Sample records for frequency sweeper seeded

  1. Adhesive Contact Sweeper

    NASA Technical Reports Server (NTRS)

    Patterson, Jonathan D.

    1993-01-01

    Adhesive contact sweeper removes hair and particles vacuum cleaner leaves behind, without stirring up dust. Also cleans loose rugs. Sweeper holds commercially available spools of inverted adhesive tape. Suitable for use in environments in which air kept free of dust; optics laboratories, computer rooms, and areas inhabited by people allergic to dust. For carpets, best used in tandem with vacuum cleaner; first pass with vacuum cleaner removes coarse particles, and second pass with sweeper extracts fine particles. This practice extends useful life of adhesive spools.

  2. Design, fabrication, installation, and testing of high energy sweeper

    SciTech Connect

    Ghosh, S.; Sarkar, A.; Sonti, S. S. K.; Rao, S.; Sivakumar, V. V.; Rai, A.; Barua, P.; Datta, S. K.; Bhowmik, R. K.; Roy, A. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2006-07-15

    A room temperature high-energy sweeper had been designed, fabricated, and installed at the postacceleration section of the Tandem accelerator. The sweeper, a part of the new pulsing system, is being used to inject the bunched beam without dark current into the linear accelerator acting as a booster of the Tandem. The resonance frequency of the sweeper was set at 6.0625 MHz and a quality factor of {approx}1300 was achieved. During off-line testing of the sweeper, a deflector voltage of {approx}30 kV had been measured for an input power of 300 W. A pair of indigenously fabricated capacitors is used for fine-tuning of the resonance frequency. The silver plated coil of the tank circuit was fabricated with two concentric copper tubes. During the successful beam test of the sweeper, a peak to dark current ratio of 97% has been achieved.

  3. RADIOLOGICAL DECONTAMINATION SWEEPER. Technical Report No. 172. Final Report

    Microsoft Academic Search

    Nehlsen

    1961-01-01

    Three types of pavement sweepers were investigated to determine their ; adaptability for high-rate radiological decontaminatibn. A runway sweeper ; utilizing an air nozzle pickup was found to be unadaptable. Ordinary street ; sweepers can perform limited services as decontamination sweepers, but are not ; suitable for complete development as high-rate units. A sweeper developed for ; Air Force decontamination

  4. PERFORMANCE TESTING OF THE DIPERNA SWEEPER

    EPA Science Inventory

    The DiPerna Sweeper, a partial-vacuum oil skimmer, was tested in a two-week test program conducted at the U.S. Environmental Test Tank (OHMSETT) in Leonardo, New Jersey. Forty-three oil recovery tests were run. The object of the program was to establish a range of best performanc...

  5. Acute Lung Function Response to Dust in Street Sweepers

    PubMed Central

    Johncy S., Smilee; G., Dhanyakumar; Samuel T., Vivian; K.T., Ajay; Bondade, Suresh Y.

    2013-01-01

    Background: Sweepers are chronically exposed to dust raised during sweeping. Dust is regarded as the most influential agent and it is perceived as a frequent cause of respiratory system illness and may cause acute and chronic lung function impairment. Aims: The aim of this study was to determine the acute lung function changes in sweepers exposed to dust generated from street sweeping. Material and Methods: This study was conducted in central Karnataka, India, on 25 female sweepers and 25 healthy female control subjects who were comparable in age, height and weight. The pulmonary function test was performed in controls, sweepers before and after sweeping, by using RMS medspiror and results were compared by Student’s unpaired ‘t’ test. Results: The results showed a significant reduction in percent predicted values and mean values of FVC, FEV1, PEFR, FEF25-75% and FEF 200-1200 between sweepers and their matched controls. Pulmonary function after sweeping also showed a significant decrease. Conclusions: On comparing the pulmonary functions of sweepers before and after sweeping, it was concluded that inhalation of dust acutely affected the lung function of sweepers in India and that sweepers were at a risk of developing occupation related lung function impairment. We recommend that the workers should use protective face masks and do wet sweeping instead of dry sweeping during sweeping activity. PMID:24298455

  6. Energy Reconstruction with the Sweeper Magnet Focal Plane Detector

    Microsoft Academic Search

    George Hitt; Michael Thoennessen; Nathan Frank; Matt Cooper; A. M. Vander Molen; Brian Nett

    2002-01-01

    The Sweeper Magnet Focal Plane Detector project is a collaboration of the National High Magnetic Field Laboratory (NHMFL) at Florida State University and the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. The NHMFL will construct the Sweeper Magnet, a large C-type magnet necessary for the bending of rigid nuclear beams. The NSCL will build the Focal Plane Detectors

  7. Nuclear-powered space debris sweeper

    NASA Technical Reports Server (NTRS)

    Metzger, John D.; Leclaire, Rene J., Jr.; Howe, Steven D.; Burgin, Karen C.

    1989-01-01

    Future spacecraft design will be affected by collisions with man-made debris orbiting the earth. Most of this orbital space debris comes from spent rocket stages. It is projected that the source of future debris will be the result of fragmentation of large objects through hypervelocity collisions. Orbiting spacecraft will have to be protected from hypervelocity debris in orbit. The options are to armor the spacecraft, resulting in increased mass, or actively removing the debris from orbit. An active space debris sweeper is described which will utilize momentum transfer to the debris through laser-induced ablation to alter its orbital parameters to reduce orbital lifetime with eventual entry into the earth's atmosphere where it will burn. The paper describes the concept, estimates the amount of velocity change (Delta V) that can be imparted to an object through laser-induced ablation, and investigates the use of a neutral particle beam for the momentum transfer. The space sweeper concept could also be extended to provide a collision avoidance system for the space station and satellites, or could be used for collision protection during interplanetary travel.

  8. Narrowband alexandrite laser injection seeded with frequency dithered diode laser

    Microsoft Academic Search

    Geary Schwemmer; H. S. Lee; Coorg Prasad

    1991-01-01

    Narrowband radiation is produced from a pulsed alexandrite laser when injection seeded with the output of a low power, tunable, continuous wave single mode diode laser. Injection seeded power oscillators are easier to frequency stabilize than etalon narrowed lasers, are more efficient and less prone to optical damage. AlGaAs diode lasers are available with wavelengths from 760 to 770 nm

  9. IMPROVED STREET SWEEPERS FOR CONTROLLING URBAN INHALABLE PARTICULATE MATTER

    EPA Science Inventory

    The report gives results of an experimental program to develop design modifications that can be used to improve the ability of municipal street sweepers to remove inhalable dust particles from streets. (Dust emissions from paved roads are a major source of urban inhalable particu...

  10. Energy Reconstruction with the Sweeper Magnet Focal Plane Detector

    NASA Astrophysics Data System (ADS)

    Hitt, George; Thoennessen, Michael; Frank, Nathan; Cooper, Matt; Vander Molen, A. M.; Nett, Brian

    2002-10-01

    The Sweeper Magnet Focal Plane Detector project is a collaboration of the National High Magnetic Field Laboratory (NHMFL) at Florida State University and the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. The NHMFL will construct the Sweeper Magnet, a large C-type magnet necessary for the bending of rigid nuclear beams. The NSCL will build the Focal Plane Detectors consisting of two Cathode Readout Drift Detectors (CRDCs) for taking precise position measurements and an Ion Chamber with plastic scintillators for taking ?E and E_tot measurements. During beam experiments, the Sweeper Magnet will bend the charged fragments for detection in the Focal Plane Detector. As fragments pass through, each CRDC will measure a position where fragments impinge. This will allow experimenters to calculate a fragment's trajectory and determine where it will strike the large stopping scintillator for the E_tot measurements. In order to obtain accurate energies of the fragments, the position sensitivity of the large scintillator must be mapped. By finding a functional relationship between the position of the impinging particles and the attenuation of the light emitted by the scintillator, one can use the known position information from the CRDCs to reconstruct the energy of fragments. The position sensitivity of the large plastic scintillator as measured with a collimated, pulsed blue diode will be presented.

  11. Frequency stabilization of a single-frequency Q-switched Tm:YAG laser by using injection seeding technique.

    PubMed

    Zhang, Yunshan; Gao, Chunqing; Gao, Mingwei; Zheng, Yan; Wang, Lei; Wang, Ran

    2011-07-20

    A stable single-frequency Q-switched Tm:YAG laser was demonstrated. The laser was injection seeded by a monolithic nonplanar ring oscillator laser utilizing the ramp-hold-fire technique. The measurements of the output parameters were presented. This paper focused on investigation of the frequency stability of the injection-seeded laser, which was measured by optical heterodyne technique. A method used to restrict the frequency jitter of the laser was discussed. The fluctuation of the laser frequency was reduced from 2.36 MHz (rms) to 1.07 MHz (rms) in 1 h by optimizing the voltage of the piezoelectric translator. PMID:21772412

  12. High Neotyphodium infection frequencies in tillers and seed of infected tall fescue plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research quantified frequencies of Neotyphodium infected (E+) tillers and mature seed from field-grown E+ plants of two wild tall fescue accessions from Morocco and Sardinia, Italy. Tiller infection rates were 100% (n = 50 from 10 E+ plants/accession) for each accession and over 99% of the seed...

  13. Frequency-asymmetric gain profile in a seeded Raman amplifier

    SciTech Connect

    Repasky, K.S.; Carlsten, J.L. [Department of Physics, Montana State University, Bozeman, Montana 59717 (United States)] [Department of Physics, Montana State University, Bozeman, Montana 59717 (United States)

    1996-11-01

    This paper examines the effect of index guiding on Raman gain. The slowly varying Maxwell wave equation including both the real and imaginary parts of the Raman susceptibility for a seeded Raman amplifier is explored. Using a Gauss-Laguerre mode expansion for the Stokes field, the output Stokes energy is numerically studied as a function of gain and detuning from the Raman resonance. The calculations indicate that the real part of the Raman susceptibility causes the Raman medium to act as a lens when the Stokes seed is detuned from the Raman resonance. This focusing effect leads to higher peak Stokes energy when the Stokes seed is tuned to the blue side of the Raman resonance. Specifically for Raman scattering in H{sub 2} with a pump laser at 532 nm and an input seed near 683 nm, the peak Stokes energy can shift by as much as 300 MHz from the Raman resonance. An experiment which confirms these predictions is also presented. {copyright} {ital 1996 The American Physical Society.}

  14. A Vehicle for Research: Using Street Sweepers to Explore the Landscape of Environmental Community Action

    E-print Network

    Aoki, Paul M.

    A Vehicle for Research: Using Street Sweepers to Explore the Landscape of Environmental Community. To inform research on mobile environmental sensing, we conducted design fieldwork with government, private" by grounding our interviews and affording us status as environmental action researchers. In this paper, we

  15. Narrowband alexandrite laser injection seeded with frequency-dithered diode laser

    Microsoft Academic Search

    Geary K. Schwemmer; Hyo Sang Lee; Coorg R. Prasad

    1991-01-01

    Narrowband radiation is produced from a pulsed alexandrite laser when injection seeded with the output of a low-power, tunable, continuous-wave, single-mode diode laser. Injection seeded power oscillators are easier to frequency stabilize than etalong narrowed lasers, are more efficient, and less prone to optical damage. AlGaAs diode lasers are available with wavelengths from 760 to 770 nm in the oxygen

  16. Absolute frequency stabilization of an injection-seeded optical parametric oscillator

    NASA Astrophysics Data System (ADS)

    Plusquellic, D. F.; Votava, O.; Nesbitt, D. J.

    1996-03-01

    A method is described that provides absolute frequency stabilization and calibration of the signal and idler waves generated by an injection-seeded optical parametric oscillator (OPO). The method makes use of a He-Ne stabilized transfer cavity (TC) to control the frequencies of the cw sources used to seed both the pump laser and OPO cavity. The TC serves as a stable calibration source for the signal and idler waves by providing marker fringes as the seed laser is scanned. Additionally, an acoustic-optic modulator (AOM) is used to shift the OPO seed laser's frequency before locking it onto the TC. The sidebands of the AOM are tunable over more than one free spectral range of the TC, thereby permitting stabilization of the signal and idler waves at any frequency. A 25-MHz residual error in the absolute frequency stabilities of the pump, signal, and idler waves is experimentally demonstrated, which is roughly 30% of the 160-MHz near-transform-limited linewidths of the signal and idler pulses.

  17. Absolute frequency stabilization of an injection-seeded optical parametric oscillator.

    PubMed

    Plusquellic, D F; Votava, O; Nesbitt, D J

    1996-03-20

    A method is described that provides absolute frequency stabilization and calibration of the signal and idler waves generated by an injection-seeded optical parametric oscillator (OPO). The method makes use of a He-Ne stabilized transfer cavity (TC) to control the frequencies of the cw sources used to seed both the pump laser and OPO cavity. The TC serves as a stable calibration source for the signal and idler waves by providing marker fringes as the seed laser is scanned. Additionally, an acoustic-optic modulator (AOM) is used to shift the OPO seed laser's frequency before locking it onto the TC. The sidebands of the AOM are tunable over more than one free spectral range of the TC, thereby permitting stabilization of the signal and idler waves at any frequency. A ±25-MHz residual error in the absolute frequency stabilities of the pump, signal, and idler waves is experimentally demonstrated, which is roughly 30% of the 160-MHz near-transform-limited linewidths of the signal and idler pulses. PMID:21085259

  18. Effect of Finite Pulse Length and Laser Frequency Chirp on HGHG and EEHG Seeding

    SciTech Connect

    Stupakov, G.; /SLAC

    2011-11-18

    Theoretical studies of high-gain harmonic generation (HGHG) and echo-enabled harmonic generation (EEHG) often start from a simplified model in which the beam is assumed infinitely long and longitudinally uniform and the laser induced energy modulation is perfectly sinusoidal and of infinite duration. In such a model the resulting seed has a spectrum consisting of a collection of delta-functions (of zero width) located at the harmonics of the laser frequency. Being a useful tool for study of the seed bunching amplitudes, such a model cannot be used for realistic analysis the spectral properties of the seed. In this paper we take into account the finite duration of the laser pulse as well as some possible laser phase errors to study their effect on the spectrum of the seed.

  19. Experimental validation of the importance of seed complement frequency to siRNA specificity

    PubMed Central

    Anderson, Emily M.; Birmingham, Amanda; Baskerville, Scott; Reynolds, Angela; Maksimova, Elena; Leake, Devin; Fedorov, Yuriy; Karpilow, Jon; Khvorova, Anastasia

    2008-01-01

    Pairing between the hexamer seed region of a small interfering RNA (siRNA) guide strand (nucleotides 2–7) and complementary sequences in the 3? UTR of mature transcripts has been implicated as an important element in off-target gene regulation and false positive phenotypes. To better understand the association between seed sequences and off-target profiles we performed an analysis of all possible (4096) hexamers and identified a nonuniform distribution of hexamer frequencies across the 3? UTR transcriptome. Subsequent microarray analysis of cells transfected with siRNAs having seeds with low, medium, or high seed complement frequencies (SCFs) revealed that duplexes with low SCFs generally induced fewer off-targets and off-target phenotypes than molecules with more abundant 3? UTR complements. These findings provide the first experimentally validated strategy for designing siRNAs with enhanced specificity and allow for more accurate interpretation of high throughput screening data generated with existing siRNA/shRNA collections. PMID:18367722

  20. Narrow-band injection seeding of a terahertz frequency quantum cascade laser: Selection and suppression of longitudinal modes

    SciTech Connect

    Nong, Hanond, E-mail: Nong.Hanond@rub.de; Markmann, Sergej; Hekmat, Negar; Jukam, Nathan, E-mail: Nathan.Jukam@rub.de [Arbeitsgruppe Terahertz Spektroskopie und Technologie, Ruhr-Universität Bochum, Bochum 44780 (Germany); Pal, Shovon [Arbeitsgruppe Terahertz Spektroskopie und Technologie, Ruhr-Universität Bochum, Bochum 44780 (Germany); Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum 44780 (Germany); Mohandas, Reshma A.; Dean, Paul; Li, Lianhe; Linfield, Edmund H.; Giles Davies, A. [School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom); Wieck, Andreas D. [Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Bochum 44780 (Germany)

    2014-09-15

    A periodically poled lithium niobate (PPLN) crystal with multiple poling periods is used to generate tunable narrow-bandwidth THz pulses for injection seeding a quantum cascade laser (QCL). We demonstrate that longitudinal modes of the quantum cascade laser close to the gain maximum can be selected or suppressed according to the seed spectrum. The QCL emission spectra obtained by electro-optic sampling from the quantum cascade laser, in the most favorable case, shows high selectivity and amplification of the longitudinal modes that overlap the frequency of the narrow-band seed. Proper selection of the narrow-band THz seed from the PPLN crystal discretely tunes the longitudinal mode emission of the quantum cascade laser. Moreover, the THz wave build-up within the laser cavity is studied as a function of the round-trip time. When the seed frequency is outside the maximum of the gain spectrum the laser emission shifts to the preferential longitudinal mode.

  1. Narrow-band injection seeding of a terahertz frequency quantum cascade laser: Selection and suppression of longitudinal modes

    NASA Astrophysics Data System (ADS)

    Nong, Hanond; Pal, Shovon; Markmann, Sergej; Hekmat, Negar; Mohandas, Reshma A.; Dean, Paul; Li, Lianhe; Linfield, Edmund H.; Giles Davies, A.; Wieck, Andreas D.; Jukam, Nathan

    2014-09-01

    A periodically poled lithium niobate (PPLN) crystal with multiple poling periods is used to generate tunable narrow-bandwidth THz pulses for injection seeding a quantum cascade laser (QCL). We demonstrate that longitudinal modes of the quantum cascade laser close to the gain maximum can be selected or suppressed according to the seed spectrum. The QCL emission spectra obtained by electro-optic sampling from the quantum cascade laser, in the most favorable case, shows high selectivity and amplification of the longitudinal modes that overlap the frequency of the narrow-band seed. Proper selection of the narrow-band THz seed from the PPLN crystal discretely tunes the longitudinal mode emission of the quantum cascade laser. Moreover, the THz wave build-up within the laser cavity is studied as a function of the round-trip time. When the seed frequency is outside the maximum of the gain spectrum the laser emission shifts to the preferential longitudinal mode.

  2. Plasma sweeper to control the coupling of RF power to a magnetically confined plasma

    DOEpatents

    Motley, Robert W. (Princeton, NJ); Glanz, James (Lawrenceville, NJ)

    1985-01-01

    A device for coupling RF power (a plasma sweeper) from a phased waveguide array for introducing RF power to a plasma having a magnetic field associated therewith comprises at least one electrode positioned near the plasma and near the phased waveguide array; and a potential source coupled to the electrode for generating a static electric field at the electrode directed into the plasma and having a component substantially perpendicular to the plasma magnetic field such that a non-zero vector cross-product of the electric and magnetic fields exerts a force on the plasma causing the plasma to drift.

  3. Spectral linewidth preservation in parametric frequency combs seeded by dual pumps.

    PubMed

    Tong, Zhi; Wiberg, Andreas O J; Myslivets, Evgeny; Kuo, Bill P P; Alic, Nikola; Radic, Stojan

    2012-07-30

    We demonstrate new technique for generation of programmable-pitch, wideband frequency combs with low phase noise. The comb generation was achieved using cavity-less, multistage mixer driven by two tunable continuous-wave pump seeds. The approach relies on phase-correlated continuous-wave pumps in order to cancel spectral linewidth broadening inherent to parametric comb generation. Parametric combs with over 200-nm bandwidth were obtained and characterized with respect to phase noise scaling to demonstrate linewidth preservation over 100 generated tones. PMID:23038314

  4. Frequency mixing in accelerator based sources and application to tunable seeded free-electron lasers

    NASA Astrophysics Data System (ADS)

    Evain, C.; Roussel, E.; Szwaj, C.; Bielawski, S.

    2014-12-01

    In this article we address the problem of tunability of seeded free-electron lasers (FELs), working typically in the domain of the vacuum ultraviolet. The seeding of FELs with an external laser permits us to obtain FEL pulses with both good longitudinal coherence and good stability properties (contrary to an amplification starting from noise). However, with a fixed external laser wavelength, only amplification at harmonics of this wavelength is possible. If full tunability is wanted, it is necessary to have a tunable external source; but this type of source has much less power, hence it is much harder to reach high harmonics numbers. Here we propose the so-called frequency mixing scheme (from its analogy with the similar process in nonlinear optics), based on two laser/electron interactions. Numerical and analytic studies show that it permits to increase significantly the tunability at short wavelengths using a low-energy tunable source. Numerical simulations are made with the parameters of FERMI-FEL 1, the first seeded FEL for user operation.

  5. The Sectoral Sweeper Scheme for Wireless Sensor Networks: Adaptive Antenna Array Based Sensor Node Management and Location Estimation

    Microsoft Academic Search

    Ayhan Erdogan; Vedat Coskun; Adnan Kavak

    2006-01-01

    We introduce a novel sensor node management and location estimation method referred as sectoral sweeper (SS) scheme that uses an adaptive antenna array (AAA) at a central node in wireless sensor networks (WSNs). With the SS scheme, the central node can activate or deactivate the nodes in a desired region which is specified by beam direction and beam width of

  6. Effects of seeding methods on the fabrication of microcrystalline silicon solar cells using radio frequency plasma enhanced chemical vapor deposition

    Microsoft Academic Search

    Yuan-Min Li; Liwei Li; J. A. Anna Selvan; Alan E. Delahoy; Roland A. Levy

    2005-01-01

    Single junction p-i-n ?c-Si:H solar cells were prepared in a low-cost, large-area single chamber radio frequency plasma enhanced chemical vapor deposition system. The effects of seeding processes on the growth of ?c-Si:H i-layers and performance of ?c-Si:H solar cells were investigated. Seeding processes, usually featured by highly hydrogen rich plasma, are effective in inducing the growth of ?c-Si:H i-layers. It

  7. Frequency-locked, injection-seeded, pulsed narrowband optical parametric generator.

    PubMed

    Reichardt, Thomas A; Bambha, Ray P; Kulp, Thomas J; Schmitt, Randal L

    2003-06-20

    A frequency-locked, injection-seeded, pulsed optical parametric generator (OPG) has been developed for short-range infrared differential absorption lidar (DIAL) applications. The periodically poled lithium niobate OPG is pumped by a passively Q-switched Nd:YAG microlaser and is seeded by a distributed feedback (DFB) diode laser. The OPG is designed for DIAL measurement of a narrow R-branch transition of methane at 3.2704 microm. The output of the OPG is a two-pulse sequence with a 100-micros temporal separation between the pulses, where the first pulse is absorbed by methane and the second pulse is not absorbed. The first pulse is actively locked to the methane absorption feature by use of the derivative of the transmission spectrum through a reference cell. Although the device was not optimized for output power, the 3.27-microm OPG output energies of the first and second pulses are 5.5 and 5.9 microJ, respectively, producing 21 mW when operated at 1818 Hz. PMID:12833962

  8. RADIO-FREQUENCY DIELECTRIC HEATING OF ALFALFA SEED FOR REDUCTION OF HUMAN PATHOGENS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The problem of bacterial contamination of vegetable seed sprouts produced for human consumption is reviewed briefly. The potential for controlling human bacterial pathogens on alfalfa seed used in the production of sprouts by dielectric heating was studied by experimental exposure of alfalfa seed a...

  9. High-frequency mechanical stirring initiates anisotropic growth of seeds requisite for synthesis of asymmetric metallic nanoparticles like silver nanorods.

    PubMed

    Mahmoud, Mahmoud A; El-Sayed, Mostafa A; Gao, Jianping; Landman, Uzi

    2013-10-01

    High-speed stirring at elevated temperatures is shown to be effective in the symmetry-breaking process needed for the growth of the hard-to-synthesize silver nanorods from the polyol reduction of silver ions. This process competes with the facile formation of more symmetrical, spherical and cubic, nanoparticles. Once the seed is formed, further growth proceeds predominantly along the long axis, with a consequent increase of the particles' aspect ratio (that of the nanorod). When stirring is stopped shortly after seed formation, nanorods with a broad distribution of aspect ratios are obtained, while when the high-frequency stirring continues the distribution narrows significantly. The width of the nanorods can only be increased if the initial concentration of Ag(+) ions increases. Reducing the stirring speeds during seed formation lowers the yield of nanorods. Molecular dynamics simulations reveal that the formation of a nanometer-scale thin boundary region between a solid facet of the nanoparticle and the liquid around it, and the accommodation processes of metal (Ag) atoms transported through this boundary region from the liquid to the solid growth interface, are frustrated by sufficiently fast shear flow caused by high-frequency stirring. This arrests growth on seed facets parallel to the flow, leading, together with the preferential binding of the capping polymer to the (100) facet, to the observed growth in the (110) direction, resulting in silver nanorods capped at the ends by (111) facets and exposing (100) facets on the side walls. PMID:24053557

  10. H{sup -} beam extraction from a cesium seeded field effect transistor based radio frequency negative hydrogen ion source

    SciTech Connect

    Ando, A.; Matsuno, T.; Funaoi, T.; Tanaka, N. [School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Tsumori, K.; Takeiri, Y. [National Institute for Fusion Science, Toki 509-5292 (Japan)

    2012-02-15

    H{sup -} beam was successfully extracted from a cesium seeded ion source operated using a field effect transistor inverter power supply as a radio frequency (RF) wave source. High density hydrogen plasma more than 10{sup 19} m{sup -3} was obtained using an external type antenna with RF frequency of lower than 0.5 MHz. The source was isolated by an isolation transformer and H{sup -} ion beam was extracted from a single aperture. Acceleration current and extraction current increased with the increase of extraction voltage. Addition of a small amount of cesium vapor into the source enhanced the currents.

  11. H- beam extraction from a cesium seeded field effect transistor based radio frequency negative hydrogen ion source.

    PubMed

    Ando, A; Matsuno, T; Funaoi, T; Tanaka, N; Tsumori, K; Takeiri, Y

    2012-02-01

    H(-) beam was successfully extracted from a cesium seeded ion source operated using a field effect transistor inverter power supply as a radio frequency (RF) wave source. High density hydrogen plasma more than 10(19) m(-3) was obtained using an external type antenna with RF frequency of lower than 0.5 MHz. The source was isolated by an isolation transformer and H(-) ion beam was extracted from a single aperture. Acceleration current and extraction current increased with the increase of extraction voltage. Addition of a small amount of cesium vapor into the source enhanced the currents. PMID:22380279

  12. Broad bandwidth light-wave frequency synthesizer in the 1 1.1-µm range

    Microsoft Academic Search

    Frederik D. Nielsen; Lars Thrane; John Black; Anders O. Bjarklev; Peter E. Andersen

    2005-01-01

    We present a novel implementation of the lightwave synthesized frequency sweeper (LSFS) based on Ytterbium doped fiber amplifiers. The source can potentially be used for swept source optical coherence tomography (SS-OCT), which has recently been shown to have an improved signal to noise ratio compared to time domain OCT systems, and development of suitable swept wavelength sources is for this

  13. USD-FH: Jamming-resistant Wireless Communication using Frequency Hopping with Uncoordinated Seed Disclosure

    E-print Network

    Dai, Huaiyu

    techniques (e.g., Frequency Hop- ping (FH), Direct Sequence Spread Spectrum (DSSS)) have been widely used. INTRODUCTION Spread spectrum techniques such as Frequency Hopping (FH) and Direct Sequence Spread Spectrum

  14. The Development of a Frequency Control System of a Seeded Laser for DGV Application

    E-print Network

    Nelson, Brent

    2010-01-15

    For an effective Doppler Global Velocimeter (DGV), there is a requirement to accurately record and tune the frequency content of the laser used. The laser used for this experiment was an ND:YAG. Adjusting the mean frequency of the ND...

  15. The Development of a Frequency Control System of a Seeded Laser for DGV Application 

    E-print Network

    Nelson, Brent

    2010-01-15

    For an effective Doppler Global Velocimeter (DGV), there is a requirement to accurately record and tune the frequency content of the laser used. The laser used for this experiment was an ND:YAG. Adjusting the mean frequency of the ND...

  16. USD-FH: Jamming-resistant Wireless Communication using Frequency Hopping with Uncoordinated Seed Disclosure

    E-print Network

    Ning, Peng

    ), Direct Sequence Spread Spectrum (DSSS)) have been widely used for anti-jamming wireless communications such as Frequency Hopping (FH) and Direct Sequence Spread Spectrum (DSSS) are widely used to mitigate jamming

  17. 18+2 W at 589 nm via frequency doubling of diode-laser-seeded 1178-nm CW PM Raman fiber amplifier for deployment at ESO VLT

    Microsoft Academic Search

    W. G. Kaenders; A. Friedenauer; B. Ernstberger; V. Karpov; V. Protopopov; W. Clements; W. Hackenberg; D. Bonaccini Calia; St. A. Lewis

    2011-01-01

    The rationale and design of a a 589-nm Laser Guide Star System, based on amplification of narrow-band diode laser seeds using ESO's patented Raman Fiber approach in the near infrared and subsequent resonant frequency doubling, developed and realized by two industrial partners is presented.

  18. Single-frequency operation of diode-pumped 2 microm Q-switched Tm:YAG laser injection seeded by monolithic nonplanar ring laser.

    PubMed

    Gao, Chunqing; Lin, Zhifeng; Gao, Mingwei; Zhang, Yunshan; Zhu, Lingni; Wang, Ran; Zheng, Yan

    2010-05-20

    We present a diode-pumped, 2mum single-frequency Q-switched Tm:YAG laser. The Q-switched laser is injection seeded by a monolithic Tm:YAG nonplanar ring oscillator with the ramp-hold-fire technique. The output energy of the 2mum single-frequency Q-switched pulse is 2.23mJ, with a pulse width of 290ns and a repetition rate of 200Hz. From the heterodyne beating measurement, the frequency difference between the seed laser and the Q-switched laser is determined to be 37.66MHz, with a half-width of the symmetric spectrum of about 2 MHz. PMID:20490245

  19. An agent-based model of cancer stem cell initiated avascular tumour growth and metastasis: the effect of seeding frequency and location.

    PubMed

    Norton, Kerri-Ann; Popel, Aleksander S

    2014-11-01

    It is very important to understand the onset and growth pattern of breast primary tumours as well as their metastatic dissemination. In most cases, it is the metastatic disease that ultimately kills the patient. There is increasing evidence that cancer stem cells are closely linked to the progression of the metastatic tumour. Here, we investigate stem cell seeding to an avascular tumour site using an agent-based stochastic model of breast cancer metastatic seeding. The model includes several important cellular features such as stem cell symmetric and asymmetric division, migration, cellular quiescence, senescence, apoptosis and cell division cycles. It also includes external features such as stem cell seeding frequency and location. Using this model, we find that cell seeding rate and location are important features for tumour growth. We also define conditions in which the tumour growth exhibits decremented and exponential growth patterns. Overall, we find that seeding, senescence and division limit affect not only the number of stem cells, but also their spatial and temporal distribution. PMID:25185580

  20. The population genetics of the self-incompatibility polymorphism in Papaver rhoeas. XI. The effects of limited pollen and seed dispersal, overlapping generations and variation in plant size on the variance of S-allele frequencies in populations at equilibrium

    Microsoft Academic Search

    R J Brooks; A M Tobias; M J Lawrence

    1996-01-01

    The effects of limited pollen and seed dispersal, of overlap between generations and of variation in plant size on the steady-state variance of S-allele frequencies have been investigated in a simulated population of size 3840 containing 16 S-alleles whose initial frequencies were exactly equal. Simulations were run with each of the 16 possible combinations of these four factors to investigate

  1. Bent crystal spectrometer for both frequency and wavenumber resolved x-ray scattering at a seeded free-electron laser

    SciTech Connect

    Zastrau, Ulf, E-mail: ulf.zastrau@uni-jena.de [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Fletcher, Luke B.; Galtier, Eric Ch.; Gamboa, Eliseo; Glenzer, Siegfried H.; Heimann, Philipp; Nagler, Bob; Schropp, Andreas; Lee, Hae Ja [Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Förster, Eckhart [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz Institute Jena, Fröbelstieg 3, 07743 Jena (Germany); Marschner, Heike; Wehrhan, Ortrud [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany)

    2014-09-15

    We present a cylindrically curved GaAs x-ray spectrometer with energy resolution ?E/E = 1.1 ×?10{sup ?4} and wave-number resolution of ?k/k = 3 ×?10{sup ?3}, allowing plasmon scattering at the resolution limits of the Linac Coherent Light Source (LCLS) x-ray free-electron laser. It spans scattering wavenumbers of 3.6 to 5.2/Å in 100 separate bins, with only 0.34% wavenumber blurring. The dispersion of 0.418 eV/13.5??m agrees with predictions within 1.3%. The reflection homogeneity over the entire wavenumber range was measured and used to normalize the amplitude of scattering spectra. The proposed spectrometer is superior to a mosaic highly annealed pyrolytic graphite spectrometer when the energy resolution needs to be comparable to the LCLS seeded bandwidth of 1 eV and a significant range of wavenumbers must be covered in one exposure.

  2. Seeding Rangeland. 

    E-print Network

    Welch, Tommy G.; Haferkamp, Marshall R.

    1987-01-01

    Co., Inc. Harpool Field Seed Inc. Horizon Seeds Sharp Bros. Seed Co. Tommy G. Welch and Marshall R. Haferkamp* Most Texas rangeland produces below its poten tial. Although production on some of this land may be improved by grazing management...

  3. Seed Germination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Initiation of seed germination is a critical decision for plants. It is important for seed populations under natural conditions to spread the timing of germination of individual seeds to maximize the probability of species survival. Therefore, seeds have evolved the multiple layers of mechanisms tha...

  4. A further discussion of the factors controlling the distribution of Pt, Pd, Rh and Au in road dust, gullies, road sweeper and gully flusher sediment in the city of Sheffield, UK.

