjacent but different plant communities, including steppe, bush and forest ecosystems. A vegetation map of the study site was digitized and then converted into a vegetation grid map from which 17 different vegetation types were chosen as the study object. A monthly mean temperature grid map and precipitation grid map of the study site were made based on the method of spatial interpolation, by using 119 meteorological data for 50 years during the period from 1951 to 2000. The thermal distribution curves and humidity distribution curves of 17 vegetation types in North China, determined the whole range and optimum range of WI and HI of 17 vegetation types. The relative proportion of each vegetation type distributed in the optimum range of WI and HI were calculated. The vegetation pattern was analyzed according to the WI and HI standard, and was described by species and their relative amount. 10 refs., 5 tabs., 3 figs.

  18. Climate change and spatial distribution of vegetation in Colombia

    Directory of Open Access Journals (Sweden)

    Juan Carlos Alarcon Hincapie

    2013-12-01

    Full Text Available Vegetation change under two climate change scenarios in different periods of the 21st Century are modeled for Colombia. Vegetation for the years 1970 to 2000 was reproduced using the Holdridge model with climate data with a spatial resolution of 900 meters. The vegetation types that occupied the most territory were sub-humid tropical forest, tropical dry forest and Andean wet forest. These results were validated by comparing with the Colombian ecosystem map (SINA, 2007, which confirmed a high degree of similarity between the modeled spatial vegetation patterns and modern ecosystem distributions. Future vegetation maps were simulated using data generated by a regional climate model under two scenarios (A2 and B2; IPCC, 2007 for the periods 2011-2040 and 2070-2100. Based on our predictions high altitude vegetation will convert to that of lower altitudes and drier provinces with the most dramatic change occurring in the A2 scenario from 2070-2100. The most affected areas are the páramo and other high Andean vegetation types, which in the timeframe of the explored scenarios will disappear by the middle of the 21st Century.

  19. Biofilm formation enhances Helicobacter pylori survivability in vegetables.

    Science.gov (United States)

    Ng, Chow Goon; Loke, Mun Fai; Goh, Khean Lee; Vadivelu, Jamuna; Ho, Bow

    2017-04-01

    To date, the exact route and mode of transmission of Helicobacter pylori remains elusive. The detection of H. pylori in food using molecular approaches has led us to postulate that the gastric pathogen may survive in the extragastric environment for an extended period. In this study, we show that H. pylori prolongs its survival by forming biofilm and micro-colonies on vegetables. The biofilm forming capability of H. pylori is both strain and vegetable dependent. H. pylori strains were classified into high and low biofilm formers based on their highest relative biofilm units (BU). High biofilm formers survived longer on vegetables compared to low biofilm formers. The bacteria survived better on cabbage compared to other vegetables tested. In addition, images captured on scanning electron and confocal laser scanning microscopes revealed that the bacteria were able to form biofilm and reside as micro-colonies on vegetable surfaces, strengthening the notion of possible survival of H. pylori on vegetables for an extended period of time. Taken together, the ability of H. pylori to form biofilm on vegetables (a common food source for human) potentially plays an important role in its survival, serving as a mode of transmission of H. pylori in the extragastric environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. The use of a commercial vegetable juice as a practical means to increase vegetable intake: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Reeves Rebecca S

    2010-09-01

    Full Text Available Abstract Background Recommendations for daily dietary vegetable intake were increased in the 2005 USDA Dietary Guidelines as consumption of a diet rich in vegetables has been associated with lower risk of certain chronic health disorders including cardiovascular disease. However, vegetable consumption in the United States has declined over the past decade; consequently, the gap between dietary recommendations and vegetable intake is widening. The primary aim of this study is to determine if drinking vegetable juice is a practical way to help meet daily dietary recommendations for vegetable intake consistent with the 2005 Dietary Guidelines and the Dietary Approaches to Stop Hypertension (DASH diet. The secondary aim is to assess the effect of a vegetable juice on measures of cardiovascular health. Methods We conducted a 12-week, randomized, controlled, parallel-arm study consisting of 3 groups of free-living, healthy volunteers who participated in study visits at the Ragle Human Nutrition Research Center at the University of California, Davis. All subjects received education on the DASH diet and 0, 8 or 16 fluid ounces of vegetable juice daily. Assessments were completed of daily vegetable servings before and after incorporation of vegetable juice and cardiovascular health parameters including blood pressure. Results Without the juice, vegetable intake in all groups was lower than the 2005 Dietary Guidelines and DASH diet recommendations. The consumption of the vegetable juice helped participants reach recommended intake. In general, parameters associated with cardiovascular health did not change over time. However, in the vegetable juice intervention groups, subjects who were pre-hypertensive at the start of the study showed a significant decrease in blood pressure during the 12-week intervention period. Conclusion Including 1-2 cups of vegetable juice daily was an effective and acceptable way for healthy adults to close the dietary vegetable

  1. Phenolation of vegetable oils

    Directory of Open Access Journals (Sweden)

    ZORAN S. PETROVIĆ

    2011-04-01

    Full Text Available Novel bio-based compounds containing phenols suitable for the syn­thesis of polyurethanes were prepared. The direct alkylation of phenols with different vegetable oils in the presence of superacids (HBF4, triflic acid as ca­talysts was studied. The reaction kinetics was followed by monitoring the de­crease of the double bond content (iodine value with time. In order to under­stand the mechanism of the reaction, phenol was alkylated with model com­pounds. The model compounds containing one internal double bond were 9-oc­tadecene and methyl oleate and those with three double bonds were triolein and high oleic safflower oil (82 % oleic acid. It was shown that the best structures for phenol alkylation are fatty acids with only one double bond (oleic acid. Fatty acids with two double bonds (linoleic acid and three double bonds (lino­lenic acid lead to polymerized oils by a Diels–Alder reaction, and to a lesser extent to phenol alkylated products. The reaction product of direct alkylation of phenol with vegetable oils is a complex mixture of phenol alkylated with poly­merized oil (30–60 %, phenyl esters formed by transesterification of phenol with triglyceride ester bonds (<10 % and unreacted oil (30 %. The phenolated vegetable oils are new aromatic–aliphatic bio-based raw materials suitable for the preparation of polyols (by propoxylation, ethoxylation, Mannich reactions for the preparation of polyurethanes, as intermediates for phenolic resins or as bio-based antioxidants.

  2. Rendering Future Vegetation Change across Large Regions of the US

    Science.gov (United States)

    Sant'Anna Dias, Felipe; Gu, Yuting; Agarwalla, Yashika; Cheng, Yiwei; Patil, Sopan; Stieglitz, Marc; Turk, Greg

    2015-04-01

    We use two Machine Learning techniques, Decision Trees (DT) and Neural Networks (NN), to provide classified images and photorealistic renderings of future vegetation cover at three large regions in the US. The training data used to generate current vegetation cover include Landsat surface reflectance images, USGS Land Cover maps, 50 years of mean annual temperature and precipitation for the period 1950 - 2000, elevation, aspect and slope data. Present vegetation cover was generated on a 100m grid. Future vegetation cover for the period 2061- 2080 was predicted using the 1 km resolution bias corrected data from the NASA Goddard Institute for Space Studies Global Climate Model E simulation. The three test regions encompass a wide range of climatic gradients, topographic variation, and vegetation cover. The central Oregon site covers 19,182 square km and includes the Ochoco and Malheur National Forest. Vegetation cover is 50% evergreen forest and 50% shrubs and scrubland. The northwest Washington site covers 14,182 square km. Vegetation cover is 60% evergreen forest, 14% scrubs, 7% grassland, and 7% barren land. The remainder of the area includes deciduous forest, perennial snow cover, and wetlands. The third site, the Jemez mountain region of north central New Mexico, covers 5,500 square km. Vegetation cover is 47% evergreen forest, 31% shrubs, 13% grasses, and 3% deciduous forest. The remainder of the area includes developed and cultivated areas and wetlands. Using the above mentioned data sets we first trained our DT and NN models to reproduce current vegetation. The land cover classified images were compared directly to the USGS land cover data. The photorealistic generated vegetation images were compared directly to the remotely sensed surface reflectance maps. For all three sites, similarity between generated and observed vegetation cover was quite remarkable. The three trained models were then used to explore what the equilibrium vegetation would look like for

  3. Carbohydrates, Dietary Fiber, and Resistant Starch in White Vegetables: Links to Health Outcomes12

    Science.gov (United States)

    Slavin, Joanne L.

    2013-01-01

    Vegetables are universally promoted as healthy. Dietary Guidelines for Americans 2010 recommend that you make half of your plate fruits and vegetables. Vegetables are diverse plants that vary greatly in energy content and nutrients. Vegetables supply carbohydrates, dietary fiber, and resistant starch in the diet, all of which have been linked to positive health outcomes. Fiber lowers the incidence of cardiovascular disease and obesity. In this paper, the important role of white vegetables in the human diet is described, with a focus on the dietary fiber and resistant starch content of white vegetables. Misguided efforts to reduce consumption of white vegetables will lower intakes of dietary fiber and resistant starch, nutrients already in short supply in our diets. PMID:23674804

  4. SHORT COMMUNICATIONS, NOTES AND REPORTS

    African Journals Online (AJOL)

    Campbell Murn

    1976). Among raptors there are those species where only the female incubates, those where the male may also incubate for short to longer periods, and those in which females and males equally share the incubation (Newton 1979). It is well known that both sexes incubate the clutch in vultures, both in the wild (Mundy et al.

  5. Impacts of vegetation change on groundwater recharge

    Science.gov (United States)

    Bond, W. J.; Verburg, K.; Smith, C. J.

    2003-12-01

    Vegetation change is the accepted cause of increasing river salt concentrations and the salinisation of millions of hectares of farm land in Australia. Replacement of perennial native vegetation by annual crops and pastures following European settlement has altered the water balance causing increased groundwater recharge and mobilising the naturally saline groundwater. The Redesigning Agriculture for Australian Landscapes Program, of which the work described here is a part, was established to develop agricultural practices that are more attuned to the delicate water balance described above. Results of field measurements will be presented that contrast the water balance characteristics of native vegetation with those of conventional agricultural plants, and indicate the functional characteristics required of new agricultural practices to reduce recharge. New agricultural practices may comprise different management of current crops and pastures, or may involve introducing totally new species. In either case, long-term testing is required to examine their impact on recharge over a long enough climate record to encompass the natural variability of rainfall that is characteristic of most Australian farming regions. Field experimentation therefore needs to be complemented and extended by computer simulation. This requires a modelling approach that is more robust than conventional crop modelling because (a) it needs to be sensitive enough to predict small changes in the residual recharge term, (b) it needs to be able to simulate a variety of vegetation in different sequences, (c) it needs to be able to simulate continuously for several decades of input data, and (d) it therefore needs to be able to simulate the period between crops, which often has a critical impact on recharge. The APSIM simulation framework will be used to illustrate these issues and to explore the effect of different vegetation combinations on recharge.

  6. Effects of metals on vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Press, N P

    1972-01-01

    Prospectors have long known that abnormal concentrations of metals in the soil overlying an ore deposit can affect the vegetation rooting in this soil; mineral deposits have even been discovered because of such vegetation changes. Recently, many people have become interested in the possibility of remote sensing such vegetation changes, and perhaps using the results in conjunction with airborne geophysics and photogeological interpretation in integrated prospecting programs.

  7. Vegetation and acidification, Chapter 5

    Science.gov (United States)

    David R. DeWalle; James N. Kochenderfer; Mary Beth Adams; Gary W. Miller

    2006-01-01

    In this chapter, the impact of watershed acidification treatments on WS3 at the Fernow Experimental Forest (FEF) and at WS9 on vegetation is presented and summarized in a comprehensive way for the first time. WS7 is used as a vegetative reference basin for WS3, while untreated plots within WS9 are used as a vegetative reference for WS9. Bioindicators of acidification...

  8. Antimicrobial Effect of Extracts of Cruciferous Vegetables

    Directory of Open Access Journals (Sweden)

    Shu-Hui Hu

    2004-12-01

    Full Text Available The cruciferous vegetables cauliflower, broccoli, cabbage, Chinese radish, Chinese kale, and Chinese kitam were used in this study to prepare water-soluble and methanol-water extracts. Crude protein extracts were also obtained by diethylaminoethyl (DEAE anion exchange chromatography. Water-soluble polysaccharides were prepared by ethanol precipitation followed by ultrafiltration. The antimicrobial effects of all these extracts were evaluated against Gram-positive bacteria, Gram-negative bacteria, and yeast. Crude protein extracts exhibited the greatest antimicrobial activity in monoculture experiments. The antimicrobial effects of cruciferous vegetables were also studied by steeping beef, carrot, and celery in chlorine (10 ppm or citric acid solution (1% containing the crude protein extract (500 ppm for different time periods. Total aerobic plate counts and coliform counts on these foods decreased significantly after 10 minutes in all steeping solutions (p < 0.05.

  9. Relishes: The new pickled vegetables

    Directory of Open Access Journals (Sweden)

    Tepić Aleksandra N.

    2006-01-01

    Full Text Available There have been an increasing interest of consumers for a ide variety of pickled vegetable products worldwide. Regarding the regional vegetable supplies and relatively poor assortment of ready-to-use products, the need to broaden the offer of domestic pickled vegetables at the market came out. In this work recipes for different vegetables, spices and condiments were developed. The best graded samples were analyzed for their main chemical composition (dry matter, proteins, oils and fats, total acidity, total sugars, sucrose, starch, cellulose, pH and energy- values.

  10. Crestridge Vegetation Map [ds211

    Data.gov (United States)

    California Natural Resource Agency — This layer represents vegetation communities in the Department of Fish and Game's Crestridge Ecological Reserve. The County of San Diego, the Conservation Biology...

  11. Encouraging children to eat vegetables

    OpenAIRE

    Buh, Alenka

    2014-01-01

    It is important for children to maintain a healthy and balanced diet throughout their childhood and youth. Children tend to skip vegetables in their meals as they are not much liked; the tastes of vegetables are also highly specific and each individual has to get used to them by repeated tasting. The aim of this undergraduate thesis was to analyse how often children eat vegetables, which types of vegetables they like and which they do not, to determine if the executed method of pedagogica...

  12. Deciphering Periodic Methanol Masers

    Science.gov (United States)

    Stecklum, Bringfried; Caratti o Garatti, Alessio; Henning, Thomas; Hodapp, Klaus; Hopp, Ulrich; Kraus, Alex; Linz, Hendrik; Sanna, Alberto; Sobolev, Andrej; Wolf, Verena

    2018-05-01

    Impressive progress has been made in recent years on massive star formation, yet the involved high optical depths even at submm/mm wavelengths make it difficult to reveal its details. Recently, accretion bursts of massive YSOs have been identified to cause flares of Class II methanol masers (methanol masers for short) due to enhanced mid-IR pumping. This opens a new window to protostellar accretion variability, and implies that periodic methanol masers hint at cyclic accretion. Pinning down the cause of the periodicity requires joint IR and radio monitoring. We derived the first IR light curve of a periodic maser host from NEOWISE data. The source, G107.298+5.639, is an intermediate-mass YSO hosting methanol and water masers which flare every 34.5 days. Our recent joint K-band and radio observations yielded first but marginal evidence for a phase lag between the rise of IR and maser emission, respectively, and revealed that both NEOWISE and K-band light curves are strongly affected by the light echo from the ambient dust. Both the superior resolution of IRAC over NEOWISE and the longer wavelengths compared to our ground-based imaging are required to inhibit the distractive contamination by the light echo. Thus, we ask for IRAC monitoring of G107 to cover one flare cycle, in tandem with 100-m Effelsberg and 2-m Wendelstein radio and NIR observations to obtain the first high-quality synoptic measurements of this kind of sources. The IR-maser phase lag, the intrinsic shape of the IR light curves and their possible color variation during the cycle allow us to constrain models for the periodic maser excitation. Since methanol masers are signposts of intermediate-mass and massive YSOs, deciphering their variability offers a clue to the dynamics of the accretion-mediated growth of massive stars and their feedback onto the immediate natal environment. The Spitzer light curve of such a maser-hosting YSO would be a legacy science product of the mission.

  13. A vegetal Geiger counter

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    In order to study the Chernobyl accident impact on ecosystems, Ukrainian and Swiss scientists have used a plant: the Arabidopsis thaliana. They have introduced in its genome a gene coding an enzyme called β-glucuronidase. This substance, when it is expressed, colours vegetal cells blue. In fact the introduced gene is divided between 2 paired chromosomes. When the plant is placed on a nuclear contaminated soil, radiation damaged chromosomes exchange fragments and the 2 parts of the enzyme gene may recombine, the enzyme can then be expressed. For low and medium contamination ( 2 ) biologists have found a correlation between the number of blue spots on the plant and the irradiation rate. (A.C.)

  14. Genetic improvement of vegetables

    International Nuclear Information System (INIS)

    Jaramillo Vasquez, J.G.

    2001-01-01

    Some genetic bases of the improvement of vegetables are given. The objectives of the genetic improvement and the fundamental stages of this process are done. The sources of genetic variation are indicated and they are related the reproduction systems of the main horticultural species. It is analyzed the concept of genetic inheritance like base to determine the procedures more appropriate of improvement. The approaches are discussed, has more than enough phenotypic value, genetic action and genotypic variance; Equally the heredability concepts and value of improvement. The conventional methods of improvement are described, like they are: the introduction of species or varieties, the selection, the pure line, the pedigree method, the selection for families, the recurrent selection, the selection for unique seed, the haploids method, the selection for heterosis and the synthetic varieties

  15. Fruits and vegetables dehydration

    International Nuclear Information System (INIS)

    De Ita, A; Flores, G; Franco, F

    2015-01-01

    Dehydration diagrams were determined by means of Differential Thermal Analysis, DTA, and Thermo Gravimetric Analysis, TGA, curves of several simultaneous fruits and vegetables, all under the same conditions. The greater mass loss is associated with water containing in the structure of the investigated materials at low temperature. In poblano chile water is lost in a single step. The banana shows a very sharply two stages, while jicama can be observed although with a little difficulty three stages. The major mass loss occurs in the poblano chile and the lower in banana. The velocity and temperature of dehydration vary within a small range for most materials investigated, except for banana and cactus how are very different

  16. Fruits and vegetables dehydration

    Science.gov (United States)

    de Ita, A.; Flores, G.; Franco, F.

    2015-01-01

    Dehydration diagrams were determined by means of Differential Thermal Analysis, DTA, and Thermo Gravimetric Analysis, TGA, curves of several simultaneous fruits and vegetables, all under the same conditions. The greater mass loss is associated with water containing in the structure of the investigated materials at low temperature. In poblano chile water is lost in a single step. The banana shows a very sharply two stages, while jicama can be observed although with a little difficulty three stages. The major mass loss occurs in the poblano chile and the lower in banana. The velocity and temperature of dehydration vary within a small range for most materials investigated, except for banana and cactus how are very different.

  17. Heavy metals in green vegetables and soils from vegetable gardens ...

    African Journals Online (AJOL)

    Edible portions of five varieties of green vegetables, namely amaranth, chinese cabbage, cowpea leaves, leafy cabbage and pumpkin leaves, collected from several areas in Dar es Salaam, were analyzed for lead, cadmium, chromium, zinc, nickel and copper. Except for zinc, the levels of heavy metals in the vegetables ...

  18. Contrast in edge vegetation structure modifies the predation risk of natural ground nests in an agricultural landscape.

    Directory of Open Access Journals (Sweden)

    Nicole A Schneider

    Full Text Available Nest predation risk generally increases nearer forest-field edges in agricultural landscapes. However, few studies test whether differences in edge contrast (i.e. hard versus soft edges based on vegetation structure and height affect edge-related predation patterns and if such patterns are related to changes in nest conspicuousness between incubation and nestling feeding. Using data on 923 nesting attempts we analyse factors influencing nest predation risk at different edge types in an agricultural landscape of a ground-cavity breeding bird species, the Northern Wheatear (Oenanthe oenanthe. As for many other bird species, nest predation is a major determinant of reproductive success in this migratory passerine. Nest predation risk was higher closer to woodland and crop field edges, but only when these were hard edges in terms of ground vegetation structure (clear contrast between tall vs short ground vegetation. No such edge effect was observed at soft edges where adjacent habitats had tall ground vegetation (crop, ungrazed grassland. This edge effect on nest predation risk was evident during the incubation stage but not the nestling feeding stage. Since wheatear nests are depredated by ground-living animals our results demonstrate: (i that edge effects depend on edge contrast, (ii that edge-related nest predation patterns vary across the breeding period probably resulting from changes in parental activity at the nest between the incubation and nestling feeding stage. Edge effects should be put in the context of the nest predator community as illustrated by the elevated nest predation risk at hard but not soft habitat edges when an edge is defined in terms of ground vegetation. These results thus can potentially explain previously observed variations in edge-related nest predation risk.

  19. Generating Vegetation Leaf Area Index Earth System Data Record from Multiple Sensors. Part 2; Implementation, Analysis and Validation

    Science.gov (United States)

    Ganguly, Sangram; Samanta, Arindam; Schull, Mitchell A.; Shabanov, Nikolay V.; Milesi, Cristina; Nemani, Ramajrushna R,; Knyazikhin, Yuri; Myneni, Ranga B.

    2008-01-01

    The evaluation of a new global monthly leaf area index (LAI) data set for the period July 1981 to December 2006 derived from AVHRR Normalized Difference Vegetation Index (NDVI) data is described. The physically based algorithm is detailed in the first of the two part series. Here, the implementation, production and evaluation of the data set are described. The data set is evaluated both by direct comparisons to ground data and indirectly through inter-comparisons with similar data sets. This indirect validation showed satisfactory agreement with existing LAI products, importantly MODIS, at a range of spatial scales, and significant correlations with key climate variables in areas where temperature and precipitation limit plant growth. The data set successfully reproduced well-documented spatio-temporal trends and inter-annual variations in vegetation activity in the northern latitudes and semi-arid tropics. Comparison with plot scale field measurements over homogeneous vegetation patches indicated a 7% underestimation when all major vegetation types are taken into account. The error in mean values obtained from distributions of AVHRR LAI and high-resolution field LAI maps for different biomes is within 0.5 LAI for six out of the ten selected sites. These validation exercises though limited by the amount of field data, and thus less than comprehensive, indicated satisfactory agreement between the LAI product and field measurements. Overall, the intercomparison with short-term LAI data sets, evaluation of long term trends with known variations in climate variables, and validation with field measurements together build confidence in the utility of this new 26 year LAI record for long term vegetation monitoring and modeling studies.

  20. Vegetable Genetic Resources in China

    Directory of Open Access Journals (Sweden)

    Haiping WANG

    2018-03-01

    Full Text Available China is recognized as an important region for plant biodiversity based on its vast and historical collection of vegetable germplasm. The aim of this review is to describe the exploration status of vegetable genetic resources in China, including their collection, preservation, evaluation, and utilization. China has established a number of national-level vegetable genetic resources preservation units, including the National Mid-term Genebank for Vegetable Germplasm Resources, the National Germplasm Repository for Vegetatively-Propagated Vegetables, and the National Germplasm Repository for Aquatic Vegetables. In 2015, at least 36 000 accessions were collected and preserved in these units. In the past decade, 44 descriptors and data standards for different species have been published, and most accessions have been evaluated for screening the germplasms for specific important traits such as morphological characteristics, disease resistance, pest resistance, and stress tolerance. Moreover, the genetic diversity and evolution of some vegetable germplasms have been evaluated at the molecular level. Recently, more than 1 000 accessions were distributed to researchers and breeders each year by various means for vegetable research and production. However, additional wild-relative and abroad germplasms from other regions need to be collected and preserved in the units to expand genetic diversity. Furthermore, there is a need to utilize advanced techniques to better understand the background and genetic diversity of a wide range of vegetable genetic resources. This review will provide agricultural scientists’ insights into the genetic diversity in China and provide information on the distribution and potential utilization of these valuable genetic resources. Keywords: vegetable, genetic resource, preservation, evaluation, utilization

  1. Evolution of periodicity in periodical cicadas.

    Science.gov (United States)

    Ito, Hiromu; Kakishima, Satoshi; Uehara, Takashi; Morita, Satoru; Koyama, Takuya; Sota, Teiji; Cooley, John R; Yoshimura, Jin

    2015-09-14

    Periodical cicadas (Magicicada spp.) in the USA are famous for their unique prime-numbered life cycles of 13 and 17 years and their nearly perfectly synchronized mass emergences. Because almost all known species of cicada are non-periodical, periodicity is assumed to be a derived state. A leading hypothesis for the evolution of periodicity in Magicicada implicates the decline in average temperature during glacial periods. During the evolution of periodicity, the determinant of maturation in ancestral cicadas is hypothesized to have switched from size dependence to time (period) dependence. The selection for the prime-numbered cycles should have taken place only after the fixation of periodicity. Here, we build an individual-based model of cicadas under conditions of climatic cooling to explore the fixation of periodicity. In our model, under cold environments, extremely long juvenile stages lead to extremely low adult densities, limiting mating opportunities and favouring the evolution of synchronized emergence. Our results indicate that these changes, which were triggered by glacial cooling, could have led to the fixation of periodicity in the non-periodical ancestors.

  2. Natural short sleeper

    Science.gov (United States)

    Sleep - natural short sleeper ... 7 to 9 hours of sleep each night. Short sleepers sleep less than 75% of what is normal for their age. Natural short sleepers are different from people who chronically do ...

  3. [Application of biotope mapping model integrated with vegetation cover continuity attributes in urban biodiversity conservation].

    Science.gov (United States)

    Gao, Tian; Qiu, Ling; Chen, Cun-gen

    2010-09-01

    Based on the biotope classification system with vegetation structure as the framework, a modified biotope mapping model integrated with vegetation cover continuity attributes was developed, and applied to the study of the greenbelts in Helsingborg in southern Sweden. An evaluation of the vegetation cover continuity in the greenbelts was carried out by the comparisons of the vascular plant species richness in long- and short-continuity forests, based on the identification of woodland continuity by using ancient woodland indicator species (AWIS). In the test greenbelts, long-continuity woodlands had more AWIS. Among the forests where the dominant trees were more than 30-year-old, the long-continuity ones had a higher biodiversity of vascular plants, compared with the short-continuity ones with the similar vegetation structure. The modified biotope mapping model integrated with the continuity features of vegetation cover could be an important tool in investigating urban biodiversity, and provide corresponding strategies for future urban biodiversity conservation.

  4. Tropical climate and vegetation cover during Heinrich event 1: Simulations with coupled climate vegetation models

    OpenAIRE

    Handiani, Dian Noor

    2012-01-01

    This study focuses on the climate and vegetation responses to abrupt climate change in the Northern Hemisphere during the last glacial period. Two abrupt climate events are explored: the abrupt cooling of the Heinrich event 1 (HE1), followed by the abrupt warming of the Bølling-Allerød interstadial (BA). These two events are simulated by perturbing the freshwater balance of the Atlantic Ocean, with the intention of altering the Atlantic Meridional Overturning Circulation (AMOC) and also of in...