    PubMed

    Prichard, H M; Sampson, J; Jackson, M

    2009-02-15

    Forty paired road dust and gully sediments from the city of Sheffield in NE England show that high platinum, palladium and rhodium concentrations derived from catalytic converters depend on proximity to both roundabouts rather than traffic lights and to topographic lows. Road dust outside schools and control samples, further away on the same road, show that Pt, Pd and Rh concentrations are dependent on passing traffic flow rather than numbers of stopping vehicles. Highest values of Pt+Pd in road dust are 852 ppb and 694 ppb in gullies. Rh has maximum values of 113 ppb in road dust and 49 ppb in gullies. Pt and Pd values of a few ppb to just over 100 ppb occur in road dust where traffic does not stop, on roads away from junctions. Pt, Pd, Rh and Au are all picked up by road sweepers and gully flushers both with maximum values of just over 100 ppb Pt and Pd. High Au values (maximum 610 ppb in a road dust) were located on pavements, in suburbs, outside schools and in road sweepers collecting in residential areas rather than on high traffic flow roads. Stratification of Pt and Pd in gullies was not observed whereas a high Au value was recorded at the bottom of a gully suggesting gravity concentration for Au. Anomalous Pd grades of 1050 ppb in road dust from a school entrance and 2040 ppb in a street sweeper sample were recorded. These high Pd- and Au-bearing samples do not have anomalous Pt or Rh values and may be sourced from jewellery or dental fillings. However, most samples have consistent Pt/Pd ratios of about 1 and Pt/Rh values of 4 to 5 indicating a catalytic converter source. Pt and Pd are concentrated in road dust at levels well above background in all the samples, including on high and low traffic flow roads. PMID:19081605

  5. Effects of ants, ground beetles and the seed-fall patterns on myrmecochory of Erythronium japonicum Decne. (Liliaceae)

    Microsoft Academic Search

    Kyohsuke Ohkawara; Seigo Higashi; Masashi Ohara

    1996-01-01

    Erythronium japonicum (Liliaceae) inhabits deciduous mesic forests of Hokkaido, northern Japan. Myrmecochory of this species was investigated, especially the dispersal frequency, the effect of seed predators and the seed fall pattern. In the quadrat census using marked seeds of E. japonicum, the ant Myrmica kotokui frequently transported the seeds. However, the frequency of seed removal was low and most seeds

  6. Seeding Rangeland 

    E-print Network

    Welch, Tommy G.; Hafercamp, Marshall R.

    2001-01-04

    Most Texas rangeland produces below its potential. Improving rangeland requires brush control and/or seeding to restore production to the site's potential. This publication is a guide to seeding rangelands, and discusses ...

  7. Seed Dispersal

    NSDL National Science Digital Library

    2012-06-26

    In this outdoor activity and bingo-like game, learners explore why and how seeds spread far from the plants that produce them. To understand natural adaptions that let seeds and fruit be dispersed, learners make modifications to dried beans and peas so they could be dispersed by natural forces like water, air, or an animal moving from one place to another. In the "Seed-Go" Game, learners match ways that seeds are dispersed, to fill rows on the game board.

  8. High-power continuous-wave mid-infrared radiation generated by difference frequency mixing of diode-laser-seeded fiber amplifiers and its application to dual-beam spectroscopy

    NASA Technical Reports Server (NTRS)

    Lancaster, D. G.; Richter, D.; Curl, R. F.; Tittel, F. K.; Goldberg, L.; Koplow, J.

    1999-01-01

    We report the generation of up to 0.7 mW of narrow-linewidth (<60-MHz) radiation at 3.3 micrometers by difference frequency mixing of a Nd:YAG-seeded 1.6-W Yb fiber amplifier and a 1.5-micrometers diode-laser-seeded 0.6-W Er/Yb fiber amplifier in periodically poled LiNbO3. A conversion efficiency of 0.09%/W (0.47 mWW-2 cm-1) was achieved. A room-air CH4 spectrum acquired with a compact 80-m multipass cell and a dual-beam spectroscopic configuration indicates an absorption sensitivity of +/-2.8 x 10(-5) (+/-1 sigma), corresponding to a sub-parts-in-10(9) (ppb) CH4 sensitivity (0.8 ppb).

  9. Seed Proteomics"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteomic analysis of seeds encounters some specific problems that do not impinge on analyses of other plant cells, tissues, or organs. There are anatomic considerations. Seeds comprise the seed coat, the storage organ(s), and the embryonic axis. Are these to be studied individually or as a compo...

  10. High-power frequency comb in the range of 2-2.15???m based on a holmium fiber amplifier seeded by wavelength-shifted Raman solitons from an erbium-fiber laser.

    PubMed

    Coluccelli, Nicola; Cassinerio, Marco; Gambetta, Alessio; Laporta, Paolo; Galzerano, Gianluca

    2014-03-15

    We demonstrate a room-temperature high-power frequency comb source covering the spectral region from 2 to 2.15 ?m. The source is based on a femtosecond erbium-fiber laser operating at 1.55 ?m with a repetition rate of 250 MHz, wavelength-shifted up to 2.06 ?m by the solitonic Raman effect, seeding a large-mode-area holmium (Ho) fiber amplifier pumped by a thulium (Tm) fiber laser emitting at 1.94 ?m. The frequency comb has an integrated power of 2 W, with overall power fluctuations as low as 0.3%. The beatnote between the comb and a high-spectral-purity, single-frequency Tm-Ho laser has a linewidth of 32 kHz over 1 ms observation time, with a signal-to-noise ratio in excess of 30 dB. PMID:24690863

  11. Magnetic-seeding filtration

    SciTech Connect

    Ying, T.Y.; Chin, C.J.; Lu, S.C.; Yiacoumi, S. [Georgia Institute of Technology, Atlanta, GA (United States). School of Civil and Environmental Engineering] [and others

    1997-10-01

    Magnetic-seeding filtration consists of two steps: heterogeneous particle flocculation of magnetic and nonmagnetic particles in a stirred tank and high-gradient magnetic filtration (HGMF). The effects of various parameters affecting magnetic-seeding filtration (HGMF). The effects of various parameters affecting magnetic seeding filtration are theoretically and experimentally investigated. A trajectory model that includes hydrodynamic resistance, van der Waals, and electrostatic forces is developed to calculate the flocculation frequency in a turbulent-shear regime. Fractal dimension is introduced to simulate the open structure of aggregates. A magnetic-filtration model that consists of trajectory analysis, a particle build-up model, a breakthrough model, and a bivariate population-balance model is developed to predict the breakthrough curve of magnetic-seeding filtration. A good agreement between modeling results and experimental data is obtained. The results show that the model developed in this study can be used to predict the performance of magnetic-seeding filtration without using empirical coefficients or fitting parameters. 35 refs., 7 figs., 1 tab.

  12. Seed size relationships in kleingrass, Panicum coloratum L 

    E-print Network

    Kieschnick, Robert Charles

    1974-01-01

    OF FIGURES Fi gure Frequency distribution of progeny of three selected parents. . . . . . . . . . . . . . . . . . . . . Scatter diagram of parent-progeny seed weights (grams per 100 seeds). Page 25 42 CHAPTER I INTRODUCTION Klei ngrass, Pani curn... of pastures from P. coloratum seed in Australia (5) and Africa (11). The difficulty was attributed to poor seed germination due to imperme- ability of the lemma and palea enclosing the caryopsis. Scarifying fresh seed or storing them for ninety days...

  13. Analysis of the plasma sweeper

    SciTech Connect

    Glanz, J.; Motley, R.W.

    1982-09-01

    The coupling of lower hybrid waves to a plasma can be modified by placing potentials on electrodes near the mouth of a phased array. Positive potentials on the electrodes create an electric field that sweeps the plasma away at a velocity c anti E x anti B/B/sup 2/. In this paper we derive the electric field created by the applied potential from the nondivergent character of the current flow and the ion momentum equation, in which ion-neutral charge-exchange collisions are retained, and we compare the predictions with experimental data.

  14. Self-Heterodyne Beating of Dual Polarization Modes in a Single-Frequency Microchip Holmium, THULIUM:YAG Laser and Injection-Seeding of a Q-Switched Oscillator

    NASA Astrophysics Data System (ADS)

    He, Chuan

    This dissertation presents results of a study on the development of an injection-seeded flashlamp-pumped, Q-switched Ho,Tm,Cr:YAG 2.1 ?m laser and a detailed study of the spectral intensity of a supposedly single-frequency, diode-laser pumped, CW 2.091 ?m Ho,Tm:YAG microchip laser. A flashlamp-pumped Ho,Tm,Cr:YAG laser was developed and modified for Q-switched operation. The maximum output energy for TEM_{00} operation was about 25 mJ/pulse with a pulse width of 150 ns. A "twisted-mode" spectral refining technique was incorporated which used two quarter-wave plates and a 1 mm etalon in the laser cavity to narrow the linewidth and reduce the spatial hole burning effect of the Q-switched Ho,Tm,Cr:YAG laser. The laser linewidth was narrowed sufficiently so that mode beating was detected. Preliminary injection -seeding experiments using a diode-laser pumped microchip Ho,Tm:YAG laser were conducted. However, difficulties in the seeding experiments were observed, leading to a more thorough study of the supposedly "single-frequency" microchip laser. After a high-resolution spectral study was made, it was determined that the supposedly CW single-frequency microchip Ho:YAG laser did not operate on a single frequency, but actually operated on two, slightly elliptical, dual -polarized orthogonal laser modes, which could not be detected by conventional spectroscopic techniques (i.e. spectrometer, Fabry-Perot). These two orthogonal modes were separated in frequency by approximately 12 MHz, and when photodetected, produced a 12 MHz self-heterodyne beat signal. Our studies indicated, for the first time to our knowledge, that the dual-polarization modes were produced by residual stress in the Ho:YAG laser crystal, which caused the normally isotropic YAG crystal to become slightly birefringent. It was found that one of the dual polarization modes could be eliminated through use of an external polarizer and a quarter-wave plate, but that small changes (< 1%) in the diode-pump power would rotate the axis of the polarized modes so that one of the dual polarization modes would leak through the polarizer and quarter-wave plate. These results have important implications for the use of the microchip Ho:YAG laser in a heterodyne detection coherent Doppler Lidar, and serve as a caution to those using lasers that are initially believed to be single-frequency. Lastly, the wavelength of the microchip Ho,Tm:YAG laser could be tuned continuously by changing either the crystal temperature or pump laser power. Crystal temperature tuning provided 20 GHz tuning range and pump power tuning provided 4 GHz fine tuning range. In order to study the wavelength tuning of the microchip laser, the laser was used as a tunable optical source to conduct preliminary laboratory absorption measurements of CO_2 in a 4 m long absorption cell. The transmission spectrum of CO_2 near 2.0922 ?m was obtained, and showed two weak CO _2 absorption lines as expected. These absorption experiments are preliminary and further studies are planned to better quantify the Ho,Tm:YAG microchip laser for absorption spectroscopic applications.

  15. Many Seeds: Estimating Hidden Seeds

    NSDL National Science Digital Library

    2012-06-26

    In this activity, learners will estimate how many seeds are in a fruit or vegetable, then count to find out. The result: mix estimation with healthy eating. Vary the level of difficulty by using different foods: for younger learners, choose something with up to about 15 seeds inside (e.g. apples, snow peas); for a medium level of difficulty, try melon slices or cucumbers; for more challenge, use pomegranates or mini-pumpkins. Available as a web page or downloadable pdf.

  16. Verticillium dahliae race 2-specific PCR reveals a high frequency of race 2 strains in commercial spinach seed lots and delineates race structure.

    PubMed

    Short, Dylan P G; Gurung, Suraj; Maruthachalam, Karunakaran; Atallah, Zahi K; Subbarao, Krishna V

    2014-07-01

    Two pathogenic races of Verticillium dahliae have been described on lettuce and tomato. Host resistance to race 1 is governed by plant immune receptors that recognize the race 1-specific fungal effector Ave1. Only partial resistance to race 2 exists in lettuce. Although polymerase chain reaction (PCR) assays are available to identify race 1, no complementary test exists to positively identify race 2, except for lengthy pathogenicity assays on host differentials. Using the genome sequences of two isolates of V. dahliae, one each from races 1 and 2, we identified potential markers and PCR primers to distinguish the two races. Several primer pairs based on polymorphisms between the races were designed and tested on reference isolates of known race. One primer pair, VdR2F-VdR2R, consistently yielded a 256-bp amplicon in all race 2 isolates exclusively. We screened DNA from 677 V. dahliae isolates, including 340 from spinach seedlots, with the above primer pair and a previously published race 1-specific primer pair. DNA from isolates that did not amplify with race 1-specific PCRs amplified with the race 2-specific primers. To validate this, two differential lines of lettuce were inoculated with 53 arbitrarily selected isolates from spinach seed and their pathogenicity and virulence were assessed in a greenhouse. The reactions of the differential cultivars strongly supported the PCR data. V. dahliae race structure was investigated in crops in coastal California and elsewhere using primers specific to the two races. All artichoke isolates from California were race 1, whereas nearly all tomato isolates were race 2. Isolates from lettuce, pepper, and strawberry from California as well as isolates from spinach seed from two of four countries comprised both races, whereas only race 2 was observed in cotton, mint, olive, and potato. This highlights the importance of identifying resistance against race 2 in different hosts. The technique developed in this study will benefit studies in ecology, population biology, disease surveillance, and epidemiology at local and global scales, and resistance breeding against race 2 in lettuce and other crops. PMID:24502204

  17. International Seed Saving Institute: Basic Seed Saving

    NSDL National Science Digital Library

    This straightforward site from the International Seed Saving Institute on Basic Seed Saving will be of use to any growers interested in learning how to save seeds from season to season. The site provides links "to specific seed saving instructions for 27 common vegetables" including many favorites like corn, carrots, broccoli, and lettuce. The site also links to a glossary of seed saving terms and a six-step Seed Saving Tutorial.

  18. Seed Catalogues

    NSDL National Science Digital Library

    The Smithsonian Institutions Libraries Web site currently features a unique collection of seed and nursery catalogs dating from 1830 to the present. Online visitors may view a portion of the exhibit, which offers a look at "the history of the seed and agricultural implement business in the United States, as well as provides a history of botany and plant research such as the introduction of plant varieties into the US." Although this site does include much material, gardeners and anyone else with a horticultural bent should enjoy a casual browse through the online exhibit.

  19. Big Seed

    NSDL National Science Digital Library

    2012-12-06

    This free iOS app helps develop spatial reasoning and strategic thinking. Users reflect seed squares (horizontally, vertically and diagonally) to grow larger pieces that eventually cover the given design space without spilling over. A graduated set of difficulty levels makes the game accessible to a wide range of ages.

  20. Seed Bargains

    NSDL National Science Digital Library

    Richard Konicek-Moran

    2008-04-01

    Children as well as adults are usually intrigued by the ideas of bargains. More seeds for less money is often enough to convince them to buy a larger, cheaper package. In this case, the children are savvy enough to question the value of either package. On

  1. Synchronous Photoinjection Using a Frequency-Doubled Gain-Switched Fiber-Coupled Seed Laser and ErYb-Doped Fiber Amplifier

    SciTech Connect

    John Hansknecht; Benard Poelker

    2006-06-01

    Light at 1.56 um from a gain-switched fiber-coupled diode laser and ErYb-doped fiber amplifier was frequency doubled to obtain over 2W average power at 780 nm with {approx} 40ps pulses and pulse repetition rate of 499 MHz. This light was used to drive the 100kV DC high voltage GaAs photoemission gun at CEBAF at Jefferson Laboratory to produce a high average current beam (100uA) of highly spin-polarized electrons (>80%). This new drive laser system represents a significant advance over laser systems used previously, providing significantly higher power and enhanced reliability.

  2. BULK SEED TENDERS FOR HANDLING PEANUT SEED

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Planting is a very labor intensive operation requiring both skilled and unskilled labor. Intense manual labor is required to load seed hoppers on the planter. A seeding rate of 112 kg/ha, requires 11.2 t of seed per 100 ha planted. Bulk seed tenders have been used in the Midwestern United States to ...

  3. ANL/APS/LS-327 A New Type of Bunch Compressor and Seeding of a Short Wave Length

    E-print Network

    Kemner, Ken

    interacting with the electron beam and thus can prepare a significantly higher frequency seed for seeded free-electron lasers. The same approach can be used for a frequency down-conversion that can be useful for generation

  4. Uses and potential of DNA technologies in forage, turf, and rangeland crop seed production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DNA markers are used at a greater frequency in seed production. It is beneficial for seed producers to understand how the DNA markers can be used and some of their limitations. These markers have been used to detect contaminants in seed lots of annual ryegrass, thus allowing seed lots to be shippe...

  5. Population consequences of changes in an ant-seed mutualism in Sanguinaria canadensis

    Microsoft Academic Search

    Ronald J. Pudlo; Andrew J. Beattie; David C. Culver

    1980-01-01

    Seed dispersal by ants was studied in three populations of the myrmecochore, Sanguinaria canadensis, located in three habitats, each of which showed a different level of disturbance. Frequency of seed removal and the distances seeds were carried by ants were related to plant density, dispersion and the relative proportions of sexual and asexual reproduction in each population. Seeds in the

  6. Seeding Steps Droplet Location

    E-print Network

    Georgiev, Atanas

    Seeding Steps Droplet Location Sample Seeding Run Crystal Detection Design and Fabrication seeding and crystal mounting Prototype Microrobotic Streak Seeding System Robotic Protein Crystal Streak Seeding Using Silicon Microtools Atanas Georgiev1, Peter Allen1, William Edstrom2, John Hunt2, Ting Song3

  7. Seed Treatment. Bulletin 760.

    ERIC Educational Resources Information Center

    Lowery, Harvey C.

    This manual gives a definition of seed treatment, the types of seeds normally treated, diseases and insects commonly associated with seeds, fungicides and insecticides used, types of equipment used for seed treatment, and information on labeling and coloring of treated seed, pesticide carriers, binders, stickers, and safety precautions. (BB)

  8. Seed Treatment. Manual 92.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Agricultural Experiment Station.

    This training manual provides information needed to meet minimum EPA standards for certification as a commercial applicator of pesticides in the seed treatment category. The text discusses pests commonly associated with seeds; seed treatment pesticides; labels; chemicals and seed treatment equipment; requirements of federal and state seed laws;…

  9. Seed Magazine

    NSDL National Science Digital Library

    Seed is an online (and print) magazine dedicated to increasing the scientific awareness and knowledge of the general public. The site is updated six days a week and features news articles, original-content articles on a variety of science topics, columns, and reviews. "Cribsheets," a downloadable feature, provide brief tutorials on scientific issues and innovations that may occur in everyday conversation. The magazine also features a collection of multimedia materials, such as podcasts, slide shows, and video content. The web site's main page features articles from the latest issue; back issues may be browsed by category, author, or date. Information about subscribing to the print version is also provided.

  10. Alfalfa Seed Testing. 

    E-print Network

    Ball, O. M. (Oscar Melville)

    1905-01-01

    of the various form may be gotten from Plate I. Note "^ AND WEED SEEDS FOUND IN ALFALFA SEED OF ALFALFA SEED OF HEALTHY COLOR. M EDICAGO SATIVA. OTHER CLOVER SEEDS SOMETIMES USED AS ADULTERANTS. I I .ILOT. WHITE. SWEET MELILOT. YELLOW. BURR CLOVER.... - MELILOTUS ALBA. MELILOTUS INDICA MEDICAGO DENTICULATA. S. PLANTAIN. TUMBLE WEED. LANCEOLATA. AMARANTHUS GRACILARIS. CARELESS WEED. AMARANTHUS HYBRIDUS. SPECIALLY NOXIOUS WEED SEEDS FREQUENTLY FOUND IN k ,' ALFALFA SEED. RUSSIAN THISTLE. , :? I...

  11. Seeding of high temperature air flow

    NASA Astrophysics Data System (ADS)

    Rusch, D.; Kempe, A.; Roesgen, T.

    2007-05-01

    Seeding of high temperature air flows is problematic because common seeding materials can ignite and may pose a threat for human health in case of inhalation. Sodium chloride is proposed as a seeding material to avoid these problems. The generation of crystals using an ultrasonic atomizer is described and the measured particle size distribution is presented. The described method has the additional advantage that the particle size can easily be adjusted. This allows the operator to comply with the experimental requirements in terms of resolvable frequencies. The described method has been successfully applied to LDA measurements in a 500°C air flow.

  12. Watermelon Seed Germination

    E-print Network

    Watermelon Seed Germination Purdue University Cooperative Extension Service BP-62 Seed Germination seeds of standard watermelon. The concept of seedless fruit seem to fit the lifestyle of consumers who bars and fruit salads. Seedless watermelon are pro- duced from seed which have three sets

  13. How Seeds Travel

    NSDL National Science Digital Library

    Mrs Liston

    2009-11-09

    Students will rotate around to 7 different stations to identify how the 7 presented seeds travel, whether it be by wind, water, or animal. They will then record it in their plant journals by illustrating the seed, listing its characteristics, and identifying the way in which it travels. Designer Seeds 7 Stations Coconut-Water Maple Seed- Wind Burdock (burrs) - Animals ...

  14. Vegetable Seed Saving Handbook

    NSDL National Science Digital Library

    This Vegetable Seed Saving Handbook online is a great resource for anyone wanting to harvest viable Fast Plants seeds to plant right away (as in selection experiments) or save for future use. Follow the instructions for cabbage family seeds (Brassica raps, in particular). If you're planning on saving your seeds, treat Fast Plants seeds as "desiccation-tolerant" as described here: http://howtosaveseeds.com/store.php

  15. Regular distribution of larvae and resource monopolization in the seed beetle Bruchidius dorsalis infesting seeds of the Japanese honey locust Gleditsia japonica

    Microsoft Academic Search

    Masakazu Shimada; Hiroyuki Kurota; Yukihiko Toquenaga

    2001-01-01

    Larvae of the wild multivoltine bruchid seed beetle Bruchidius dorsalis infest dry mature seeds of the Japanese honey locust Gleditsia japonica. The frequency distribution of B. dorsalis larvae per seed was examined in the laboratory. First, preliminary observation showed that the first-instar B. dorsalis larva crawled from an eggshell and traveled in excess of 25 cm before boring into a

  16. The effects of endophytes on seed production and seed predation of tall fescue and meadow fescue.

    PubMed

    Saari, Susanna; Helander, Marjo; Faeth, Stanley H; Saikkonen, Kari

    2010-11-01

    Fungal endophytes of grasses are often included in agricultural management and in ecological studies of natural grass populations. In European agriculture and ecological studies, however, grass endophytes are largely ignored. In this study, we determined endophyte infection frequencies of 13 European cultivars and 49 wild tall fescue (Schedonorus phoenix) populations in Northern Europe. We then examined seed production and seed predation of endophyte-infected (E+) and endophyte-free (E-) tall fescue (in wild grass populations and in a field experiment) and meadow fescue (Schedonorus pratensis; in a field experiment only). Endophytes were detected in only one of the 13 cultivars. In contrast, >90% of wild tall fescue plants harbored endophytes in 45 wild populations but were absent in three inland populations in Estonia. In three wild tall fescue study sites, 17%, 22%, and 56% of the seeds were preyed upon by the cocksfoot moth. Endophyte infection did not affect seed mass of tall fescue in the field experiment. However, seed predation was lower in E+ than E- grasses in the two tall fescue populations with higher predation rates. For meadow fescue, the mean number of seeds from E+ plants was higher than E- plants, but E- and E+ seeds had equal rates of predation by the moth. Our results suggest that the effects of grass endophytes on seed production and cocksfoot moth seed predation vary considerably among grass species, and the effects may depend on herbivore pressure and other environmental conditions. PMID:20871988

  17. The Seed Biology Place

    NSDL National Science Digital Library

    Leubner, Gerhard

    2012-02-10

    This remarkable site was created by Professor Gerhard Leubner and his colleagues at the University of Freiburg in Germany. Here, visitors can take advantage of a veritable cornucopia of reference materials related to seed biology, such as diagrams and illustrations of seed germination, plant hormones, endosperm weakening, and seed dormancy. Neophytes may wish to start by looking at the Seed Structure and Anatomy area, which features a concise and well-written overview of the structure, anatomy, and morphology of mature seeds. The same section contains information on the seed structure of the castor bean and other legumes. Another fascinating section on the site is dedicated to Seed Evolution. Visitors can discover a wealth of information here, including such topics as the evolutionary trends of angiosperm seeds and the seed ferns of the Late Permian period. All told, the site is a wonderful resource, and visitors will want to share it with friends.

  18. Spectro-temporal dynamics of Kerr combs with parametric seeding.

    PubMed

    Lin, Guoping; Martinenghi, Romain; Diallo, Souleymane; Saleh, Khaldoun; Coillet, Aurélien; Chembo, Yanne K

    2015-03-20

    We report a joint theoretical and experimental investigation of the parametric seeding of a primary Kerr optical frequency comb. Electro-optic modulation sidebands matching multiple free-spectral ranges of an ultrahigh-Q millimeter-size magnesium fluoride disk resonator are used as seed signals. These seed signals interact through four-wave mixing with the spectral components of a stable primary comb and give rise to complex spectro-temporal patterns. We show that the new frequency combs feature multiscale frequency spacing, with major frequency gaps in the order of a few hundred gigahertz, and minor frequency spacing in the order of a few tens of gigahertz. The experimental results are in agreement with numerical simulations using the Lugiato-Lefever equation. We expect such versatile and coherent optical frequency combs to have potential applications in optical communications systems where frequency management assigns predefined spectral windows at the emitter stage. PMID:25968529

  19. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

  20. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

  1. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

  2. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

  3. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Other agricultural seeds (crop seeds). 201.18 Section 201.18 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling...

  4. Seed Dispersal: Animals

    NSDL National Science Digital Library

    Pulse of the Planet

    2007-08-02

    The guest scientist in this two-minute radio program discusses seed dispersal in plants. He first explains why it is important for seeds to be distributed away from the mother plant. Then he contrasts wind-dispersed seeds with animal-dispersed seeds, pointing out that animals can disperse larger seeds that contain more nutrients for an emerging seedling. The program, which is available here in audio and text, is part of a Pulse of the Planet series on seed dispersal. Copyright 2005 Eisenhower National Clearinghouse

  5. Inside a Seed

    NSDL National Science Digital Library

    2007-12-12

    This image from Biology by Kenneth R. Miller and Joseph Levine illustrates the five most important parts of a seed: the seed coat, the endosperm, and the embryos primary root, cotyledon, and embryonic leaves.

  6. Postfire seeding and plant community recovery in the Great Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As wildland fire frequency increases around the globe, increased understanding of plant community recovery in burned landscapes is needed to improve effectiveness of rehabilitation efforts. We measured establishment of seeded species, colonization of Bromus tectorum L. (cheatgrass), and recovery of ...

  7. SEED Database Requirements

    Microsoft Academic Search

    Robert Coyne; Robert Woodbury; Shang-Chia Chiou; Bongjin Choi; Han Kiliccote; Teng-Weng Chang; Sheng-Fen Chien; Jim Snyder

    SEED is an acronym for Software Environment to Support the Early Phases in Building Design. The overall architecture of SEED is based on a division of the preliminary design process into phases, each of which addresses a specific task. SEED intends to support each phase by an individual support module based on a shared logic and architecture. The modules envisioned

  8. What Are Chia Seeds?

    MedlinePLUS

    ... diet? Chia seeds come from the desert plant Salvia hispanica , a member of the mint family. Salvia hispanica seed is often sold under its common ... Aztec diet. The seeds of a related plant, Salvia columbariae (golden chia), were used primarily by Native ...

  9. Seeding date and polymer seed coating effects on plant establishment and yield of fall-seeded

    E-print Network

    Lawrence, Rick L.

    Seeding date and polymer seed coating effects on plant establishment and yield of fall-seeded. and Kirkland, K. J. 2004. Seeding date and polymer seed coating effects on plant establishment and yield of fall-seeded canola in the Northern Great Plains. Can. J. Plant Sci. 84: 955­963. The time interval

  10. Precision metering of germinated seeds 

    E-print Network

    Elliot, Gregory Lawrence

    1990-01-01

    Seeds Purpose and Objectives REVIEW OF LITERATURE Precision Planters and Meters for Dry Seeds Trapping Seeds in Cells Trapping Seeds by Air Pressure Using Other Methods for Dry Seeds Planters and Meters for Seeds in Liquid Extruding a Continuous... require only that a certain plant population density be achieved. Willey (1982) points out that this type of crop may be planted with nonprecision planters or broadcast seeders, which control only the rate at which seeds are distributed. However...

  11. Relaxation and transport phenomena in corn seeds

    NASA Astrophysics Data System (ADS)

    Laudat, J.; Pissis, Polycarpos; Konsta, A. A.

    1997-06-01

    The low-frequency dynamics in cereal seeds has been studied by measurements of d.c. conductivity, thermally stimulated depolarization current techniques and by broadband a.c. dielectric spectroscopy with the aim to understand its relation to their biological behavior. Such a broad overall frequency and temperature range allows to investigate simultaneously the mobility of water molecules in seeds, influence of water on molecular mobility of seeds constituents and change mobility. Our results indicate, that water in seeds freeze for concentration higher than critical hydration, whereas for lower hydration it undergoes a glass- like transition. Temperature of this transition strongly depends on water content in the sample and shifts by seeds drying from 180 K up to room temperature. D.c. protonic conductivity increases sharply above glass transition temperature. Its dependence on water content indicates percolative transport of protons along threads of hydrogen- bonded water molecules with a percolation thresholding the range of 0.15-0.30 g water/g dry material. The biological implications of these findings will be discussed.

  12. Control of Weeds at a Pinyon-Juniper Site by Seeding Grasses

    Microsoft Academic Search

    Sherel Goodrich; Dustin Rooks

    An area seeded to perennial grasses and an adjacent nonseeded area both within a burned Colorado pinyon\\/Utahjuniper (Pinus edulis Engelm.\\/Juniperus osteosperma (Torr.) Little) com­ munity provided an opportunity to contrast frequency of plant species in the two treatments. Lower frequencies for cheatgrass (Bromus tectorum L.) and yellow salsify (Tragopogon dubius Scop.), which are introduced annuals, were found in the seeded

  13. Swirling-Sweepers: Constant-Volume Modeling

    E-print Network

    Toronto, University of

    into lattices. [5] use controllers for main- taining the implicit surface that coats a set of particles considered as a very useful constraint for the intuitive modeling of shapes. [10] propose an optimization

  14. The effect of burial depth on removal of seeds of Phytolacca americana.

    SciTech Connect

    Orrock, John, L.: Damschen, Ellen, I.

    2007-04-01

    Abstract - Although burial is known to have important effects on seed predation in a variety of habitats, the role of burial depth in affecting the removal of seeds in early successional systems is poorly known. Phytolacca American (pokeweed) is a model species to examine the role of burial depth in affecting seed removal because it is common in early-successional habitats, studies suggest that seed removal is indicative of seed predation, and seed predation is related to the recruitment of mature plants. To determine how burial depth affects P. americana seed removal, 20 seeds of P. americana were buried at depths of 0, 1, or 3 cm in early-successional habitats at the Savannah River Site in South Carolina for over 6 weeks. The frequency with which seeds were encountered (as measured by the removal of at least one seed) and the proportion of seeds removed was significantly greater when seeds were on the soil surface (0 cm depth) compared to seeds that were buried 1 cm or 3 cm; there was no difference in encounter or removal between seeds at 1 cm or 3 cm. Our findings suggest that burial may have important consequences for P. americana population dynamics, because seed survival depends upon whether or not the seed is buried, and relatively shallow burial can yield large increases in seed survival. Because seed limitation is known to be an important determinant of plant community composition in early successional systems, our work suggests that burial may play an unappreciated role in the dynamics of these communities by reducing predator-mediated seed limitation.

  15. Examining Children's Models of Seed.

    ERIC Educational Resources Information Center

    Jewell, Natalie

    2002-01-01

    Reports research that examines children's models of seed. Explores the conceptions held by children (N=75) of germination and seed formation. Concludes that children hold a restricted meaning for the term 'seed'. (DDR)

  16. Planting Seeds of Involvement

    ERIC Educational Resources Information Center

    Allyn, David

    2004-01-01

    In New Jersey, bright elementary and middle school students whose parents are financially limited have an opportunity to participate in a program called New Jersey SEEDS (Scholars, Educators, Excellence, Dedication, Success). SEEDS provides intellectually challenging academic enrichment classes on Saturdays and during the summer so that students…

  17. Needs of Seeds

    NSDL National Science Digital Library

    Francis Eberle

    2007-01-01

    The purpose of this assessment probe is to elicit students' ideas about seeds. It specifically probes to find out if students recognize that a seed has needs, similar to other organisms that allow it to develop into the next stage of its life cycle.

  18. Imprinting and Seed Development

    Microsoft Academic Search

    Mary Gehring; Yeonhee Choi; Robert L. Fischer

    2004-01-01

    Fertilization Seeds consist of three genetically distinct components: embryo, endosperm, and seed coat. In plants, mitosis follows meiosis to produce the haploid phase of the plant life cycle, the male and female gametophytes. The angiosperm female gametophyte, the site of fertilization, is completely embedded within the maternal sporophytic tissues of the ovule. The most prevalent type of mature female gametophyte

  19. Planning cloud seeding research

    Microsoft Academic Search

    F. H. Ludlam

    1955-01-01

    It is suggested that a theory of cloud seeding needs to be developed before seeding experiments can be properly planned and assessed. This theory will arise from improved knowledge of cloud processes gained by the study of natural clouds. Some techniques used in observing shower clouds in Sweden are described, and some preliminary results mentioned.