  5. Short QT syndrome

    Directory of Open Access Journals (Sweden)

    Fiorenzo Gaita

    2011-12-01

    Full Text Available The short QT syndrome (SQTS is a recently described genetic arrhythmogenic disorder, characterized by abnormally short QT intervals on surface electrocardiogram (ECG and a high incidence of sudden death (SD during life, including the first months of life. The inheritance of SQTS is autosomal dominant, with genetic heterogeneity. Gain-of-function mutations in 3 genes encoding potassium channels have been associated to the disease: KCNH2 encoding IKr (SQT1, KCNQ1 encoding IKs (SQT2, and KCNJ2 encoding IK1 (SQT3. Loss-of-function mutations in 3 genes encoding the cardiac L-type calcium channel, CACNA1C, CACNB2b and CACNA2D1 may underlie a mixed phenotype of Brugada pattern ECG (or non-specific repolarization changes in case of CACNA2D1 and shorter than normal QT intervals. Clinical presentation is often severe, as cardiac arrest represents the first clinical presentation in most subjects. Moreover, often a noticeable family history of cardiac SD is present. Atrial fibrillation may be observed, also in young individuals. At electrophysiological study, short atrial and ventricular refractory periods are found, and atrial and ventricular fibrillation are easily induced by programmed electrical stimulation. The outcome of patients with SQTS becomes relatively safe when they are identified and treated. Currently, the suggested therapeutic strategy is an implantable cardioverter- defibrillator (ICD in patients with personal history of aborted SD or syncope. In asymptomatic adult patients from highly symptomatic families and in newborn children pharmacological treatment with hydroquinidine, which has been shown to prolong the QT interval and reduce the inducibility of ventricular arrhythmias, may be proposed.

  6. Toxicología Vegetal

    OpenAIRE

    García Fernández, Antonio Juan

    2010-01-01

    Presentaciones de clase de los temas de Toxicología Vegetal de la licenciatura de Veterinaria de la Universidad de Murcia del curso 2011/12. Presentaciones de Toxicología Vegetal de la asignatura de Toxicología de la Licenciatura de Veterinaria del curso 2011/12

  7. Effect of long-term organic fertilization on the soil pore characteristics of greenhouse vegetable fields converted from rice-wheat rotation fields.

    Science.gov (United States)

    Xu, L Y; Wang, M Y; Shi, X Z; Yu, Q B; Shi, Y J; Xu, S X; Sun, W X

    2018-08-01

    The shift from rice-wheat rotation (RWR) to greenhouse vegetable soils has been widely practiced in China. Several studies have discussed the changes in soil properties with land-use changes, but few studies have sought to address the differences in soil pore properties, especially for fields based on long-term organic fertilization under greenhouse vegetable system from RWR fields. This study uses the X-ray computed tomography (CT) scanning and statistical analysis to compare the long-term effects of the conversion of organic greenhouse vegetable fields (over one year, nine years, and fourteen years) from RWR fields on the soil macropore structure as well as the influencing factors from samples obtained in Nanjing, Jiangsu, China, using the surface soil layer and triplicate samples. The results demonstrated that the macropore structure became more complex and stable, with a higher connectivity, fractal dimension (FD) and a lower degree of anisotropy (DA), as the greenhouse vegetable planting time increased. The total topsoil macroporosity increased considerably, but the rate of increase gradually decelerated with time. The transmission pores (round pores ranging from 50 to 500μm) increased with time, but the biopores (>2000μm) clearly decreased after nine years of use as greenhouse vegetable fields. Soil organic matter (OM) has a significant relationship with the soil pore structure characteristics, especially for the transmission pores. In addition, organic fertilization on the topsoil had a short-term effect on the pores, but the effect stabilized and had a weak influence on the pores over longer periods. These results suggested that organic fertilization was conducive for controlling soil degradation regarding it physical quality for water and oxygen availability in the short term. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Study of Wetland Ecosystem Vegetation Using Satellite Data

    Science.gov (United States)

    Dyukarev, E. A.; Alekseeva, M. N.; Golovatskaya, E. A.

    2017-12-01

    The normalized difference vegetation index (NDVI) is used to estimate the aboveground net production (ANP) of wetland ecosystems for the key area at the South Taiga zone of West Siberia. The vegetation index and aboveground production are related by linear dependence and are specific for each wetland ecosystem. The NDVI grows with an increase in the ANP at wooded oligotrophic ecosystems. Open oligotrophic bogs and eutrophic wetlands are characterized by an opposite relation. Maps of aboveground production for wetland ecosystems are constructed for each study year and for the whole period of studies. The average aboveground production for all wetland ecosystems of the key area, which was estimated with consideration for the area they occupy and using the data of satellite measurements of the vegetation index, is 305 g C/m2/yr. The total annual carbon accumulation in aboveground wetland vegetation in the key area is 794600 t.

  9. Comparison of Modeling Grassland Degradation with and without Considering Localized Spatial Associations in Vegetation Changing Patterns

    Directory of Open Access Journals (Sweden)

    Yuwei Wang

    2018-01-01

    Full Text Available Grassland ecosystems worldwide are confronted with degradation. It is of great importance to understand long-term trajectory patterns of grassland vegetation by advanced analytical models. This study proposes a new approach called a binary logistic regression model with neighborhood interactions, or BLR-NIs, which is based on binary logistic regression (BLR, but fully considers the spatio-temporally localized spatial associations or characterization of neighborhood interactions (NIs in the patterns of grassland vegetation. The BLR-NIs model was applied to a modeled vegetation degradation of grasslands in the Xilin river basin, Inner Mongolia, China. Residual trend analysis on the normalized difference vegetation index (RESTREND-NDVI, which excluded the climatic impact on vegetation dynamics, was adopted as a preprocessing step to derive three human-induced trajectory patterns (vegetation degradation, vegetation recovery, and no significant change in vegetation during two consecutive periods, T1 (2000–2008 and T2 (2007–2015. Human activities, including livestock grazing intensity and transportation accessibility measured by road network density, were included as explanatory variables for vegetation degradation, which was defined for locations if vegetation recovery or no significant change in vegetation in T1 and vegetation degradation in T2 were observed. Our work compared the results of BLR-NIs and the traditional BLR model that did not consider NIs. The study showed that: (1 both grazing intensity and road density had a positive correlation to vegetation degradation based on the traditional BLR model; (2 only road density was found to positively correlate to vegetation degradation by the BLR-NIs model; NIs appeared to be critical factors to predict vegetation degradation; and (3 including NIs in the BLR model improved the model performance substantially. The study provided evidence for the importance of including localized spatial

  10. Accumulation and health risk of heavy metals in vegetables from harmless and organic vegetable production systems of China.

    Science.gov (United States)

    Chen, Yong; Hu, Wenyou; Huang, Biao; Weindorf, David C; Rajan, Nithya; Liu, Xiaoxiao; Niedermann, Silvana

    2013-12-01

    Heavy metal accumulation in vegetables is a growing concern for public health. Limited studies have elucidated the heavy metal accumulation characteristics and health risk of different vegetables produced in different facilities such as greenhouses and open-air fields and under different management modes such as harmless and organic. Given the concern over the aforementioned factors related to heavy metal accumulation, this study selected four typical greenhouse vegetable production bases, short-term harmless greenhouse vegetable base (SHGVB), middle-term harmless greenhouse vegetable base (MHGVB), long-term harmless greenhouse vegetable base (LHGVB), and organic greenhouse vegetable base (OGVB), in Nanjing City, China to study heavy metal accumulation in different vegetables and their associated health risks. Results showed that soils and vegetables from SHGVB and OGVB apparently accumulated fewer certain heavy metals than those from other bases, probably due to fewer planting years and special management, respectively. Greenhouse conditions significantly increased certain soil heavy metal concentrations relative to open-air conditions. However, greenhouse conditions did not significantly increase concentrations of As, Cd, Cu, Hg, and Zn in leaf vegetables. In fact, under greenhouse conditions, Pb accumulation was effectively reduced. The main source of soil heavy metals was the application of large amounts of low-grade fertilizer. There was larger health risk for producers' children to consume vegetables from the three harmless vegetable bases than those of residents' children. The hazard index (HI) over a large area exceeded 1 for these two kinds of children in the MHGVB and LHGVB. There was also a slight risk in the SHGVB for producers' children solely. However, the HI of the whole area of the OGVB for two kinds of children was below 1, suggesting low risk of heavy metal exposure through the food chain. Notably, the contribution rate of Cu and Zn to the HI were

  11. Night sleep in patients with vegetative state.

    Science.gov (United States)

    Pavlov, Yuri G; Gais, Steffen; Müller, Friedemann; Schönauer, Monika; Schäpers, Barbara; Born, Jan; Kotchoubey, Boris

    2017-10-01

    Polysomnographic recording of night sleep was carried out in 15 patients with the diagnosis vegetative state (syn. unresponsive wakefulness syndrome). Sleep scoring was performed by three raters, and confirmed by means of a spectral power analysis of the electroencephalogram, electrooculogram and electromyogram. All patients but one exhibited at least some signs of sleep. In particular, sleep stage N1 was found in 13 patients, N2 in 14 patients, N3 in nine patients, and rapid eye movement sleep in 10 patients. Three patients exhibited all phenomena characteristic for normal sleep, including spindles and rapid eye movements. However, in all but one patient, sleep patterns were severely disturbed as compared with normative data. All patients had frequent and long periods of wakefulness during the night. In some apparent rapid eye movement sleep episodes, no eye movements were recorded. Sleep spindles were detected in five patients only, and their density was very low. We conclude that the majority of vegetative state patients retain some important circadian changes. Further studies are necessary to disentangle multiple factors potentially affecting sleep pattern of vegetative state patients. © 2017 European Sleep Research Society.

  12. A Phenology-Based Method for Monitoring Woody and Herbaceous Vegetation in Mediterranean Forests from NDVI Time Series

    OpenAIRE

    David Helman; Itamar M. Lensky; Naama Tessler; Yagil Osem

    2015-01-01

    We present an efficient method for monitoring woody (i.e., evergreen) and herbaceous (i.e., ephemeral) vegetation in Mediterranean forests at a sub pixel scale from Normalized Difference Vegetation Index (NDVI) time series derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). The method is based on the distinct development periods of those vegetation components. In the dry season, herbaceous vegetation is absent or completely dry in Mediterranean forests. Thus the mean NDVI ...

  13. Monitoring temporal Vegetation changes in Lao tropical forests

    International Nuclear Information System (INIS)

    Phompila, Chittana; Lewis, Megan; Clarke, Kenneth; Ostendorf, Bertram

    2014-01-01

    Studies on changes in vegetation are essential for understanding the interaction between humans and the environment. These studies provide key information for land use assessment, terrestrial ecosystem monitoring, carbon flux modelling and impacts of global climate change. The primary purpose of this study was to detect temporal vegetation changes in tropical forests in the southern part of Lao PDR from 2001-2012. The study investigated the annual vegetation phenological response of dominant land cover types across the study area and relationships to seasonal precipitation and temperature. Improved understanding of intra-annual patterns of vegetation variation was useful to detect longer term changes in vegetation. The breaks for additive season and trend (BFAST) approach was implemented to detect changes in these land cover types throughout the 2001-2012 period. We used the enhanced vegetation index (EVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) (MOD13Q1 products) and monthly rainfall and temperature data obtained from the Meteorology and Hydrology Department, Ministry of Agriculture-Forestry, published by Lao National Statistical Centre in this research. EVI well documented the annual seasonal growth of vegetation and clearly distinguished the characteristic phenology of four different land use types; native forest, plantation, agriculture and mixed wooded/cleared area. Native forests maintained high EVI throughout the year, while plantations, wooded/cleared areas and agriculture showed greater inter-annual variation, with minimum EVI at the end of the dry season in April and maximum EVI in September-October, around two months after the wet season peak in rainfall. The BFAST analysis detected abrupt temporal changes in vegetation in the tropical forests, especially in a large conversion of mixed wooded/cleared area into plantation. Within the study area from 2001-2012 there has been an overall decreasing trend of vegetation cover for

  14. Coder period - amplitude; Codeur periode - amplitude

    Energy Technology Data Exchange (ETDEWEB)

    Da Costa Viera, D; Mourchou, R; Calvet, A; Pacchiani, L; Tattegrain, A

    1966-07-01

    For some flowmeters on nuclear reactors, apparatus which deliver an ac signal proportional to the flow, are usually used. This frequency information is converted into a continuous voltage with a coder. The described coder was studied for the Cabri reactor which was requiring a short response delay. (A.L.B.)

  15. INITIAL BREEDING MATERIAL OF VEGETABLE BEAN FOR DEVELOPMENT OF EARLY-RIPENING VARIETIES IN NORTH PART OF FOREST STEPPE OF THE UKRAINE

    Directory of Open Access Journals (Sweden)

    E. N. Grishenko

    2015-01-01

    Full Text Available The collection of vegetable bean varieties was screened for duration of vegetative and interstage periods. The initial breeding material as a source of early-ripeness was selected.