  20. Ant–seed mutualisms

    Microsoft Academic Search

    Jennifer A Zettler; Timothy P Spira; Craig R Allen

    2001-01-01

    Invasion by the red imported fire ant, Solenopsis invicta, has had negative impacts on individual animal and plant species, but little is known about how S. invicta affects complex mutualistic relationships. In some eastern forests of North America, 30% of herbaceous species have ant-dispersed seeds. We conducted experiments to determine if fire ants are attracted to seeds of these plant

  1. The Seed Ecology of

    Microsoft Academic Search

    Richy J. Harrodl; Charles B. Halpern

    2005-01-01

    We examined the seed ecology of Iliamna longisepala as an aid to developing a conserva- tion strategy for this rare endemic forb of northcentral Washington. We conducted field, greenhouse, and laboratory studies to quantify: (1) densities of buried viable seed among sites with different histories of burning, (2) post-fire spatial distributions of germinants relative to reproductive plants and bum se-

  2. When Seed Dispersal Matters

    NSDL National Science Digital Library

    HENRY F. HOWE and MARIA N. MIRITI (; )

    2004-07-01

    This peer-reviewed resource from Bioscience journal is about the varying importance of seed dispersal within plant communities. A profusion of fruit forms implies that seed dispersal plays a central role in plant ecology, yet the chance that an individual seed will ultimately produce a reproductive adult is low to infinitesimal. Extremely high variance in survival implies that variations in fruit production or transitions from seed to seedling will contribute little to population growth. The key issue is that variance in survival of plant life-history stages, and therefore the importance of dispersal, differs greatly among and within plant communities. In stable communities of a few species of long-lived plants, variances in seed and seedling survival are immense, so seed-to-seedling transitions have little influence on overall population dynamics. However, when seedlings in different circumstances have very different chances of survival--in ecological succession, for example, or when dispersed seeds escape density-dependent mortality near parent trees--the biased survival of dispersed seeds or seedlings in some places rather than others results in pervasive demographic impacts.

  3. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 3 2011-01-01 2011-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture...REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants...

  4. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 3 2013-01-01 2013-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture...REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants...

  5. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 3 2010-01-01 2010-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture...REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants...

  6. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 3 2012-01-01 2012-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture...REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants...

  7. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 3 2014-01-01 2014-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture...REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants...

  8. Magnetic stimulation of marigold seed

    NASA Astrophysics Data System (ADS)

    Afzal, I.; Mukhtar, K.; Qasim, M.; Basra, S. M. A.; Shahid, M.; Haq, Z.

    2012-10-01

    The effects of magnetic field treatments of French marigold seeds on germination, early seedling growth and biochemical changes of seedlings were studied under controlled conditions. For this purpose, seeds were exposed to five different magnetic seed treatments for 3 min each. Most of seed treatments resulted in improved germination speed and spread, root and shoot length, seed soluble sugars and a-amylase activity. Magnetic seed treatment with 100 mT maximally improved germination, seedling vigour and starch metabolism as compared to control and other seed treatments. In emergence experiment, higher emergence percentage (4-fold), emergence index (5-fold) and vigorous seedling growth were obtained in seeds treated with 100 mT. Overall, the enhancement of marigold seeds by magnetic seed treatment with 100 mT could be related to enhanced starch metabolism. The results suggest that magnetic field treatments of French marigold seeds have the potential to enhance germination, early growth and biochemical parameters of seedlings.

  9. Empty seeds reduce seed predation by birds in Juniperus osteosperma

    E-print Network

    Fuentes, Marcelino

    Empty seeds reduce seed predation by birds in Juniperus osteosperma MARCELINO FUENTES1 and EUGENE W juniper (Juniperus osteosperma) is one of many plant species that produce large numbers of fruits to demonstrate discrimination based on seed ®lling at the level of whole plants. Keywords: empty seeds; Juniperus

  10. Seed Dispersal: Lemurs

    NSDL National Science Digital Library

    Pulse of the Planet

    2007-09-20

    Trees in Madagascar's forests have evolved traits that promote the dispersal of their seeds by lemurs. This two-minute radio program focuses on the interaction between forest plants and lemurs--the main seed dispersers in the forests. A guest scientist explains why lemurs ingest seeds that are large relative to their body size. He also notes that the fruits of Madagascar's trees have evolved to be strong smelling but drably colored in accordance with lemurs' keen sense of smell and poor vision. The program is available in text and audio formats. The latter includes audio of ring-tailed lemurs. Copyright 2005 Eisenhower National Clearinghouse

  11. SEED ARCHIVE AND STORAGE FACILITIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugar beet seed storage facilities were updated, and seed is stored at 4C and 25% relative humidity. Over 15,000 packages of seed have been moved into the new storage facility. We used results from field scale germination studies to discard over 3,500 seedlots that showed no emergence. Current seed ...

  12. Seed output and the seed bank in Vallisneria americana (Hydrocharitaceae).

    PubMed

    Lokker, C; Lovett-Doust, L; Lovett-Doust, J

    1997-10-01

    Seed banks and sexual reproduction are known to be significant in colonization and re-establishment of some aquatic macrophyte communities. For highly clonal aquatic macrophytes, however, there is a lack of information on seed production and seed fate as compared with annual sexual species. The seed bank for three populations of Vallisneria americana in the Huron-Erie corridor of the Great Lakes was sampled and quantified in the spring of 1994, and related to seed production in the previous season at these sites. Seed deposition rates during 1994 were also assessed. Sites varied in the proportion of plants flowering and in their tertiary sex ratios, but did not differ in seed numbers produced per unit area. The size of the seed bank was not significantly related to the previous season's seed output, and estimates of seed deposition in the following year tended to be approximately tenfold greater than seed densities found in the seed bank. The stages between seed production and subsequent seed germination are generally very dynamic, with dispersal, mortality, and predation as likely regulating factors. The potential for seedling establishment in V. americana needs to be assessed more fully before the role of seeds in population processes can be determined. PMID:21708549

  13. Seed weight variation of Wyoming sagebrush in northern Nevada.

    PubMed

    Busso, Carlos A; Perryman, Barry L

    2005-12-01

    Seed size is a crucial plant trait that may potentially affect not only immediate seedling success but also the subsequent generation. We examined variation in seed weight of Wyoming sagebrush (Artemisia tridentata ssp. wyomingensis Beetle and Young), an excellent candidate species for rangeland restoration. The working hypothesis was that a major fraction of spatial and temporal variability in seed size (weight) of Wyoming sagebrush could be explained by variations in mean monthly temperatures and precipitation. Seed collection was conducted at Battle Mountain and Eden Valley sites in northern Nevada, USA, during November of 2002 and 2003. Frequency distributions of seed weight varied from leptokurtic to platykurtic, and from symmetry to skewness to the right for both sites and years. Mean seed weight varied by a factor of 1.4 between locations and years. Mean seed weight was greater (P < 0.05) in 2003 than in 2002 at both sites. This can partially be attributed to 55% greater precipitation in 2003 than 2002, since mean monthly temperatures were similar (P > 0.05) in all study situations. Simple linear regression showed that monthly precipitation (March to November) explained 85% of the total variation in mean seed weight (P = 0.079). Since the relationship between mean monthly temperature (June-November) and mean seed weight was not significant (r2 = 0.00, P = 0.431), this emphasizes the importance of precipitation as an important determinant of mean seed weight. Our results suggest that the precipitation regime to which the mother plant is exposed can have a significant effect on sizes of seeds produced. Hence, seasonal changes in water availability would tend to alter size distributions of produced offspring. PMID:16524249

  14. Evaluating Cotton Seed Quality

    E-print Network

    Boman, Randy

    2005-10-05

    High-quality cotton seed is critical for establishing good stands. Over the last several years, producers have scrutinized costs and benefits of numerous new cotton varieties. With the increase in cost of most current cotton varieties and the use...

  15. Fishing for Seeds.

    ERIC Educational Resources Information Center

    Science and Children, 2001

    2001-01-01

    Describes a method to collect seeds that are dispersed from weeds while avoiding some outdoor hazards such as rough terrain or animals. Describes a plan for creating a weed fishing pole and includes a materials list. (SAH)

  16. Evaluating Cotton Seed Quality 

    E-print Network

    Boman, Randy

    2005-10-05

    High-quality cotton seed is critical for establishing good stands. Over the last several years, producers have scrutinized costs and benefits of numerous new cotton varieties. With the increase in cost of most current cotton varieties and the use...

  17. Easy PEAsy Seed Germination

    NSDL National Science Digital Library

    2012-04-09

    In this activity, learners determine the necessary conditions for pea seed germination. This activity encourages learners to make predictions and think about how they might investigate the effects of variables like light, temperature, and moisture.

  18. QUALITY SEED: SEED IMPROVEMENT, CULTIVAR AND HEALTHY SEED LOT SELECTION, AND THE CERTIFICATION PROCESS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter on seed certification and selecting healthy seed lots is included in Potato Health Management, 2nd edition, an APS series manual. It includes outlines of the certification process including inspections, testing and tagging seed. Certified seed class terminology is explained. It also ...

  19. Anaphylaxis to sunflower seed.

    PubMed

    Noyes, J H; Boyd, G K; Settipane, G A

    1979-04-01

    The clinical and immunological investigation of three patients with an acute anaphylaxis after ingesting commercial varieties of sunflower seeds is presented. Specific IgE-mediated hypersensitivity has been demonstrated in all three patients to sunflower seed extract by history, direct skin tests, and positive radioallergosorbent test (RAST) titers. RAST inhibition was positive in two patients tested. Similar tests on controls were negative. PMID:429702

  20. Alfalfa Seed Testing.

    E-print Network

    Ball, O. M. (Oscar Melville)

    1905-01-01

    of the embryo with part of the outer covering still attached. At the sides are smaller figures giving natural sizes of the seeds. Rib (Plantago laneeolata.) This is one of the weed seeds al- Grass. most universally found in alfalfa growu in northern.... ......... .... . .... ,I-+,Q,: : : : : z-: +A: fi: =: i g; i i j ~i ~l RibGrass,Plantago lance- ........... .... olata. : : : : : : : : : : : : : : Ql: : : : ': : : : w: : : N: : + Pig Weed, Amaranthus re...

  1. Seed Transmission of Pseudoperonospora cubensis

    PubMed Central

    Cohen, Yigal; Rubin, Avia E.; Galperin, Mariana; Ploch, Sebastian; Runge, Fabian; Thines, Marco

    2014-01-01

    Pseudoperonospora cubensis, an obligate biotrophic oomycete causing devastating foliar disease in species of the Cucurbitaceae family, was never reported in seeds or transmitted by seeds. We now show that P. cubensis occurs in fruits and seeds of downy mildew-infected plants but not in fruits or seeds of healthy plants. About 6.7% of the fruits collected during 2012–2014 have developed downy mildew when homogenized and inoculated onto detached leaves and 0.9% of the seeds collected developed downy mildew when grown to the seedling stage. This is the first report showing that P. cubensis has become seed-transmitted in cucurbits. Species-specific PCR assays showed that P. cubensis occurs in ovaries, fruit seed cavity and seed embryos of cucurbits. We propose that international trade of fruits or seeds of cucurbits might be associated with the recent global change in the population structure of P. cubensis. PMID:25329308

  2. Automated seed manipulation and planting

    NASA Technical Reports Server (NTRS)

    Garcia, Ray; Herrera, Javier; Holcomb, Scott; Kelly, Paul; Myers, Scott; Rosendo, Manny; Sivitz, Herbert; Wolsefer, Dave

    1988-01-01

    The Mechanical Division fabricated three seed separators utilizing pressure gradients to move and separate wheat seeds. These separators are called minnow buckets and use air, water, or a combination of both to generate the pressure gradient. Electrostatic fields were employed in the seed separator constructed by the Electrical Division. This separator operates by forcing a temporary electric dipole on the wheat seeds and using charged electrodes to attract and move the seeds. Seed delivery to the hydroponic growth tray is accomplished by the seed cassette. The cassette is compatible with all the seed separators, and it consists of a plastic tube threaded with millipore filter paper. During planting operations, the seeds are placed in an empty cassette. The loaded cassette is then placed in the growth tray and nutrient solution provided. The solution wets the filter paper and capillary action draws the nutrients up to feed the seeds. These seeding systems were tested and showed encouraging results. Seeds were effectively separated and the cassette can support the growth of wheat plants. Problems remaining to be investigated include improving the success of delivering the seeds to the cassette and providing adequate spacing between seeds for the electric separator.

  3. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...establishment, for cleaning or processing for seeding purposes, need...show that it is “Seed for processing,” or, if the seed is in...container bears a label with the words “Seed for processing.” If any such seed...

  4. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...establishment, for cleaning or processing for seeding purposes, need...show that it is “Seed for processing,” or, if the seed is in...container bears a label with the words “Seed for processing.” If any such seed...

  5. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...establishment, for cleaning or processing for seeding purposes, need...show that it is “Seed for processing,” or, if the seed is in...container bears a label with the words “Seed for processing.” If any such seed...

  6. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...establishment, for cleaning or processing for seeding purposes, need...show that it is “Seed for processing,” or, if the seed is in...container bears a label with the words “Seed for processing.” If any such seed...

  7. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...establishment, for cleaning or processing for seeding purposes, need...show that it is “Seed for processing,” or, if the seed is in...container bears a label with the words “Seed for processing.” If any such seed...

  8. Seeding rate and seed size as management techniques for ryegrass (Lolium Multiflorum, Lam) in winter wheat 

    E-print Network

    Cook, Casey Lee

    2005-08-29

    Higher seeding rates and larger seed sizes could enhance the competitiveness of wheat with ryegrass. Growth room and field research evaluated the effects of wheat seeding rates and seed size in competition with Italian ryegrass. Winter wheat seeds...

  9. Proteins of Soybean Seeds

    PubMed Central

    Hill, J. E.; Breidenbach, R. W.

    1974-01-01

    Fresh weight and dry weight as well as quantitative and qualitative protein changes in the developing soybean (Glycine max) seed were described from 12 days after flowering until maturity. The seed proteins were separated on sucrose density gradients into three major fractions, having average sedimentation coefficients of 2.2S, 7.5S, and 11.8S. The 2.2S sedimenting proteins predominated at very early stages of development (12 days after flowering) and decreased proportionately throughout maturation. The 7.5S and 11.8S components appeared to be synthesized later in maturity and in larger amounts than the 2.2S proteins. Electrophoretic studies on extracts from whole seeds and on isolated protein fractions confirmed the early abundance of proteins in the 2.2S fraction and revealed temporal differences in the accumulation of three components of the 7.5S fraction. The 11.8S sedimenting fraction appeared throughout seed development as a homogeneous protein which accumulated in the seed with a time course similar to that of the total 7.5S protein fraction. PMID:16658782

  10. How many seeds in a seeded breadfruit, Artocarpus altilis (Moraceae)?

    Microsoft Academic Search

    F. D. Bennett; C. Nozzolillo

    1987-01-01

    Despite their demonstrated nutritional value, yield of seeded breadfruit trees (Artocarpus altilis) has not been investigated\\u000a in any detail. In the present study, the average number of seeds per seeded breadfruit harvested from a single 6-yr-old tree\\u000a over a period of 7 months was 59. Individual fruits contained as many as 151 or as few as 12. The average seed

  11. 7 CFR 948.6 - Seed potatoes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Agriculture 8 2012-01-01 2012-01-01 false Seed potatoes. 948.6 Section 948.6 Agriculture...Order Regulating Handling Definitions § 948.6 Seed potatoes. Seed potatoes or seed means any potatoes which...

  12. 7 CFR 948.6 - Seed potatoes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Agriculture 8 2014-01-01 2014-01-01 false Seed potatoes. 948.6 Section 948.6 Agriculture...Order Regulating Handling Definitions § 948.6 Seed potatoes. Seed potatoes or seed means any potatoes which...

  13. 7 CFR 948.6 - Seed potatoes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Agriculture 8 2013-01-01 2013-01-01 false Seed potatoes. 948.6 Section 948.6 Agriculture...Order Regulating Handling Definitions § 948.6 Seed potatoes. Seed potatoes or seed means any potatoes which...

  14. Frequency Modulation

    Microsoft Academic Search

    B. Van Der Pol

    1930-01-01

    The differential equation of a frequency modulated transmitter is considered and the expression of the current as a function of time is derived. Frequency analysis of this function is made for two specific cases, (A) sinusoidal frequency modulation (telephony) and (B), right-angle frequency modulation (telegraphy with \\

  15. Frequency curves

    USGS Publications Warehouse

    Riggs, H.C.

    1968-01-01

    This manual describes graphical and mathematical procedures for preparing frequency curves from samples of hydrologic data. It also discusses the theory of frequency curves, compares advantages of graphical and mathematical fitting, suggests methods of describing graphically defined frequency curves analytically, and emphasizes the correct interpretations of a frequency curve.

  16. SEED Grant Guidelines Revised February 2014 UNBC RESEARCH SEED GRANT

    E-print Network

    Northern British Columbia, University of

    SEED Grant Guidelines ­ Revised February 2014 UNBC RESEARCH SEED GRANT GUIDELINES OBJECTIVE. 4.2 If the project is similar to one previously funded through a UNBC seed grant, the researcher outline how the funds contributed to the researcher's external grant proposal. Failure to provide

  17. Empty seeds reduce seed predation by birds in Juniperus osteosperma

    Microsoft Academic Search

    Marcelino Fuentes; Eugene W. Schupp

    1998-01-01

    Utah juniper (Juniperus osteosperma) is one of many plant species that produce large numbers of fruits containing parthenocarpic or otherwise empty or inviable seeds. We tested the hypothesis that production of empty fruits in this species results in reduced levels of predation on fertile seeds. In a population in west-central Utah, we estimated the proportion of fruits with filled seeds

  18. Lignins of Rumex acetosa Seeds

    Microsoft Academic Search

    G. N. Dalimova; D. N. Dalimov; M. K. Bkhatt

    2004-01-01

    Spinach seeds were analyzed quantitatively. Wilstetter lignin was isolated and characterized by alkaline hydrolysis of spinach seed-lignocarbohydrate complex. Its elemental composition and molecular weight were determined. Its IR spectrum was analyzed.

  19. Chia seed oil

    Microsoft Academic Search

    WALTER F. BAUGItMAN; George S. Jamieson

    1929-01-01

    Summary  The results of the determination of the chemical composition of chia seed oil are furnished below. The composition of two\\u000a samples of linseed oil determined by Kaufmann and Keller9 is given for comparison.\\u000a \\u000a \\u000a \\u000a The chia seed oil contains a very small amount of oleic glyceride—much less than linseed oil, practically the same amount\\u000a of linolenic glyceride as the Calcutta linseed

  20. Efficient Seeds Computation Michalis Christou, Maxime Crochemore,

    E-print Network

    Lonardi, Stefano

    Efficient Seeds Computation Revisited Michalis Christou, Maxime Crochemore, Costas S. Iliopoulos a b a Seed: every letter of the string is covered by some occurrence of the seed, occurrences may. Another problem: Seed computation find the shortest seed (all the seeds) of a string 4/1 #12;Main related

  1. Tansley review The evolution of seeds

    E-print Network

    Leubner, Gerhard

    Tansley review The evolution of seeds Authors for correspondence: Gerhard Leubner-Metzger Tel: +49, comparative seed biology, dormancy, endosperm and perisperm, gymnosperms, seed development, seed evolution, seed mass. Summary The evolution of the seed represents a remarkable life-history transition for photo

  2. Tree Seed Technology Training Course: Student Outline.

    ERIC Educational Resources Information Center

    Bonner, F. T.; And Others

    This manual is intended primarily to train seed collectors, seed-plant managers, seed analysts, and nursery managers, but can serve as a resource for any training course in forest regeneration. It includes both temperate and tropical tree species of all intended uses and covers the following topics: seed biology, seed collection, seed handling,…

  3. Seeds of the world : Journey to Forever

    NSDL National Science Digital Library

    Keith Addison

    2001-01-01

    Seeds of the world: Journey to Forever - No seeds, no food, vanishing seeds, most crop varieties already lost, rendezvous with extinction, seed saving, biodiversity, world hunger This site discusses the importance of seeds to humans and the global economy. It provides extension information about genetically modified seeds and the Green Revolution.

  4. SEED DORMANCY IN LEAFY SPURGE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leafy spurge reproduces asexually via crown and root buds and sexually by seeds. Our unit has largely focused on dormancy in buds and vegetative reproduction. However, dormant seeds in the soil play a key role in the persistence of weeds. For example, leafy spurge seeds can remain dormant and viable...

  5. Characteristics of Echinacea seed oil

    Microsoft Academic Search

    B. Dave Oomah; Delphine Dumon; Anaberta Cardador-Martínez; David V. Godfrey

    2006-01-01

    Seed oils from three commonly cultivated Echinacea species, Echinacea Angustifolia, Echinacea Pallida and Echinacea Purpurea, harvested in 1998 and 1999, were evaluated for physicochemical characteristics. Oil yield ranged from 13% to 23%, depending on Echinacea species and seed weight. UV\\/VIS and fluorescence spectra distinguished Echinacea seed oil by species. Vitamin E content of the oils ranged from 29 to 85

  6. Cloud Seeding Frequently Asked Questions

    NSDL National Science Digital Library

    Griffith, Don

    This site is provided by North American Weather Consultants, Inc. The site briefly answers questions such as "when did application of modern cloud seeding technology begin?," "Is cloud seeding effective?," and "Do the commonly used seeding materials pose any direct health or environmental risks?"

  7. Onion Seed Production in California

    E-print Network

    Bradford, Kent

    Onion Seed Production in California RONALD E. VOSS, Cooperative Extension Vegetable Specialist, Colusa County; KENT BRADFORD, Professor and Seed Physiologist, Department of Vegetable Crops, University Center, Imperial Valley. P R O D U C T I O N A R E A S A N D S E A S O N S Commercial seed production

  8. Should seeds fly or not?

    Microsoft Academic Search

    Tatsuo Unemi

    This paper describes some results of our computer sim- ulation concerning ecological competition on the target area of seed dispersal. It is better for any kinds of plants to disperse their seeds as far as possible because it might spread in new frontier earlier than the others. But, it would be better to put the seeds down just at the

  9. [Seed dispersal efficiency of forest herbaceous plant species by the ant Myrmica ruginodis].

    PubMed

    Delatte, Emilie; Chabrerie, Olivier

    2008-04-01

    We compared the ability of 33 plant species collected in forest to have their seeds dispersed by the wood red ant Myrmica ruginodis. The elaiosome-bearing seeds (species Chelidonium majus, Colchicum autumnale, Luzula forsteri, Viola reichenbachiana, Luzula multiflora, Melica uniflora) and the small and light caryopses of the grasses (Holcus mollis, Agrostis capillaris, Deschampsia flexuosa, Poa trivialis, Holcus lanatus) are the most efficiently collected by ants. The seed quantity removed by ants is correlated negatively with their length. No significant correlation is found between the rate of seed removal and the frequency of the plants in the field at the scale of the study. PMID:18355754

  10. Managing Stress. Project Seed.

    ERIC Educational Resources Information Center

    Muto, Donna; Wilk, Jan

    One of eight papers from Project Seed, this paper describes a stress management project undertaken with high school sophomores. Managing Stress is described as an interactive workshop that offers young people an opportunity to examine specific areas of stress in their lives and to learn effective ways to deal with them. The program described…

  11. OPTIMIZING SEED BANKING PROCEDURES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper outlines factors important for genebanking. Optimizing genebanking procedures is often interpreted as storing seeds under environmental conditions that give them maximum longevity. This paper argues that even this narrow view of optimized genebanking is difficult to define or predict and ...

  12. Seed Cotton Handling & Storage

    E-print Network

    Mukhtar, Saqib

    Seed Cotton Handling & Storage #12;S.W. Searcy Texas A&M University College Station, Texas M) Lubbock, Texas E.M. Barnes Cotton Incorporated Cary, North Carolina Acknowledgements: Special thanks for the production of this document has been provided by Cotton Incorporated, America's Cotton Producers

  13. Grass and grain seeds

    NSDL National Science Digital Library

    Olivia Worland (Purdue University; Biological Sciences)

    2008-06-03

    Many types of grasses grow back after they have been cut back or mowed. Some weeds also do this, but other kinds of weeds stop growing once cut. Grains are seeds, but they are also valuable sources of food for humans and animals.

  14. The SEED Initiative

    ERIC Educational Resources Information Center

    Teich, Carolyn R.

    2011-01-01

    Committed to fulfilling the promise of the green economy, the American Association of Community Colleges (AACC) launched the Sustainability Education and Economic Development (SEED) initiative (www.theseedcenter.org) in October 2010. The project advances sustainability and clean energy workforce development practices at community colleges by…

  15. SEED Software Annotations.

    ERIC Educational Resources Information Center

    Bethke, Dee; And Others

    This document provides a composite index of the first five sets of software annotations produced by Project SEED. The software has been indexed by title, subject area, and grade level, and it covers sets of annotations distributed in September 1986, April 1987, September 1987, November 1987, and February 1988. The date column in the index…

  16. The Seeds of Change.

    ERIC Educational Resources Information Center

    Viola, Herman J.

    1991-01-01

    Discusses "Seeds of Change," a Columbian quincentenary exhibition at the Smithsonian Institution. Describes the rapid transformation of the Americas after contact with the Europeans. Reports that the exhibit explores the destruction of the native population by disease, war, slavery, the ongoing decimation of the rain forest, and the transformation…

  17. Dielectric characterization of the seeds of invasive Chinese tallow tree.

    PubMed

    Fennell, Laura Picou; Boldor, Dorin

    2013-01-01

    Biofuels have the potential to replace a significant portion of the transportation needs of the USA and the world. Low-cost lipid feedstock (i.e. tallow tree seeds) can be used for production of biodiesel, but these seeds need to be dried. Microwave drying is utilized to dry various seeds and grain, but for this process to be most efficient the dielectric properties of the materials need to be known. This study presents, for the first time, the dielectric properties of the seeds of the Chinese tallow tree. The dielectric constant and dielectric loss factor were determined using a modified free-space method for different moisture contents at frequency ranges centered around 915 and 2450 MHz respectively. The dielectric constant decreased with frequency in those respective ranges, and increased linearly with increasing moisture content, from 1.96 at 0% m.c. to 2.3 at 7% m.c. at 915 MHz, and from 2.08 at 0% m.c. to 2.42 at 7.6% m.c. at 2450 MHz. The dielectric loss factor generally decreased with frequency in both frequency ranges, and increased linearly with moisture content from a low of 0.16 at 0% m.c. to 0.21 at 7.56% at 915 MHz, respectively from a low of 0.13 at 0% m.c. to 0.2 at 7.6% m.c. at 2450 MHz. These results can be used to design microwave processing operations and systems for drying of tallow tree seeds, as well as for non-destructive determination of theses seeds' moisture content. PMID:24779226

  18. Sensitive Technique For Detecting Alignment Of Seed Laser

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.

    1994-01-01

    Frequency response near resonance measured. Improved technique for detection and quantification of alignment of injection-seeding laser with associated power-oscillator laser proposed. Particularly useful in indicating alignment at spectral purity greater than 98 percent because it becomes more sensitive as perfect alignment approached. In addition, implemented relatively easily, without turning on power-oscillator laser.

  19. Unified Microwave Moisture Sensing Technique for Grain and Seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A unified method for moisture sensing in grain and seed from a single calibration equation, which is obtained from measurement of their dielectric properties at a single microwave frequency is presented. The method is based on a complex permittivity calibration function that is independent of both b...

  20. Crop protection by seed coating.

    PubMed

    Ehsanfar, S; Modarres-Sanavy, S A M

    2005-01-01

    Providence of sufficient and healthy food for increasing human population clears the importance of notice to increasing crop production in company with environmental loss reduction. Growth and yield of every plant with sexual reproduction, depends on germination & emergence of sown seeds. Seed is a small alive plant that its biological function is protection and nutrition of embryo. Biological, chemical and physiological characteristics of seed, affect on plant performance & its resistance to undesirable environmental conditions, and even on its total yield. So attention to seed and try to increase its performance is so important. One of the factors that cause reduction in germination percentage and seedling establishment, is seed disease. It's possible to control these diseases by treating the seed before planting it. Coating the seed with pesticides, is one of the ways to gain this goal. Seed coating is a technique in which several material as fertilizers, nutritional elements, moisture attractive or repulsive agents, plant growth regulators, rhizobium inocolum, chemical & pesticide etc, add to seed by adhesive agents and cause to increase seed performance and germination. Seed coating, leads to increase benefits in seed industry, because seeds can use all of their genetic vigor. This technique is used for seeds of many garden plants, valuable crops (such as corn, sunflower, canola, alfalfa,...) and some of the grasses. In this technique that was first used in coating cereal seeds in 1930, a thin and permeable layer of pesticide is stuck on seed surface and prevent damage of seedborn pathogens. This layer is melted or splited after absorption of moisture and suitable temperature by seed, and let the radical to exit the seed. In this approach materials are used accurately with seed, evaporation & leakage of pesticide and also adverse effects of some pesticides on seeds are diminished, and these factors cause to increase the accuracy and performance of pesticide, decrease their consumption, environmental pollution and costs. This technique in new and there is a few information about it. So after searching and studying about this technique this paper is written to introduce it and its applications in crop protection. PMID:16637182

  1. Empty Seeds Are Not Always Bad: Simultaneous Effect of Seed Emptiness and Masting on Animal Seed Predation

    PubMed Central

    Perea, Ramón; Venturas, Martin; Gil, Luis

    2013-01-01

    Seed masting and production of empty seeds have often been considered independently as different strategies to reduce seed predation by animals. Here, we integrate both phenomena within the whole assemblage of seed predators (both pre and post-dispersal) and in two contrasting microsites (open vs. sheltered) to improve our understanding of the factors controlling seed predation in a wind-dispersed tree (Ulmus laevis). In years with larger crop sizes more avian seed predators were attracted with an increase in the proportion of full seeds predated on the ground. However, for abundant crops, the presence of empty seeds decreased the proportion of full seeds predated. Empty seeds remained for a very long period in the tree, making location of full seeds more difficult for pre-dispersal predators and expanding the overall seed drop period at a very low cost (in dry biomass and allocation of C, N and P). Parthenocarpy (non-fertilized seeds) was the main cause of seed emptiness whereas seed abortion was produced in low quantity. These aborted seeds fell prematurely and, thus, could not work as deceptive seeds. A proportion of 50% empty seeds significantly reduced ground seed predation by 26%. However, a high rate of parthenocarpy (beyond 50% empty seeds) did not significantly reduce seed predation in comparison to 50% empty seeds. We also found a high variability and unpredictability in the production of empty seeds, both at tree and population level, making predator deception more effective. Open areas were especially important to facilitate seed survival since rodents (the main post-dispersal predators) consumed seeds mostly under shrub cover. In elm trees parthenocarpy is a common event that might work as an adaptive strategy to reduce seed predation. Masting per se did not apparently reduce the overall proportion of seeds predated in this wind-dispersed tree, but kept great numbers of seeds unconsumed. PMID:23776503

  2. Pollination, seed set and seed predation on a landscape scale.

    PubMed Central

    Steffan-Dewenter, I.; Münzenberg, U.; Tscharntke, T.

    2001-01-01

    We analysed the combined effects of pollination and seed predation on seed set of Centaurea jacea in 15 landscapes differing in structural complexity. In the centre of each landscape, a patch of Centaurea plants was established for standardized measurements of flower visitation, seed predation and seed set. Both the number of flower-visiting bees and the proportion of flower heads damaged by seed predators increased with landscape complexity, which was measured as the proportion of semi-natural habitats. The mean number of seeds per flower head did not increase with the proportion of semi-natural habitats, presumably because of the counterbalancing effects of pollination and seed predation. For a subset of undamaged flower heads, the number of seeds per flower head was positively correlated with the number of flower visits. Further reasons for the unexpected failure to detect a correlation between landscape complexity and seed set appeared to be changes in flower-visitor behaviour and the contrasting responses of honeybees and wild bees to habitat context. Landscape analyses at eight spatial scales (radius of landscape sectors, 250-3000 m) showed that different groups perceived the landscape at different spatial scales. Changes in pollinator numbers could be explained only at small scales (up to 1000 m), while the seed predators also responded to large scales (up to 2500 m). PMID:11506681

  3. Pollination, seed set and seed predation on a landscape scale.

    PubMed

    Steffan-Dewenter, I; Münzenberg, U; Tscharntke, T

    2001-08-22

    We analysed the combined effects of pollination and seed predation on seed set of Centaurea jacea in 15 landscapes differing in structural complexity. In the centre of each landscape, a patch of Centaurea plants was established for standardized measurements of flower visitation, seed predation and seed set. Both the number of flower-visiting bees and the proportion of flower heads damaged by seed predators increased with landscape complexity, which was measured as the proportion of semi-natural habitats. The mean number of seeds per flower head did not increase with the proportion of semi-natural habitats, presumably because of the counterbalancing effects of pollination and seed predation. For a subset of undamaged flower heads, the number of seeds per flower head was positively correlated with the number of flower visits. Further reasons for the unexpected failure to detect a correlation between landscape complexity and seed set appeared to be changes in flower-visitor behaviour and the contrasting responses of honeybees and wild bees to habitat context. Landscape analyses at eight spatial scales (radius of landscape sectors, 250-3000 m) showed that different groups perceived the landscape at different spatial scales. Changes in pollinator numbers could be explained only at small scales (up to 1000 m), while the seed predators also responded to large scales (up to 2500 m). PMID:11506681

  4. Radiobiological experiments with plant seeds aboard the biosatellite Cosmos 1887

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Anikeeva, I. D.; Akatov, Yu. A.; Vaulina, E. N.; Kostina, L. N.; Marenny, A.; Portman, A. I.; Rusin, S. V.

    1995-01-01

    The effects of spaceflight factors on the seeds of Arabidopsis thaliana and Crepis capillaris were studied. The seeds were located inside the satellite in an open space, protected with aluminum foil and also exposed without the foil cover. When the seeds were in open space without any protection, their viability was found to be suppressed; the survival rate and fertility of plants grown from these seeds were also diminished. An increase in the frequency of chromosome aberrations (CA) and in the number of multiple injuries was registered in this case. Experiments with the aluminum foil shielding showed a decrease in the suppression of the seeds' viability, but mutational changes were found to be even more increased, while the survival rate and fertility of the plants decreased. An increase in the thickness of shielding resulted in a decrease in the effects up to the level of the control, except for the effects connected with CA and fertility of the plants. Analysis of the results shows that these impairments can be ascribed to the action of single heavy charged particles (HCP). The seeds can thus be regarded as an integral biological 'dosimeter' which allows estimation of the total effects of radiation, ecological and biological factors.

  5. Bacteria within ovules and seeds.

    PubMed Central

    Mundt, J O; Hinkle, N F

    1976-01-01

    Surface-sterilized ovules and seeds of 27 species of plants were cultured in the water of syneresis of a nutrient medium low in agar content. Bacteria were obtained from 30% of the ovules, 15% of the seeds of herbaceous plants, 16% of the seeds of woody plants, 5.4% of the overwintered noncereal seeds, and 13.5% of overwintered cereal seeds. In no instance did every ovule or seed of a plant species contain bacteria. No bacteria were obtained from the hard, waxy seeds of mimosa or yellowwood. They were not obtained from ovules with unbroken coats or from seeds with coats that were not ruptured during the swelling of the seed. Only one species of bacteria was recovered in 93% of the instances in which bacteria were obtained. Bacteria were obtained from seeds that were embedded in the acidic parenchyma of the lemon or surrounded by the thickened flesh of the cucurbits. The bacteria were distributed among 19 genera and 46 species. The species isolated in greatest numbers were Bacillus megaterium, B. cereus, Erwinia herbicola, Flavobacterium devorans, and Pseudomonas fluorescens. Bacteria recovered less frequently were in the genera Achromobacter, Acinetobacter, Alcaligenes, Brevibacterium, Corynebacterium, Cytophaga, Leuconostoc, Micrococcus, Nocardia, Proteus, Streptococcus, Streptomyces, and Xanthomonas. Members of 11 genera and 15 species of bacteria were isolated once. PMID:984839

  6. Construct Arguments: Pumpkin Seeds

    NSDL National Science Digital Library

    WGHB Boston

    2013-01-01

    This professional development video clip shows students engaged in the Common Core Practice Standard #3—Construct viable arguments for conclusions reached and critique the reasoning of others. In this lesson, learners work in groups to discuss and revise their estimates of how many seeds are in a small pumpkin. Additional resources include a video transcript, teaching tips, and a link to a professional development reflection activity based upon the video.

  7. Within canopy distribution of cotton seed N

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whole cotton seeds can be an important component of dairy rations. Nitrogen content of the seed is an important determinant of the feed value of the seed. Efforts to increase the seed value as feed will be enhanced with knowledge of the range and distribution of seed N within the cotton crop. This s...

  8. 90% pump depletion and good beam quality in a pulse-injection-seeded nanosecond optical parametric oscillator

    Microsoft Academic Search

    D. J. Armstrong; A. V. Smith

    2006-01-01

    We measured 90% pump depletion in a singly resonant image-rotating nanosecond optical parametric oscillator that was pulse-injection seeded by a self-generated signal pulse. The oscillator was pumped by an 8 ns duration single-frequency 532 nm pulse from an injection-seeded Q-switched Nd:YAG laser and resonated an 803 nm signal. The pump and pulsed-seed beams had flat-topped spatial fluence profiles with diameters

  9. Dormancy studies in blackberry seed

    E-print Network

    Lasheen, Abdel Moty

    1954-01-01

    been extensive, very little dealt with dormancy of blackberry seeds. Indeed, all the avail? able literature is limited to the practical side of the problem. As early as 1919 Rose (62) suggested that dormancy in Rubus idaeus was probably due... acid treatment was inadvisable. Hottes (39) stated that when raspberry and blackberry seeds are soaked in vinegar their germination will be hastened. Afanasiev (l), in suggesting means to overcome dormancy in blackberry (Rubus spp.),reported the seed...

  10. Seed Dispersal by Japanese Macaques

    Microsoft Academic Search

    Tatsuya Otani

    \\u000a Seed dispersal is a crucial process in recruitment of plant populations, as well as for pollen dispersal. The location of\\u000a dispersed seeds affects the survival of seedlings and the spatial distribution pattern of plants. Plants employ various strategies\\u000a for effective seed dispersal, and diaspores have unique structures that utilize biotic and\\/or abiotic factors such as fleshy\\u000a arils for endozoochory, thorny

  11. Post-fire seeding on Wyoming big sagebrush ecological sites: regression analyses of seeded nonnative and native species densities.

    PubMed

    Eiswerth, Mark E; Krauter, Karl; Swanson, Sherman R; Zielinski, Mike

    2009-02-01

    Since the mid-1980s, sagebrush rangelands in the Great Basin of the United States have experienced more frequent and larger wildfires. These fires affect livestock forage, the sagebrush/grasses/forbs mosaic that is important for many wildlife species (e.g., the greater sage grouse (Centrocercus urophasianus)), post-fire flammability and fire frequency. When a sagebrush, especially a Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis (Beetle & A. Young)), dominated area largely devoid of herbaceous perennials burns, it often transitions to an annual dominated and highly flammable plant community that thereafter excludes sagebrush and native perennials. Considerable effort is devoted to revegetating rangeland following fire, but to date there has been very little analysis of the factors that lead to the success of this revegetation. This paper utilizes a revegetation monitoring dataset to examine the densities of three key types of vegetation, specifically nonnative seeded grasses, nonnative seeded forbs, and native Wyoming big sagebrush, at several points in time following seeding. We find that unlike forbs, increasing the seeding rates for grasses does not appear to increase their density (at least for the sites and seeding rates we examined). Also, seeding Wyoming big sagebrush increases its density with time since fire. Seeding of grasses and forbs is less successful at locations that were dominated primarily by annual grasses (cheatgrass (Bromus tectorum L.)), and devoid of shrubs, prior to wildfire. This supports the hypothesis of a "closing window of opportunity" for seeding at locations that burned sagebrush for the first time in recent history. PMID:18790557

  12. Dung beetles as secondary seed dispersers: impact on seed predation and germination

    Microsoft Academic Search

    VIRGINIA E. SHEPHERD; COLIN A. CHAPMAN

    1998-01-01

    Dispersal of seeds away from the parent plant may facilitate escape from density-dependent seed mortality. However, many post-dispersal events can have a profound influence on the survival of dispersed seeds. By incorporating seeds in the dung that dung beetles process for consumption and oviposition, dung beetles could enhance seed survival if they remove seeds from areas of high pre- dation

  13. The rheological properties of the seed coat mucilage of Capsella bursa-pastoris L. Medik. (shepherd's purse).

    PubMed

    Deng, Wenni; Iannetta, Pietro P M; Hallett, Paul D; Toorop, Peter E; Squire, Geoffrey R; Jeng, Dong-Sheng

    2013-01-01

    The outer surface of myxospermous seed coats contains mucilage which absorbs large amounts of water relative to its dry weight. Ecologically, the seed mucilage can affect seed germination and dormancy. Upon hydration, a large proportion of the seed mucilage is lost to the soil and the physics of soil-seed mucilage interactions has not been assessed. Towards that end, the dynamic rheological properties of mucilage extracted from Capsella bursa-pastoris L. Medik. (shepherd's purse) seeds were assessed as a function of mucilage concentration (1-10% [w/w]), temperature (0-80°C) and shear frequency (0.1-100 rad s-1). The seed mucilage was shear thinning and was classified as a highly viscous "weak gel". The relationship between the viscoelastic parameters (viscosity, ?*, storage and loss modulus, G' and G?, yield and flow stresses, ?y and ?f) and mucilage concentration were well fitted by power law models. The values of ?*, G' and G? increased as temperature increased above 40°C and were also slightly frequency dependent. The shepherd's purse seed mucilage is more viscous than that from other plant parts, such as fruits and roots. These properties highlight the possibility that seed mucilage may affect soil conditions and therefore present an additional facilitative ecological role (beyond that already reported, which directly affect seed biology); and this is discussed. PMID:23619153

  14. Frequency-shifted feedback amplifier for broadband laser cooling

    NASA Astrophysics Data System (ADS)

    Lim, Michael; van Kooy, Alexander; Yanakas, Michael

    2014-03-01

    We have developed a compact, all-solid state laser amplifier for generating asymmetric sidebands with controlled number and spacing of optical frequencies. The gain element is a tapered semiconductor amplifier, used in conjunction with an acousto-optic modulator that generates red-detuned feedback frequencies. This results in asymmetric sidebands that are all lower in optical frequency than the narrowband seed laser frequency. The output laser spectrum has a well-defined edge (the input laser frequency) and multiple sidebands whose number, frequency spacing, and power are fully controlled by the seed laser characteristics and a single radio frequency input. The number of sidebands can be varied in a controlled way, and the output optical power is variable up to the Watt level of the amplifier chip. The system will be used for broadband laser cooling.

  15. Seed to Seed, The Secret Life of Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is a book review of "Seed to Seed, The Secret Life of Plants", by Nicholas Harberd. The book is a diary of ruminations/introspections about plant development and about the main research topic of Nick Harberd’s laboratory. His intended audience is initially nonscientists; many of the explanation...

  16. Seed-cotton Cleaning Effects on Seed Coat Fragments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Processing problems in textile mills have been linked to seed coat fragments (SCF), so cotton ginning facilities should take steps to prevent them from forming. The objective of this experiment was to determine if the use of seed-cotton cleaners prior to the extractor-feeder/gin stand caused increa...

  17. 9 CFR 101.7 - Seed organisms.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Seed organisms. 101.7 Section 101.7...AND VECTORS DEFINITIONS § 101.7 Seed organisms. When used in conjunction with or in reference to seed organisms, the following shall...

  18. 7 CFR 946.12 - Seed potatoes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Agriculture 8 2012-01-01 2012-01-01 false Seed potatoes. 946.12 Section 946.12 Agriculture...Order Regulating Handling Definitions § 946.12 Seed potatoes. Seed potatoes means and includes all potatoes...

  19. 7 CFR 947.12 - Seed potatoes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Agriculture 8 2012-01-01 2012-01-01 false Seed potatoes. 947.12 Section 947.12 Agriculture...Order Regulating Handling Definitions § 947.12 Seed potatoes. Seed potatoes means and includes all potatoes...

  20. 7 CFR 947.12 - Seed potatoes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Agriculture 8 2014-01-01 2014-01-01 false Seed potatoes. 947.12 Section 947.12 Agriculture...Order Regulating Handling Definitions § 947.12 Seed potatoes. Seed potatoes means and includes all potatoes...

  1. 7 CFR 946.12 - Seed potatoes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Agriculture 8 2013-01-01 2013-01-01 false Seed potatoes. 946.12 Section 946.12 Agriculture...Order Regulating Handling Definitions § 946.12 Seed potatoes. Seed potatoes means and includes all potatoes...

  2. 9 CFR 101.7 - Seed organisms.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Seed organisms. 101.7 Section 101.7...AND VECTORS DEFINITIONS § 101.7 Seed organisms. When used in conjunction with or in reference to seed organisms, the following shall...

  3. 7 CFR 947.12 - Seed potatoes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Agriculture 8 2013-01-01 2013-01-01 false Seed potatoes. 947.12 Section 947.12 Agriculture...Order Regulating Handling Definitions § 947.12 Seed potatoes. Seed potatoes means and includes all potatoes...

  4. PSU SEED Team 1 Report Summary

    E-print Network

    Demirel, Melik C.

    PSU SEED Team 1 Report Summary For our project, we worked in conjunction with SEED (Students for Environmentally Enlightened Design) and SEED Team 2 to complete a design for a library based out of a standard 40

  5. 7 CFR 946.12 - Seed potatoes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Agriculture 8 2014-01-01 2014-01-01 false Seed potatoes. 946.12 Section 946.12 Agriculture...Order Regulating Handling Definitions § 946.12 Seed potatoes. Seed potatoes means and includes all potatoes...

  6. 9 CFR 101.7 - Seed organisms.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Seed organisms. 101.7 Section 101.7...AND VECTORS DEFINITIONS § 101.7 Seed organisms. When used in conjunction with or in reference to seed organisms, the following shall...

  7. The Seed Scene: An Outdoor Teaching Technique

    ERIC Educational Resources Information Center

    Rillo, Thomas J.

    1974-01-01

    A discussion of the historical background of man's use of seeds is followed by an explanation of some of the basic concepts relating to seeds. Collecting seeds is discussed, and eight classroom activities are described. (DT)

  8. Simulation of free-electron lasers seeded with broadband radiation

    SciTech Connect

    Bajlekov, Svetoslav; Fawley, William; Schroeder, Carl; Bartolini, Riccardo; Hooker, Simon

    2011-03-10

    The longitudinal coherence of free-electron laser (FEL) radiation can be enhanced by seeding the FEL with high harmonics of an optical laser pulse. The radiation produced by high-harmonic generation (HHG), however, has a fast-varying temporal profile that can violate the slowly varying envelope approximation and limited frequency window that is employed in conventional free-electron laser simulation codes. Here we investigate the implications of violating this approximation on the accuracy of simulations. On the basis of both analytical considerations and 1D numerical studies, it is concluded that, for most realistic scenarios, conventional FEL codes are capable of accurately simulating the FEL process even when the seed radiation violates the slowly varying envelope approximation. We additionally discuss the significance of filtering the harmonic content of broadband HHG seeds.

  9. Teaching Through Trade Books: Secrets of Seeds

    NSDL National Science Digital Library

    Emily Morgan

    2009-02-01

    From a tiny radish seed to a giant coconut, seeds come in a multitude of shapes and sizes. They all share one amazing secret: the potential to grow into a new plant when conditions are right. In this month's column, students observe a variety of seeds, match seeds to the plants they grow into, explore what seeds need to germinate and grow, and design investigations with seeds.

  10. Genebanking seeds from natural populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional storage protocols have been developed to preserve genetic diversity of seeds of crops in genebanks. These same principles have been applied to preserve seeds from wild populations. While most principles for conventional storage protocols are applicable to a broad range of wild species...

  11. Multiple-Seed TPG Structures

    Microsoft Academic Search

    Dimitri Kagaris

    2003-01-01

    Linear feedback shift registers (LFSRs) are popular mechanisms for built-in test pattern generation (TPG). They are normally used with a primitive characteristic polynomial because, in that case, only one initialization state (seed) is required. We show that if the characteristic polynomial is nonprimitive irreducible, the required seeds can still be efficiently generated. We establish a formula that shows how the

  12. Morphological Analysis of Rubus Seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Rubus exhibits morphological diversity and a wide range of reproductive systems and habitats. We examined seed coat ultrastructural morphology of seed accessions of 10 subgenera preserved at the US Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Reposito...

  13. Two light yellow seed embryos

    NSDL National Science Digital Library

    Katie Hale (CSUF; Biological Sciences)

    2007-06-19

    The style of the carpel of a flower (female reproductive structure) leads to the ovary. The ovary holds eggs, which become seeds once fertilized. Seeds hold embryos. The embryo becomes a new plant. In animals, the embryo becomes a new animal.

  14. Insecticide seed treatments for sugarbeet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pest feeding and vectoring of viruses cause serious problems in sugarbeet production worldwide. In order to ameliorate pest and disease problems on sugarbeet, two seed treatments, Poncho Beta (60 g a.i. clothianidin + 8 g a.i. beta-cyfluthrin/100,000 seed) and Cruiser Tef (60 g a.i. thiamethoxam + 8...

  15. Physical properties of psyllium seed

    NASA Astrophysics Data System (ADS)

    Ahmadi, R.; Kalbasi-Ashtari, A.; Gharibzahedi, S. M. T.

    2012-02-01

    Physical properties ie dimensions, volume, surface area, sphericity, true density, porosity, angle of repose, terminal velocity, static and dynamic friction coefficients on plywood, stainless steel, glass and galvanized iron sheet, force required for initiating seed rupture in horizontal and vertical orientations of psyllium seed at a moisture content of 7.2% (w.b.)were determined.

  16. Differential predation of forage seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent field experiments we observed that the main invertebrate seed predators of overseeded tall fescue (Festuca arundinacea Schreb.) or Italian ryegrass (Lolium multiflorum Lam.) seed in unimproved pastures were harvester ants (Pogonomyrmex sp.) and common field crickets (Gryllus sp.) To determ...

  17. Microwave drying of seed cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A small lab dryer was designed for use in drying seed cotton with components of a microwave generator mounted thereon. The magnetron emitted radiation directly into the seed cotton and a fan directed air cross-flow to the radiation direction. The microwave components were a 1.1 kW magnetron, trans...

  18. Seed dormancy in Mexican teosinte

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed dormancy in wild Zea species may affect fitness and relate to ecological adaptation. The primary objective of this study was to characterize the variation in seed germination of the wild species of the genus Zea that currently grow in Mexico, and to relate this variation to their ecological zon...

  19. Seed Cotton Handling and Storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Storage of harvested seed cotton in the field prior to ginning has changed over the years to methods that decoupled harvesting and ginning operations and reduced labor. Prior to the introduction of the module builder, seed cotton was placed in trailers for transport to the gin where producers would ...

  20. MAINE MUSSEL SEED CONSERVATION AREAS

    EPA Science Inventory

    SEED shows point locations of Maine mussel seed conservation areas at 1:24,000 scale. Data for this coverage were screen digitized on a 1:24000 scale base using descriptions contained in Maine Department of Marine Resources (MDMR) rules. Coastal arcs from Maine Office of GIS 1:24...

  1. Banking on the past: seed banks as a reservoir for rare and native species in restored vernal pools

    PubMed Central

    Faist, Akasha M.; Ferrenberg, Scott; Collinge, Sharon K.

    2013-01-01

    Soil seed banks serve as reservoirs for future plant communities, and when diverse and abundant can buffer vegetation communities against environmental fluctuations. Sparse seed banks, however, may lead to future declines of already rare species. Seed banks in wetland communities are often robust and can persist over long time periods making wetlands model systems for studying the spatial and temporal links between above- and belowground communities. Using collected soils and germination trials, we assessed species diversity and density in the seed banks of restored, ephemeral wetlands (vernal pools) in California's Central Valley, USA. Using long-term vegetation surveys, we compared the community structure of seed banks to that of aboveground vegetation and assessed the temporal links between below- and aboveground communities. We also compared the proportional abundances of different cover classes as well as the abundance of native plants in seed banks to aboveground communities. The proportional abundances of both rare and native species were greater in seed bank samples than in aboveground samples, yet the seed bank had lower species richness than aboveground vegetation. However, the seed bank had greater levels of differentiation among pools (beta diversity; ?) than aboveground samples. Additionally, the seed bank was more similar to the earlier (2003–06) aboveground community than the more recent (2007–10) aboveground community. The correlation of species composition in the current seed bank to an earlier aboveground community suggests that seed banks exhibit storage effects while aboveground species composition in this system is not driven by seed bank composition, but is perhaps due to environmental filtering. We conclude that the seed bank of these pools is neither prone to the same temporal rates of invasion as the aboveground community, nor is seed abundance presently a limiting factor in the aboveground frequency of native species or a promoting factor in plant invasions of these restored habitats.

  2. On subset seeds for protein alignment.

    PubMed

    Roytberg, Mikhail; Gambin, Anna; Noé, Laurent; Lasota, Slawomir; Furletova, Eugenia; Szczurek, Ewa; Kucherov, Gregory

    2009-01-01

    We apply the concept of subset seeds to similarity search in protein sequences. The main question studied is the design of efficient seed alphabets to construct seeds with optimal sensitivity/selectivity trade-offs. We propose several different design methods and use them to construct several alphabets. We then perform a comparative analysis of seeds built over those alphabets and compare them with the standard Blastp seeding method, as well as with the family of vector seeds. While the formalism of subset seeds is less expressive (but less costly to implement) than the cumulative principle used in Blastp and vector seeds, our seeds show a similar or even better performance than Blastp on Bernoulli models of proteins compatible with the common BLOSUM62 matrix. Finally, we perform a large-scale benchmarking of our seeds against several main databases of protein alignments. Here again, the results show a comparable or better performance of our seeds versus Blastp. PMID:19644175

  3. Seed coat thickness data clarifies seed size-seed persistence tradeoffs in Abutilon theophrasti (Malvaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Theoretical models predict that seed size and seedbank persistence evolve interdependently such that strong selection for one trait corresponds with weak selection for the other. This framework is supported by empirical data but conclusive evidence is lacking. In this study, we expand the seed size-...

  4. Seed biology and in vitro seed germination of Cypripedium.

    PubMed

    Zeng, Songjun; Zhang, Yu; Teixeira da Silva, Jaime A; Wu, Kunlin; Zhang, Jianxia; Duan, Jun

    2014-12-01

    Cypripedium orchids have high horticultural value. The populations of most species are very geographically restricted and they are becoming increasingly rare due to the destruction of native habitats and illegal collection. Reduction of the commercial value through large-scale propagation in vitro is a preferable option to reduce pressure from illegal collection. Cypripedium species are commercially propagated via seed germination in vitro. This review focuses on in vitro seed germination and provides an in-depth analysis of the seed biology of this genus. PMID:24191720

  5. 2012 Virginia Polytechnic Institute and State University BSE-48NP Virginia Cooperative Extension programs and employment are open to all, regardless of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or

    E-print Network

    Liskiewicz, Maciej

    , is mowing grass. Other selected examples of tractor uses include towing, tilling, raking, sweeping, seeding jobs. Selected examples of these attachments may include #12;2 sweepers, seeder, blades and tillers

  6. Effects of prolonged exposure to space flight factors for 175 days on lettuce seeds

    NASA Astrophysics Data System (ADS)

    Nevzgodina, L. V.; Maximova, E. N.; Akatov, Yu. A.

    We have studied the effects of prolonged (up to 175 days) exposure of Lactuca sativa seeds to space flight factors, including primary cosmic radiation heavy ions. The data obtained evidence a significant fourfold increase ofs pontaneous mutagenesis in seeds both with regard to the total number of aberrant cells as well as the formation of single cells with multiple aberrations. Comparison of the present experiment with earlier works shows that the frequency of such aberrations increases with the duration of the flight.

  7. Self fertilization and seed set in Trifolium repens L. by in situ and in vitro pollination

    Microsoft Academic Search

    G. C. Douglas; V. Connolly

    1989-01-01

    The frequency of seed formation has been determined from self-pollination in situ (by hand) and in vitro for Trifolium repens. Selfing in situ was measured over a period of 3 years in which plants were held either at 35 °C for 24 h post-pollination (1984 and 1985) or held at ambient temperatures (1986). Mean yield of self-seed per 100 florets

  8. Topic in Depth - Cloud Seeding

    NSDL National Science Digital Library

    This Topic in Depth is about cloud seeding, a type of weather modification in which substances, such as silver iodide or dry ice, are added to the air in order to produce changes in the weather. Cloud seeding is most commonly used to increase precipitation, but may also be used to suppress certain weather patterns as well, such as hail and high winds. While there is some controversy about whether or not cloud seeding actually does produce more precipitation, it can be a highly useful tool for areas that have very arid conditions and need additional rainfall to help produce more viable crops and minimize drought-like conditions.

  9. 7 CFR 948.6 - Seed potatoes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Seed potatoes. 948.6 Section 948.6 Agriculture...DEPARTMENT OF AGRICULTURE IRISH POTATOES GROWN IN COLORADO Order Regulating Handling Definitions § 948.6 Seed potatoes. Seed potatoes or seed means...

  10. 7 CFR 948.6 - Seed potatoes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Seed potatoes. 948.6 Section 948.6 Agriculture...DEPARTMENT OF AGRICULTURE IRISH POTATOES GROWN IN COLORADO Order Regulating Handling Definitions § 948.6 Seed potatoes. Seed potatoes or seed means...

  11. Materials used for Seed Storage Containers: Response

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Efficient seed storage is a shared concern among the growing number of seed banks established for crop improvement or ex situ conservation. Container properties greatly affect seed interactions with the environment and the overall cost and success of seed banking operations. Several material proper...

  12. Seed pathology progress in academia and industry.

    PubMed

    Munkvold, Gary P

    2009-01-01

    Seed pathology involves the study and management of diseases affecting seed production and utilization, as well as disease management practices applied to seeds. In this paper, three aspects of seed pathology are discussed: research innovations in detection of seedborne pathogens and elucidation of their epidemiology; advances in development and use of seed treatments; and progress toward standardization of phytosanitary regulations and seed health testing methods. The application of nucleic-acid based detection methods in seed health testing has been facilitated by integrating conventional or real-time PCR with other technologies (e.g., BIO-PCR, IMS-PCR, MCH-PCR). PCR-based methods and pathogen marker technologies are being applied to epidemiological research on seedborne pathogens, e.g., seed transmission mechanisms, the influence of external biotic and abiotic factors on seed transmission, and tracking progress of seed-transmitted pathogens. Seed treatment use is discussed in terms of the revolutionary expansion in seed-applied insecticide use, impacts of new fungicide active ingredients, and the effects of some seed treatments on crop physiology. International seed trade has been affected significantly by changing phytosanitary regulations, not always based on science. Efforts are underway to revise phytosanitary regulations to reflect pest risk analysis outcomes and to develop standards for seed health testing methods that facilitate safe and efficient international trade in seeds. PMID:19400648

  13. Superiority of Spaced Seeds for Homology Search

    E-print Network

    Zhang, Louxin

    Superiority of Spaced Seeds for Homology Search Louxin Zhang Abstract--In homology search, good spaced seeds have higher sensitivity for the same cost (weight). However, elucidating the mechanism that confers power to spaced seeds and characterizing optimal spaced seeds still remain unsolved. This paper

  14. Removal of seeds from Neotropical frugivore droppings

    Microsoft Academic Search

    Michael Kaspari; Tucson Arizona

    1993-01-01

    In a Costa Rican rain forest, the majority of tree and shrub species have their seeds dispersed by vertebrates. Over a third of the species' seeds are of a size accessible to, and primarily carried away by, ants. Frugivorous bird droppings come in sizes from a few seeds to over a thousand, with number of seeds isometric with bird body

  15. 46 CFR 148.310 - Seed cake.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Special Requirements for Certain Materials § 148.310 Seed cake. (a) This part does not apply to solvent-extracted rape seed meal, pellets, soya bean meal, cotton seed meal, or sunflower seed meal that— (1) Contains a maximum of 4...

  16. 7 CFR 201.50 - Weed seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Weed seed. 201.50 Section 201.50 ...Administration of the Act § 201.50 Weed seed. Seeds (including bulblets or tubers) of plants shall be considered weed seeds when recognized as weed...

  17. 7 CFR 201.50 - Weed seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Weed seed. 201.50 Section 201.50 ...Administration of the Act § 201.50 Weed seed. Seeds (including bulblets or tubers) of plants shall be considered weed seeds when recognized as weed...

  18. 7 CFR 201.50 - Weed seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Weed seed. 201.50 Section 201.50 ...Administration of the Act § 201.50 Weed seed. Seeds (including bulblets or tubers) of plants shall be considered weed seeds when recognized as weed...

  19. 7 CFR 201.50 - Weed seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Weed seed. 201.50 Section 201.50 ...Administration of the Act § 201.50 Weed seed. Seeds (including bulblets or tubers) of plants shall be considered weed seeds when recognized as weed...

  20. Flowering, Capsule and Seed Characteristics in Cuphea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We modeled the flowering and capsule set dynamics, quantified the level of variation in seed characteristics, elucidated the inter-relationships among seed and capsule physical dimensions, and quantified their impact on single seed weight as the main determinant of seed yield in the indeterminate, p...

  1. Hypoxia and Imbibition Injuries to Aging Seeds

    Microsoft Academic Search

    T. V. Veselova; V. A. Veselovskii; P. D. Usmanov; O. V. Usmanova

    2003-01-01

    The development of hypoxia and primary injuries were examined during the imbibition of aging pea seeds (Pisum sativum L., cv. Nemchinovskii). The distribution of air-dry pea seeds by their room-temperature phosphorescence revealed the presence of two fractions (I and II) in a seed lot with 72% germinability and three fractions (I, II, and III) in a seed lot with 50%

  2. INTESPECIIC DIFFERENCES IN GRASS SEED IMBIBITION

    EPA Science Inventory

    Seeds from 12 grass species were studied relative to mode of wetting and time of exposure to water to document interspecific differences in imbibition characteristics. Imbibition causes seeds to become wet, and wet seeds are more detectable to consumers than dry seeds. Thus, ge...

  3. SEED ORCHARDS ON RECLAIMED MINED LAND

    Microsoft Academic Search

    D Terrance Booth

    2005-01-01

    Reclaimed mined lands often have restricted public access, a situation that could encourage sagebrush seed growers to invest in methods for increasing seed production and improving seed purity and quality. I tested the agronomic benefit of 2 seeding methods and fabric mulch and a cross-linked polyacrylamide polymer soil amendment by using these practices to establish 3 Wyoming big sagebrush (Artemisia

  4. Succeeding with seeding: some practical advice

    Microsoft Academic Search

    Terese Bergfors

    2007-01-01

    Seeding is a powerful and versatile method for optimizing crystal growth conditions. This article discusses, from a practical\\u000a point of view, what seeding is, the selection and transfer of seeds, and into what conditions they should be transferred.\\u000a The most common causes of failures in seeding experiments are also analyzed.

  5. Comments on relationships between native seed preferences of shrub-steppe granivores and seed nutritional characteristics

    Microsoft Academic Search

    Stephen H. Jenkins

    1988-01-01

    Kelrick et al. (1986) argued that seed preferences of desert granivores are strongly influenced by soluble carbohydrate contents of native seed species. They assumed that bitterbrush (Purshia tridentata) seeds are eaten in their entirety by rodents, but in fact these granivores eat only embryos of bitterbrush seeds. Embryos have a much lower percentage of soluble carbohydrate than whole bitterbrush seeds,

  6. Regeneration of Cyperaceae, with particular reference to seed ecology and seed banks

    Microsoft Academic Search

    Mary Allessio Leck; Wolfgang Schütz

    2005-01-01

    Cyperaceae (sedges) are an important component of many ecosystems. To understand better their regeneration, we examined seed ecology, including dispersal, seed characteristics, and germination behavior that relate to seed bank development and persistence. We also evaluated sedge seed banks from 104 studies, representing a wide array of habitats. Sedge seed bank development and persistence were associated with germination and dormancy

  7. Automated seed detection and 3D reconstruction I: Seed Localization from Fluoroscopic Images or Radiographs.

    E-print Network

    Pouliot, Jean

    Automated seed detection and 3D reconstruction I: Seed Localization from Fluoroscopic Images of radioactive seeds on fluoroscopic images or scanned radiographs is presented. The extracted positions of seed, 92% of the seeds are detected automatically. The orientation is found with an error lower then 5

  8. Changes in Chenopodium rubrum seeds with aging.

    PubMed

    Mitrovi?, Aleksandra; Duci?, Tanja; Liric-Rajli?, Ivana; Radoti?, Ksenija; Zivanovi?, Branka

    2005-06-01

    We studied antioxidative system, germination, growth, and flowering in vitro in Chenopodium rubrum seeds of different ages. Peroxidase, superoxide dismutase, and catalase activity, as well as glutathione status, were determined in 2.5-h imbibed seeds. Germination was tested under controlled conditions. Growth and flowering of plants were tested in vitro. The enzyme activities and glutathione content were higher in younger seeds. Germination declines with seed age. Plants derived from older seeds were smaller, and flowering percentage was lower compared to plants derived from younger seeds. Gibberellic acid reduced the difference in growth and flowering between plants derived from seeds different in age. PMID:16154987

  9. Can Soil Seed Banks Serve as Genetic Memory? A Study of Three Species with Contrasting Life History Strategies

    PubMed Central

    Mandák, Bohumil; Zákravský, Petr; Mahelka, Václav; Pla?ková, Ivana

    2012-01-01

    We attempted to confirm that seed banks can be viewed as an important genetic reservoir by testing the hypothesis that standing (aboveground) plants represent a nonrandom sample of the seed bank. We sampled multilocus allozyme genotypes from three species with different life history strategies: Amaranthus retroflexus, Carduus acanthoides, Pastinaca sativa. In four populations of each species we analysed the extent to which allele and genotype frequencies vary in consecutive life history stages including the summer seed bank, which has been overlooked up to now. We compared the winter seed bank (i.e., seeds collected before the spring germination peak), seedlings, rosettes, the summer seed bank (i.e., seeds collected after the spring germination peak) and fruiting plants. We found that: (1) All three species partitioned most of their genetic diversity within life history stages and less among stages within populations and among populations. (2) All genetic diversity parameters, except for allele frequencies, were similar among all life history stages across all populations in different species. (3) There were differences in allele frequencies among life history stages at all localities in Amaranthus retroflexus and at three localities in both Carduus acanthoides and Pastinaca sativa. (4) Allele frequencies did not differ between the winter and summer seed bank in most Carduus acanthoides and Pastinaca sativa populations, but there was a marked difference in Amaranthus retroflexus. In conclusion, we have shown that the summer seed bank is not genetically depleted by spring germination and that a majority of genetic diversity remains in the soil through summer. We suggest that seed banks in the species investigated play an important role by maintaining genetic diversity sufficient for recovery rather than by accumulating new genetic diversity at each locality. PMID:23185340

  10. Rangeland Risk Management for Texans: Seeding Rangeland

    E-print Network

    Rector, Barron S.

    2000-11-01

    as you envisioned, at least not right away. Managers need patience, because grass seed may germinate over several years. Native grasses such as big bluestem may require 3 years or longer to become fully established. Requirements for Successful Seeding... of grasses and other kinds of plants gives the manager greater flexibility in using the land. 3) Moisture. Successful seeding requires planning. To capitalize on moisture cycles, seeding should take place when the soil contains enough moisture for seeds...

  11. In vitro comparative study of vibro-acoustography versus pulse-echo ultrasound in imaging permanent prostate brachytherapy seeds

    PubMed Central

    Mitri, F.G.; Davis, B.J.; Greenleaf, J.F.; Fatemi, M.