  16. Special study on vegetative covers

    International Nuclear Information System (INIS)

    1988-11-01

    This report describes the findings of a special study on the use of vegetative covers to stabilize tailings piles for the Uranium Mill Tailings Remedial Action (UMTRA) Project. The principal rationale for using plants would be to establish a dynamic system for controlling water balance. Specifically, vegetation would be used to intercept and transpire precipitation to the atmosphere, rather than allowing water to drain into the tailings and mobilize contaminants. This would facilitate compliance with groundwater standards proposed for the UMTRA Project by the Environmental Protection Agency. The goals of the study were to evaluate the feasibility of using vegetative covers on UMTRA Project piles, define the advantages and disadvantages of vegetative covers, and develop general guidelines for their use when such use seems reasonable. The principal method for the study was to analyze and apply to the UMTRA Project the results of research programs on vegetative covers at other US Department of Energy (DOE) waste management facilities. The study also relied upon observations made of existing stabilized piles at UMTRA Project sites where natural vegetation is growing on the rock-covered surfaces. Water balance and erosion models were also used to quantify the long-term performance of vegetative covers planned for the topslopes of stabilized piles at Grand Junction and Durango, Colorado, two UMTRA Project sites where the decision was made during the course of this special study to use vegetative covers. Elements in the design and construction of the vegetative covers at these two sites are discussed in the report, with explanations of the differing features that reflect differing environmental conditions. 28 refs., 18 figs., 9 tabs

  17. Use of Vegetation Health Data for Estimation of Aus Rice Yield in Bangladesh

    OpenAIRE

    Rahman, Atiqur; Roytman, Leonid; Krakauer, Nir Y.; Nizamuddin, Mohammad; Goldberg, Mitch

    2009-01-01

    Rice is a vital staple crop for Bangladesh and surrounding countries, with interannual variation in yields depending on climatic conditions. We compared Bangladesh yield of aus rice, one of the main varieties grown, from official agricultural statistics with Vegetation Health (VH) Indices [Vegetation Condition Index (VCI), Temperature Condition Index (TCI) and Vegetation Health Index (VHI)] computed from Advanced Very High Resolution Radiometer (AVHRR) data covering a period of 15 years (1991...

  18. Radiation and the vegetable industry

    International Nuclear Information System (INIS)

    Roberts, P.B.

    1984-01-01

    The possible uses of irradiation in the vegetable industry are considered. Interest has been increasing because of possible bans on chemical fumigants and clearance of irradiation as an acceptable process, up to certain dose limits, by Codex Alimentarius and the US FDA. Inhibition of sprouting in potatoes and onions would be one possibility for exploitation. However, the main incentive for vegetable irradiation would be as a quarantine treatment for exported products. The shelf-life of a few vegetables could also be increased by combining radiation with heat treatments. Costs in New Zealand and consumer attitudes are briefly considered

  19. Pesticide Residues, Results from the period 2004-2011

    DEFF Research Database (Denmark)

    Petersen, Annette; Jensen, Bodil Hamborg; Andersen, Jens Hinge

    The present report presents the results from the 2004-2011 period of the monitoring programmes conducted by The Danish Veterinary and Food Administration. The programmes included commodities of fruit, vegetable, cereals and animal origin using random sampling from food on the Danish market. Since...... the beginning of the 1960, Denmark has monitored fruit and vegetables for pesticides residues. For the periods 1993-1997 and 1998-2003, results were collated and the dietary exposure was calculated. In this report data for the analyses carried out in the period 2004-2011 are reported as well as the exposure...

  20. Post-wildfire natural restoration of riparian vegetation under stable hydro-geomorphic conditions: Nahal Grar, Northern Negev Desert, Israel

    Science.gov (United States)

    Egozi, Roey

    2015-04-01

    Wildfires are common to the Mediterranean region due to its defined dry season and long historical anthropogenic activities. Most of post-wildfire studies focus on mountains areas and thus refer to the hill-slope and its physical characteristics, e.g. morphology, length, angles, and aspect; its soil characteristics, e.g. type, infiltration rate, repellency; and its vegetative covers, e.g. planted trees vs. natural forest or native vs. exotic vegetation. In contrary there is very limited literature focusing on ecological and hydro-geomorphic aspects of post-wildfire of riparian vegetation / zone probably because of its negligible burned area relative to the spread of the fire, sometimes, over the whole watershed area. The limited literature on the topic is surprising given the fact that riparian vegetation zone has been acknowledged as a unique and important habitat supporting rich biodiversity. Herein we report on a wildfire event occurred on October 14th 2009 in a river section of Nahal Grar, Northern Negev Desert, Israel. The wildfire although was limited in its area (only 3 hectare) extended over the channel alone from bank to bank and thus provide a unique case study of completely burn down of riparian vegetation, mainly dense stands of Common Red (Australis Phragmites. Therefore a detailed study of this event provides an opportunity to tackle one of the basics questions which is determining the rate of natural restoration process that act at the immediate time after the wildfire event occurred. This type of information is most valuable to professional and stakeholders for better management of post-fire riparian zones. The results of the study suggest that under stable conditions, i.e. no major flood events occurred; disturbance time was short and ranged over 200 days due to, almost, immediate recovery of the riparian vegetation. However the re-growth of the riparian vegetation was not even but rather deferential and more complex then reported in the literature

  1. Soil-geomorphic heterogeneity governs patchy vegetation dynamics at an arid ecotone.

    Science.gov (United States)

    Bestelmeyer, Brandon T; Ward, Judy P; Havstad, Kris M

    2006-04-01

    Soil properties are well known to affect vegetation, but the role of soil heterogeneity in the patterning of vegetation dynamics is poorly documented. We asked whether the location of an ecotone separating grass-dominated and sparsely vegetated areas reflected only historical variation in degradation or was related to variation in inherent soil properties. We then asked whether changes in the cover and spatial organization of vegetated and bare patches assessed using repeat aerial photography reflected self-organizing dynamics unrelated to soil variation or the stable patterning of soil variation. We found that the present-day ecotone was related to a shift from more weakly to more strongly developed soils. Parts of the ecotone were stable over a 60-year period, but shifts between bare and vegetated states, as well as persistently vegetated and bare states, occurred largely in small (<40 m2) patches throughout the study area. The probability that patches were presently vegetated or bare, as well as the probability that vegetation persisted and/or established over the 60-year period, was negatively related to surface calcium carbonate and positively related to subsurface clay content. Thus, only a fraction of the landscape was susceptible to vegetation change, and the sparsely vegetated area probably featured a higher frequency of susceptible soil patches. Patch dynamics and self-organizing processes can be constrained by subtle (and often unrecognized) soil heterogeneity.

  2. Vegetation - McKenzie Preserve [ds703

    Data.gov (United States)

    California Natural Resource Agency — The California Native Plant Society (CNPS) Vegetation Program produced a vegetation map and classification for approximately 11,600 acres primarily within Millerton...

  3. Significant impacts of nutrient enrichment on High Arctic vegetation and soils despite two decades of recovery

    Science.gov (United States)

    Street, L. E.; Burns, N. R.; Woodin, S. J.

    2012-04-01

    We re-visit a unique field manipulation study in Svalbard to assess the long-term recovery of plant species composition, leaf tissue chemistry and total ecosystem carbon storage from nutrient enrichment. The experiment was established in 1991. The original aim was to quantify the 'critical load' of nitrogen (N) for tundra; that is, the minimum rate of N deposition affecting ecosystem structure and function. Dissolved N was applied to heath vegetation, both alone and in combination with phosphorous (P), during the growing season over three years. The rates of N addition were lower than in most other nutrient manipulation studies, and were designed to represent typical rates of deposition in the Scottish highlands (50 kg N ha-1 yr-1) and maximum deposition rates experienced in the Arctic (10 kg N ha-1 yr-1). Significant changes in shrub cover, the greenness and N content of the moss layer, and the extent of ecosystem N saturation had occurred by the end of the treatment period. After 18 years of recovery without further treatment, we assessed primary productivity using CO2 flux measurements, and the 'greenness' of vegetation using the Normalised Difference Vegetation Index. We made destructive measurements of above- and below-ground carbon and nutrient stocks, quantified species composition and sampled leaf tissue for chemical analysis. Total carbon storage in organic soils and vegetation was c. 40 % lower in the plots treated with 50 kg N ha-1 yr-1 compared to controls. Species composition in N treated plots also differed significantly, but there was no clear treatment effect on primary productivity. Where 50 kg N ha-1 yr-1 was applied in combination with P (at 5 kg P ha-1 yr-1 ), organic carbon storage was c. 70 % greater than controls, the vegetation was greener, and primary productivity higher. Effects of the treatments were also still clearly apparent in moss tissue nutrient status, even at the lower nitrogen application rate. Our results imply that the effects

  4. Permafrost warming and vegetation changes in continental Antarctica

    International Nuclear Information System (INIS)

    Guglielmin, Mauro; Dalle Fratte, Michele; Cannone, Nicoletta

    2014-01-01

    Continental Antarctica represents the last pristine environment on Earth and is one of the most suitable contexts to analyze the relations between climate, active layer and vegetation. In 2000 we started long-term monitoring of the climate, permafrost, active layer and vegetation in Victoria Land, continental Antarctica. Our data confirm the stability of mean annual and summer air temperature, of snow cover, and an increasing trend of summer incoming short wave radiation. The active layer thickness is increasing at a rate of 0.3 cm y −1 . The active layer is characterized by large annual and spatial differences. The latter are due to scarce vegetation, a patchy and very thin organic layer and large spatial differences in snow accumulation. The active layer thickening, probably due to the increase of incoming short wave radiation, produced a general decrease of the ground water content due to the better drainage of the ground. The resultant drying may be responsible for the decline of mosses in xeric sites, while it provided better conditions for mosses in hydric sites, following the species-specific water requirements. An increase of lichen vegetation was observed where the climate drying occurred. This evidence emphasizes that the Antarctic continent is experiencing changes that are in total contrast to the changes reported from maritime Antarctica. (paper)

  5. Multi-scale associations between vegetation cover and woodland bird communities across a large agricultural region.

    Directory of Open Access Journals (Sweden)

    Karen Ikin

    Full Text Available Improving biodiversity conservation in fragmented agricultural landscapes has become an important global issue. Vegetation at the patch and landscape-scale is important for species occupancy and diversity, yet few previous studies have explored multi-scale associations between vegetation and community assemblages. Here, we investigated how patch and landscape-scale vegetation cover structure woodland bird communities. We asked: (1 How is the bird community associated with the vegetation structure of woodland patches and the amount of vegetation cover in the surrounding landscape? (2 Do species of conservation concern respond to woodland vegetation structure and surrounding vegetation cover differently to other species in the community? And (3 Can the relationships between the bird community and the woodland vegetation structure and surrounding vegetation cover be explained by the ecological traits of the species comprising the bird community? We studied 103 woodland patches (0.5 - 53.8 ha over two time periods across a large (6,800 km(2 agricultural region in southeastern Australia. We found that both patch vegetation and surrounding woody vegetation cover were important for structuring the bird community, and that these relationships were consistent over time. In particular, the occurrence of mistletoe within the patches and high values of woody vegetation cover within 1,000 ha and 10,000 ha were important, especially for bird species of conservation concern. We found that the majority of these species displayed similar, positive responses to patch and landscape vegetation attributes. We also found that these relationships were related to the foraging and nesting traits of the bird community. Our findings suggest that management strategies to increase both remnant vegetation quality and the cover of surrounding woody vegetation in fragmented agricultural landscapes may lead to improved conservation of bird communities.

  6. Vegetation - Lassen Foothills [ds564

    Data.gov (United States)

    California Natural Resource Agency — In 2007 Aerial Information Systems, Inc. (AIS) was contracted by the California Native Plant Society (CNPS) to produce a vegetation map for approximately 100,000...

  7. in Leafy Vegetable and Pharmaceutical

    African Journals Online (AJOL)

    Bheema

    successfully employed for the determination of copper (II) in leafy vegetable and pharmaceutical samples. ... Our previous studies of transition metal ions such as zinc, cobalt and ..... A new method for extractive photometric determination of.

  8. Buffers and vegetative filter strips

    Science.gov (United States)

    Matthew J. Helmers; Thomas M. Isenhart; Michael G. Dosskey; Seth M. Dabney

    2008-01-01

    This chapter describes the use of buffers and vegetative filter strips relative to water quality. In particular, we primarily discuss the herbaceous components of the following NRCS Conservation Practice Standards.

  9. Resilience of soils and vegetation subjected to different grazing ...

    African Journals Online (AJOL)

    The resilience of rangeland soils and vegetation to different levels of grazing is still poorly understood. A study was conducted to determine the recovery of a rangeland grazed at different intensities and allowed a two-year rest period. The following treatments were applied to 0.5 hectare plots: 0, 4, 8 and 16 heifers per ...