    2010-01-01

    Background Permanent prostate brachytherapy (PPB) is a common treatment for early stage prostate cancer. While the modern approach using trans-rectal ultrasound guidance has demonstrated excellent outcome, the efficacy of PPB depends on achieving complete radiation dose coverage of the prostate by obtaining a proper radiation source (seed) distribution. Currently, brachytherapy seed placement is guided by trans-rectal ultrasound imaging and fluoroscopy. A significant percentage of seeds are not detected by trans-rectal ultrasound because certain seed orientations are invisible making accurate intra-operative feedback of radiation dosimetry very difficult, if not impossible. Therefore, intra-operative correction of suboptimal seed distributions cannot easily be done with current methods. Vibro-acoustography (VA) is an imaging modality that is capable of imaging solids at any orientation, and the resulting images are speckle free. Objective and methods The purpose of this study is to compare the capabilities of VA and pulse-echo ultrasound in imaging PPB seeds at various angles and show the sensitivity of detection to seed orientation. In the VA experiment, two intersecting ultrasound beams driven at f1 = 3.00 MHz and f2 = 3.020 MHz respectively were focused on the seeds attached to a latex membrane while the amplitude of the acoustic emission produced at the difference frequency 20 kHz was detected by a low frequency hydrophone. Results Finite element simulations and results of experiments conducted under well-controlled conditions in a water tank on a series of seeds indicate that the seeds can be detected at any orientation with VA, whereas pulse-echo ultrasound is very sensitive to the seed orientation. Conclusion It is concluded that vibro-acoustography is superior to pulse-echo ultrasound for detection of PPB seeds. PMID:18538365

  12. Fractionation of blackcurrant seed oil

    Microsoft Academic Search

    H. Traifler; H. J. Wille; A. Studer

    1988-01-01

    Blackcurrant seed oil is known to be one of the richest natural sources of ?-linolenic (allcis-6,9,12-octadecatrienoic) acid, with values of up to 20% of this acid. These concentrations are sufficient for most applications\\u000a of the oil, but some utilizations require higher concentrations of ?-linolenic acid. Blackcurrant seed oil also contains up\\u000a to 14%?-linolenic (allcis-9,12,15-octadecatrienoic) acid. Different fractionation techniques have been

  13. Diamond Synthesis Employing Nanoparticle Seeds

    NASA Technical Reports Server (NTRS)

    Uppireddi, Kishore (Inventor); Morell, Gerardo (Inventor); Weiner, Brad R. (Inventor)

    2014-01-01

    Iron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.

  14. [Animal predation and dispersal of Sorbus pohuashanensis fruits and seeds].

    PubMed

    Zhang, Xiu-liang; Xu, Jian-wei; Shen, Hai-long; Huang, Jian; Zhang, Peng

    2010-10-01

    Sorbus pohuashanensis is an important non-timber tree species in Northeast China. There are two approaches for its fruit- and seed dispersal, i. e. , natural dispersal and animal dispersal. In this paper, a field observation was conducted to study the characteristics of animal predation and dispersal of S. pohuashanensis fruits and seeds, and the effects of the predation and dispersal on the natural regeneration of the tree species. During the fruit-ripening stage of S. pohuashanensis in 2008 and 2009, there were 8 species of birds visiting S. pohuashanensis fruits, among which, three pulp-eating species Turdus naumanni, Cyanopica cyana, and Dendrocopos leucotos could disperse S. pohuashanensis seeds. The visiting frequency of the three species to S. pohuashanensis fruits was 54%, 12%, and 7%, respectively, and the first stop spot after predation was mainly within 5-10 m away from the visited trees (with a proportion of 68.2%), secondly within 5 m (27.3%), and only 4.5% was out of 10 m. The retention time of S. pohuashanensis fruits in the digestive tract of the bird dispersers was up to 20 min, implying a long potential dispersal distance. Fruit- and seed placement tests showed that the fruits artificially placed in different habitats were disappeared within 6-7 days, and the fruit predators on the ground were mainly rodents and ground-feeding birds, with the predation rates being 50% -70%, while the seed predators on the ground were rodents, ground-feeding birds, and ants, with the predation rates only 1% -5%. S. pohuashanensis could provide food for a variety of frugivorous animals, and in return, the animals could disperse S. pohuashanensis seeds, which might have profound effects on the natural regeneration of S. pohuashanensis. PMID:21328960

  15. Seed-coat thickness data clarify seed sizeseed-bank persistence trade-offs in Abutilon theophrasti (Malvaceae)

    E-print Network

    Sims, Gerald K.

    Seed-coat thickness data clarify seed size­seed-bank persistence trade-offs in Abutilon theophrasti after revision 19 March 2014) Abstract Theoretical models predict that seed size and seed- bank is lacking. We expanded the seed size­persistence framework to include seed- coat thickness, a defence trait

  16. The Seed Challenge - `How many seeds can you get from a single seed?

    NSDL National Science Digital Library

    The Wisconsin Fast Plants Program

    A 23-page PDF file (644 KB) with a complete set of activities for elementary students (can also work with middle level) to learn about the life cycle of flowering plants. Students predict how many seeds their Fast Plant will produce and engage in planting, growing, observing doing supporting learning activities to understand the life cycle.Carolina Biological sells a kit to accompany this activity for a class of 32 students, containing the seeds and planting materials. Alternatively, the activity can be taught using seeds from a packet of Standard Wisconsin Fast Plants (or seeds from Fast Plants you grow yourself) and your own potting mix and growing system.A 24-hour fluorescent light source is needed for this activity.

  17. Multiple frequency optical mixer and demultiplexer and apparatus for remote sensing

    NASA Technical Reports Server (NTRS)

    Chen, Jeffrey R. (Inventor)

    2010-01-01

    A pulsed laser system includes a modulator module configured to provide pulsed electrical signals and a plurality of solid-state seed sources coupled to the modulator module and configured to operate, responsive to the pulsed electrical signals, in a pulse mode. Each of the plurality of solid-state seed sources is tuned to a different frequency channel separated from any adjacent frequency channel by a frequency offset. The pulsed laser system also includes a combiner that combines outputs from each of the solid state seed sources into a single optical path and an optical doubler and demultiplexer coupled to the single optical path and providing each doubled seed frequency on a separate output path.

  18. Effect of Ovule Position within the Pod on the Probability of Seed Production in Bauhinia ungulata (Fabaceae)

    PubMed Central

    MENA-ALÍ, JORGE I.; ROCHA, OSCAR J.

    2004-01-01

    • Background and Aims It has been claimed that ovules linearly ordered within a fruit differ in their probabilities of reaching maturity. This was investigated by studying the effect the position of an ovule within the pod has on seed abortion and seed production in Bauhinia ungulata. • Methods Fruits collected during the dry seasons of 1999, 2000 and 2001 were opened, and the number, position and status of each ovule within the fruit were recorded. A GLM model was used to assess the effects of population, tree identity and ovule position within the pod on ovule fertilization, seed abortion, seed damage and seed maturation in two populations of B. ungulata. • Key Results Nearly 30 % of the ovules were not fertilized in 1999; this percentage dropped to 5 % the following two years. Seed abortion (50 %) and seed damage (15 %) were the same every year during the study period. Only 15 % of the initial ovules developed into mature seeds in 1999; this value increased to 35 % in 2000 and 2001. However, seed survivorship was dependent on the position of the ovule within the pod; non-fertilized and early aborted ovules were found more often near the basal end of the ovary. The frequency of seed damage was not affected by position. Mature seeds were found mainly in the stylar half of fruits, where ovules are likely to be fertilized by fast pollen tubes. • Conclusions The pattern of seed production in B. ungulata is non-random but is dependent upon the position of the ovule within the pod. The results suggest that the seeds produced within a fruit might differ in their vigour. PMID:15596452

  19. Chemometric characterization of sunflower seeds.

    PubMed

    Monferrere, Gastón Lancelle; Azcarate, Silvana Mariela; Cantarelli, Miguel Ángel; Funes, Israel German; Camiña, José Manuel

    2012-09-01

    The spectroscopic characterization of different varieties of sunflower seeds based on their oleic acid content is proposed. One hundred fifty samples of sunflower seeds from different places of Argentina were analyzed by near-infrared diffuse reflectance spectroscopy (NIRDRS). Seed samples were grounded and sieved without chemical treatment previous to the analysis. For the characterization, the used multivariate methods were: principal component analysis (PCA), cluster analysis (CA), linear discriminant analysis (LDA), and partial least square discriminant analysis (PLS-DA). By using PCA, CA, and LDA, and from the point of view of varieties of sunflower seeds, 2 groups were differentiated, based on the concentration of oleic acid: a low oleic group, which ranged from 15% to 25% w/w oleic acid; and the other one (mid-high oleic varieties) which ranged from 26% to 90% w/w oleic acid. However, by using the PLS-DA, 3 groups were correctly differentiated based on the concentration of oleic acid: low oleic (from 15% to 25% w/w oleic acid); mid oleic (26% to 76% w/w oleic acid); and high oleic (? than 77% w/w oleic acid), demonstrating the high classification ability of this method. This multivariate characterization of sunflower seed varieties did not require chromatographic analysis to generate the matrix of concentrations, and only direct measures of NIRDRS spectra were required. This characterization can be useful to quickly know the variety of sunflower seed in the grain market. Practical Applications: This manuscript describes a method to determine 3 varieties of sunflower seeds (high, mid, and low oleic) The advantage of this method is to avoid the use of techniques that require long-time analysis. PMID:22897646

  20. Seed Mucilage Improves Seedling Emergence of a Sand Desert Shrub

    PubMed Central

    Yang, Xuejun; Baskin, Carol C.; Baskin, Jerry M.; Liu, Guangzheng; Huang, Zhenying

    2012-01-01

    The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling emergence in a low precipitation regime and under conditions of sand burial. In a greenhouse experiment, two types of Artemisia sphaerocephala achenes (intact and demucilaged) were exposed to different combinations of burial depth (0, 5, 10, 20, 40 and 60 mm) and irrigation regimes (low, medium and high, which simulated the precipitation amount and frequency in May, June and July in the natural habitat, respectively). Seedling emergence increased with increasing irrigation. It was highest at 5 mm sand burial depth and ceased at burial depths greater than 20 mm in all irrigation regimes. Mucilage significantly enhanced seedling emergence at 0, 5 and 10 mm burial depths in low irrigation, at 0 and 5 mm burial depths in medium irrigation and at 0 and 10 mm burial depths in high irrigation. Seed mucilage also reduced seedling mortality at the shallow sand burial depths. Moreover, mucilage significantly affected seedling emergence time and quiescence and dormancy percentages. Our findings suggest that seed mucilage plays an ecologically important role in successful seedling establishment of A. sphaerocephala by improving seedling emergence and reducing seedling mortality in stressful habitats of the sandy desert environment. PMID:22511952

  1. Unique Method for Generating Design Earthquake Time History Seeds

    SciTech Connect

    R. E. Spears

    2008-07-01

    A method has been developed which takes a single seed earthquake time history and produces multiple similar seed earthquake time histories. These new time histories possess important frequency and cumulative energy attributes of the original while having a correlation less than 30% (per the ASCE/SEI 43-05 Section 2.4 [1]). They are produced by taking the fast Fourier transform of the original seed. The averaged amplitudes are then pared with random phase angles and the inverse fast Fourier transform is taken to produce a new time history. The average amplitude through time is then adjusted to encourage a similar cumulative energy curve. Next, the displacement is modified to approximate the original curve using Fourier techniques. Finally, the correlation is checked to ensure it is less than 30%. This process does not guarantee that the correlation will be less than 30% for all of a given set of new curves. It does provide a simple tool where a few additional iterations of the process should produce a set of seed earthquake time histories meeting the correlation criteria.

  2. Laser Phase Errors in Seeded FELs

    SciTech Connect

    Ratner, D.; Fry, A.; Stupakov, G.; White, W.; /SLAC

    2012-03-28

    Harmonic seeding of free electron lasers has attracted significant attention from the promise of transform-limited pulses in the soft X-ray region. Harmonic multiplication schemes extend seeding to shorter wavelengths, but also amplify the spectral phase errors of the initial seed laser, and may degrade the pulse quality. In this paper we consider the effect of seed laser phase errors in high gain harmonic generation and echo-enabled harmonic generation. We use simulations to confirm analytical results for the case of linearly chirped seed lasers, and extend the results for arbitrary seed laser envelope and phase.

  3. Seed source, seed traits, and frugivore habits: Implications for dispersal quality of two sympatric primates.

    PubMed

    Benítez-Malvido, Julieta; González-Di Pierro, Ana Ma; Lombera, Rafael; Guillén, Susana; Estrada, Alejandro

    2014-06-11

    • Premise of the study: Frugivore selection of fruits and treatment of seeds together with seed deposition site are crucial for the population dynamics of vertebrate-dispersed plants. However, frugivore species may influence dispersal quality differently even when feeding on the same fruit species and, while animals disperse some seeds, others simply fall beneath the parent plant.• Methods: In southern Mexico, we investigated to see if within-species seed traits (i.e., length, width, weight, and volume) and germination success differed according to seed source. For five tropical tree species we obtained ingested seeds from two sources, howler monkey (Alouatta pigra) and spider monkey (Ateles geoffroyi) feces; and noningested seeds from two sources, the ground and tree crowns (with predispersed seeds used as control).• Key results: A principal components' analysis showed that traits of seeds ingested by howler monkeys differed from other sources while seeds ingested by spider monkeys were similar to noningested seeds. Howlers consumed on average the larger seeds in Ampelocera hottlei, Brosimum lactescens, and Dialium guianense. Both primate species consumed the smaller seeds in Spondias mombin, while no seed trait differences among seed sources were found in Spondias radlkoferi. For all five tree species, germination rate was greatest for seeds ingested by howler monkeys.• Conclusions: For the studied plant species, seed ingestion by howler monkeys confers higher dispersal quality than ingestion by spider monkeys or nondispersal. Dispersal services of both primate species, however, are not redundant and may contribute to germination heterogeneity within plant populations in tropical forests. PMID:24920763

  4. CT, MR, and ultrasound image artifacts from prostate brachytherapy seed implants: The impact of seed size

    SciTech Connect

    Robertson, Andrew K. H.; Basran, Parminder S.; Thomas, Steven D.; Wells, Derek [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada) and Department of Medical Physics, British Columbia Cancer Agency-Vancouver Island Cancer Centre, Victoria, British Columbia V8R 6V5 (Canada); Department of Medical Physics, British Columbia Cancer Agency-Fraser Valley Cancer Centre, Victoria, British Columbia V3V 1Z2 (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada) and Department of Medical Physics, British Columbia Cancer Agency-Vancouver Island Cancer Centre, Victoria, British Columbia V8R 6V5 (Canada)

    2012-04-15

    Purpose: To investigate the effects of brachytherapy seed size on the quality of x-ray computed tomography (CT), ultrasound (US), and magnetic resonance (MR) images and seed localization through comparison of the 6711 and 9011 {sup 125}I sources. Methods: For CT images, an acrylic phantom mimicking a clinical implantation plan and embedded with low contrast regions of interest (ROIs) was designed for both the 0.774 mm diameter 6711 (standard) and the 0.508 mm diameter 9011 (thin) seed models (Oncura, Inc., and GE Healthcare, Arlington Heights, IL). Image quality metrics were assessed using the standard deviation of ROIs between the seeds and the contrast to noise ratio (CNR) within the low contrast ROIs. For US images, water phantoms with both single and multiseed arrangements were constructed for both seed sizes. For MR images, both seeds were implanted into a porcine gel and imaged with pelvic imaging protocols. The standard deviation of ROIs and CNR values were used as metrics of artifact quantification. Seed localization within the CT images was assessed using the automated seed finder in a commercial brachytherapy treatment planning system. The number of erroneous seed placements and the average and maximum error in seed placements were recorded as metrics of the localization accuracy. Results: With the thin seeds, CT image noise was reduced from 48.5 {+-} 0.2 to 32.0 {+-} 0.2 HU and CNR improved by a median value of 74% when compared with the standard seeds. Ultrasound image noise was measured at 50.3 {+-} 17.1 dB for the thin seed images and 50.0 {+-} 19.8 dB for the standard seed images, and artifacts directly behind the seeds were smaller and less prominent with the thin seed model. For MR images, CNR of the standard seeds reduced on average 17% when using the thin seeds for all different imaging sequences and seed orientations, but these differences are not appreciable. Automated seed localization required an average ({+-}SD) of 7.0 {+-} 3.5 manual corrections in seed positions for the thin seed scans and 3.0 {+-} 1.2 manual corrections in seed positions for the standard seed scans. The average error in seed placement was 1.2 mm for both seed types and the maximum error in seed placement was 2.1 mm for the thin seed scans and 1.8 mm for the standard seed scans. Conclusions: The 9011 thin seeds yielded significantly improved image quality for CT and US images but no significant differences in MR image quality.

  5. 7 CFR 201.69 - Classes of certified seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Classes of certified seed. 201.69 Section 201.69 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Certified Seed § 201.69...

  6. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427...PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature...

  7. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427...PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature...

  8. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427...PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature...

  9. 7 CFR 1427.165 - Eligible seed cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Eligible seed cotton. 1427.165 Section 1427.165 ...PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton. (a) Seed cotton pledged as...

  10. 7 CFR 201.24a - Inoculated seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Inoculated seed. 201.24a Section 201.24a Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds §...

  11. 7 CFR 1427.165 - Eligible seed cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Eligible seed cotton. 1427.165 Section 1427.165 ...PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton. (a) Seed cotton pledged as...

  12. 7 CFR 201.69 - Classes of certified seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Classes of certified seed. 201.69 Section 201.69 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Certified Seed § 201.69...

  13. 7 CFR 201.24a - Inoculated seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Inoculated seed. 201.24a Section 201.24a Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds §...

  14. 7 CFR 75.16 - Accessibility of seeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2013-01-01 false Accessibility of seeds. 75.16 Section 75.16 Agriculture...CERTIFICATION OF QUALITY OF AGRICULTURAL AND VEGETABLE SEEDS Inspection § 75.16 Accessibility of seeds. Each lot of seed for which a lot...

  15. 7 CFR 201.24a - Inoculated seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Inoculated seed. 201.24a Section 201.24a Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds §...

  16. 7 CFR 75.16 - Accessibility of seeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2014-01-01 false Accessibility of seeds. 75.16 Section 75.16 Agriculture...CERTIFICATION OF QUALITY OF AGRICULTURAL AND VEGETABLE SEEDS Inspection § 75.16 Accessibility of seeds. Each lot of seed for which a lot...

  17. 7 CFR 75.16 - Accessibility of seeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2011-01-01 false Accessibility of seeds. 75.16 Section 75.16 Agriculture...CERTIFICATION OF QUALITY OF AGRICULTURAL AND VEGETABLE SEEDS Inspection § 75.16 Accessibility of seeds. Each lot of seed for which a lot...

  18. 7 CFR 75.16 - Accessibility of seeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 2012-01-01 false Accessibility of seeds. 75.16 Section 75.16 Agriculture...CERTIFICATION OF QUALITY OF AGRICULTURAL AND VEGETABLE SEEDS Inspection § 75.16 Accessibility of seeds. Each lot of seed for which a lot...

  19. 7 CFR 201.69 - Classes of certified seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Classes of certified seed. 201.69 Section 201.69 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Certified Seed § 201.69...

  20. 7 CFR 201.69 - Classes of certified seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Classes of certified seed. 201.69 Section 201.69 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Certified Seed § 201.69...

  1. 7 CFR 201.24a - Inoculated seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Inoculated seed. 201.24a Section 201.24a Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds §...

  2. 7 CFR 201.69 - Classes of certified seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Classes of certified seed. 201.69 Section 201.69 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Certified Seed § 201.69...

  3. 7 CFR 75.16 - Accessibility of seeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 false Accessibility of seeds. 75.16 Section 75.16 Agriculture...CERTIFICATION OF QUALITY OF AGRICULTURAL AND VEGETABLE SEEDS Inspection § 75.16 Accessibility of seeds. Each lot of seed for which a lot...

  4. 7 CFR 201.24a - Inoculated seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Inoculated seed. 201.24a Section 201.24a Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds §...

  5. 7 CFR 1427.165 - Eligible seed cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Eligible seed cotton. 1427.165 Section 1427.165 ...PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton. (a) Seed cotton pledged as...

  6. 7 CFR 201.58a - Indistinguishable seeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...kind, variety, or type of seed or determination that seed is hybrid is not possible by seed characteristics, identification...sweetclover from the percentage of Melilotus spp. pure seed. (c) Wheat. In determining varietal purity, the phenol test may...

  7. Nematicide Treatments of Turfgrass Seed

    PubMed Central

    Walker, J. T.; Melin, J.

    1981-01-01

    Seed treatments of improved Kentucky bluegrass and fescue cultivars with carbofuran, oxamyl, and phenamiphos dissolved in acetone reduced seedling emergence, but treatments were not extremely phytotoxic. Phenamiphos was the most toxic, particularly at the 5,000 ?g/ml concentration. Fresh weight of grass clippings 35 d following planting generally was greater in treatments than in controls except for the 5,000 ?g/ml phenamiphos treatments on certain cultivars. All nematicide seed treatments reduced the number of Pratylenchus penetrans subsequently recovered from Pennlawn creeping red fescue roots 4-5 wk after treatment. The infusion of nematicides into grass seed with organic solvents appears to be an effective means of reducing nematode damage to turfgrass seedling with little environmental hazard. PMID:19300783

  8. Smoke signals and seed dormancy

    PubMed Central

    Waters, Mark T; Nelson, David C

    2011-01-01

    The Arabidopsis thaliana F-box protein MAX2 has been discovered in four separate genetic screens, indicating that it has roles in leaf senescence, seedling photosensitivity, shoot outgrowth and seed germination. Both strigolactones and karrikins can regulate A. thaliana seed germination and seedling photomorphogenesis in a MAX2-dependent manner, but only strigolactones inhibit shoot branching. How MAX2 mediates specific responses to both classes of structurally-related signals, and the origin of its dual role remains unknown. The moss Physcomitrella patens utilizes strigolactones and MAX2 orthologs are present across the land plants, suggesting that this signaling system could have an ancient origin. The seed of parasitic Orobanchaceae species germinate preferentially in response to strigolactones over karrikins, and putative Orobanchaceae MAX2 orthologs form a sub-clade distinct from those of other dicots. These observations suggest that lineage-specific evolution of MAX2 may have given rise to specialized responses to these signaling molecules. PMID:22019642

  9. Flowering time and seed dormancy control use external coincidence to generate life history strategy.

    PubMed

    Springthorpe, Vicki; Penfield, Steven

    2015-01-01

    Climate change is accelerating plant developmental transitions coordinated with the seasons in temperate environments. To understand the importance of these timing advances for a stable life history strategy, we constructed a full life cycle model of Arabidopsis thaliana. Modelling and field data reveal that a cryptic function of flowering time control is to limit seed set of winter annuals to an ambient temperature window which coincides with a temperature-sensitive switch in seed dormancy state. This coincidence is predicted to be conserved independent of climate at the expense of flowering date, suggesting that temperature control of flowering time has evolved to constrain seed set environment and therefore frequency of dormant and non-dormant seed states. We show that late flowering can disrupt this bet-hedging germination strategy. Our analysis shows that life history modelling can reveal hidden fitness constraints and identify non-obvious selection pressures as emergent features. PMID:25824056

  10. Seed composition, seedling emergence and early seeding vigour of red kidney bean seed produced at elevated temperature and Carbon dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding effects of temperature and carbon dioxide (CO2) on seed quality is important under present and future climates. The objective was to determine the effects of elevated growth temperature and CO2 during seed-filling of parent plants on seed composition and ensuing seedling emergence and ...

  11. Holographic laser sweeper for in-process debris removal

    NASA Astrophysics Data System (ADS)

    Sakuma, Kazuki; Hasegawa, Satoshi; Takahashi, Hidetomo; Ota, Michiharu; Hayasaki, Yoshio

    2015-06-01

    Debris deposited around laser-processed structures is a critical issue in high-precision laser processing and should be removed. We demonstrated a new debris removal method that is performed during laser processing. A line-focused beam that is radiated onto a target material simultaneously with a processing beam sweeps away the debris generated by laser ablation. Two physical processes are involved: One is direct photon excitation of the attached debris, similar to laser ablation, due to a smaller ablation threshold of the debris, and the other is blowing away the debris with a laser-induced pressure wave. The laser processing setup for debris sweeping has a simple and practical configuration composed of beam transmission optics from a laser source to the target and a spatial light modulator that displays a computer-generated hologram. This in-process debris removal method has the advantages of needing no additional equipment other than the optics, no additional operations, no special materials, and no specific operating environment.

  12. Seed Grant Recipients Year Investigator Institution Title

    E-print Network

    Arnold, Jonathan

    Seed Grant Recipients 1 Year Investigator Institution Title 1999 Balan, Aparna Vijayan University of West Georgia 1999 Shambare, Jonathan T. State University of West Georgia #12;Seed Grant Recipients 2

  13. Microwave Background Anisotropies from Scaling Seed Perturbations

    E-print Network

    Durrer, Ruth

    Microwave Background Anisotropies from Scaling Seed Perturbations Ruth Durrer and Mairi, Switzerland Abstract We study microwave background anisotropies induced by scaling seed pertur- bations. Thus, compensation, which is mainly the consequence of physically sensible initial conditions, is very

  14. Lipid composition of perilla seed

    Microsoft Academic Search

    Hyo-Sun Shin; Sung-Whan Kim

    1994-01-01

    The composition of lipids and oil characteristics from perilla [Perilla frutescens (L.) Britt.] seed cultivars are reported. Total lipid contents of the five perilla seed cultivars ranged from 38.6 to 47.8%\\u000a on a dry weight basis. The lipids consisted of 91.2–93.9% neutral lipids, 3.9–5.8% glycolipids and 2.0–3.0% phospholipids.\\u000a Neutral lipids consisted mostly of triacylglycerols (88.1–91.0%) and small amounts of sterol

  15. SEEDS Moving Group Status Update

    NASA Technical Reports Server (NTRS)

    McElwain, Michael

    2011-01-01

    I will summarize the current status of the SEEDS Moving Group category and describe the importance of this sub-sample for the entire SEEDS survey. This presentation will include analysis of the sensitivity for the Moving Groups with general a comparison to other the other sub-categories. I will discuss the future impact of the Subaru SCExAO system for these targets and the advantage of using a specialized integral field spectrograph. Finally, I will present the impact of a pupil grid mask in order to produce fiducial spots in the focal plane that can be used for both photometry and astrometry.

  16. SEEDS: A Celebration of Science

    NASA Technical Reports Server (NTRS)

    Melton, Bob

    1991-01-01

    The major goal of the project of Space Exposed Experiment Developed for Students (SEEDS) was to stimulate interest in science through the active involvement of all participants. Youthful investigators utilized the basic and integrated science process skills as they conducted the research necessary to complete the data reports used in the compilation of this document. Participants described many unique activities designed to promote critical thinking and problem solving. Seeds made a significant impact toward enhancing the teaching, learning, and enjoyment of science for students worldwide.

  17. The Great Kansas Seed Swindle

    E-print Network

    Hoeflich, Michael H.

    2007-05-01

    The Great Kansas Seed Swindle MH. Hoeflich' In February, 1885, the Kansas legislature approved a law that made it a misdemeanor punishable by a fine of "not less than ten dollars nor more than two hundred dollars, or by imprisonment in a county jail... agents. In the West, in particular, commercial agents sold everything from books to pans, including seeds, plants, and trees. This was also a period in which the printing industry had made great leaps forward in techniques, particularly in color printing...

  18. Diversity of plant oil seed-associated fungi isolated from seven oil-bearing seeds and their potential for the production of lipolytic enzymes.

    PubMed

    Venkatesagowda, Balaji; Ponugupaty, Ebenezer; Barbosa, Aneli M; Dekker, Robert F H

    2012-01-01

    Commercial oil-yielding seeds (castor, coconut, neem, peanut, pongamia, rubber and sesame) were collected from different places in the state of Tamil Nadu (India) from which 1279 endophytic fungi were isolated. The oil-bearing seeds exhibited rich fungal diversity. High Shannon-Index H' was observed with pongamia seeds (2.847) while a low Index occurred for coconut kernel-associated mycoflora (1.018). Maximum Colonization Frequency (%) was observed for Lasiodiplodia theobromae (176). Dominance Index (expressed in terms of the Simpson's Index D) was high (0.581) for coconut kernel-associated fungi, and low for pongamia seed-borne fungi. Species Richness (Chao) of the fungal isolates was high (47.09) in the case of neem seeds, and low (16.6) for peanut seeds. All 1279 fungal isolates were screened for lipolytic activity employing a zymogram method using Tween-20 in agar. Forty isolates showed strong lipolytic activity, and were morphologically identified as belonging to 19 taxa (Alternaria, Aspergillus, Chalaropsis, Cladosporium, Colletotrichum, Curvularia, Drechslera, Fusarium, Lasiodiplodia, Mucor, Penicillium, Pestalotiopsis, Phoma, Phomopsis, Phyllosticta, Rhizopus, Sclerotinia, Stachybotrys and Trichoderma). These isolates also exhibited amylolytic, proteolytic and cellulolytic activities. Five fungal isolates (Aspergillus niger, Chalaropsis thielavioides, Colletotrichum gloeosporioides, Lasiodiplodia theobromae and Phoma glomerata) exhibited highest lipase activities, and the best producer was Lasiodiplodia theobromae (108 U/mL), which was characterized by genomic sequence analysis of the ITS region of 18S rDNA. PMID:22806781

  19. Evaluation of antioxidant and antiradical properties of Pomegranate (Punica granatum L.) seed and defatted seed extracts.

    PubMed

    Basiri, Shadi

    2015-02-01

    Pomegranate seeds are byproducts of the Pomegranate juice industries that contains functional compounds such as phenols. This study was aimed to evaluate the effect of solvents on extraction from Pomegranate seed and Pomegranate defatted seed and to measure the yield extract and phenolic content and antioxidant properties. For this purpose, the seeds and defatted seeds were directly isolated from fruits and seeds by cold pressing respectively, then were crushed and extracted with different solvents, including water, Methanol, Acetone, Ethyl acetate and Hexane and finally the extracts of them were evaluted. Phenolic compounds, ferric reducing-antioxidant power and radicals scavenging property of extracts were measured. The results showed the highest extraction efficiencies were for Hexane and Acetone solvents in extraction of seed and defatted seed respectively. The highest phenolic content was obtained from Methanol seed extract. Reducing activity test proved that the Methanol extracts of Pomegranate seed and Pomegranate defatted seed had the highest reducing strength. Results of radical scavenging activity were similar to reducing activity results. The order of antioxidant capacity of Pomegranate seed and Pomegranate defatted seed were found to be Methanol > Water > Acetone > Butanol > Ethyl acetate > Hexane. It can be concluded Pomegranate seed, which possesses high levels of polyphenols, can be one of the sources of the natural antioxidants. The Methanol extract had a higher antioxidant efficiency than seed and defatted seed extracts. PMID:25694727

  20. PRESSURIZED FLUID EXTRACTION OF PUMPKIN SEED AND PUMPKIN SEED PRESSED CAKE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pumpkin seed oil is one of the top three nutritional oils (hemp seed oil, flax seed oil, pumpkin seed oil) that provide the highest essential fatty acids (Omega 3 and Omega 6) required for healthy mind/body functioning. It is known to prevent and alleviate bladder and prostate problems. The oil th...

  1. Seed size and provenance mediate the joint effects of disturbance and seed predation on community

    E-print Network

    Seed size and provenance mediate the joint effects of disturbance and seed predation on community regional factors that limit seeds of any given species from reaching a local site as well as local interactions such as post-dispersal seed predation and disturbance, which dictate what species actually

  2. ORIGINAL PAPER Internal dispersal of seeds by waterfowl: effect of seed size

    E-print Network

    Green, Andy J.

    ORIGINAL PAPER Internal dispersal of seeds by waterfowl: effect of seed size on gut passage time structure. The dispersal of many plants depends on transport by vertebrate seed dispersers. The shapes of seed shadows produced by vertebrates depend both on movement patterns of the dispersers

  3. LIQUID NITROGEN CONTROLS SEED-BORNE CHALCIDS WITHOUT REDUCING GERMINATION IN CORIANDER SEEDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coriander (Coriandrum sativum) seeds are susceptible to infestation by chalcid (Systole) wasps which often render the seeds inviable. Control of chalcids in seeds is a prerequisite for supplying coriander germplasm to requestors throughout the world. Levels of chalcid infestation in coriander seed...

  4. Another Wintertime Cloud Seeding Case Study with Strong Evidence of Seeding Effects

    Microsoft Academic Search

    Arlen W. Huggins

    In the 1990s numerous winter orographic cloud seeding experiments were conducted over Utah's Wasatch Plateau. Several previously published case studies suc- cessfully documented the physical response in clouds and precipitation to ground-based seeding with silver iodide and liquid propane. A previously unpublished case study that shows additional evidence of positive seeding effects is presented here. Careful docu- mentation of seeding

  5. Identification of thickspike wheatgrass accessions with superior rhizome spread, seed production, and seed quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thickspike wheatgrass is widely used for rangeland seeding and revegetation projects in western areas of North America. However, thickspike wheatgrass does not produce high seed yields, and seed is often of poor quality, which often results in high seed prices and poor establishment following seedi...

  6. Ovule number, seed number and seed size in Mexican and North American species of Podostemaceae

    Microsoft Academic Search

    C. Thomas Philbrick; R. Alejandro Novelo

    1997-01-01

    The purpose of this study is to present and analyze empirical data on seed production and seed characteristics of Mexican and North American species of Podostemaceae. Species of Marathrum, Oserya, Podostemum, Tristicha and Vanroyenella were studied. Podostemaceae flower annually in abundance. Eight of the nine species examined produced seeds in abundance. Podostemum ricciiforme (Liebmann) Royen seldom produces seed. Significant differences

  7. Global analysis of gene activity during Arabidopsis seed development and identification of seed-specific

    E-print Network

    Goldberg, Robert B.

    Global analysis of gene activity during Arabidopsis seed development and identification of seed for review February 19, 2010) Most of the transcription factors (TFs) responsible for controlling seed development are not yet known. To identify TF genes expressed at specific stages of seed development

  8. Update on Legume Seed Development Using Genomics to Study Legume Seed Development1

    E-print Network

    Goldberg, Robert B.