  10. Perfluoroctano líquido como tamponante vitreorretiniano de curta duração no pós-operatório de portadores de descolamento de retina por ruptura gigante Perfluoroctane liquid as a short-term vitreous-retinal tamponade in the postoperative period in patients with retinal detachment due to giant tears

    Directory of Open Access Journals (Sweden)

    Marcelo Carvalho Ventura

    2007-06-01

    Full Text Available OBJETIVOS: Relatar os resultados de vitrectomia via pars plana com utilização de perfluocarbono líquido (Perfluoroctano-Ophtalmos®, como tamponante vítreo-retiniano de curta duração, no pós-operatório de portadores de descolamento de retina, por ruptura gigante. MÉTODOS: Estudaram-se dez desses pacientes. Todos os casos eram complicados por vitreorretinopatia proliferativa grau B ou pior com rupturas que variavam em extensão de 90º a 210º. O perfluorocarbono líquido foi introduzido, por via pars plana, com o volume necessário para ultrapassar o limite posterior da ruptura, permanecendo no pós-operatório por cinco dias, estando os pacientes em decúbito dorsal. Após esse período submetiam-se a segunda intervenção para troca do perfluorocarbono líquido para gás ou óleo de silicone. RESULTADOS: Após período de acompanhamento médio de 16,2 ± 12,4 meses (2 a 43 meses, 80% das retinas estavam aplicadas, sendo necessária a repetição desta técnica em 1 caso (10% caso e em 2 casos (20% não houve reaplicação da retina por vitreorretinopatia avançada. Houve melhora da acuidade visual em 5 casos (50%. CONCLUSÃO: Observaram-se bons resultados quanto à aplicação da retina (80% e melhora da acuidade visual (50% quando do uso do perfluorocarbono líquido como tamponante vitreorretiniano de curta duração no pós-operatório de cirurgias de descolamento de retina por rupturas gigantes.PURPOSE: To report pars plana vitrectomy results of intravitreous use of liquid perfluorocarbon as a short-term postoperative tamponade in retinal detachment due to giant tears in a series of patients. METHODS: Ten of those patients, all of them complicated by proliferative vitreoretinopathy grade B or worse, with tear extension varying from 90º to 210º were studied. Perfluorocarbon liquid was injected via pars plana until the posterior tear limit, remaining in the postoperative period during five days, with the patients in supine position

  11. Effects of sulfur dioxide on vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Whitby, G S

    1939-11-11

    A discussion is presented on the effects of sulfur dioxide on vegetation as observed at Trail, British Columbia. The investigation was carried out over a period of eight years, 1929 to 1937. The concentration of sulfur dioxide at the United States border was carefully determined throughout the crop season at a point 16 miles from the source of sulfur dioxide. Maximum and average concentrations in part per million are given. The sulfur content of vegetation was determined and was found to diminish as the distance from the smelter increased. It was determined that the sulfur content may rise to four times the normal amount without injurious effect. This is particularly so with prolonged low concentration. The effect on the soil was determined by measuring soluble sulfate, pH and exchangeable bases. The soil near the plant was affected, but this fell off rapidly with increase in distance so that eight miles from the smelter the soil was substantially normal. No effect on water supplies was found. An appreciable retardation in growth, as determined by annular rings, was noted for trees exposed to the sulfur dioxide. This effect was lost following installation of sulfur dioxide control at Trail. Conifers were found more susceptible during periods of active growth than when dormant. Also, transplanted conifers were more severly affected than native trees. Seedlings were less resistant that older trees.

  12. The transfer factors of I, Ba, Sr, Y and Zr from soil to leafy vegetables

    International Nuclear Information System (INIS)

    Luo Daling; Li Mianfeng; Weng Senhan; Wen Guanghao; Liu Xiaowei; Zhang Cunxiang; Zhang Zeng; Yu Junyue

    1996-01-01

    The transfer factors of I, Ba, Sr, Y and Zr from soil to leafy vegetables have been determined using method of radioisotope tracers and element content analysis. The effects of growth period, size of the vegetables, contents of the isotopes in the soil and other climatic factors on the transfer factors have also been studied

  13. Yield estimation using SPOT-VEGETATION products: A case study of wheat in European countries

    NARCIS (Netherlands)

    Kowalik, W.; Dabrowska-Zielinska, K.; Meroni, M.; Raczka, T.U.; Wit, de A.J.W.

    2014-01-01

    In the period 1999-2009 ten-day SPOT-VEGETATION products of the Normalized Difference Vegetation Index (NDVI) and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) at 1 km spatial resolution were used in order to estimate and forecast the wheat yield over Europe. The products were

  14. Impact of Vegetative Cover on Runoff and Soil Erosion at Hillslope Scale in Lanjaron, Spain

    NARCIS (Netherlands)

    Duran Zuazo, V.H.; Francia-Martinez, J.R.; Martinez-Raya, A.

    2004-01-01

    Soil loss and surface runoff patterns over a four-year period (1997¿2000) were studied in erosion plots from three hillslopes under different vegetative covers (Rosmarinus officinalis, Triticum aestivum and natural-spontaneous vegetation) in Lanjaron (Alpujarras) on the south flank of the Sierra

  15. Post-fire saguaro community: impacts on associated vegetation still apparent 10 years later

    Science.gov (United States)

    Marcia Narog; Ruth Wilson

    2005-01-01

    Fire impacts on saguaro (Carnegiea gigantea) associated vegetation were studied in unburned and burned areas over a 10 year post-fire period after the 1993 Vista View fire, Tonto National Forest, Arizona. Many associated species, crucial for saguaro survival, regenerate by vegetative growth after fire. Bushes were the most common nearest-neighbor,...

  16. Characteristic elements of "Mediterranean Diet": the consumption of vegetables and legumes in Greece (1950-2005)

    NARCIS (Netherlands)

    Vasileiou, K.Z.; Sotiropoulos, I.; Georgakopoulos, G.

    2012-01-01

    on).This paper describes the dietary consumption of vegetables and legumes in Greece during the period 1950 to 2005. All dimensions of alimentary consumption patterns of vegetables and legumes are examined here with a specific focus on: a) their natural characteristics; b) technical features of the

  17. Advances in Studies on Natural Preservativesfor Fruits and Vegetables

    Science.gov (United States)

    Gao, Haisheng; Shi, Pengbao; Zhao, Yuhua

    The author introduced g eneral research and application situations of natural preservatives for fruits and vegetables all over the world these years, and summarized application of vegetation of Murraya in Rutaceae, Cinnamomum in Lauraceae, Artemisia in Compositae and other families and genera on fruits and vegetables preservation and fresh-keeping. Decoction or extraction of Chinese traditional medicine, such as Alpinia Officinarum, Amarphalus Konjac K., stemona etc, could be used in fresh-keeping for orange, apple, strawberry, edible fungi and so on. Garlic could be used in fresh-keeping for orange. Phytic acid and fresh-keeping agents compounded with Phytic acid could extend storage periods of easily rotting fruits and vegetables, such as strawberry, banana, cantaloup, edible fungi and so on, and better keep original fresh condition. Extraction of Snow Fresh, Semper Fresh, Arthropod shell extraction, and halite also had better effect on preservation and fresh-keeping for fruits and vegetables. Main problems exsited in the application of natural preservatives for fruits and vegetables were showed in this article and the applying prospect were discussed too.

  18. Plant functional diversity affects climate-vegetation interaction

    Science.gov (United States)

    Groner, Vivienne P.; Raddatz, Thomas; Reick, Christian H.; Claussen, Martin

    2018-04-01

    We present how variations in plant functional diversity affect climate-vegetation interaction towards the end of the African Humid Period (AHP) in coupled land-atmosphere simulations using the Max Planck Institute Earth system model (MPI-ESM). In experiments with AHP boundary conditions, the extent of the green Sahara varies considerably with changes in plant functional diversity. Differences in vegetation cover extent and plant functional type (PFT) composition translate into significantly different land surface parameters, water cycling, and surface energy budgets. These changes have not only regional consequences but considerably alter large-scale atmospheric circulation patterns and the position of the tropical rain belt. Towards the end of the AHP, simulations with the standard PFT set in MPI-ESM depict a gradual decrease of precipitation and vegetation cover over time, while simulations with modified PFT composition show either a sharp decline of both variables or an even slower retreat. Thus, not the quantitative but the qualitative PFT composition determines climate-vegetation interaction and the climate-vegetation system response to external forcing. The sensitivity of simulated system states to changes in PFT composition raises the question how realistically Earth system models can actually represent climate-vegetation interaction, considering the poor representation of plant diversity in the current generation of land surface models.

  19. Vegetation Water Content Mapping for Agricultural Regions in SMAPVEX16

    Science.gov (United States)

    White, W. A.; Cosh, M. H.; McKee, L.; Berg, A. A.; McNairn, H.; Hornbuckle, B. K.; Colliander, A.; Jackson, T. J.

    2017-12-01

    Vegetation water content impacts the ability of L-band radiometers to measure surface soil moisture. Therefore it is necessary to quantify the amount of water held in surface vegetation for an accurate soil moisture remote sensing retrieval. A methodology is presented for generating agricultural vegetation water content maps using Landsat 8 scenes for agricultural fields of Iowa and Manitoba for the Soil Moisture Active Passive Validation Experiments in 2016 (SMAPVEX16). Manitoba has a variety of row crops across the region, and the study period encompasses the time frame from emergence to reproduction, as well as a forested region. The Iowa study site is dominated by corn and soybeans, presenting an easier challenge. Ground collection of vegetation biomass and water content were also collected to provide a ground truth data source. Errors for the resulting vegetation water content maps ranged depending upon crop type, but generally were less than 15% of the total plant water content per crop type. Interpolation is done between Landsat overpasses to produce daily vegetation water content maps for the summer of 2016 at a 30 meter resolution.

  20. Vegetation management with fire modifies peatland soil thermal regime.

    Science.gov (United States)

    Brown, Lee E; Palmer, Sheila M; Johnston, Kerrylyn; Holden, Joseph

    2015-05-01

    Vegetation removal with fire can alter the thermal regime of the land surface, leading to significant changes in biogeochemistry (e.g. carbon cycling) and soil hydrology. In the UK, large expanses of carbon-rich upland environments are managed to encourage increased abundance of red grouse (Lagopus lagopus scotica) by rotational burning of shrub vegetation. To date, though, there has not been any consideration of whether prescribed vegetation burning on peatlands modifies the thermal regime of the soil mass in the years after fire. In this study thermal regime was monitored across 12 burned peatland soil plots over an 18-month period, with the aim of (i) quantifying thermal dynamics between burned plots of different ages (from post burning), and (ii) developing statistical models to determine the magnitude of thermal change caused by vegetation management. Compared to plots burned 15 + years previously, plots recently burned (management effects. Temperatures measured in soil plots burned vegetation regrows. Our findings that prescribed peatland vegetation burning alters soil thermal regime should provide an impetus for further research to understand the consequences of thermal regime change for carbon processing and release, and hydrological processes, in these peatlands. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Vegetation of wetlands of the prairie pothole region

    Science.gov (United States)

    Kantrud, H.A.; Millar, J.B.; Van Der Valk, A.G.; van der Valk, A.

    1989-01-01

    Five themes dominate the literature dealing with the vegetation of palustrine and lacustrine wetlands of the prairie pothole region: environmental conditions (water or moisture regime, salinity), agricultural disturbances (draining, grazing, burning, sedimentation, etc.), vegetation dynamics, zonation patterns, and classification of the wetlands.The flora of a prairie wetland is a function of its water regime, salinity, and disturbance by man. Within a pothole, water depth and duration determines distribution of species. In potholes deep enough to have standing water even during droughts, the central zone will be dominated by submersed species (open water). In wetlands that go dry during periods of drought or annually, the central zone will be dominated by either tall emergent species (deep marsh) or midheight emergents (shallow marsh), respectively. Potholes that are only flooded briefly in the spring are dominated by grasses, sedges, and forbs (wet meadow). Within a pothole, the depth of standing water in the deepest, usually central, part of the basin determines how many zones will be present. Lists of species associated with different water regimes and salinity levels are presented.Disturbances due to agricultural activities have impacted wetlands throughout the region. Drainage has eliminated many potholes, particularly in the southern and eastern parts of the region. Grazing, mowing, and burning have altered the composition of pothole vegetation. The composition of different vegetation types impacted by grazing, haying, and cultivation is presented in a series of tables. Indirect impacts of agriculture (increased sediment, nutrient, and pesticide inputs) are widespread over the region, but their impacts on the vegetation have never been studied.Because of the periodic droughts and wet periods, many palustrine and lacustrine wetlands undergo vegetation cycles associated with water-level changes produced by these wet-dry cycles. Periods of above normal

  2. NEW GREENHOUSE TECHNOLOGIES FOR VEGETABLE PRODUCTION

    Directory of Open Access Journals (Sweden)

    S. M. Sirota

    2016-01-01

    Full Text Available First decade of XXI century is characterized by significant augmentation in vegetable world’s production. Average annual vegetable production has been 346 million tons, and it has exceeded the average annual potato production (318 million tons. It has occurred due to the use of up-to-date technologies for vegetable production and, particularly, in greenhouses. In Russian Federation, the total production of vegetables was 5 275.6 thousand tons in 2015 that was 13.3% more than in 2014. But the total vegetable production in greenhouses was only 722.8 thousand tons, that was 0.7% less than in 2014 (728.1 thousand tons. It can be explained that the old technologies have been used for many greenhouses around Russia. Up-to-date technologies for greenhouses are described in the article. Small-volume hydroponics. Plants are grown in mineral wadding, packed up in the special chutes. Mineral nutrition and water are supplied through special pipe with many branch pipes toward each plant. Advantage: pH and nutrition are maintained, consumption of water and mineral nutrition are optimized, and that improves plants grow control. Expenditures of labor decreased, quality of fruit became better and the yield increased significantly by 45-50 kg/m2 comparing with growing on the soil (25-30 kg/m2. Hydroponics with flowing water (salad production lines. Conveyor for salad and vegetable growing on horizontal moving chutes with flowing water and nutrition was developed. Advantage: high level of automation and mechanization of all processes of growing increased the effectiveness of the use of greenhouse areas (we can place 30% plants more at the same area. Seedling production lines. Production lines for seedlings enable to grow vegetables and leafy vegetables on stationary benches, being furnished with periodical nutrition and water supply at times. Advantage: 700 seedlings additionally on each m2 a year. Future technologies are

  3. Simulating sub-Milankovitch climate variations associated with vegetation dynamics

    Directory of Open Access Journals (Sweden)

    E. Tuenter

    2007-01-01

    Full Text Available Climate variability at sub-Milankovitch periods (between 2 and 15 kyr is studied in a set of transient simulations with a coupled atmosphere/ocean/vegetation model of intermediate complexity (CLIMBER-2. Focus is on the region influenced by the African and Asian summer monsoon. Pronounced variations at periods of about 10 kyr (Asia and Africa and about 5 kyr (Asia are found in the monsoonal runoff in response to the precessional forcing. In the model this is due to the following mechanism. For low summer insolation (precession maximum precipitation is low and desert expands at the expense of grass, while for high insolation (precession minimum precipitation is high and the tree fraction increases also reducing the grass fraction. This induces sub-Milankovitch variations in the grass fraction and associated variations in the water holding capacity of the soil. The runoff does not exhibit sub-Milankovitch variability when vegetation is kept fixed. High-latitude vegetation also exhibits sub-Milankovitch variability under both obliquity and precessional forcing. We thus hypothesize that sub-Milankovitch variability can occur due to the dynamic response of the vegetation. However, this mechanism should be further tested with more sophisticated climate/vegetation models.