    Update on Legume Seed Development Using Genomics to Study Legume Seed Development1 Brandon H. Le2 Sciences, University of California, Davis, California 95616 (J.J.H.) Seeds are essential for flowering the next sporophytic generation. In addition, seeds contain energy re- sources that sustain the young

  9. INVESTIGATION OF CORDAITEAN PHYLOGENESIS WITH CORDAITEAN SEEDS 

    E-print Network

    Correa, Julian 1990-

    2012-05-03

    .................................................................................................. 16 1 CHAPTER I INTRODUCTION Cordaiteans represent a key stage in the evolutionary development of gymnosperms (seed-bearing plants). Cordaitean seeds have an integumentary system similar to modern gymnosperms, sealing the ovule... the generic assignment of cordaitean seeds. Note that these characters (three integumentary layers, post-pollination sealing of the ovule at the micropyle and nucellar beak, 180 0 rotational symmetry) are found in some seeds not previously considered...

  10. Patterns and kinetics of water uptake by soybean seeds

    Microsoft Academic Search

    Chris J. Meyer; Ernst Steudle; Carol A. Peterson

    2007-01-01

    Soybean (Glycine max (L.) Merr.) plants produce some seeds (called stone or impermeable seeds) that do not take up water for long periods of time. The present investigation confirmed that the stone seed trait is a feature of the seed coat: isolated embryos from both stone and permeable seeds took up water equally quickly. A whole, permeable seed typically imbibed

  11. A unifying framework for seed sensitivity and its application to subset seeds.

    PubMed

    Kucherov, Gregory; Noé, Laurent; Roytberg, Mikhail

    2006-04-01

    We propose a general approach to compute the seed sensitivity, that can be applied to different definitions of seeds. It treats separately three components of the seed sensitivity problem--a set of target alignments, an associated probability distribution, and a seed model--that are specified by distinct finite automata. The approach is then applied to a new concept of subset seeds for which we propose an efficient automaton construction. Experimental results confirm that sensitive subset seeds can be efficiently designed using our approach, and can then be used in similarity search producing better results than ordinary spaced seeds. PMID:16819802

  12. A unifying framework for seed sensitivity and its application to subset seeds

    PubMed Central

    Kucherov, Gregory; Noé, Laurent; Roytberg, Mihkail

    2006-01-01

    We propose a general approach to compute the seed sensitivity, that can be applied to different definitions of seeds. It treats separately three components of the seed sensitivity problem – a set of target alignments, an associated probability distribution, and a seed model – that are specified by distinct finite automata. The approach is then applied to a new concept of subset seeds for which we propose an efficient automaton construction. Experimental results confirm that sensitive subset seeds can be efficiently designed using our approach, and can then be used in similarity search producing better results than ordinary spaced seeds. PMID:16819802

  13. Frequency-dependent fitness in gynodioecious Lobelia siphilitica.

    PubMed

    Rivkin, L Ruth; Case, Andrea L; Caruso, Christina M

    2015-05-01

    Selection is frequency dependent when an individual's fitness depends on the frequency of its phenotype. Frequency-dependent selection should be common in gynodioecious plants, where individuals are female or hermaphroditic; if the fitness of females is limited by the availability of pollen to fertilize their ovules, then they should have higher fitness when rare than when common. To test whether the fitness of females is frequency dependent, we manipulated the sex ratio in arrays of gynodioecious Lobelia siphilitica. To test whether fitness was frequency dependent because of variation in pollen availability, we compared open-pollinated and supplemental hand-pollinated plants. Open-pollinated females produced more seeds when they were rare than when they were common, as expected if fitness is negatively frequency dependent. However, hand-pollinated females also produced more seeds when they were rare, indicating that variation in pollen availability was not the cause of frequency-dependent fitness. Instead, fitness was frequency dependent because both hand- and open-pollinated females opened more flowers when they were rare than when they were common. This plasticity in the rate of anthesis could cause fitness to be frequency dependent even when reproduction is not pollen limited, and thus expand the conditions under which frequency-dependent selection operates in gynodioecious species. PMID:25824809

  14. LEAFY SPURGE (EUPHORBIA ESULA) SEED DORMANCY.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leafy spurge is a herbaceous perennial weed that reproduces asexually through adventitious vegetative buds and sexually by seed. Seeds can remain viable in the soil for up to 8 yr. The objectives of this research were to identify seed components which restrict germination and to determine if afterri...

  15. 7 CFR 946.12 - Seed potatoes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Seed potatoes. 946.12 Section 946.12 Agriculture...DEPARTMENT OF AGRICULTURE IRISH POTATOES GROWN IN WASHINGTON Order Regulating Handling Definitions § 946.12 Seed potatoes. Seed potatoes means and...

  16. 7 CFR 946.12 - Seed potatoes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Seed potatoes. 946.12 Section 946.12 Agriculture...DEPARTMENT OF AGRICULTURE IRISH POTATOES GROWN IN WASHINGTON Order Regulating Handling Definitions § 946.12 Seed potatoes. Seed potatoes means and...

  17. 7 CFR 947.12 - Seed potatoes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Seed potatoes. 947.12 Section 947.12 Agriculture...DEPARTMENT OF AGRICULTURE IRISH POTATOES GROWN IN MODOC AND SISKIYOU COUNTIES...Handling Definitions § 947.12 Seed potatoes. Seed potatoes means and...

  18. 7 CFR 947.12 - Seed potatoes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Seed potatoes. 947.12 Section 947.12 Agriculture...DEPARTMENT OF AGRICULTURE IRISH POTATOES GROWN IN MODOC AND SISKIYOU COUNTIES...Handling Definitions § 947.12 Seed potatoes. Seed potatoes means and...

  19. Formative Assessment Probes: Seeds in a Bag

    ERIC Educational Resources Information Center

    Keeley, Page

    2014-01-01

    Many young children come to school with prior experiences planting seeds in a garden or in a pot, watering them, and seeing them grow. These early scientific investigations are designed to help children understand that seeds need water, something to grow in (such as soil), and the right temperature to sprout--if these conditions are met, a seed

  20. Development of a guayule seed harvester

    Microsoft Academic Search

    Coates

    2009-01-01

    Development of a non-destructive harvester for guayule, Parthenium argentatum, seed has been underway at the University of Arizona since 1978. The initial design used a rotating brush to dislodge seeds but this was found to be too aggressive. Present models rely primarily on suction to dislodge seeds. Harvesting heads are adjustable to accommodate plants of various shapes and sizes. A

  1. Proteome Analysis of Poplar Seed Vigor

    PubMed Central

    Zhang, Hong; Wang, Wei-Qing; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

    2015-01-01

    Seed vigor is a complex property that determines the seed’s potential for rapid uniform emergence and subsequent growth. However, the mechanism for change in seed vigor is poorly understood. The seeds of poplar (Populus × Canadensis Moench), which are short-lived, were stored at 30°C and 75±5% relative humidity for different periods of time (0–90 days) to obtain different vigor seeds (from 95 to 0% germination). With decreasing seed vigor, the temperature range of seed germination became narrower; the respiration rate of the seeds decreased markedly, while the relative electrolyte leakage increased markedly, both levelling off after 45 days. A total of 81 protein spots showed a significant change in abundance (? 1.5-fold, P < 0.05) when comparing the proteomes among seeds with different vigor. Of the identified 65 proteins, most belonged to the groups involved in metabolism (23%), protein synthesis and destination (22%), energy (18%), cell defense and rescue (17%), and storage protein (15%). These proteins accounted for 95% of all the identified proteins. During seed aging, 53 and 6 identified proteins consistently increased and decreased in abundance, respectively, and they were associated with metabolism (22%), protein synthesis and destination (22%), energy (19%), cell defense and rescue (19%), storage proteins (15%), and cell growth and structure (3%). These data show that the decrease in seed vigor (aging) is an energy-dependent process, which requires protein synthesis and degradation as well as cellular defense and rescue. PMID:26172265

  2. WEATHER MODIFICATION BY AIRCRAFT CLOUD SEEDING

    E-print Network

    Vali, Gabor

    WEATHER MODIFICATION BY AIRCRAFT CLOUD SEEDING BERYULEV G.P. Head, Department of Cloud;#12; Precipitation Enhancement An aircraft cloud seeding by iceforming or hygroscopic agents is a basis of the technology. The seeding is produced from aircrafts of a types IL18, AN12, AN26, AN 30, YaK40, equipped

  3. Chilling requirement of commercial Echinacea seed

    Microsoft Academic Search

    G. A. Parmenter; L. C. Burton; R. P. Littlejohn

    1996-01-01

    This study aimed to determine the effect of the moist chilling of seed on germination of Echinacea angustifolia DC. and Echinacea purpurea (L.) Moench, and the effect of seed coat trimming on the germination of E. angustifolia. Seed of E. angustifolia stratified for more than 2 weeks achieved maximum germination rates of 65–80%. Maximum germination rates of E. purpurea (84%)

  4. Applications of Computers in Seed Technology

    Microsoft Academic Search

    Y. Sako; A. Hoffmaster; K. Fujimura; M. B. McDonald; M. A. Bennett

    Seed vigor testing provides valuable information for assessing seed lot quality. However, vigor testing has not experienced widespread use because it is labor intensive, high in cost, and test results are often variable from laboratory to laboratory. An automated seed vigor assessment system is presented for lettuce (Lactuca sativa L.) and soybeans (Glycine max (L.) Merr.) that is objective, economical,

  5. Seeds: The Delivery System for Crop Science

    Microsoft Academic Search

    Dennis M. TeKrony

    2006-01-01

    Seeds have always played a dominant role in agriculture, serving as the primary mechanism by which crop plants are propagated. During the past 50 yr, seed science has matured to gain recognition as a sub- discipline of crop science, which was enhanced by the establishment of graduate training in seed biology at many land grant universities. These programs have provided

  6. Predation of italian ryegrass (Lolium multiflorum) seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Italian ryegrass (Lolium multiflorum Lam.) can be a productive and high-quality cool-season forage, but is considered a weed in some pastures. Italian ryegrass does not form a persistent seed bank and needs to produce sufficient seed annually for effective re-establishment. Before the re-seeding ...

  7. Genetics of seed transmission Soybean mosaic virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean mosaic virus (SMV) is an aphid- and seed-transmitted member of the Potyviridae that infects soybean plants and, in years when virus infections are widespread, can cause significant reductions in the quantity and quality of seed harvested. Because seed-borne infections are the primary sources...

  8. Tansley review Seed dispersal effectiveness revisited

    E-print Network

    Jordano, Pedro

    , it is a necessary expansion if we are to understand the central relevance of seed dispersal in plant ecology by increasing appre- ciation that seed dispersal is critical to many ecological questions; it is centralTansley review Seed dispersal effectiveness revisited: a conceptual review Author

  9. Subset Seed Automaton Gregory Kucherov1

    E-print Network

    Noé, Laurent

    Subset Seed Automaton Gregory Kucherov1 , Laurent No´e1 , Mikhail Roytberg2 1 LIFL, Universit 2007, Prague, July 16-18 2007 Gregory Kucherov1, Laurent No´e1, Mikhail Roytberg2 Subset Seed Automaton #12;My talk in a few words ... Motivation : pairwise sequence alignment. Seeds : filtration to speed

  10. Plant Populations and Seeding Rates for Soybeans

    E-print Network

    Holland, Jeffrey

    Plant Populations and Seeding Rates for Soybeans Andrew P. Robinson Department of Agronomy www input costs for soybean growers, so it's important for growers to plant the right amount of seed to minimize input costs and increase profitability. Seeding rate, plant population, and row spacing are tied

  11. Performance of laser Doppler velocimeter with polydisperse seed particles in high speed flows

    NASA Technical Reports Server (NTRS)

    Samimy, M.; Bhattacharyya, S.; Abu-Hijleh, B. A./K.

    1988-01-01

    The flowfield behind an oblique shock wave, where the LDV measured velocities are seed particle size dependent, was used to investigate the effects of LDV system parameters on the range of detectable polydisperse seed particles. The parameters included frequency shifting, laser power, scattered signal amplification level, and number of required fringe crossings. The results showed that with polydisperse seed particles ranging from 0.1 to 4.0 microns available in the flow, the average diameter of the detected particles could change from 0.2 to 3.0 microns by changing different LDV system parameters. The effects of this shift in the range of detectable particles on the frequency response of LDV was discussed.

  12. Performance of laser Doppler velocimeter with polydisperse seed particles in high-speed flows

    NASA Technical Reports Server (NTRS)

    Samimy, M.; Abu-Hijleh, B. A. K.

    1989-01-01

    The flowfield behind an oblique shock wave, where the LDV measured velocities are seed-particle-size dependent, was used to investigate the effects of LDV system parameters on the range of detectable polydisperse seed particles. The parameters included frequency shifting, laser power, scattered signal amplification level, and number of required fringe crossings. The results showed that with polydisperse seed particles ranging from 0.1 to 4.0 microns available in the flow, the average diameter of the detected particles could change from 0.2 to 3.0 microns by changing different LDV system parameters. The effects of this shift in the range of detectable particles on the frequency response of LDV are discussed.

  13. Two-phase seed dispersal: linking the effects of frugivorous birds and seed-caching rodents

    Microsoft Academic Search

    Stephen B. Vander Wall; Kellie M. Kuhn; Jennifer R. Gworek

    2005-01-01

    Frugivorous birds disperse the seeds of many fruit-bearing plants, but the fate of seeds after defecation or regurgitation\\u000a is often unknown. Some rodents gather and scatter hoard seeds, and some of these may be overlooked, germinate, and establish\\u000a plants. We show that these two disparate modes of seed dispersal are linked in some plants. Rodents removed large (>25 mg)\\u000a seeds from

  14. Early Spring Seeds/Pound..............

    E-print Network

    Thomas, David D.

    at Rosemount and in 2002 and 2006 at Kura clover is a low-growing, spreading, perennial legume. It is best used per year at Rosemount and twice per year at Grand Rapids. Dry matter yield, in tons per acre, and vigor of kura clover varieties seeded at 2 locations. Vigor** Rosemount Grand Rapids Variety 5

  15. Sowing the Seeds of Neuroscience

    NSDL National Science Digital Library

    Dr. Eric Chudler

    2014-04-04

    Sowing the Seeds of Neuroscience seeks to increase student interest and understanding of neuroscience through simple, safe lab investigations using plants. The site contains 8 laboratory investigations exploring properties of compounds found in plants and their effect on the behavior and growth of invertebrates. The site also provides general neuroscience and medicinal plant information.

  16. Ecosourcing seed in urban Auckland

    Microsoft Academic Search

    Leslie Haines

    In an urban context, is it possible to effectively ecosource seed from the urban remnants of indigenous vegetation? Urban vegetation is vulnerable to genetic pollution from plantings within or nearby to natural areas. Urban revegetation projects aiming to reinforce local genetic integrity potentially are flawed by lack of identification of pure local gene pools or by limited gene pools of

  17. Chemical composition of papaya seeds

    Microsoft Academic Search

    Calvino Passera; Paolo Spettoli

    1981-01-01

    Seeds of papaya cultivated in Somalia, which accounted for about 16% of the fresh fruit weight, were divided into sarcotesta and endosperm. Sarcotesta showed higher percentages of ash, crude protein, and crude fiber than did endosperm, but was lacking in fat. In contrast, endosperm contained 60% fat. Oil extract showed very high levels of oleic and palmitic acids. The essential

  18. Seed microRNA Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MicroRNAs (miRNAs) are key regulatory molecules that play critical roles in gene expression. The biological functions of miRNAs are important for developmental processes in plants and animals. Little is known about the functions of miRNAs in seeds. To gain a better understand-ing of the regulation o...

  19. Climate Kids: Make Seed Paper

    NSDL National Science Digital Library

    2013-12-03

    The recycled paper produced from the instructions provided contains an additional component - wildflower seeds. The entire paper disc can be planted; the sprouting of the flowers can be observed and analyzed. The Climate Kids website is a NASA education resource featuring articles, videos, images and games focused on the science of climate change.

  20. Advanced backward Raman amplification seeding

    NASA Astrophysics Data System (ADS)

    Malkin, Vladimir; Fisch, Nathaniel

    2010-11-01

    Next generations of ultrapowerful laser pulses, reaching exawatt and zetawatt powers within reasonably compact facilities, might be based on the backward Raman amplification (BRA) in plasmas. Amplified pulse intensities hundreds times higher than the pump intensity are already observed experimentally. More advanced BRA stages should produce even higher intensities. The largest nonfocused intensity, limited primarily by instabilities associated with the relativistic electron nonlinearity of the amplified laser pulse, is, roughly speaking, 0.1 of the fully relativistic value. It corresponds to the amplified pulse final (and shortest) duration be about the electron plasma wave period. The needed seed pulse should be at least that short then to stay ahead of the amplified pulse, rather than be shadowed by it (which would much reduce the seeding efficiency). However, at earlier BRA stages, when the amplified pulse is longer, the optimal duration of the seed pulse is also longer. This work proposes the use of self-contracting seed pulses for further optimizing the advanced BRA.

  1. Withanolides from hyoscyamus niger seeds

    PubMed

    Ma; Williams; Che

    1999-10-01

    Three withanolide class steroids were isolated from the seeds of Hyoscyamus niger. Two of them were identified as daturalactone-4 (1) and Nic-3 (which is now named hyoscyamilactol) (2). The new compound was elucidated as 16alpha-acetoxyhyoscyamilactol (3) on the basis of spectroscopic properties and X-ray crystallographic analysis. PMID:10543915

  2. Improved Seeds and Green Revolution

    Microsoft Academic Search

    Jagtar S. Dhiman; Manjit S. Kang; V. R. Parshad; P. K. Khanna; S. S. Bal; S. S. Gosal

    2010-01-01

    The purpose of this review is to share with developing countries how a dedicated agricultural university helped enhance food production and thwart Malthusian scenario. The Indian adequacy on the food-front has largely been attributed to the development of improved seeds of different crops, in particular wheat and rice, efficient system of agro-technology generation and its transfer to farmers, and useful

  3. Noise Amplification in HGHG Seeding

    SciTech Connect

    Stupakov, Gennady

    2010-08-25

    An essential element of seeded FEL based on high-gain harmonic generation (HGHG) or echo-enabled harmonic generation (EEHG) is an undulator-modulator, in which interaction with a laser beam modulates the beam energy. We study how the interaction of electrons in this undulator-modulator changes the noise properties of the beam.

  4. Getting of the seeds-and-tools treadmill with CRS seed vouchers and fairs.

    PubMed

    Remington, Tom; Maroko, Jeremiah; Walsh, Stephen; Omanga, Paul; Charles, Edward

    2002-12-01

    The free distribution of seeds and tools is the standard approach to agricultural recovery. The predominance of this approach is partly attributable to the: (1) perception that farmer seed quality is poor, (2) insistence on seed certification, (3) promotion of researcher varieties, (4) misdiagnosis of unavailability, (5) difficulty accessing farmer seed, and (6) support for the commercial seed sector. This paper presents a Seed Security Assessment Framework to distinguish among the causes of seed insecurity and focuses on three principal concepts: seed availability; access to seed; and factors associated with seed utilisation. Using this diagnostic framework, Catholic Relief Services (CRS) has developed a better approach to promoting seed system-based agricultural recovery. It involves a combination of seed voucher distribution and the organization of seed fairs, which bring together a range of sellers from whom the holders of vouchers may purchase seed. This approach is advantageous because it: strengthens farmer seed procurement systems; is cost efficient; in economic terms, has a multiplier effect in the community; is straightforward to plan and implement; allows commercial sector participation; provides an opportunity to promote improved varieties for farmer evaluation; brings together different communities. PMID:12518508

  5. DIELECTRIC STUDY OF BINDING MODES OF WATER IN GRAIN AND SEED AT LOW TEMPERATURES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dielectric behavior of bound water in grain and seed was investigated through measurement of the dielectric properties at microwave frequencies over a wide temperature range between minus 70 degrees C and +21 degrees C. Samples of wheat and soybeans were cooled to minus 70 degrees C and then their...

  6. Improved efficiency of somatic embryogenesis from zygotic embryos in Hyoscyamus niger by seed water-soaking

    Microsoft Academic Search

    Shanjun Tu; R. S. Sangwan; B. S. Sangwan-Norreel

    2005-01-01

    We describe an efficient procedure to obtain somatic embryos from mature zygotic embryos of Hyoscyamus niger (black henbane). It has several advantages over previous regeneration methods, which are: the use of mature seeds, an average 80% somatic embryogenesis rate and a high (eight-fold higher than the control) plant regeneration frequency. The critical step in this protocol was soaking of the

  7. UNIFIED ALGORITHM FOR MICROWAVE SENSING OF MOISTURE IN GRAIN AND SEED

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A unified calibration algorithm for moisture sensing in grain and seed from a single calibration equation, which is obtained from measurement of their dielectric properties at a single microwave frequency is presented. This algorithm is based on a calibration function that is expressed in terms of t...

  8. Observation of frequency doubling in tantalum doped silica fibres

    NASA Technical Reports Server (NTRS)

    Driscoll, T. J.; Lawandy, N. M.; Killian, A.; Rienhart, L.; Morse, T. F.

    1991-01-01

    Second harmonic conversion efficients of 3 x 0,0001 in tantalum-doped silica fibers prepared by the seeding technique are reported. A series of experiments were conducted to characterize the frequency doubling in this fiber and to compare the results to the behavior observed in germanosilicate and rare earth-doped aluminosilicate fibers.

  9. MICROWAVE AND RADIO-FREQUENCY POWER APPLICATIONS IN AGRICULTURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A brief review is presented of potential applications for radio-frequency and microwave power applications in agriculture. Included are applications for stored-product insect control, seed treatment to improve germination and seedling performance, conditioning of products to improve nutritional val...

  10. The antifungal compound totarol of Thujopsis dolabrata var. hondai seeds selects for fungi on seedling root surfaces.

    PubMed

    Yamaji, Keiko; Mori, Shigeta; Akiyama, Masaru; Kato, Atsushi; Nakashima, Tadakazu

    2007-12-01

    Hinoki-asunaro (Thujopsis dolabrata Sieb. et Zucc. var. hondai Makino) is a tree endemic in Japan whose seeds produce several terpenoids. We hypothesized that antifungal compounds in seeds might select for fungi on the root surfaces of T. dolabrata var. hondai seedlings. We examined seed and soil fungi, their sensitivity to methanol extracts of the seeds, the fungi on root surfaces of seedlings grown in Kanuma pumice (a model mineral soil) and nursery soil, and the frequency at which each fungus was detected on the seedling root surface. We calculated correlation coefficients between fungal detection frequency on root surfaces and fungal sensitivity to seed extracts. We also isolated from the seeds the antifungal compound totarol that selected for fungi on root surfaces. Species of Alternaria, Cladosporium, Pestalotiopsis, and Phomopsis were the most frequently isolated fungi from seeds. Mortierella and Mucor were the dominant fungi isolated from Kanuma pumice, whereas Umbelopsis and Trichoderma were the main fungi isolated from nursery soil. Alternaria, Cladosporium, Mortierella, Pestalotiopsis, and Phomopsis were the dominant fungi isolated from root surfaces of seedlings grown in Kanuma pumice, and Alternaria, Cladosporium, Pestalotiopsis, Phomopsis, and Trichoderma were the main root-surface fungi isolated from seedlings grown in nursery soil. The fungal detection frequencies on root surfaces in both soils were significantly and negatively correlated with fungal sensitivity to the seed extract. A similar correlation was found between the fungal detection frequency on root surfaces and fungal sensitivity to totarol. We conclude that totarol is one factor that selects for fungi on root surfaces of T. dolabrata var. hondai in the early growth stage. PMID:18026796

  11. Morphological rates of angiosperm seed size evolution.

    PubMed

    Sims, Hallie J

    2013-05-01

    The evolution of seed size among angiosperms reflects their ecological diversification in a complex fitness landscape of life-history strategies. The lineages that have evolved seeds beyond the upper and lower boundaries that defined nonflowering seed plants since the Paleozoic are more dispersed across the angiosperm phylogeny than would be expected under a neutral model of phenotypic evolution. Morphological rates of seed size evolution estimated for 40 clades based on 17,375 species ranged from 0.001 (Garryales) to 0.207 (Malvales). Comparative phylogenetic analysis indicated that morphological rates are not associated with the clade's seed size but are negatively correlated with the clade's position in the overall distribution of angiosperm seed sizes; clades with seed sizes closer to the angiosperm mean had significantly higher morphological rates than clades with extremely small or extremely large seeds. Likewise, per-clade taxonomic diversification rates are not associated with the seed size of the clade but with where the clade falls within the angiosperm seed size distribution. These results suggest that evolutionary rates (morphological and taxonomic) are elevated in densely occupied regions of the seed morphospace relative to lineages whose ecophenotypic innovations have moved them toward the edges. PMID:23617912

  12. HANDLING ARABIDOPSIS PLANTS AND SEEDS Methods used by the Arabidopsis Biological Resource Center

    E-print Network

    Meier, Iris

    HANDLING ARABIDOPSIS PLANTS AND SEEDS Methods used by the Arabidopsis Biological Resource Center · Growth conditions · Control of pests · Plant isolation and harvesting SEED HANDLING AND PRESERVATION Threshing Seed drying Seed moisture content determination Seed packaging for storage Seed storage

  13. Frequency domain optical parametric amplification

    PubMed Central

    Schmidt, Bruno E.; Thiré, Nicolas; Boivin, Maxime; Laramée, Antoine; Poitras, François; Lebrun, Guy; Ozaki, Tsuneyuki; Ibrahim, Heide; Légaré, François

    2014-01-01

    Today’s ultrafast lasers operate at the physical limits of optical materials to reach extreme performances. Amplification of single-cycle laser pulses with their corresponding octave-spanning spectra still remains a formidable challenge since the universal dilemma of gain narrowing sets limits for both real level pumped amplifiers as well as parametric amplifiers. We demonstrate that employing parametric amplification in the frequency domain rather than in time domain opens up new design opportunities for ultrafast laser science, with the potential to generate single-cycle multi-terawatt pulses. Fundamental restrictions arising from phase mismatch and damage threshold of nonlinear laser crystals are not only circumvented but also exploited to produce a synergy between increased seed spectrum and increased pump energy. This concept was successfully demonstrated by generating carrier envelope phase stable, 1.43?mJ two-cycle pulses at 1.8??m wavelength. PMID:24805968

  14. Wind-dispersed Seed Deposition Patterns and Seedling Recruitment of Artemisia halodendron in a Moving Sandy Land

    PubMed Central

    LI, FENG-RUI; WANG, TAO; ZHANG, AI-SHENG; ZHAO, LI-YA; KANG, LING-FEN; CHEN, WEN

    2005-01-01

    • Background and Aims Artemisia halodendron is a native sub-shrub that occurs mainly in moving and semi-fixed sandy lands in Inner Mongolia, China. Information on the spatial patterns of wind-dispersed seed deposition and seedling recruitment of A. halodendron inhabiting moving sandy lands is very limited. The aim of this study was to examine wind-dispersed seed deposition patterns and post-dispersal recruitment of A. halodendron seedlings. •Methods The spatial patterns of wind-dispersed seed deposition and seedling recruitment of A. halodendron were examined by investigating the numbers of deposited seeds, emerged and surviving seedlings using sampling points at a range of distances from the parent plant in eight compass directions for two consecutive growing seasons. •Key Results Wind-dispersed seed deposition showed considerable variation between directions and years. Wind transported A. halodendron seeds only a few meters away from the parent plant in all eight directions. Seedling emergence and establishment also showed between-direction and between-year variability, but the spatial pattern of seedling distribution differed from that of seed deposition. Only a very small fraction (<1 %) of the deposited seeds emerged in the field and survived for long enough to be included in our seedling censuses at the end of the growing season. •Conclusions The spatial variation in wind speed and frequency strongly affects the pattern of seed deposition, although the variation in seed deposition does not determine the spatial pattern of seedling recruitment. Seeds of A. halodendron are not dispersed very well by wind. The low probability of recruitment success for A. halodendron seedlings suggests that this species does not rely on seedling recruitment for its persistence and maintenance of population. PMID:15857850

  15. Antidiarrhoeal activity of Strychnos potatorum seed extract in rats.

    PubMed

    Biswas, Swati; Murugesan, T; Sinha, Sanghamitra; Maiti, Kuntal; Gayen, Jiaur Rahaman; Pal, M; Saha, B P

    2002-02-01

    The antidiarrhoeal activity of the methanol extract of the dried seeds of Strychnos potatorum (MESP) has been evaluated out in rats using different models (castor oil-induced diarrhoea, effects on gastrointestinal motility and on PGE(2)-induced gastric enteropooling. MESP (100, 200 and 400 mg/kg, p.o.) significantly (P<0.001) inhibited the frequency of defaecation and reduced the wetness of faecal droppings in castor oil-induced diarrhoea, decreased the propulsion of charcoal meal through the gastrointestinal tract, and also reduced the PGE(2)-induced enteropooling. PMID:11864763

  16. Conflicting selection from fire and seed predation drives fine-scaled phenotypic variation in a widespread North American conifer.

    PubMed

    Talluto, Matthew V; Benkman, Craig W

    2014-07-01

    Recent work has demonstrated that evolutionary processes shape ecological dynamics on relatively short timescales (eco-evolutionary dynamics), but demonstrating these effects at large spatial scales in natural landscapes has proven difficult. We used empirical studies and modeling to investigate how selective pressures from fire and predispersal seed predation affect the evolution of serotiny, an ecologically important trait. Serotiny is a highly heritable key reproductive trait in Rocky Mountain lodgepole pine (Pinus contorta subsp. latifolia), a conifer that dominates millions of hectares in western North America. In these forests, the frequency of serotiny determines postfire seedling density with corresponding community- and ecosystem-level effects. We found that serotinous individuals have a selective advantage at high fire frequencies and low predation pressure; however, very high seed predation shifted the selective advantage to nonserotinous individuals even at high fire frequencies. Simulation modeling suggests that spatial variation in the frequency of serotiny results from heterogeneity in these two selective agents. These results, combined with previous findings showing a negative association between the density of seed predators and the frequency of serotiny at both landscape and continental scales, demonstrate that contemporary patterns in serotiny reflect an evolutionary response to conflicting selection pressures from fire and seed predation. Thus, we show that variation in the frequency of a heritable polygenic trait depends on spatial variation in two dominant selective agents, and, importantly, the effects of the local trait variation propagate with profound consequences to the structure and function of communities and ecosystems across a large landscape. PMID:24979772

  17. Conflicting selection from fire and seed predation drives fine-scaled phenotypic variation in a widespread North American conifer

    PubMed Central

    Talluto, Matthew V.; Benkman, Craig W.

    2014-01-01

    Recent work has demonstrated that evolutionary processes shape ecological dynamics on relatively short timescales (eco-evolutionary dynamics), but demonstrating these effects at large spatial scales in natural landscapes has proven difficult. We used empirical studies and modeling to investigate how selective pressures from fire and predispersal seed predation affect the evolution of serotiny, an ecologically important trait. Serotiny is a highly heritable key reproductive trait in Rocky Mountain lodgepole pine (Pinus contorta subsp. latifolia), a conifer that dominates millions of hectares in western North America. In these forests, the frequency of serotiny determines postfire seedling density with corresponding community- and ecosystem-level effects. We found that serotinous individuals have a selective advantage at high fire frequencies and low predation pressure; however, very high seed predation shifted the selective advantage to nonserotinous individuals even at high fire frequencies. Simulation modeling suggests that spatial variation in the frequency of serotiny results from heterogeneity in these two selective agents. These results, combined with previous findings showing a negative association between the density of seed predators and the frequency of serotiny at both landscape and continental scales, demonstrate that contemporary patterns in serotiny reflect an evolutionary response to conflicting selection pressures from fire and seed predation. Thus, we show that variation in the frequency of a heritable polygenic trait depends on spatial variation in two dominant selective agents, and, importantly, the effects of the local trait variation propagate with profound consequences to the structure and function of communities and ecosystems across a large landscape. PMID:24979772

  18. Water binding in legume seeds

    NASA Technical Reports Server (NTRS)

    Vertucci, C. W.; Leopold, A. C.

    1987-01-01

    The physical status of water in seeds has a pivotal role in determining the physiological reactions that can take place in the dry state. Using water sorption isotherms from cotyledon and axis tissue of five leguminous seeds, the strength of water binding and the numbers of binding sites have been estimated using van't Hoff analyses and the D'Arcy/Watt equation. These parameters of water sorption are calculated for each of the three regions of water binding and for a range of temperatures. Water sorption characteristics are reflective of the chemical composition of the biological materials as well as the temperature at which hydration takes place. Changes in the sorption characteristics with temperature and hydration level may suggest hydration-induced structural changes in cellular components.

  19. Local Evolution of Seed Flotation in Arabidopsis

    PubMed Central

    Saez-Aguayo, Susana; Rondeau-Mouro, Corinne; Macquet, Audrey; Kronholm, Ilkka; Ralet, Marie-Christine; Berger, Adeline; Sallé, Christine; Poulain, Damien; Granier, Fabienne; Botran, Lucy; Loudet, Olivier; de Meaux, Juliette; Marion-Poll, Annie; North, Helen M.

    2014-01-01

    Arabidopsis seeds rapidly release hydrophilic polysaccharides from the seed coat on imbibition. These form a heavy mucilage layer around the seed that makes it sink in water. Fourteen natural Arabidopsis variants from central Asia and Scandinavia were identified with seeds that have modified mucilage release and float. Four of these have a novel mucilage phenotype with almost none of the released mucilage adhering to the seed and the absence of cellulose microfibrils. Mucilage release was modified in the variants by ten independent causal mutations in four different loci. Seven distinct mutations affected one locus, coding the MUM2 ?-D-galactosidase, and represent a striking example of allelic heterogeneity. The modification of mucilage release has thus evolved a number of times independently in two restricted geographical zones. All the natural mutants identified still accumulated mucilage polysaccharides in seed coat epidermal cells. Using nuclear magnetic resonance (NMR) relaxometry their production and retention was shown to reduce water mobility into internal seed tissues during imbibition, which would help to maintain seed buoyancy. Surprisingly, despite released mucilage being an excellent hydrogel it did not increase the rate of water uptake by internal seed tissues and is more likely to play a role in retaining water around the seed. PMID:24625826

  20. Stealth seeds: Bioproperty, biosafety, biopolitics

    Microsoft Academic Search

    Ronald J. Herring

    2007-01-01

    Transgenic seeds in both India (Bt cotton) and Brazil (glyphosate-resistant soybeans) spread widely and rapidly through farming communities outside the reach of biosafety or bioproperty institutions. Stealth transgenics are saved, cross-bred, repackaged, sold, exchanged and planted in an anarchic agrarian capitalism that defies surveillance and control of firms and states. The outcome is more pro-poor than alternative modes of diffusion,

  1. MHD seed recovery and regeneration

    NASA Astrophysics Data System (ADS)

    1988-10-01

    The TRW Econoseed MHD Seed Regeneration Process is based on the reaction of calcium formate with potassium sulfate spent seed from an MHD electric power generation plant. The process was tested at bench scale, design a proof of concept (POC) test plant, plan and cost a Phase 2 project for a POC plant evaluation and prepare a conceptual design of a 300 MW (t) commercial plant. The results of the project are as follows: (1) each of the unit operations is demonstrated, and (2) the data are incorporated into a POC plant design and project cost, as well as a 300 MW (t) commercial retrofit plant design and cost estimate. Specific results are as follows: (1) calcium formate can be produced at 100 percent yield in a total retention time of less than 5 minutes, (2) utilizing the calcium formate, spent seed can quantitatively be converted to potassium formate, potassium carbonate or mixtures of these with potassium sulfate as per the commercial design without measurable loss of potassium to insolubles at a total retention time under 20 minutes and ambient pressure, (3) the solid rejects form the process meet RCRA EP Toxicity requirements for safe disposal, and (4) filtration and evaporation data, as well as reaction data cited above, show that the Econoseed technology is ready for scale up to POC plant scale. Economics forecast studies show that the total cost per unit of potassium for seed regeneration by the Econoseed Process is in the range of $0.23 to $0.27/lb, a cost which is less than half the potassium cost of $0.63/lb for purchasing new potassium carbonate.

  2. Lipids of Viburnum opulus seeds

    Microsoft Academic Search

    S. G. Yunusova; E. G. Zinurova; M. S. Yunusov; E. G. Galkin; A. R. Karimova

    1998-01-01

    Lipid components of the seeds ofViburnum opulus (Caprifoliaceae family) were investigated. The neutral lipids consist of eight classes, the glycolipids consist of three classes, and the\\u000a phospholipids contain seven classes. The fatty-acid contents of all of the acyl-containing lipids were determined. The 18?2\\u000a fatty acid is the main component of all the lipid fractions. The content of saturated acids is

  3. Seed physiological maturity in Cuphea

    Microsoft Academic Search

    Marisol T. Berti; Burton L. Johnson; Linda K. Manthey

    2007-01-01

    Cuphea (Cuphea viscosissima Jacq.×C. lanceolata f. silenoides W.T. Aiton, line PSR23) is a new crop being developed in the North Central United States, as an industrial oilseed crop. Cuphea PSR23 seed oil is rich in medium-chain-length fatty acids such as capric acid used to manufacture soaps and detergents. The objective of this research was to determine the time when physiological

  4. Generation of Particles and Seeding

    NASA Technical Reports Server (NTRS)

    Meyers, James F.

    1991-01-01

    One of the most important elements in laser velocimetry, yet the most neglected, is the small particle embedded in the flow field that scatters the light necessary to make velocity measurements. An attempt to remove the confusion in choosing a seeding method by assessing many of the techniques currently used is presented. Their characteristics and typical limitations imposed by various applications are outlined. The ramifications of these methods on measurement accuracy are addressed.

  5. Nitrogen analysis of whole seeds

    Microsoft Academic Search

    J. F. Cavins

    1980-01-01

    Whole seeds were digested in sulfuric acid with catalyst in conical beakers on a hot plate and the digest was analyzed for\\u000a nitrogen. The nitrogen analysis of the digest can be performed by distillation-titration or colorimetrically, using manual\\u000a or automatic procedures, linear regression analyses of 8 samples of 16 soybeans each gave values that agreed within 2% of\\u000a those obtained

  6. Experimental and Numerical Investigation of Single Frequency Amplifier with Photonic Bandgap Fiber at 1178 nm

    NASA Astrophysics Data System (ADS)

    Wang, Jian-Hua; Cui, Shu-Zhen; Hu, Jin-Meng; Cao, Fen; Fang, Yong; Lu, Hui-Ling

    2014-06-01

    A single frequency photonic bandgap fiber amplifier at 1178 nm is investigated experimentally and numerically. With a pump power of 81 W, a single frequency 1178 nm fiber laser of 10.3 W is obtained with a 3W seed laser and a 20 m gain fiber. Numerical simulation is conducted with a rate equation model taking amplified spontaneous emission and stimulated Brillouin scattering (SBS) into consideration. Temperature distribution along the fiber is applied for SBS suppression, more than 50 W single frequency fiber laser at 1178 nm is predicted theoretically with a 5W seed laser and a 40 m long gain fiber with five temperature steps.

  7. Effects of rodent species, seed species, and predator cues on seed fate

    USGS Publications Warehouse

    Sivy, Kelly J.; Ostoja, Steven M.; Schupp, Eugene W.; Durham, Susan

    2011-01-01

    Seed selection, removal and subsequent management by granivorous animals is thought to be a complex interaction of factors including qualities of the seeds themselves (e.g., seed size, nutritional quality) and features of the local habitat (e.g. perceived predator risk). At the same time, differential seed selection and dispersal is thought to have profound effects on seed fate and potentially vegetation dynamics. In a feeding arena, we tested whether rodent species, seed species, and indirect and direct predation cues influence seed selection and handling behaviors (e.g., scatter hoarding versus larder hoarding) of two heteromyid rodents, Ord's kangaroo rat (Dipodomys ordii) and the Great Basin pocket mouse (Perognathus parvus). The indirect cue was shrub cover, a feature of the environment. Direct cues, presented individually, were (1) control, (2) coyote (Canis latrans) vocalization, (3) coyote scent, (4) red fox (Vulpes vulpes) scent, or (5) short-eared owl (Asio flammeus) vocalization. We offered seeds of three sizes: two native grasses, Indian ricegrass (Achnatherum hymenoides) and bluebunch wheatgrass (Pseudoroegneria spicata), and the non-native cereal rye (Secale cereale), each in separate trays. Kangaroo rats preferentially harvested Indian ricegrass while pocket mice predominately harvested Indian ricegrass and cereal rye. Pocket mice were more likely to scatter hoard preferred seeds, whereas kangaroo rats mostly consumed and/or larder hoarded preferred seeds. No predator cue significantly affected seed preferences. However, both species altered seed handling behavior in response to direct predation cues by leaving more seeds available in the seed pool, though they responded to different predator cues. If these results translate to natural dynamics on the landscape, the two rodents are expected to have different impacts on seed survival and plant recruitment via their different seed selection and seed handling behaviors.

  8. Joshua tree (Yucca brevifolia) seeds are dispersed by seed-caching rodents

    USGS Publications Warehouse

    Vander Wall, S. B.; Esque, T.; Haines, D.; Garnett, M.; Waitman, B.A.

    2006-01-01

    Joshua tree (Yucca brevifolia) is a distinctive and charismatic plant of the Mojave Desert. Although floral biology and seed production of Joshua tree and other yuccas are well understood, the fate of Joshua tree seeds has never been studied. We tested the hypothesis that Joshua tree seeds are dispersed by seed-caching rodents. We radioactively labelled Joshua tree seeds and followed their fates at five source plants in Potosi Wash, Clark County, Nevada, USA. Rodents made a mean of 30.6 caches, usually within 30 m of the base of source plants. Caches contained a mean of 5.2 seeds buried 3-30 nun deep. A variety of rodent species appears to have prepared the caches. Three of the 836 Joshua tree seeds (0.4%) cached germinated the following spring. Seed germination using rodent exclosures was nearly 15%. More than 82% of seeds in open plots were removed by granivores, and neither microsite nor supplemental water significantly affected germination. Joshua tree produces seeds in indehiscent pods or capsules, which rodents dismantle to harvest seeds. Because there is no other known means of seed dispersal, it is possible that the Joshua tree-rodent seed dispersal interaction is an obligate mutualism for the plant.

  9. Tannin concentration enhances seed caching by scatter-hoarding rodents: An experiment using artificial ‘seeds

    NASA Astrophysics Data System (ADS)

    Wang, Bo; Chen, Jin

    2008-11-01

    Tannins are very common among plant seeds but their effects on the fate of seeds, for example, via mediation of the feeding preferences of scatter-hoarding rodents, are poorly understood. In this study, we created a series of artificial 'seeds' that only differed in tannin concentration and the type of tannin, and placed them in a pine forest in the Shangri-La Alpine Botanical Garden, Yunnan Province of China. Two rodent species ( Apodemus latronum and A. chevrieri) showed significant preferences for 'seeds' with different tannin concentrations. A significantly higher proportion of seeds with low tannin concentration were consumed in situ compared with seeds with a higher tannin concentration. Meanwhile, the tannin concentration was significantly positively correlated with the proportion of seeds cached. The different types of tannin (hydrolysable tannin vs condensed tannin) did not differ significantly in their effect on the proportion of seeds eaten in situ vs seeds cached. Tannin concentrations had no significant effect on the distance that cached seeds were carried, which suggests that rodents may respond to different seed traits in deciding whether or not to cache seeds and how far they will transport seeds.

  10. Pulsing Cl- channels in coat cells of developing bean seeds linked to hypo-osmotic turgor regulation.

    PubMed

    Zhang, Wen-Hao; Walker, N Alan; Patrick, John W; Tyerman, Stephen D

    2004-05-01

    Seed coat cells in the developing seeds of grain legumes release nutrients to the developing embryo. This occurs into an apoplastic space that separates the maternal (seed coat) and filial (embryo) generations. Protoplasts of seed coat cells from coats of Phaseolus vulgaris L. seeds were isolated and whole-cell current across their plasma membranes was characterized using the patch-clamp technique. A pulsing inward current that displayed a spontaneous activation and voltage-dependent inactivation was observed. The frequency and magnitude of the current pulses were positively dependent on cytoplasmic Cl(-) concentrations and independent of external cations. The pulse current was inhibited by DIDS and La(3+), but not by Gd(3+). Single channel events (conductance=18 pS) could be identified with the inactivating phase of the pulses. Together, these findings are consistent with the current being carried by a burst of Cl(-) efflux through Cl(-)-permeable channels that activate almost simultaneously. Neomycin caused a reversible inhibition of the pulsed current, suggesting that its activation is likely to be modulated by an IP(3)-dependent intracellular Ca(2+) release. The pharmacological profiles of Cl(-) efflux from excised seed coats were comparable with those of the Cl(-) channels in the whole cell configuration, suggesting that the Cl(-) channels may underpin Cl(-) efflux from the seed coats. Efflux of Cl(-) from the seed coats was also stimulated by hypo-osmotic treatment as was the frequency and magnitude of Cl(-) channel in whole-cell patch clamp experiments. This implies that the Cl(-) channels responsible for the pulsed Cl(-) currents are likely to be a component of the turgor-regulatory mechanism in developing bean seeds. PMID:15047765

  11. Seed set for Scots pine grafts is difficult to predict

    Microsoft Academic Search

    Dag Lindgren; Yordan Tellalov; Finnvid Prescher

    Extended abstract Having predictions for breeding values of clones for both seed set and the genetic quality of the seeds, these two desirabilities may be balanced when choosing clones for a seed orchard (Lindgren et al 2004), but to do that we must know more about the genetics and predictability of seed set. The study is based on predicted seed

  12. Applicator Training Manual for: Seed Treatment Pest Control.

    ERIC Educational Resources Information Center

    TeKrony, Dennis M.

    This manual gives general information on seed treatment and type of seeds which can be treated. Also discussed are the problems and pests commonly associated with seed diseases and the fungicides and insecticides used for seed treatment. Information is also given on seed treatment equipment such as dust treaters, slurry treaters, and direct…

  13. Inheritance of seed colour in turnip rape ( Brassica campestris L.)

    Microsoft Academic Search

    A. Schwetka

    1982-01-01

    The inheritance of seed colour was investigated in the progenies of crosses between seven yellow seeded forms and a brown seeded one of turnip rape (Brassica campestris L.). Seed colour differences were found to be determined in each case by one or two genes with epistatic effect. Moreover, independent inheritance of hilum colour was observed. Seed colour was predominantly but

  14. The evolution of radar echo in a seeded cloud

    Microsoft Academic Search

    Marianne English; John D. Marwitz

    1982-01-01

    A convective cloud extending above a stratocumulus deck was seeded with droppable AgI flares at about the — 7°C level. Ten minutes after seeding, an echo was observed front the cloud at about the seeding level and downwind from the seeding location. The echo was very elongated and oriented parallel to the seeding track. Since the cloud was located only

  15. Modification of Seed Germination Performance through Cold Plasma Chemistry Technology

    Microsoft Academic Search

    John C. Volin; Ferencz S. Denes; Raymond A. Young; Scott M. T. Park

    2000-01-01

    growth regulators to seeds (Silcock and Smith, 1982; Taylor and Harman, 1990; Zarnstorff et al., 1994). One This study was conducted to determine if an alternate seed treat- such treatment is seed coating, the direct application of ment approach based on plasma chemistry would offer a more viable material to a seed surface. Seeds can be treated by alternative over

  16. Dormancy and Impotency of Cocklebur Seeds

    PubMed Central

    Esashi, Yohji; Katoh, Hajime; Leopold, A. Carl

    1977-01-01

    Germination of nondormant but impotent small cocklebur seeds (Xanthium pennsylvanicum Wallr.) was promoted profoundly with thiourea or benzyladenine, and slightly with gibberellic acid. Gibberellic acid was ineffective in causing the germination of dormant cocklebur seeds, although thiourea and benzyladenine were effective. Experiments with excised seed pieces showed that the promotive effects of thiourea, benzyladenine, and gibberellic acid on cocklebur seed germination were associated with the enhancement of growth of seed parts; thiourea stimulated predominantly the axial growth, whereas benzyladenine stimulated predominantly the cotyledonary growth. Potassium nitrate or indoleacetic acid had little effect on the initial growth of either axes or cotyledons. Except for gibberellic acid, all of the compounds employed enhanced ethylene production, but in general, the ethylene production seemed more likely to be a consequence of growth rather than a cause of it. We concluded that the chemical regulation of seed germination may be a consequence of the alteration of growth capabilities in either the axes or cotyledons, or both. PMID:16659798

  17. Rice seeds as sources of endophytic bacteria.

    PubMed

    Kaga, Hiroko; Mano, Hironobu; Tanaka, Fumiko; Watanabe, Asuka; Kaneko, Satoshi; Morisaki, Hisao

    2009-01-01

    Endophytic bacteria are considered to originate from the external environment. To examine the hypothesis that rice (Oryza sativa, cultivar Kinuhikari) seeds are a source of endophytic bacteria, we isolated endophytic bacteria from the shoots, remains of the seeds, and roots of rice seedlings that were aseptically cultivated in vitro from surface-disinfected seeds. Of the various bacterial strains isolated, the closest relatives, identified by 16S rRNA gene sequencing, were: Bacillus firmus, B. fusiformis, B. pumilus, Caulobacter crescentus, Kocuria palustris, Micrococcus luteus, Methylobacterium fujisawaense, Me. radiotolerans, and Pantoea ananatis. The latter three species have been detected frequently inside both rice seedlings and mature rice plants. These results indicate that rice seeds are an important source of endophytic bacteria. The bacteria that colonize the seed interior appear to infect the subsequent generation via rice seeds and become the dominant endophytic species in the mature plant. PMID:21566368

  18. Two-Color Radiation Generated in a Seeded Free-Electron Laser with Two Electron Beams

    NASA Astrophysics Data System (ADS)

    Petralia, A.; Anania, M. P.; Artioli, M.; Bacci, A.; Bellaveglia, M.; Carpanese, M.; Chiadroni, E.; Cianchi, A.; Ciocci, F.; Dattoli, G.; Di Giovenale, D.; Di Palma, E.; Di Pirro, G. P.; Ferrario, M.; Giannessi, L.; Innocenti, L.; Mostacci, A.; Petrillo, V.; Pompili, R.; Rau, J. V.; Ronsivalle, C.; Rossi, A. R.; Sabia, E.; Shpakov, V.; Vaccarezza, C.; Villa, F.

    2015-07-01

    We present the experimental evidence of the generation of coherent and statistically stable two-color free-electron laser radiation obtained by seeding an electron beam double peaked in energy with a laser pulse single spiked in frequency. The radiation presents two neat spectral lines, with time delay, frequency separation, and relative intensity that can be accurately controlled. The analysis of the emitted radiation shows a temporal coherence and a shot-to-shot regularity in frequency significantly enhanced with respect to the self-amplified spontaneous emission.

  19. Lifetime and decay of seeded breathers in the FPU system

    NASA Astrophysics Data System (ADS)

    Westley, Matthew; Demeglio, Nicholas; Sen, Surajit; Mohan, T. R. Krishna

    2014-03-01

    The Fermi-Pasta-Ulam problem consists of a chain of N oscillators with linear and nonlinear nearest neighbor interactions. Using velocity-Verlet integration, we study the evolution of the system after a perturbation that consists of a single stretched bond at the center of the chain. This perturbation results in the localization of most of the system's energy in the center particles in the form of a ``breather'' up to reasonably long times, which leaks energy at a rate depending on the potential parameters and the perturbation amplitude. The breather eventually undergoes a catastrophic breakdown, releasing all of its energy into acoustic noise and solitary waves. We explore the conditions on the amplitude and the parameters ?, ? for which a seeded breather will be most or least stable. Also we show how the overlap or lack thereof between the breather's primary frequencies and the acoustic frequencies influences its long-time stability. Research supported by a US Army Research Office STIR grant.

  20. High pressure extraction of oil seed

    Microsoft Academic Search

    R. Eggers; U. Sievers; W. Stein

    1985-01-01

    For calculation of phase equilibria of the system seed oil\\/CO2, an equation of state published in the literature has been fitted to experimental data of that system. The results thus obtained\\u000a are of only limited use in designing a supercritical extraction process. The experimental investigation of the mass transfer\\u000a kinetics is much more significant. Mechanical processing of the oil seed’s

  1. Cotton Planting Seed and Related Fiber Qualities.

    E-print Network

    Paulson, W. E.; Ward, J. M.

    1956-01-01

    Cotton Planting Seed and Related Fiber Qzlalities TEXAS AGRICULTURAL EXPERIMENT STATION R. D. LEWIS. DIRECTOR. COLLEGE STATION-. TEXAS SUMMARY This bulletin gives the results of a study conducted on the procurement and distribution of cotton... planting seed in Texas. Cottonseed oil mills and cotton gins are the growers' principal source of planting seed in several of the major cotton growing areas. The oil mills are the wholesalers; the gin5 are the retailers. The quality of the cotton produced...

  2. Gene expression analysis of flax seed development

    Microsoft Academic Search

    Prakash Venglat; Daoquan Xiang; Shuqing Qiu; Sandra L Stone; Chabane Tibiche; Dustin Cram; Michelle Alting-Mees; Jacek Nowak; Sylvie Cloutier; Michael Deyholos; Faouzi Bekkaoui; Andrew Sharpe; Edwin Wang; Gordon Rowland; Gopalan Selvaraj; Raju Datla

    2011-01-01

    Background  Flax, Linum usitatissimum L., is an important crop whose seed oil and stem fiber have multiple industrial applications. Flax seeds are also well-known\\u000a for their nutritional attributes, viz., omega-3 fatty acids in the oil and lignans and mucilage from the seed coat. In spite\\u000a of the importance of this crop, there are few molecular resources that can be utilized toward

  3. Chemical solution seed layer for rabits tapes

    SciTech Connect

    Goyal, Amit; Paranthaman, Mariappan; Wee, Sung-Hun

    2014-06-10

    A method for making a superconducting article includes the steps of providing a biaxially textured substrate. A seed layer is then deposited. The seed layer includes a double perovskite of the formula A.sub.2B'B''O.sub.6, where A is rare earth or alkaline earth metal and B' and B'' are different rare earth or transition metal cations. A superconductor layer is grown epitaxially such that the superconductor layer is supported by the seed layer.

  4. Some Physical Properties of Gilaburu Seed

    Microsoft Academic Search

    Nihat SÖNMEZ; H. A. ALIZADEH; Ramazan ÖZTÜRK

    In this study, the physical properties of gilaburu (Viburnum opulus L.) seed have been investigated. The average length, width, thickness and geometric mean diameter values in 54% of moisture content of gilaburu seed were between 6.56 and 8.44 mm, 6.24 and 8.57 mm, 1.62 and 2.52 mm, 4.19 and 5.31 mm, respectively. Sphericity, surface area, thousand seed mass and terminal

  5. Formation of cloud microstructure during hygroscopic seeding

    Microsoft Academic Search

    A. S. Drofa

    2006-01-01

    The evolution of cloud microstructure initiated by hygroscopic seeding is studied on the basis of numerical simulation of\\u000a cloud formation in the initial stage of condensation. The influence of both physicochemical properties of atmospheric aerosol\\u000a and atmospheric conditions controlling the cloud type on the microstructure of a developing cloud (without hygroscopic seeding)\\u000a is analyzed. It is shown that cloud seeding

  6. Transport processes in pea seed coats

    Microsoft Academic Search

    Joost Thomas van Dongen

    2001-01-01

    The research described in this thesis concerns transport processes in coats of developing pea seeds. The scope\\u000a of the investigation ranges from seed coat anatomy, via transport studies to the cloning of cDNA encoding\\u000a proteinaceous membrane pores, and the heterologous expression of these proteins to analyse their function.\\u000a Pea seed coats do not have an extensive vascular web. Nevertheless, assimilates

  7. S-Seed Switching, Noise, and Applications

    Microsoft Academic Search

    Lup Meng Loh

    1994-01-01

    The switching and noise characteristics of the Symmetric Self Electrooptic Effect Device (S-SEED) are studied in detail. The resulting analysis provides concise, closed form expressions for the S-SEED switching condition, the switching voltage of the device, and its switching time, all for a noiseless S-SEED model. A noise analysis, using a carrier state diagram, produced Bit Error Rate (BER) curves

  8. Gulls (Laridae) as frugivores and seed dispersers

    Microsoft Academic Search

    Maria Calvino-Cancela

    2011-01-01

    Many gull species (Laridae) are opportunistic feeders with diverse diets. Seeds and fruits are common in gull diets, often\\u000a in small proportions but sometimes dominant in certain periods and areas. Moreover, the large body sizes and high population\\u000a densities of gulls increase their ecological importance. Hence, they can be significant seed dispersers even with relatively\\u000a few seeds in diets. Gulls

  9. Supercritical fluid extraction of vegetable oil seeds

    Microsoft Academic Search

    N. R. Bulley; M. Fattori; A. Meisen; L. Moyls

    1984-01-01

    The extraction of oil from canola seeds using supercritical carbon dioxide was investigated. The basic equations which govern\\u000a the oil extraction from a bed of seeds were derived from first principles. The equations can be solved by standard numerical\\u000a techniques using experimentally determined parameters for the concentration of oil in the solvent in equilibrium with seeds\\u000a having a known oil

  10. Effect of heating conditions of grape seeds on the antioxidant activity of grape seed extracts

    Microsoft Academic Search

    So-Young Kim; Seok-Moon Jeong; Woo-Po Park; K. C. Nam; D. U. Ahn; Seung-Cheol Lee

    2006-01-01

    This study was carried out to evaluate the effect of heating and physical conditions of grape seeds on the antioxidant activity of their extracts. Two forms of grape seeds, whole and powdered forms, were heated at four different temperatures ?50, 100, 150 and 200°C. After heating, grape seeds were extracted with 70% ethanol (0.1g grape seed\\/10mL of 70% ethanol), and

  11. Chemical characterization of Central American pitaya (Hylocereussp.) seeds and seed oil

    Microsoft Academic Search

    M. G. Villalobos-Gutiérrez; R. M. Schweiggert; R. Carle; P. Esquivel

    2012-01-01

    Central American red pitaya (Hylocereussp.) seeds were studied for their chemical and nutritional traits with particular reference to the fatty acid (FA) profile of the seed oil. Proximate seed composition averaged 352 g\\/kg, 302 g\\/kg, 296 g\\/kg, 206 g\\/kg, 126 g\\/kg, and 21 g\\/kg for total carbohydrates, dietary fiber, fat, protein, moisture, and ash, respectively. FA composition of pitaya seed

  12. Ground seed density patterns under conditions of strongly overlapping seed shadows in Abies alba Mill. stands

    Microsoft Academic Search

    Jaros?aw G. Paluch

    In three subsequent years, seeds were collected from 66 to 75 seed traps in three Abies alba stands that differed in vertical structure and the number of potentially reproducing trees. The objective was to compare\\u000a empirical patterns of seed density with a random (Poisson) model, which assumes that seed density would be the same in every\\u000a location, and a binomial

  13. The restoration of sedge meadows: seed viability, seed germination requirements, and seedling growth of Carex species

    Microsoft Academic Search

    Arnold G. van der Valk; Tony L. Bremholm; Elizabeth Gordon

    1999-01-01

    To better understand how to establishCarex species from seed in created and restored wetlands, a series of experimental studies was conducted onCarex seed and seedlings. These studies included (1) the effect of seed age (1 to 18 months after collection) on viability and\\u000a germination, (2) storage conditions (+4,-4 or +4\\/-4°C; wet or dry) on seed germination, (3) soil moisture on

  14. Parasitoid wasps indirectly suppress seed production by stimulating consumption rates of their seed-feeding hosts.

    PubMed

    Xi, Xinqiang; Eisenhauer, Nico; Sun, Shucun

    2015-07-01

    In parasitoid-herbivore-plant food chains, parasitoids may be simultaneously linked with both herbivore hosts and plants, as occurs when herbivores attacked by parasitoids continue to consume plants although they are destined to die. This peculiar property may cause parasitoids to confer a differential trophic cascading effect on plants than that known for typical predators. We hypothesized that larval koinobiont parasitoids would confer an immediate negative effect on plant seed production by stimulating consumption of their seed-predator hosts. We tested this hypothesis in an alpine parasitic food chain of plant seeds, pre-dispersal seed predators (tephritid fly larvae) and koinobiont parasitoids using field observations, a field experiment and a microcosm study. We first compared observed seed production in (i) non-infected capitula, (ii) capitula infected only by seed predators (tephritid flies) and (iii) capitula infected by both seed predators and their parasitoids in five Asteraceae species. Consistent with our hypothesis, seed loss in the capitula with both seed predators and parasitoids was significantly greater than in the capitula infested only by seed predators. This effect was replicated in a controlled field experiment focusing on the most common parasitoid-seed predator-plant interaction chain in our system, in which confounding factors (e.g. density and phenology) were excluded. Here, we show that parasitoids indirectly decreased plant seed production by changing the behaviour of seed predators. In a microcosm study, we show that larval parasitoids significantly extended the growth period and increased the terminal size of their host tephritid maggots. Thus, parasitoids suppressed plant seed production by stimulating the growth and consumption of the fly maggots. In contrast to the typical predator-induced trophic cascade, we highlight the significance of parasitoids indirectly decreasing plant fitness by stimulating consumption by seed predators. Future studies on trophic interactions should consider the net effect of both increased consumption by seed predators and their death after development of parasitoids. PMID:25803150

  15. The dehydration and rehydration characteristics of the seeded breadfruit or breadnut seed

    Microsoft Academic Search

    L. Harrynanan; C. K. Sankat

    2008-01-01

    Harrynanan, L. and Sankat, C. K. 2008. The dehydration and rehydration characteristics of the seeded breadfruit or breadnut seed. Canadian Biosystems Engineering\\/Le genie des biosystems auCanada 50: 3.373.45. Experiments were carried out to determine the effects of dehydration and rehydration of in-shell mature breadnut seeds. Pretreated (cooked in salted water) and untreated in-shell mature breadnut seeds were dried in a

  16. Nitric oxide reduces seed dormancy in Arabidopsis.

    PubMed

    Bethke, Paul C; Libourel, Igor G L; Jones, Russell L

    2006-01-01

    Dormancy is a property of many mature seeds, and experimentation over the past century has identified numerous chemical treatments that will reduce seed dormancy. Nitrogen-containing compounds including nitrate, nitrite, and cyanide break seed dormancy in a range of species. Experiments are described here that were carried out to further our understanding of the mechanism whereby these and other compounds, such as the nitric oxide (NO) donor sodium nitroprusside (SNP), bring about a reduction in seed dormancy of Arabidopsis thaliana. A simple method was devised for applying the products of SNP photolysis through the gas phase. Using this approach it was shown that SNP, as well as potassium ferricyanide (Fe(III)CN) and potassium ferrocyanide (Fe(II)CN), reduced dormancy of Arabidopsis seeds by generating cyanide (CN). The effects of potassium cyanide (KCN) on dormant seeds were tested and it was confirmed that cyanide vapours were sufficient to break Arabidopsis seed dormancy. Nitrate and nitrite also reduced Arabidopsis seed dormancy and resulted in substantial rates of germination. The effects of CN, nitrite, and nitrate on dormancy were prevented by the NO scavenger c-PTIO. It was confirmed that NO plays a role in reducing seed dormancy by using purified NO gas, and a model to explain how nitrogen-containing compounds may break dormancy in Arabidopsis is presented. PMID:16377732

  17. Effects of Gut Passage, Feces, and Seed Handling on Latency and Rate of Germination in Seeds Consumed by

    E-print Network

    Fedigan, Linda M.

    Effects of Gut Passage, Feces, and Seed Handling on Latency and Rate of Germination in Seeds, University of Calgary, Calgary, AB, T2N-1N4, Canada KEY WORDS seed dispersal; Cebus capucinus; Santa Rosa of primary seed dispersal by animals is the quality of seed dispersal (Schupp: Plant Ecol 107/108 [1993] 15

  18. Greater seed production in elevated CO2 is not accompanied by reduced seed quality in Pinus taeda L.

    E-print Network

    Jackson, Robert B.

    Greater seed production in elevated CO2 is not accompanied by reduced seed quality in Pinus taeda L often increases seed production but usually leads to decreased seed quality. However, the effects to the composition of future forests. We determined how seed quantity and quality differed for pine trees grown

  19. Latitude, seed predation and seed mass A. T. Moles* and M. Westoby Department of Biological Sciences, Macquarie University,

    E-print Network

    Moles, Angela

    Latitude, seed predation and seed mass A. T. Moles* and M. Westoby Department of Biological of pre- and post-dispersal seed pre- dation would be higher towards the tropics, across a broad range of the relationship between seed mass and latitude both within and across species. Methods Seed mass, pre

  20. Male genotype influences seed set and seed size in controlled crosses of American chestnut (Castanea dentata [Marsh] Borhk)

    E-print Network

    Male genotype influences seed set and seed size in controlled crosses of American chestnut the influence of pollen donor genotype on seed set and seed mass. Pollen from ten American chestnut or American chestnut hybrids was applied to the five mother trees. The seeds were harvested, counted, and individually

  1. Gene differences in heading date, height, seed weight and seed yield between two pure line varieties of Triticum aestivum L.

    PubMed

    Wehrhahn, C F; Tai, G C

    1988-09-01

    Reciprocal sets of homozygous inbred backcross lines were developed by crossing two pure line varieties (Baart 46 and Ramona) of Triticum aestivum L., followed by two backcrosses to each of the two parent varieties, and six to eight generations of selfing. Data on each inbred backcross line was obtained from twelve plots (from replications in three years). Five genes were responsible for over 95% of the genetic variation for heading date. These genes had pleiotropic effects on plant height that were proportional to their effects on heading date. Two additional genes had detectable effects on plant height. The genes with a measurable effect on height accounted for 90% of the genetic variation in the Baart 46 genetic background. One gene affected seed weight. In the Ramona background, this gene accounted for 80% of the genetic variation in seed weight and 16% of the genetic variation in seed yield. Two genes, responsible for the earliest and latest heading date classes, had large pleiotropic effects on seed yield. They accounted for 60% of the genetic variation in yield. One gene, with no effect on heading date, caused a detectable reduction in yield of 23% in the Baart 46 inbred backcross lines. This gene had no apparent effect in the Ramona genetic background. Quantitative trait genes are sparsely distributed in the genome: fewer than one in four chromosome arms carries a gene with a detectable effect. Gene effects on quantitative traits are not small and similar. The distribution of 22 gene effects for heading date and height is slightly skewed to the right: as the magnitude of effect increases, the frequency of genes having the effect decreases. PMID:24232197

  2. Living boundaries: tracking weed seed movement with non-dormant seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synthetic seed banks are a useful tool for increasing precision of counts in weed demography studies. By sowing a known number of seeds of a single accession within a spatially well-described area, an investigator can greatly improve the signal to noise ratio, relative to the ambient weed seed bank,...

  3. Irrigation and Seed Quality Development in Rapid-cycling Brassica: Seed Germination and Longevity

    Microsoft Academic Search

    U. R. S INNIAH; R. H. E LLIS; P. J OHN

    Irrigation of rapid-cycling brassica (Brassica campestris (rapa) L.) plants either ended 16 or 24 days after pollination (DAP) or continued throughout the experiment (control). Seeds were harvested serially from these plants during their development and maturation. The earlier irrigation to the mother plant ended, the earlier mass maturity (end of seed- filling phase) occurred, the lower the final seed dry

  4. Effects of Cotton Seed and Cotton Seed Meal on Butter, Beef Tallow, Lard and Sheep Suet.

    E-print Network

    Harrington, H. H. (Henry Hill); Adriance, Duncan

    1893-01-01

    TEX 347. ON. BULLETIN NO. 29. DECEMBER, 1893. Effects of Cottt :d and Cotton Seed MI In BUTTER. REEF TALLOW, LARD AND SHEEP SUET. ACotton Seed and Cotton Seed Meal 011 Butter, Reef Tallon., Lard and Sheep Suet. RY H H. HARRINGTON, 31. SC. .kXD DUSCAN ADRIANCR, 31. S. SUMXIARP OF CONCLUSIOSS. 1st...