  4. A Test Bed for Short Pulse OA Detection of Optical Directors in Amphibious Operations

    National Research Council Canada - National Science Library

    Ertem, M

    1999-01-01

    ...) system to detect optical directors of potential threats in amphibious operations. The use of a short pulse duration allows discrimination of retroreflections from natural sources such as rock formations and vegetation...

  5. Handling Procedures of Vegetable Crops

    Science.gov (United States)

    Perchonok, Michele; French, Stephen J.

    2004-01-01

    The National Aeronautics and Space Administration (NASA) is working towards future long duration manned space flights beyond low earth orbit. The duration of these missions may be as long as 2.5 years and will likely include a stay on a lunar or planetary surface. The primary goal of the Advanced Food System in these long duration exploratory missions is to provide the crew with a palatable, nutritious, and safe food system while minimizing volume, mass, and waste. Vegetable crops can provide the crew with added nutrition and variety. These crops do not require any cooking or food processing prior to consumption. The vegetable crops, unlike prepackaged foods, will provide bright colors, textures (crispy), and fresh aromas. Ten vegetable crops have been identified for possible use in long duration missions. They are lettuce, spinach, carrot, tomato, green onion, radish, bell pepper, strawberries, fresh herbs, and cabbage. Whether these crops are grown on a transit vehicle (e.g., International Space Station) or on the lunar or planetary surface, it will be necessary to determine how to safely handle the vegetables while maintaining acceptability. Since hydrogen peroxide degrades into water and oxygen and is generally recognized as safe (GRAS), hydrogen peroxide has been recommended as the sanitizer. The objective of th is research is to determine the required effective concentration of hydrogen peroxide. In addition, it will be determined whether the use of hydrogen peroxide, although a viable sanitizer, adversely affects the quality of the vegetables. Vegetables will be dipped in 1 % hydrogen peroxide, 3% hydrogen peroxide, or 5% hydrogen peroxide. Treated produce and controls will be stored in plastic bags at 5 C for up to 14 days. Sensory, color, texture, and total plate count will be measured. The effect on several vegetables including lettuce, radish, tomato and strawberries has been completed. Although each vegetable reacts to hydrogen peroxide differently, the

  6. Drought impact on vegetation growth and mortality

    Science.gov (United States)

    Xu, C.; Wang, M.; Allen, C. D.; McDowell, N. G.; Middleton, R. S.

    2017-12-01

    Vegetation is a key regulator of the global carbon cycle via CO2 absorption through photosynthesis and subsequent growth; however, low water availability, heat stress, and disturbances associated with droughts could substantially reduce vegetation growth and increase vegetation mortality. As far as we know, there are few studies have assessed the drought impact on vegetation growth and mortality at regional and global scales. In this study, we analyzed 13 Earth System models (ESMs) to quantify the impact of drought on GPP and linked the remote-sensing based tree mortality to observed drought indices to assess the drought impact on tree mortality in continental US (CONUS). Our analysis of 13 Earth System models (ESMs) shows that the average global gross primary production (GPP) reduction per year associated with extreme droughts over years 2075-2099 is predicted to be 3-5 times larger than that over years 1850-1999. The annual drought-associated reduction in GPP over years 2075-2099 could be 52 and 74 % of annual fossil fuel carbon emission during years 2000-2007. Increasing drought impacts on GPP are driven primarily by the increasing drought frequency. The risks of drought-associated GPP reduction are particularly high for temperate and tropical regions. The consistent prediction of higher drought-associated reduction in NPP across 13 ESMs suggests increasing impacts of drought on the global carbon cycle with atmospheric warming. Our analysis of drought impact on tree mortality showed that drought-associated carbon loss accounts for 12% of forest carbon loss in CONUS for 2000-2014, which is about one-fifth of that resulting from timber harvesting and 1.35 % of average annual fossil fuel emissions in the U.S. for the same period. The carbon stock loss from natural disturbances for 2000-2014 is approximately 75% of the total carbon loss from anthropogenic disturbance (timber harvesting), suggesting that natural disturbances play a very important role on forest

  7. Will European agricultural policy for school fruit and vegetables improve public health? A review of school fruit and vegetable programmes.

    Science.gov (United States)

    de Sa, Joia; Lock, Karen

    2008-12-01

    For the first time, public health, particularly obesity, is being seen as a driver of EU agricultural policy. In 2007, European Ministers of Agriculture were asked to back new proposals for school fruit and vegetable programmes as part of agricultural reforms. In 2008, the European Commission conducted an impact assessment to assess the potential impact of this new proposal on health, agricultural markets, social equality and regional cohesion. A systematic review of the effectiveness of interventions to promote fruit and/or vegetable consumption in children in schools, to inform the EC policy development process. School schemes are effective at increasing both intake and knowledge. Of the 30 studies included, 70% increased fruits and vegetables (FV) intake, with none decreasing intake. Twenty-three studies had follow-up periods >1 year and provide some evidence that FV schemes can have long-term impacts on consumption. Only one study led to both increased fruit and vegetable intake and reduction in weight. One study showed that school fruit and vegetable schemes can also help to reduce inequalities in diet. Effective school programmes have used a range of approaches and been organized in ways which vary nationally depending on differences in food supply chain and education systems. EU agriculture policy for school fruits and vegetables schemes should be an effective approach with both public health and agricultural benefits. Aiming to increase FV intake amongst a new generation of consumers, it will support a range of EU policies including obesity and health inequalities.

  8. Shortness of Breath

    Science.gov (United States)

    ... filled with air (called pneumotho- rax), it will hinder expansion of the lung, resulting in shortness of ... of Chest Physi- cians. Shortness of Breath: Patient Education. http: / / www. onebreath. org/ document. doc? id= 113. ...

  9. Accumulation of Carbonates Contributes to Coastal Vegetated Ecosystems Keeping Pace With Sea Level Rise in an Arid Region (Arabian Peninsula)

    KAUST Repository

    Saderne, Vincent; Cusack, Michael; Almahasheer, Hanan; Serrano, Oscar; Masqué , Pere; Arias-Ortiz, Ariane; Krishnakumar, Periyadan Kadinjappalli; Rabaoui, Lotfi; Qurban, Mohammad Ali; Duarte, Carlos M.

    2018-01-01

    Anthropogenic sea level rise (SLR) presents one of the greatest risks to human lives and infrastructures. Coastal vegetated ecosystems, that is, tidal marshes, seagrass meadows, and mangrove forests, elevate the seabed through soil accretion, providing a natural coastline protection against SLR. The soil accretion of these ecosystems has never been assessed in hot desert climate regions, where water runoff is negligible. However, tropical marine ecosystems are areas of intense calcification that may constitute an important source of sediment supporting seabed elevation, compensating for the lack of terrestrial inputs. We estimated the long-term (C-centennial) and short-term (Pb-20th century) soil accretion rates (SARs) and inorganic carbon (C) burial in coastal vegetated ecosystems of the Saudi coasts of the central Red Sea and the Arabian Gulf. Short-term SARs (±SE) in mangroves of the Red Sea (0.27 ± 0.22 cm/year) were twofold the SLR for that region since 1925 (0.13 cm/year). In the Arabian Gulf, only mangrove forest SAR is equivalent to local SLR estimates for the period 1979-2007 (0.21 ± 0.09 compared to 0.22 ± 0.05 cm/year, respectively). Long-term SARs are comparable or higher than the global estimates of SLR for the late Holocene (0.01 cm/year). In all habitats of the Red Sea and Arabian Gulf, SARs are supported by high carbonate accretion rates, comprising 40% to 60% of the soil volume. Further studies on the role of carbonates in coastal vegetated ecosystems are required to understand their role in adaptation to SLR.

  10. Accumulation of Carbonates Contributes to Coastal Vegetated Ecosystems Keeping Pace With Sea Level Rise in an Arid Region (Arabian Peninsula)

    KAUST Repository

    Saderne, Vincent

    2018-04-12

    Anthropogenic sea level rise (SLR) presents one of the greatest risks to human lives and infrastructures. Coastal vegetated ecosystems, that is, tidal marshes, seagrass meadows, and mangrove forests, elevate the seabed through soil accretion, providing a natural coastline protection against SLR. The soil accretion of these ecosystems has never been assessed in hot desert climate regions, where water runoff is negligible. However, tropical marine ecosystems are areas of intense calcification that may constitute an important source of sediment supporting seabed elevation, compensating for the lack of terrestrial inputs. We estimated the long-term (C-centennial) and short-term (Pb-20th century) soil accretion rates (SARs) and inorganic carbon (C) burial in coastal vegetated ecosystems of the Saudi coasts of the central Red Sea and the Arabian Gulf. Short-term SARs (±SE) in mangroves of the Red Sea (0.27 ± 0.22 cm/year) were twofold the SLR for that region since 1925 (0.13 cm/year). In the Arabian Gulf, only mangrove forest SAR is equivalent to local SLR estimates for the period 1979-2007 (0.21 ± 0.09 compared to 0.22 ± 0.05 cm/year, respectively). Long-term SARs are comparable or higher than the global estimates of SLR for the late Holocene (0.01 cm/year). In all habitats of the Red Sea and Arabian Gulf, SARs are supported by high carbonate accretion rates, comprising 40% to 60% of the soil volume. Further studies on the role of carbonates in coastal vegetated ecosystems are required to understand their role in adaptation to SLR.

  11. Study on Climatic Variation and Its Effect on Vegetable Type Soybean Genotypes at Khumaltar, Lalitpur in the Last Ten Years

    Directory of Open Access Journals (Sweden)

    Santosh Raj Tripathi

    2015-04-01

    Full Text Available Soybean (Glycine max L. Merril is widely grown in the mid hills as intercrop with maize or in paddy bunds, while it is gaining popularity as sole crop in terai and inner terai. Mean temperature at Khumaltar during soybean growing period was mostly fluctuating; but we observed an increasing trend in temperature. Amount of rainfall was not changed dramatically but number of rainy days was decreased during study period. Rainfall during germination time increase soil moisture which also increase germination and found higher early stand. Days from sowing to 50% flowering and 90% maturity were short in the case of higher minimum temperature and low rainfall. Among the genotypes, AGS-377, AGS-378, AGS-379 and Tarkari Bhattmas-1 were more sensitive. However, seed yield decreased in the case of higher temperatures and low rainfall. Cool night temperatures and high moisture increased disease incidence in soybean which, eventually reduced yield. In last three years, plant suffered from moisture stress during early vegetative stage and high moisture during late vegetative stage which reduced seed yield and seed weight. In conclusion, we found that genotypes like AGS- 360, Sathiya and Tarkari Bhatmas-1 are very sensitive to climatic variation.

  12. Effects of climate factors and vegetation on the CO2 fluxes and δ13C from re-established grassland

    Science.gov (United States)

    Bezyk, Yaroslav; Dorodnikov, Maxim; Sówka, Izabela

    2017-11-01

    The relationship between stable carbon isotope composition (δ13C -CO2) of soil CO2 flux, vegetation cover and weather conditions was investigated in a short-term campaign at a temperate re-established grassland in Germany. During August-September 2016, we measured surface CO2 flux with a closed-chamber method at high and low soil moisture content (`wet', `dry'), with and without above ground vegetation (`planted', `clear-cut') and estimated the effects of treatments on respective δ13C -CO2 values. The concentration and stable carbon isotope composition of CO2 were determined using the gas chromatography and mass spectrometry analyses. The δ13C -CO2 of the soil fluxes decreased over sampling time for the `dry-warm' conditions and canopy manipulation. The ecosystem-derived δ13C -CO2 values (corrected for the atmospheric δ13C -CO2) which included predominately soil-and rhizosphere respiration were -26.2 ± 0.8‰ for the `dry-warm' conditions and decreased down to -28.1 ± 1.4‰ over a period of 28 days from late August to the end of September. The decrease coincided with the lowering of CO2 flux and could be attributed to changes in plant physiological processes at the end of the vegetation season. Though the removal of shoots did not significantly affect the δ13C -CO2 values as compared with the control, the pattern of further δ13C -CO2 decrease (down to -28.8 ± 0.8‰) supported the role of living vegetation in a contribution of 13C-enriched CO2 to the ecosystem respiration.

  13. Integrated High Resolution Monitoring of Mediterranean vegetation

    Science.gov (United States)

    Cesaraccio, Carla; Piga, Alessandra; Ventura, Andrea; Arca, Angelo; Duce, Pierpaolo; Mereu, Simone

    2017-04-01

    The study of the vegetation features in a complex and highly vulnerable ecosystems, such as Mediterranean maquis, leads to the need of using continuous monitoring systems at high spatial and temporal resolution, for a better interpretation of the mechanisms of phenological and eco-physiological processes. Near-surface remote sensing techniques are used to quantify, at high temporal resolution, and with a certain degree of spatial integration, the seasonal variations of the surface optical and radiometric properties. In recent decades, the design and implementation of global monitoring networks involved the use of non-destructive and/or cheaper approaches such as (i) continuous surface fluxes measurement stations, (ii) phenological observation networks, and (iii) measurement of temporal and spatial variations of the vegetation spectral properties. In this work preliminary results from the ECO-SCALE (Integrated High Resolution Monitoring of Mediterranean vegetation) project are reported. The project was manly aimed to develop an integrated system for environmental monitoring based on digital photography, hyperspectral radiometry , and micrometeorological techniques during three years of experimentation (2013-2016) in a Mediterranean site of Italy (Capo Caccia, Alghero). The main results concerned the analysis of chromatic coordinates indices from digital images, to characterized the phenological patterns for typical shrubland species, determining start and duration of the growing season, and the physiological status in relation to different environmental drought conditions; then the seasonal patterns of canopy phenology, was compared to NEE (Net Ecosystem Exchange) patterns, showing similarities. However, maximum values of NEE and ER (Ecosystem respiration), and short term variation, seemed mainly tuned by inter annual pattern of meteorological variables, in particular of temperature recorded in the months preceding the vegetation green-up. Finally, green signals

  14. Short-circuit logic

    NARCIS (Netherlands)

    Bergstra, J.A.; Ponse, A.

    2010-01-01

    Short-circuit evaluation denotes the semantics of propositional connectives in which the second argument is only evaluated if the first argument does not suffice to determine the value of the expression. In programming, short-circuit evaluation is widely used. A short-circuit logic is a variant of

  15. Chapter 3: Status and trends of vegetation

    Science.gov (United States)

    James M. Guldin; Frank R. Thompson; Lynda L. Richards; Kyra C. Harper

    1999-01-01

    This chapter provides information about the vegetation cover of the Assessment area. The types and areal extent of vegetation in the Highlands are of interest for many reasons. Vegetation cover largely determines the availability of habitat for terrestrial animals, plants, and other organisms. Vegetation cover strongly influences what uses {e.g., timber, forage,...

  16. Vegetables and other core food groups

    NARCIS (Netherlands)

    Poelman, Astrid A.M.; Delahunty, Conor M.; Graaf, de Kees

    2017-01-01

    Vegetables are the food category least liked by children. This research investigated the sensory properties of vegetables vis-a-vis other core foods that comprise children's diets, to determine to what degree low acceptance of vegetables can be attributed to sensory properties. Vegetables (n =

  17. 18 CFR 1304.203 - Vegetation management.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Vegetation management...-Owned Residential Access Shoreland § 1304.203 Vegetation management. No vegetation management shall be approved on TVA-owned Residential Access Shoreland until a Vegetation Management Plan meeting the...

  18. Diurnal Reflectance Changes in Vegetation Observed with AVIRIS

    Science.gov (United States)

    Vanderbilt, V. C.; Ambrosia, V. G.; Ustin, S. L.

    1998-01-01

    Among the most important short-term dynamic biological processes are diurnal changes in canopy water relations. Plant regulation of water transport through stomatal openings affects other gaseous transport processes, often dramatically decreasing photosynthetic fixation of carbon dioxide during periods of water stress. Water stress reduces stomatal conductance of water vapor through the leaf surface and alters the diurnal timing of stomatal opening. Under non-water stressed conditions, stomates typically open soon after dawn and transpire water vapor throughout the daylight period. During stress periods, stomates may close for part of the day, generally near mid-day. Under prolonged stress conditions, stomatal closure shifts to earlier times during the day; stomates may close by mid-morning and remain closed until the following morning - or remain closed entirely. Under these conditions the relationship between canopy greenness (e.g., measured with a vegetation index or by spectral mixture analysis) and photosynthetic fixation of carbon is lost and the remotely sensed vegetation metric is a poor predictor of gas exchange. Prediction of stomatal regulation and exchange of water and trace gases is critical for ecosystem and climate models to correctly estimate budgets of these gases and understand or predict other processes like gross and net ecosystem primary production. Plant gas exchange has been extensively studied by physiologists at the leaf and whole plant level and by biometeorologists at somewhat larger scales. While these energy driven processes follow a predictable if somewhat asymmetric diurnal cycle dependent on soil water availability and the constraints imposed by the solar energy budget, they are nonetheless difficult to measure at the tree and stand levels using conventional methods. Ecologists have long been interested in the potential of remote sensing for monitoring physiological changes using multi-temporal images. Much of this research has

  19. Assessing Sahelian vegetation and stress from seasonal time series of polar orbiting and geostationary satellite imagery

    DEFF Research Database (Denmark)

    Olsen, Jørgen Lundegaard

    that short term variations in anomalies from seasonally detrended time series of indices could carry information on vegetation stress was examined and confirmed. However, it was not found sufficiently robust on pixel level to be implemented for monitoring vegetation water stress on a per-pixel basis...... provide good sensitivity to canopy water content, which can make vegetation stress detection possible. Furthermore, the high frequency observations in the optical spectrum now available from geostationary instruments have the potential for detection of changes in vegetation related surface properties...... on short timescales, which are challenging from polar orbiting instruments. Geostationary NDVI and the NIR and SWIR based Shortwave Infrared Water Stress Index (SIWSI) indices are compared with extensive field data from the Dahra site, supplemented by data from the Agoufou and Demokeya sites. The indices...

  20. Attribution of trends in global vegetation greenness from 1982 to 2011

    Science.gov (United States)

    Zhu, Z.; Xu, L.; Bi, J.; Myneni, R.; Knyazikhin, Y.

    2012-12-01

    Time series of remotely sensed vegetation indices data provide evidence of changes in terrestrial vegetation activity over the past decades in the world. However, it is difficult to attribute cause-and-effect to vegetation trends because variations in vegetation productivity are driven by various factors. This study investigated changes in global vegetation productivity first, and then attributed the global natural vegetation with greening trend. Growing season integrated normalized difference vegetation index (GSI NDVI) derived from the new GIMMS NDVI3g dataset (1982-2011was analyzed. A combined time series analysis model, which was developed from simper linear trend model (SLT), autoregressive integrated moving average model (ARIMA) and Vogelsang's t-PST model shows that productivity of all vegetation types except deciduous broadleaf forest predominantly showed increasing trends through the 30-year period. The evolution of changes in productivity in the last decade was also investigated. Area of greening vegetation monotonically increased through the last decade, and both the browning and no change area monotonically decreased. To attribute the predominant increase trend of productivity of global natural vegetation, trends of eight climate time series datasets (three temperature, three precipitation and two radiation datasets) were analyzed. The attribution of trends in global vegetation greenness was summarized as relaxation of climatic constraints, fertilization and other unknown reasons. Result shows that nearly all the productivity increase of global natural vegetation was driven by relaxation of climatic constraints and fertilization, which play equally important role in driving global vegetation greenness.; Area fraction and productivity change fraction of IGBP vegetation land cover classes showing statistically significant (10% level) trend in GSI NDVIt;

  1. Vegetation change, malnutrition and violence in the Horn of Africa

    Science.gov (United States)

    Rowhani, P.; Degomme, O.; Linderman, M.; Guha-Sapir, D.; Lambin, E.

    2008-12-01

    In certain circumstances, climate change in association with a broad range of social factors may increase the risk of famines and subsequently, violent conflict. The impacts of climate change on society will be experienced both through changes in mean conditions over long time periods and through increases in extreme events. Recent studies have shown the historical effects of long term climate change on societies and the importance of short term climatic triggers on armed conflict. However, most of these studies are at the state level ignoring local conditions. Here we use detailed information extracted from wide-swath satellite data (MODIS) to analyze the impact of climate variability change on malnutrition and violent conflict. More specifically, we perform multivariate logistic regression analysis in order to explain the geographical distribution of malnutrition and conflict in the Horn of Africa on a sub-national level. This region, constituted by several unstable and poor states, has been affected by droughts, floods, famines, and violence in the past few years. Three commonly used nutrition and mortality indicators are used to characterize the health situation (CE-DAT database). To map violence we use the georeferenced Armed Conflicts dataset developed by the Center for the Study of Civil War. Explanatory variables include several socio-economic variables and environmental variables characterizing land degradation, vegetation activity, and interannual variability in land-surface conditions. First results show that interannual variability in land-surface conditions is associated with malnutrition but not with armed conflict. Furthermore, land degradation seems not to be associated with either malnutrition or armed conflict.

  2. Mutation breeding in vegetable crops

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Takashi

    1984-03-01

    Vegetables breed by seeds and vegetative organs. In main vegetables, the differentiation of clopping types, the adoption of monoculture and year-round production and shipment are carried out, adapting to various socio-economic and cultivation conditions. Protected agriculture has advanced mainly for fruit vegetables, and the seeds for sale have become almost hybrid varieties. Reflecting this situation, the demand for breeding is diversified and characteristic. The present status of mutation breeding of vegetables is not yet well under way, but reports of about 40 raised varieties have been published in the world. The characters introduced by induced mutation and irradiation are compact form, harvesting aptitude, the forms and properties of stems and leaves, anti-lodging property, the size, form and uniformity of fruits, male sterility and so on. The radiation sources used were mostly gamma ray or X-ray, but sometimes, combined irradiation was used. Results obtained in Japan include: burdocks as an example to gamma ray irradiation of seeds; tomatoes as an example of inducing compound resistance against disease injury; and lettuce as an example of internal beta irradiation. (Kako, I.).

  3. Mutation breeding in vegetable crops

    International Nuclear Information System (INIS)

    Yamaguchi, Takashi

    1984-01-01

    Vegetables breed by seeds and vegetative organs. In main vegetables, the differentiation of clopping types, the adoption of monoculture and year-round production and shipment are carried out, adapting to various socio-economic and cultivation conditions. Protected agriculture has advanced mainly for fruit vegetables, and the seeds for sale have become almost hybrid varieties. Reflecting the situation like this, the demand for breeding is diversified and characteristic, and the case of applying mutation breeding seems to be many. The present status of the mutation breeding of vegetables is not yet well under way, but about 40 raised varieties have been published in the world. The characters introduced by induced mutation and irradiation were compact form, harvesting aptitude, the forms and properties of stems and leaves, anti-lodging property, the size, form and uniformity of fruits, male sterility and so on. The radiation sources used were mostly gamma ray or X-ray, but sometimes, combined irradiation was used. As the results obtained in Japan, burdocks as an example of gamma ray irradiation to seeds, tomatoes as an example of inducing the compound resistance against disease injury and lettuces as an example of internal beta irradiation are reported. (Kako, I.)

  4. Spatial Modeling of Urban Vegetation and Land Surface Temperature: A Case Study of Beijing

    Directory of Open Access Journals (Sweden)

    Chudong Huang

    2015-07-01

    Full Text Available The coupling relationship between urban vegetation and land surface temperature (LST has been heatedly debated in a variety of environmental studies. This paper studies the urban vegetation information and LST by utilizing a series of remote sensing imagery covering the period from 1990 to 2007. Their coupling relationship is analyzed, in order to provide the basis for ecological planning and environment protection. The results show that the normalized difference vegetation index (NDVI, urban vegetation abundance (UVA and urban forest abundance (UFA are negatively correlated with LST, which means that both urban vegetation and urban forest are capable in decreasing LST. The apparent influence of urban vegetation and urban forest on LST varies with the spatial resolution of the imagery, and peaks at the resolutions ranging from 90 m to 120 m.

  5. The Periodic Pyramid

    Science.gov (United States)

    Hennigan, Jennifer N.; Grubbs, W. Tandy

    2013-01-01

    The chemical elements present in the modern periodic table are arranged in terms of atomic numbers and chemical periodicity. Periodicity arises from quantum mechanical limitations on how many electrons can occupy various shells and subshells of an atom. The shell model of the atom predicts that a maximum of 2, 8, 18, and 32 electrons can occupy…

  6. Book Reviews in Periodicals.

    Science.gov (United States)

    Ettelt, Harold J.

    All recent issues of periodicals found which contain indexed book reviews are listed in this compilation from Drake Memorial Library at the New York State University at Brockport. The periodicals are listed by 29 subject headings in this informal guide designed to be used at Drake Library. The number of reviews in the periodical in a recent year…

  7. Absorption of some mineral salts by root system of different woody species and accumulation over a whole vegetative cycle (1963); Absorption de quelques sels par l'appareil radiculaire de differentes especes ligneuses et accumulation au cours d'un cycle vegetatif complet (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Gagnaire, J; Gerard, J M [Commisariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1963-07-01

    The concentration power of plant tissues and the translocation speed of mineral salts are considerably varying with the absorbed salt, the botanical species, the considered tissue and the part of the vegetative cycle. In Grenoble, with Picea excelsa, the 'true dormancy' is short (half-november, end of december). It is accompanied by a pre-dormancy period (October, half-november) and a post dormancy period (January, february, march). In vegetative period, Picea excelsa leaves are less concentrating mineral salt than Acer campestris leaves (coefficient 2 for calcium - 3 for phosphates) and Populus nigra leaves (coefficient 3 for calcium, coefficient 5 for phosphates). (author) [French] Le pouvoir de concentration de tissus vegetaux, et particulierement la vitesse de transport des sels mineraux varient beaucoup selon le sel mineral absorbe, l'espece vegetale, le tissu considere ainsi que la periode du cycle vegetatif. A Grenoble, pour les epiceas 'la dormance veritable' est courte (mi-novembre, fin decembre). Elle est encadree par des periodes de pre-dormance (octobre, mi-novembre) et de post-dormance (janvier, fevrier, mars). Pendant la periode vegetative, le pouvoir de concentration de sels mineraux des aiguilles d'epiceas est plus faible que celui des feuilles d'erables (coefficient 2 pour le calcium - coefficient 3 pour les phosphates) ou que celui des feuilles de peupliers (coefficient 3 pour le calcium - coefficient 5 pour les phosphates). (auteur)

  8. Seleção para duração do ciclo vegetativo em batata e relação com a produtividade de tubérculos Selection for vegetative growth period and its relationship to tuber yield of potato

    Directory of Open Access Journals (Sweden)

    Gabriel B Rodrigues

    2009-09-01

    Full Text Available As cultivares de batata no Brasil geralmente apresentam ciclo vegetativo de 90 a 110 dias, sendo bem mais longo em países de clima temperado, podendo chegar até 150 dias. O ciclo vegetativo longo nestes países proporciona maior produtividade e constitui-se em alternativa para aumento da produção de tubérculos sob condições tropicais. Os objetivos deste trabalho foram avaliar o potencial da seleção para aumentar ou diminuir o ciclo vegetativo da batata e verificar a relação entre a duração do ciclo vegetativo e a produção de tubérculos em condições tropicais. Na primeira geração clonal foram avaliados a produção de tubérculos e o ciclo vegetativo de 1.561 genótipos oriundos de 22 famílias clonais. Na segunda geração clonal foram avaliadas as mesmas características em 320 genótipos selecionados para ciclo vegetativo precoce, intermediário e tardio. A seleção nas gerações iniciais foi eficiente, tanto para diminuir permitiu obter maior ganho do que a seleção entre famílias. Os genótipos mais tardios foram mais produtivos que os mais precoces.Potato cultivars in Brazil generally present a growth cycle duration ranging from 90 to 110 days, whereas in countries located in temperate climate it can reach up to 150 days. Longer vegetative growth cycle in these countries confer higher tuber yield and, in tropical countries it also could be an alternative to increase tuber yield. In this work we evaluated the selection potential for longer or shorter growth cycle duration of potato clones and we determined the relationship between growth cycle duration and tuber yield. In the first clonal generation tuber yield and growth cycle duration were evaluated on 1561 genotypes derived from 22 clonal families. In the second clonal generation, the same traits were evaluated on 320 genotypes selected for earliness, intermediate and late vegetative cycle. Selection in the initial generations was efficient both to decrease and to

  9. Global isoprene and monoterpene emissions under changing climate, vegetation, CO2 and land use

    DEFF Research Database (Denmark)

    Hantson, Stijn; Knorr, Wolfgang; Schurgers, Guy

    2017-01-01

    Plants emit large quantities of isoprene and monoterpenes, the main components of global biogenic volatile organic compound (BVOC) emissions. BVOCs have an important impact on the atmospheric composition of methane, and of short-lived radiative forcing agents (e.g. ozone, aerosols etc.). It is th......Plants emit large quantities of isoprene and monoterpenes, the main components of global biogenic volatile organic compound (BVOC) emissions. BVOCs have an important impact on the atmospheric composition of methane, and of short-lived radiative forcing agents (e.g. ozone, aerosols etc.......). It is therefore necessary to know how isoprene and monoterpene emissions have changed over the past and how future changes in climate, land-use and other factors will impact them. Here we present emission estimates of isoprene and monoterpenes over the period 1901–2 100 based on the dynamic global vegetation...... model LPJ-GUESS, including the effects of all known important drivers. We find that both isoprene and monoterpene emissions at the beginning of the 20th century were higher than at present. While anthropogenic land-use change largely drives the global decreasing trend for isoprene over the 20th century...

  10. Comparison of vegetable shortening and cocoa butter as vehicles for cortisol manipulation in Salmo trutta

    DEFF Research Database (Denmark)

    Birnie-Gauvin, Kim; Peiman, K. S.; Larsen, M. H.

    2018-01-01

    This study demonstrates that vegetable shortening and cocoa butter are two effective vehicles for intraperitoneal cortisol implants in juvenile teleosts, specifically brown trout Salmo trutta, residing in north temperate freshwater environments. Each vehicle showed a different pattern of cortisol...... elevation. Vegetable shortening was found to be a more suitable vehicle for long-term cortisol elevation [elevated at 3, 6 and 9 days post treatment (dpt)], while cocoa butter may be better suited for short-term cortisol elevation (only elevated at 3 dpt). Additionally, plasma cortisol levels were higher...... with cortisol–vegetable shortening than with cortisol–cocoa butter implants. Plasma glucose levels were elevated 6 and 9 dpt for fishes injected with cortisol–vegetable shortening, but did not change relative to controls and shams in cortisol–cocoa butter fishes. In conclusion, vegetable shortening and cocoa...

  11. ROOT VEGETABLES, BREEDING TRENDS, RESULTS

    Directory of Open Access Journals (Sweden)

    M. I. Fedorova

    2017-01-01

    Full Text Available The main advantage of root vegetables is their unique specificity and high economic importance. The benefits and medicinal properties of root vegetables being highly demanded by the market requirements to the commodity are highlighted in the article. The main directions of breeding program for root vegetable crops, including species of Apiaceae family with carrot, parsnips; Chenopodioideae family with red beet; Brassicaceae family with radish, Daikon, Raphanus sativus L. var. lobo Sazonova & Stank, turnip and rutabaga. Initial breeding accessions of carrot, red beet, radish, Daikon, Raphanus sativus L. var. lobo Sazonova & Stank, turnip and rutabaga have been selected out to be used for breeding program for heterosis. The mf and ms breeding lines were developed, and with the use of them the new gene pool was created. Variety supporting breeding program and methods were also proposed. 

  12. Novel Bioplastics and biocomposites from Vegetable Oils

    Energy Technology Data Exchange (ETDEWEB)

    Henna, Phillip H. [Iowa State Univ., Ames, IA (United States)

    2008-01-01

    divided into four chapters. The first chapter discusses the synthesis and characterization of biobased thermosets prepared by the free radical polymerization of conjugated linseed oil with commercially available monomers. The second chapter covers the synthesis and characterization of a chemically modified castor oil and its copolymerization with cyclooctene via ring opening metathesis polymerization (ROMP). The third chapter looks at the ROMP of a commercially available vegetable oil containing an unsaturated bicyclic moiety with dicyclopentadiene (DCPD) and characterization of the resulting materials. The fourth chapter discusses the reinforcement of a ROMP resin using short glass fibers to make composite materials.

  13. Local vegetables in Cameroon: Corchorus species used as a vegetable.

    NARCIS (Netherlands)

    Westphal-Stevels, J.M.C.

    1986-01-01

    An agro-botanical study of local vegetables in Cameroon is in preparation, including the taxonomy, identity, morphology, agronomy and nutritional value of about 70 species. Corchorus olitorius L. and other edible species of the genus Corchorus L. (Tiliaceae) are part of this study. The wide

  14. Reproducibility and relative validity of a brief quantitative food frequency questionnaire for assessing fruit and vegetable intakes in North-African women.

    Science.gov (United States)

    Landais, E; Gartner, A; Bour, A; McCullough, F; Delpeuch, F; Holdsworth, M

    2014-04-01

    In the context of a rapidly increasing prevalence of noncommunicable diseases, fruit and vegetables could play a key preventive role. To date, there is no rapid assessment tool available for measuring the fruit and vegetable intakes of North-African women. The present study aimed to investigate the reproducibility and relative validity of an eight-item quantitative food frequency questionnaire that measures the fruit and vegetable intakes (FV-FFQ) of Moroccan women. During a 1-week period, 100 women, living in the city of Rabat, Morocco (aged 20-49 years) completed the short FV-FFQ twice: once at baseline (FV-FFQ1) and once at the end of the study (FV-FFQ2). In the mean time, participants completed three 24-h dietary recalls. All questionnaires were administered by interviewers. Reproducibility was assessed by computing Spearman's correlation coefficients, intraclass correlation (ICC) coefficients and kappa statistics. Relative validity was assessed by computing Wilcoxon signed-rank tests and Spearman's correlation coefficients, as well as by performing Bland-Altman plots. In terms of reproducibility, Spearman's correlation coefficient was 0.56; ICC coefficient was 0.68; and weighted kappa was 0.35. In terms of relative validity, compared with the three 24-h recalls, the FV-FFQ slightly underestimated mean fruit and vegetable intakes (-10.9%; P = 0.006); Spearman's correlation coefficient was 0.69; at the individual level, intakes measured by the FV-FFQ were between 0.39 and 2.19 times those measured by the 24-h recalls. The brief eight-item FV-FFQ is a reliable and relatively valid tool for measuring mean fruit and vegetable intakes at the population level, although this is not the case at the individual level. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

  15. Orbital scale vegetation change in Africa

    Science.gov (United States)

    Dupont, Lydie

    2011-12-01

    Palynological records of Middle and Late Pleistocene marine sediments off African shores is reviewed in order to reveal long-term patterns of vegetation change during climate cycles. Whether the transport of pollen and spores from the source areas on the continent to the ocean floor is mainly by wind or predominantly by rivers depends on the region. Despite the differences in transportation, accumulation rates in the marine sediments decline exponentially with distance to the shore. The marine sediments provide well-dated records presenting the vegetation history of the main biomes of western and southern Africa. The extent of different biomes varied with the climate changes of the glacial interglacial cycle. The Mediterranean forest area expanded during interglacials, the northern Saharan desert during glacials, and the semi-desert area in between during the transitions. In the sub-Saharan mountains ericaceous scrubland spread mainly during glacials and the mountainous forest area often increased during intermediate periods. Savannahs extended or shifted to lower latitudes during glacials. While the representation of the tropical rain forest fluctuated with summer insolation and precession, that of the subtropical biomes showed more obliquity variability or followed the pattern of glacial and interglacials.

  16. Final vegetative cover for closed waste sites

    International Nuclear Information System (INIS)

    Cook, J.R.; Salvo, S.K.

    1993-01-01

    Low-level, hazardous, and mixed waste disposal sites normally require some form of plant material to prevent erosion of the final closure cap. Waste disposal sites are closed and capped in a complex scientific manner to minimize water infiltration and percolation into and through the waste material. Turf type grasses are currently being used as an interim vegetative cover for most sites. This coverage allows for required monitoring of the closure cap for settlement and maintenance activities. The purpose of this five year study was to evaluate plant materials for use on wastes sites after the post-closure care period that are quickly and easily established and economically maintained, retard water infiltration, provide maximum year-round evapotranspiration, are ecologically acceptable and do not harm the closure cap. The results of the study suggest that two species of bamboo (Phyllostachys (P.) bissetii and P. rubromarginata) can be utilized to provide long lived, low maintenance, climax vegetation for the waste sites after surveillance and maintenance requirements have ceased

  17. The influence of vegetation dynamics on anthropogenic climate change

    Directory of Open Access Journals (Sweden)

    U. Port

    2012-11-01

    Full Text Available In this study, vegetation–climate and vegetation–carbon cycle interactions during anthropogenic climate change are assessed by using the Earth System Model of the Max Planck Institute for Meteorology (MPI ESM that includes vegetation dynamics and an interactive carbon cycle. We assume anthropogenic CO2 emissions according to the RCP 8.5 scenario in the time period from 1850 to 2120. For the time after 2120, we assume zero emissions to evaluate the response of the stabilising Earth System by 2300.

    Our results suggest that vegetation dynamics have a considerable influence on the changing global and regional climate. In the simulations, global mean tree cover extends by 2300 due to increased atmospheric CO2 concentration and global warming. Thus, land carbon uptake is higher and atmospheric CO2 concentration is lower by about 40 ppm when considering dynamic vegetation compared to the static pre-industrial vegetation cover. The reduced atmospheric CO2 concentration is equivalent to a lower global mean temperature. Moreover, biogeophysical effects of vegetation cover shifts influence the climate on a regional scale. Expanded tree cover in the northern high latitudes results in a reduced albedo and additional warming. In the Amazon region, declined tree cover causes a regional warming due to reduced evapotranspiration. As a net effect, vegetation dynamics have a slight attenuating effect on global climate change as the global climate cools by 0.22 K due to natural vegetation cover shifts in 2300.

  18. Effect of ecological factors on the zonation of wetland vegetation

    Directory of Open Access Journals (Sweden)

    Richard Hrivnák

    2011-01-01

    Full Text Available The influence of some ecological factors to aquatic and marsh vegetation was studied during 1998-2000. Three basic vegetation units (Caricetum buekii, Typhetum latifoliae and Ceratophylletum submersi and three transitional communities were defined in the belt transect, which was established along the moisture gradient. The content of available soil nutrients in individual vegetation types differed only in case of the Ceratophyllum submersum community, where a higher magnesium and nitrogen content accumulated due to specific environmental conditions. Water and marsh vegetation is usually characterised by a pronounced spatial and temporal dynamics. In the studied area, its zonation was dependent from the terrain morphology, and both depth and duration of floods. The fluctuation of ground and surface water table during a three-year period caused changes in the occurrence and cover of several species (e.g. Carex buekii, Typha latifolia, aquatic macrophytes. Pronounced changes in the cover of some species occurred even within a single vegetation season due to the long-term sink of water table below the ground surface.

  19. Vegetables, Coctails & Reflections / Marco Laimre

    Index Scriptorium Estoniae

    Laimre, Marko, 1968-

    2006-01-01

    Pealkirja "Vegetables, Coctails & Reflections" kandis Tallinna Kunstihoones 8.04.-28.05.2006 avatud Elin Kardi, Marko Mäetamme, Marco Laimre ja Andres Tali ühisnäitusel "Vägivald ja propaganda" Marco Laimre installatsioon. Marco Laimre esinemine raadiosaates "kunst.er" Klassikaraadios 16.04.2006

  20. Vegetable Crop Pests. MEP 311.

    Science.gov (United States)

    Kantzes, James G.; And Others

    As part of a cooperative extension service series by the University of Maryland, this publication introduces the identification and control of common agricultural pests of vegetable crops. The first of the five sections defines "pest" and "weed" and generally introduces different kinds of pests in the categories of insects,…