  5. Seed bank versus seed rain in the regeneration of a tropical pioneer tree

    Microsoft Academic Search

    Elena R. Alvarez-Buylla; Miguel Martínez-Ramos

    1990-01-01

    We used the tropical pioneer tree, Cecropia obtusifolia to evaluate the relative importance of different sources of seeds in the regeneration of species that depend on ephemeral sites. We studied seed production in a population established in a 5 ha plot, and dispersal, dormancy and seed predation in two recent treefall gaps (35 years since disturbed) for a one year

  6. Supplementing seed banks to rehabilitate disturbed Mojave Desert shrublands: where do all the seeds go?

    USGS Publications Warehouse

    DeFalco, Lesley A.; Esque, Todd C.; Nicklas, Melissa B.; Kane, Jeffrey M.

    2012-01-01

    Revegetation of degraded arid lands often involves supplementing impoverished seed banks and improving the seedbed, yet these approaches frequently fail. To understand these failures, we tracked the fates of seeds for six shrub species that were broadcast across two contrasting surface disturbances common to the Mojave Desert—sites compacted by concentrated vehicle use and trenched sites where topsoil and subsurface soils were mixed. We evaluated seedbed treatments that enhance soil-seed contact (tackifier) and create surface roughness while reducing soil bulk density (harrowing). We also explored whether seed harvesting by granivores and seedling suppression by non-native annuals influence the success of broadcast seeding in revegetating degraded shrublands. Ten weeks after treatments, seeds readily moved off of experimental plots in untreated compacted sites, but seed movements were reduced 32% by tackifier and 55% through harrowing. Harrowing promoted seedling emergence in compacted sites, particularly for the early-colonizing species Encelia farinosa, but tackifier was largely ineffective. The inherent surface roughness of trenched sites retained three times the number of seeds than compacted sites, but soil mixing during trench development likely altered the suitability of the seedbed thus resulting in poor seedling emergence. Non-native annuals had little influence on seed fates during our study. In contrast, the prevalence of harvester ants increased seed removal on compacted sites, whereas rodent activity influenced removal on trenched sites. Future success of broadcast seeding in arid lands depends on evaluating disturbance characteristics prior to seeding and selecting appropriate species and seasons for application.

  7. Two-phase seed dispersal: linking the effects of frugivorous birds and seed-caching rodents.

    PubMed

    Vander Wall, Stephen B; Kuhn, Kellie M; Gworek, Jennifer R

    2005-09-01

    Frugivorous birds disperse the seeds of many fruit-bearing plants, but the fate of seeds after defecation or regurgitation is often unknown. Some rodents gather and scatter hoard seeds, and some of these may be overlooked, germinate, and establish plants. We show that these two disparate modes of seed dispersal are linked in some plants. Rodents removed large (>25 mg) seeds from simulated bird feces (pseudofeces) at rates of 8-50%/day and scatter hoarded them in soil. Ants (Formica sibylla) also harvested some seeds and carried them to their nests. Rodents carried seeds 2.5+/-3.2 m to cache sites (maximum 12 m) and buried seeds at 8+/-7 mm depth. Enclosure studies suggest that yellow pine chipmunks (Tamias amoenus) and deer mice (Peromyscus maniculatus) made the caches. In spring, some seeds germinated from rodent caches and established seedlings, but no seedlings established directly from pseudofeces. This form of two-phase seed dispersal is important because each phase offers different benefits to plants. Frugivory by birds permits relatively long-range dispersal and potential colonization of new sites, whereas rodent caching moves seeds from exposed, low-quality sites (bird feces on the ground surface) to a soil environment that may help maintain seed viability and promote successful seedling establishment. PMID:15959820

  8. Seed and regeneration ecology in dry Afromontane forests of Ethiopia: I. Seed production - population structures

    Microsoft Academic Search

    DEMEL TEKETAY

    2005-01-01

    A series of events occur in the process of regeneration, namely flowering, seed production and dispersal, incorporation of seeds into the soil, seed predation or germination, seedling establishment and growth and formation of seedling banks. Forests are subjected to both natural and anthropogenic disturbances, which disrupt the process of plant regeneration. In response to these disturbances, succession is triggered in

  9. Intrapopulation variation in Abutilon theophrasti seed mass and its relationship to seed germinability

    Microsoft Academic Search

    Hameed A. Baloch; Antonio DiTommaso; Alan K. Watson

    2001-01-01

    The relationship between seed mass variation and germinability in ten Abutilon theophrasti Medic. plants from a single agricultural population was examined under controlled environmental conditions. Seeds were collected in the autumn of 1995 and dry-stored in paper bags at 4°C until the start of trials in the spring of 1998. For each plant, between 549 and 1000 randomly selected seeds

  10. Breaking seed coat dormancy with physical and chemical methods in tamarind (Tamarindus indica L.) seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tamarind (Tamarindus indica L.) is an important tree crop in Africa and Asia. It is primarily propagated by grafting, which involves the generation of rootstock material. Tamarind seeds have an impermeable seed coat and need scarification for improved germination. In this study, tamarind seeds colle...

  11. MOISTURE, SEED COAT CHARACTERISTICS, AND DISINFECTION OF ARTIFICIALLY INOCULATED ALFALFA SEEDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetable sprouts can be a vehicle for food borne illness. The seeds used for sprouts are considered the probable source of the pathogen contamination. Since naturally contaminated seeds have a very low pathogen level, artificially inoculated seeds are used to test decontamination methods. There a...

  12. A seed predator drives the evolution of a seed dispersal mutualism

    Microsoft Academic Search

    Adam M. Siepielski; Craig W. Benkman

    2008-01-01

    Although antagonists are hypothesized to impede the evolution of mutualisms, they may simultaneously exert selection favouring the evolution of alternative mutualistic interactions. We found that increases in limber pine (Pinus flexilis) seed defences arising from selection exerted by a pre-dispersal seed predator (red squirrel Tamiasciurus hudsonicus) reduced the efficacy of limber pine's primary seed disperser (Clark's nutcracker Nucifraga columbiana) while

  13. Seeding date influence on camelina seed yield, yield components, and oil content in Chile

    Microsoft Academic Search

    Marisol Berti; Rosemarie Wilckens; Susana Fischer; Alejandro Solis; Burton Johnson

    2011-01-01

    Camelina (Camelina sativa L.) was introduced for the first time in Chile in 2008 as a potential feedstock for biodiesel and also as high omega-3-containing seed oil for the salmon feed industry. The objective of this study was to determine the optimum seeding date to maximize camelina seed yield in South Central Chile. The experiment was conducted under dryland conditions

  14. Dispersal of mimetic seeds of three species of Ormosia (Leguminosae)

    USGS Publications Warehouse

    Foster, M.S.; DeLay, L.S.

    1998-01-01

    Seeds with 'imitation arils' appear wholly or partially covered by pulp or aril but actually carry no fleshy material. The mimetic seed hypothesis to explain this phenomenon proposes a parasitic relationship in which birds are deceived into dispersing seeds that resemble bird-dispersed fruits, without receiving a nutrient reward. The hard-seed for grit hypothesis proposes a mutualistic relationship in which large, terrestrial birds swallow the exceptionally hard 'mimetic' seeds as grit for grinding the softer seeds on which they feed. They defecate, dispersing the seeds, and abrade the seed surface, enhancing germination. Any fruit mimicry is incidental. Fruiting trees of Ormosia spp. (Leguminosae: Papilionoideae) were observed to ascertain mechanisms of seed dispersal and the role of seemingly mimetic characteristics of the seeds in that dispersal. Seed predation and seed germination were also examined. Ormosia isthamensis and O. macrocalyx (but not O. bopiensis) deceived arboreally-foraging frugivorous birds into taking their mimetic seeds, although rates of seed dispersal were low. These results are consistent with the mimetic seed hypothesis. On the other hand, the rates of disappearance of seeds from the ground under the Ormosia trees, hardness of the seeds, and enhancement of germination with the abrasion of the seed coat are all consistent with the hard-seed for grit hypothesis.

  15. 7 CFR 1427.165 - Eligible seed cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Eligible seed cotton. 1427.165 Section 1427.165 Agriculture...AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton....

  16. 7 CFR 1427.165 - Eligible seed cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Eligible seed cotton. 1427.165 Section 1427.165 Agriculture...AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton....

  17. 7 CFR 945.7 - Certified seed potatoes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 false Certified seed potatoes. 945.7 Section 945.7 Agriculture...DEPARTMENT OF AGRICULTURE IRISH POTATOES GROWN IN CERTAIN DESIGNATED COUNTIES...Definitions § 945.7 Certified seed potatoes. Certified seed potatoes means...

  18. 7 CFR 945.7 - Certified seed potatoes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 false Certified seed potatoes. 945.7 Section 945.7 Agriculture...DEPARTMENT OF AGRICULTURE IRISH POTATOES GROWN IN CERTAIN DESIGNATED COUNTIES...Definitions § 945.7 Certified seed potatoes. Certified seed potatoes means...

  19. Morphology, physiology and environmental effects of triploid watermelon seed germination

    E-print Network

    Grange, Stacie Lee

    2001-01-01

    -part approach to the problem. First, the morphology of the seed coat was examined. In the morphology section, scanning electron microscopy (SEM) was used to determine the basic structural differences in the seed coat. Seed components characteristics were also...

  20. Morphology, physiology and environmental effects of triploid watermelon seed germination 

    E-print Network

    Grange, Stacie Lee

    2001-01-01

    -part approach to the problem. First, the morphology of the seed coat was examined. In the morphology section, scanning electron microscopy (SEM) was used to determine the basic structural differences in the seed coat. Seed components characteristics were also...

  1. 29 CFR 780.113 - Seeds, spawn, etc.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Labor 3 2013-07-01 2013-07-01 false Seeds, spawn, etc. 780.113 Section 780.113 ...Agricultural Or Horticultural Commodities § 780.113 Seeds, spawn, etc. Seeds and seedlings of agricultural and horticultural...

  2. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Number of seeds for germination. 201.54 Section 201.54 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the...

  3. 7 CFR 810.1801 - Definition of sunflower seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 false Definition of sunflower seed. 810.1801 Section 810.1801 Agriculture...GRAIN United States Standards for Sunflower Seed Terms Defined § 810.1801 Definition of sunflower seed. Grain that, before the removal...

  4. 7 CFR 945.7 - Certified seed potatoes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Certified seed potatoes. 945.7 Section 945.7 Agriculture...Regulating Handling Definitions § 945.7 Certified seed potatoes. Certified seed potatoes means and includes all potatoes...

  5. 7 CFR 810.1801 - Definition of sunflower seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 false Definition of sunflower seed. 810.1801 Section 810.1801 Agriculture...GRAIN United States Standards for Sunflower Seed Terms Defined § 810.1801 Definition of sunflower seed. Grain that, before the removal...

  6. 7 CFR 201.64 - Pure live seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Pure live seed. 201.64 Section 201.64 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.64 Pure...

  7. 29 CFR 780.113 - Seeds, spawn, etc.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Labor 3 2011-07-01 2011-07-01 false Seeds, spawn, etc. 780.113 Section 780.113 ...Agricultural Or Horticultural Commodities § 780.113 Seeds, spawn, etc. Seeds and seedlings of agricultural and horticultural...

  8. 7 CFR 201.64 - Pure live seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Pure live seed. 201.64 Section 201.64 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.64 Pure...

  9. 29 CFR 780.113 - Seeds, spawn, etc.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Labor 3 2014-07-01 2014-07-01 false Seeds, spawn, etc. 780.113 Section 780.113 ...Agricultural Or Horticultural Commodities § 780.113 Seeds, spawn, etc. Seeds and seedlings of agricultural and horticultural...

  10. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Source of seeds for germination. 201.53 Section 201.53 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the...

  11. Intellectual Property over Seeds versus Civil Liberties Birgit Mller

    E-print Network

    Paris-Sud XI, Université de

    Intellectual Property over Seeds versus Civil Liberties Birgit Müller that farmers were unable to seed certain fields. Yet some fields were covered thick with beautiful canola plants, which germinated from the seeds that had fallen

  12. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Number of seeds for germination. 201.54 Section 201.54 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the...

  13. 7 CFR 810.1801 - Definition of sunflower seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 false Definition of sunflower seed. 810.1801 Section 810.1801 Agriculture...GRAIN United States Standards for Sunflower Seed Terms Defined § 810.1801 Definition of sunflower seed. Grain that, before the removal...

  14. 7 CFR 201.49 - Other crop seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Other crop seed. 201.49 Section 201.49 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Purity Analysis in the...

  15. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Source of seeds for germination. 201.53 Section 201.53 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the...

  16. 7 CFR 201.49 - Other crop seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Other crop seed. 201.49 Section 201.49 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Purity Analysis in the...

  17. 7 CFR 945.7 - Certified seed potatoes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Certified seed potatoes. 945.7 Section 945.7 Agriculture...Regulating Handling Definitions § 945.7 Certified seed potatoes. Certified seed potatoes means and includes all potatoes...

  18. 7 CFR 201.49 - Other crop seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Other crop seed. 201.49 Section 201.49 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Purity Analysis in the...

  19. 29 CFR 780.113 - Seeds, spawn, etc.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Labor 3 2012-07-01 2012-07-01 false Seeds, spawn, etc. 780.113 Section 780.113 ...Agricultural Or Horticultural Commodities § 780.113 Seeds, spawn, etc. Seeds and seedlings of agricultural and horticultural...

  20. 7 CFR 201.49 - Other crop seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Other crop seed. 201.49 Section 201.49 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Purity Analysis in the...

  1. 7 CFR 810.1801 - Definition of sunflower seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 false Definition of sunflower seed. 810.1801 Section 810.1801 Agriculture...GRAIN United States Standards for Sunflower Seed Terms Defined § 810.1801 Definition of sunflower seed. Grain that, before the removal...

  2. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Number of seeds for germination. 201.54 Section 201.54 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the...

  3. 29 CFR 780.113 - Seeds, spawn, etc.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Labor 3 2010-07-01 2010-07-01 false Seeds, spawn, etc. 780.113 Section 780.113 ...Agricultural Or Horticultural Commodities § 780.113 Seeds, spawn, etc. Seeds and seedlings of agricultural and horticultural...

  4. 7 CFR 201.64 - Pure live seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Pure live seed. 201.64 Section 201.64 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.64 Pure...

  5. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Number of seeds for germination. 201.54 Section 201.54 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the...

  6. 7 CFR 201.64 - Pure live seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Pure live seed. 201.64 Section 201.64 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.64 Pure...

  7. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Number of seeds for germination. 201.54 Section 201.54 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the...

  8. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Source of seeds for germination. 201.53 Section 201.53 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the...

  9. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Source of seeds for germination. 201.53 Section 201.53 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the...

  10. 7 CFR 810.1801 - Definition of sunflower seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 false Definition of sunflower seed. 810.1801 Section 810.1801 Agriculture...GRAIN United States Standards for Sunflower Seed Terms Defined § 810.1801 Definition of sunflower seed. Grain that, before the removal...

  11. 7 CFR 945.7 - Certified seed potatoes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Certified seed potatoes. 945.7 Section 945.7 Agriculture...Regulating Handling Definitions § 945.7 Certified seed potatoes. Certified seed potatoes means and includes all potatoes...

  12. 7 CFR 201.64 - Pure live seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Pure live seed. 201.64 Section 201.64 Agriculture Regulations...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.64 Pure...

  13. The California Seed Industry: A Measure of Economic Activity and

    E-print Network

    Ferrara, Katherine W.

    The California Seed Industry: A Measure of Economic Activity and Contribution of California Agricultural Issues Center. #12; The California Seed Industry: A Measure of Economic Activity and Contribution to California Agriculture Executive Summary Seed industry activities have been

  14. SEED PHYSIOLOGY, PRODUCTION & TECHNOLOGY Fusarium graminearum Infection during Wheat Seed Development and Its Effect on Seed Quality

    Microsoft Academic Search

    Jason Argyris; David Van Sanford; Dennis TeKrony

    and germination (Bechtel et al., 1985). Infected seed is often contaminated with DON, a mycotoxin produced Fusarium head blight (FHB) caused by Fusarium graminearum by F. graminearum. Contamination of grain with DON Schwabe causes losses in wheat (Triticum aestivum L.) seed quality has been significantly correlated with SI (Snijders and and yield. Field studies were conducted in 2000 and 2001

  15. Sterols in pumpkin seed oil

    Microsoft Academic Search

    M. Basti?; Lj. Basti?; J. A. Jovanovi?; G. Spiteller

    1977-01-01

    and summary  The sterol fraction of unsaponifiable matter obtained from a Yugoslav pumpkin seed ripening was investigated by gas liquid\\u000a chromatography on a glass capillary column. It contained at least 14 different sterols ten of which were identified primarily\\u000a by combined gas chromatography-mass spectrometry as cholesterol, brassicasterol, campesterol, stigmasterol, 24-methylcholest-7-en-3?-ol,\\u000a ?7,22,25-stimastatrien-3?-ol, ?-spinasterol, ?7,25-stigmastadien-3?-ol, ?7,25-stigmastenol, and ?7-avenasterol. It was shown that the

  16. Lectins from Griffonia simplicifolia seeds

    Microsoft Academic Search

    Irwin J. Goldstein

    1983-01-01

    The physical-chemical and carbohydrate binding specificity ofGriffonia simplicifolia I (GS I) isolectins, one of the 4 lectins isolated fromGriffonia simplicifolia seeds, are described.\\u000a \\u000a Association constants for the binding of methyl ?- and ?-D-galactopyranoside and methyl 2-acetamido-2-deoxy-?-D-galactopyranoside\\u000a to the A4, A2 B2 and B4 isolectins are reported.\\u000a \\u000a \\u000a \\u000a Precipitation reactions of theGriffonia simplicifolia isolectins with guaran and type B blood group substance

  17. Seed Anatomy and Water Uptake in Relation to Seed Dormancy in Opuntia tomentosa (Cactaceae, Opuntioideae)

    PubMed Central

    Orozco-Segovia, A.; Márquez-Guzmán, J.; Sánchez-Coronado, M. E.; Gamboa de Buen, A.; Baskin, J. M.; Baskin, C. C.

    2007-01-01

    Background and Aims There is considerable confusion in the literature concerning impermeability of seeds with ‘hard’ seed coats, because the ability to take up (imbibe) water has not been tested in most of them. Seeds of Opuntia tomentosa were reported recently to have a water-impermeable seed coat sensu lato (i.e. physical dormancy), in combination with physiological dormancy. However, physical dormancy is not known to occur in Cactaceae. Therefore, the aim of this study was to determine if seeds of O. tomentosa are water-permeable or water-impermeable, i.e. if they have physical dormancy. Methods The micromorphology of the seed coat and associated structures were characterized by SEM and light microscopy. Permeability of the seed-covering layers was assessed by an increase in mass of seeds on a wet substrate and by dye-tracking and uptake of tritiated water by intact versus scarified seeds. Key Results A germination valve and a water channel are formed in the hilum–micropyle region during dehydration and ageing in seeds of O. tomentosa. The funicular envelope undoubtedly plays a role in germination of Opuntia seeds via restriction of water uptake and mechanical resistance to expansion of the embryo. However, seeds do not exhibit any of three features characteristic of those with physical dormancy. Thus, they do not have a water-impermeable layer(s) of palisade cells (macrosclereids) or a water gap sensu stricto and they imbibe water without the seed coat being disrupted. Conclusions Although dormancy in seeds of this species can be broken by scarification, they have physiological dormancy only. Further, based on information in the literature, it is concluded that it is unlikely that any species of Opuntia has physical dormancy. This is the first integrative study of the anatomy, dynamics of water uptake and dormancy in seeds of Cactaceae subfamily Opuntioideae. PMID:17298989

  18. Modeling and analysis of a density-dependent stochastic integral projection model for a disturbance specialist plant and its seed bank.

    PubMed

    Eager, Eric Alan; Rebarber, Richard; Tenhumberg, Brigitte

    2014-07-01

    In many plant species dormant seeds can persist in the soil for one to several years. The formation of these seed banks is especially important for disturbance specialist plants, as seeds of these species germinate only in disturbed soil. Seed movement caused by disturbances affects the survival and germination probability of seeds in the seed bank, which subsequently affect population dynamics. In this paper, we develop a stochastic integral projection model for a general disturbance specialist plant-seed bank population that takes into account both the frequency and intensity of random disturbances, as well as vertical seed movement and density-dependent seedling establishment. We show that the probability measures associated with the plant-seed bank population converge weakly to a unique measure, independent of initial population. We also show that the population either persists with probability one or goes extinct with probability one, and provides a sharp criteria for this dichotomy. We apply our results to an example motivated by wild sunflower (Helianthus annuus) populations, and explore how the presence or absence of a "storage effect" impacts how a population responds to different disturbance scenarios. PMID:24916367

  19. Wheat and barley seed systems in Ethiopia and Syria

    Microsoft Academic Search

    Z. Bishaw

    2004-01-01

    Keywords: Wheat,Triticum<\\/span>spp<\\/span>., Barley,Hordeum<\\/span>vulgare<\\/span> L., Seed Systems, Formal Seed Sector, Informal Seed Sector, National Seed Program, Seed Source, Seed Selection, Seed Management, Seed Quality, Genetic Diversity, Ethiopia, Syria<\\/o:p><\\/ins><\\/span><\\/span>

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  1. Polysaccharides from seeds of Strychnos species.

    PubMed

    Corsaro, M M; Giudicianni, I; Lanzetta, R; Marciano, C E; Monaco, P; Parrilli, M

    1995-08-01

    The chemical composition of polysaccharide fractions from Strychnos nux-vomica and S. innocua seeds and comparison with those from S. potatorum seeds are reported. The structural features of the galactomannans from the three Strychnos species are also discussed. PMID:7669279

  2. Elastohydrodynamic (EHD) traction properties of seed oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The elastohydrodynamic traction coefficient (tc) properties of nine seed oils of varying chemical structures, PAO and hexadecane, were investigated using a ball-on disk traction apparatus. The seed oils were: castor oil, a triglyceride with hydroxyl functional group; jojoba, a monoglyceride; and sev...

  3. Elastohydrodynamic Traction Properties of Seed Oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The elastohydrodynamic traction coefficient (tc) properties of nine seed oils of varying chemical structures, PAO and hexadecane, were investigated using a ball-on disk traction apparatus. The seed oils were: castor oil, a triglyceride with hydroxyl functional group; jojoba, a monoglyceride; and s...

  4. Variation for seed phytosterols in sunflower germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sunflower (Helianthus annuus L.) seeds and oils are rich sources of phytosterols, which are important compounds for human nutrition. There is limited information on variability for seed phytosterols in sunflower germplasm. The objective of the present research was to evaluate kernel phytosterol cont...

  5. The Seed Concepts Constraint in Code Switching.

    ERIC Educational Resources Information Center

    Naval, Uday C.

    1989-01-01

    Discusses the seed concepts constraint (SCC) principle, which suggests that the seed concepts in the intrasententially code-switched speech of the bilingual are marked in the phonetics of the first language in contradistinction to the second language. It is suggested that the SCC suffices to replace various particularistic grammatical claims…

  6. Formative Assessment Probes: Needs of Seeds

    NSDL National Science Digital Library

    Page Keeley

    2011-02-01

    The "Needs of Seeds" formative assessment probe can be used to find out whether students recognize that seeds have needs both similar to and different from plants and other living organisms (Keeley, Eberle, and Tugel 2007). The probe reveals whether stude

  7. Antidiabetic oligocyclitols in seeds of Mucuna pruriens.

    PubMed

    Donati, Donato; Lampariello, Lucia Raffaella; Pagani, Roberto; Guerranti, Roberto; Cinci, Giuliano; Marinello, Enrico

    2005-12-01

    Using a combination of chromatographic and NMR techniques, the presence of D-chiro-inositol and its two galacto-derivatives is demonstrated in Mucuna pruriens seeds. The quantities detected explain the well-established antiglycaemic effect of Mucuna pruriens seeds. PMID:16372373

  8. SELECTION OF METHIONINE-ENRICHED SOYBEAN SEEDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The nutritional quality of soybeans is limited by low levels of methionine. Methionine overproducing soybeans were developed by mutagenizing soybean seeds and selecting either for resistance to ethionine or for dark green foliage characteristic of methionine over-producing plants. Seeds from the m...

  9. Genetics of seed dormancy in Papaver rhoeas

    Microsoft Academic Search

    M J Lawrence

    1995-01-01

    Seed dormancy in a cross between wild Papaver rhoeas and its ‘Shirley’ cultivar appeared to be controlled by genes that displayed additive effects, dominance in the direction of low dormancy and non-allelic interaction of the duplicate type; in addition, there was a small maternal dominance effect in the direction of high dormancy. The genetics of seed dormancy in this cross

  10. Statistical Evaluation of Cloud Seeding Operations

    Microsoft Academic Search

    K. A. Brownlee

    1960-01-01

    Modern commercial cloud seeding dates from the discovery in 1946 that silver iodide crystals are good nuclei for the formation of precipitation from cold clouds. Whether silver iodide seeding does actually increase the precipitation over what would occur naturally has been a controversial question.In 1953 Congress established the Advisory Committee on Weather Control, one of its responsibilities being to determine

  11. Seed predation in the legume Crotalaria

    Microsoft Academic Search

    L. R. Moore

    1978-01-01

    In order to evaluate the role of seed predators as selective agents within a population of conspecific plants, the intensity of predispersal seed predation by chewing insects and the variation in predation intensity with individual and season were measured for the legume shrub Crotalaria pallida. In a native, tropical (East African) population, predation intensity averaged 49% for late dry season—early

  12. Abscisic Acid Levels and Seed Dormancy

    PubMed Central

    Sondheimer, E.; Tzou, D. S.; Galson, Eva C.

    1968-01-01

    Dormant seeds from Fraxinus species require cold-temperature after-ripening prior to germination. Earlier, we found that abscisic acid (ABA) will inhibit germination of excised nondormant embryos and that this can be reversed with a combination of gibberellic acid and kinetin. Using Milborrow's quantitative “racemate dilution” method the ABA concentration in 3 types of Fraxinus seed and pericarp were determined. While ABA was present in all tissues, the highest concentration was found in the seed and pericarp of dormant F. americana. During the chilling treatment of F. americana the ABA levels decreased 37% in the pericarp and 68% in the seed. The ABA concentration of the seed of the nondormant species, F. ornus, is as low as that found in F. americana seeds after cold treatment. Experiments with exogenously added ABA solutions indicate that it is unlikely that the ABA in the pericarp functions in the regulation of seed dormancy. However, the ABA in the seed does seem to have a regulatory role in germination. Images PMID:16656935

  13. Request for Applications: Biomedical Research Seed Grants

    E-print Network

    Farritor, Shane

    Page | 1 Request for Applications: Biomedical Research Seed Grants Office of Research of the Biomedical Research Seed Grants program is to enhance the competitiveness of University of Nebraska-Lincoln (UNL) faculty submitting grant proposals requesting biomedical research funding from the National

  14. Organic acids as seed germination inhibitors

    Microsoft Academic Search

    A. Saviozzi; R. Riffaldi

    1994-01-01

    Phytotoxicity of aromatic and aliphatic acids was tested by a wheat seed bioassay. Wheat seed germination was found to be influenced by the number of hydroxy and methoxy groups, the molecular position of single and double hydroxy groups, the length of the aliphatic chain, as well as by the pKa of the acid solutions. Orto and meta coumaric, ferulic and

  15. Seed Dormancy Mechanisms in Vegetable Crop Species

    Microsoft Academic Search

    Mark A. Bennett; Andrew F. Evans

    Seed dormancy is a physical or physiological condition of a viable seed which prevents germination even in the presence of otherwise favorable conditions for germination. This paper will review the types of dormancy observed for various vegetable crop species, and the methods available for dormancy breaking.

  16. [Linoleic acid synthesis in oleaginous seeds].

    PubMed

    Cherif, A

    1981-01-01

    Fats are synthetized in oleaginous seeds according to the following diagram: lipid synthesis, very slow immediately after fecundation, becomes very intensive between the second and the fifth weeks after florescence and is reduced to zero at the end of maturation. The desaturating activity of ammonium oleate is important in the first stages of development of the seeds. PMID:7316620

  17. Puncturevine seed response to postemergence herbicides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Puncturevine (Tribulus terrestris) continues to plague growers, vegetation managers, and home gardeners. Puncturevine is a summer annual weed with spiny fruits that split into five segments, each containing one to four seeds. The seed nearest the pointed end of the bur is the largest and usually ge...

  18. Grass Seed Structure and Seedling Emergence

    NSDL National Science Digital Library

    This activity discusses both seed structure and seedling emergence in monocots. Through active learning elements, photos and text students will discover the basic anatomy of seeds and the function of each structure. The process of seedling emergence is presented in detail including the difference between emergence in cool-season and warm-season grasses.

  19. FAMILY GUIDE FOR FRUITS AND SEEDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The accurate, scientific identification of all fruits and seeds is essential to assure the quality control of many agricultural products and to prevent the movement of weeds and invasive plant species. This database includes the 418 seed-plant families accepted by GRIN. There are 328 characters reco...

  20. Seed Development in Lesquerellar fendleri (L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The morphological, physiological and biochemical changes during seed development of Lesquerella fendleri was investigated from 7 days after pollination (DAP) to desiccation. The entire course of seed development lasted about 49 days and it can be divided to seven continuous stages (I to VII). During...

  1. Fungal endophytes in green coffee seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Green coffee seeds from Colombia, Guatemala, India, Kenya, Papua New Guinea, Puerto Rico, and Vietnam were sampled for the presence of fungal endophytes. Sections of surface sterilized seeds were plated on yeast malt agar, and fungal growth was isolated for subsequent DNA extraction and sequencing....

  2. Wildfire, Ryegrass Seeding, and Watershed Rehabilitation1

    E-print Network

    Standiford, Richard B.

    Wildfire, Ryegrass Seeding, and Watershed Rehabilitation1 R. D. Taskey, C.L. Curtis, and J. Stone2, emergency rehabilitation practice following wildfire in California. Replicated study plots on unseeded plots. These results suggest that ryegrass seeding for emergency rehabilitation of burned areas

  3. Molecular regulation of seed and fruit set.

    PubMed

    Ruan, Yong-Ling; Patrick, John W; Bouzayen, Mondher; Osorio, Sonia; Fernie, Alisdair R

    2012-11-01

    Seed and fruit set are established during and soon after fertilization and determine seed and fruit number, their final size and, hence, yield potential. These processes are highly sensitive to biotic and abiotic stresses, which often lead to seed and fruit abortion. Here, we review the regulation of assimilate partitioning, including the potential roles of recently identified sucrose efflux transporters in seed and fruit set and examine the similarities of sucrose import and hydrolysis for both pollen and ovary sinks, and similar causes of abortion. We also discuss the molecular origins of parthenocarpy and the central roles of auxins and gibberellins in fruit set. The recently completed strawberry (Fragaria vesca) and tomato (Solanum lycopersicum) genomes have added to the existing crop databases, and new models are starting to be used in fruit and seed set studies. PMID:22776090

  4. Genotyping of Endosperms to Determine Seed Dormancy Genes Regulating Germination Through Embryonic, Endospermic, or Maternal Tissues in Rice

    PubMed Central

    Gu, Xing-You; Zhang, Jinfeng; Ye, Heng; Zhang, Lihua; Feng, Jiuhuan

    2014-01-01

    Seed dormancy is imposed by one or more of the embryo, endosperm, and maternal tissues that belong to two generations and represent two ploidy levels. Many quantitative trait loci (QTL) have been identified for seed dormancy as measured by gross effects on reduced germination rate or delayed germination in crop or model plants. This research developed an endosperm genotype?based genetic approach to determine specific tissues through which a mapped QTL regulates germination using rice as a model. This approach involves testing germination velocity for partially after-ripened seeds harvested from single plants heterozygous for a tested QTL and genotyping endosperms from individual germinated and nongerminated seeds with a codominant DNA marker located on the QTL peak region. Information collected about the QTL includes genotypic frequencies in germinated and/or nongerminated subpopulations; allelic frequency distributions during a germination period; endosperm or embryo genotypic differences in germination velocity; and genotypic frequencies for gametes involved in the double fertilization to form the sampled seeds. Using this approach, the seed dormancy loci SD12, SD1-2, and SD7-1 were determined to regulate germination through the embryo, endosperm, and maternal tissues, respectively; SD12 and SD1-2 acted additively on germination velocity in the offspring tissues; and SD12 also was associated with the preferential fertilization of male gametes in rice. This new genetic approach can be used to characterize mapped genes/QTL for tissue-specific functions in endospermic seeds and for marker-assisted selection of QTL alleles before or immediately after germination in crop breeding. PMID:25480961

  5. Triple Modulator-Chicane Scheme for Seeding Sub-Nanometer X-Ray Free Electron Lasers

    SciTech Connect

    Xiang, Dao; Stupakov, Gennady; /SLAC

    2011-07-06

    We propose a novel triple modulator-chicane (TMC) scheme to convert external input seed to shorter wavelengths. In the scheme high power seed lasers are used in the first and third modulator while only very low power seed is used in the second modulator. By properly choosing the parameters of the lasers and chicanes, we show that ultrahigh harmonics can be generated in the TMC scheme while simultaneously keeping the energy spread growth much smaller than beam's initial slice energy spread. As an example we show the feasibility of generating significant bunching at 1 nm and below from a low power ({approx} 100 kW) high harmonic generation seed at 20 nm assisted by two high power ({approx} 100 MW) UV lasers at 200 nm while keeping the energy spread growth within 40%. The supreme up-frequency conversion efficiency of the proposed TMC scheme together with its unique advantage in maintaining beam energy spread opens new opportunities for generating fully coherent x-rays at sub-nanometer wavelength from external seeds.

  6. Frequency Measurement & Analysis Service

    E-print Network

    Magee, Joseph W.

    NIST Frequency Measurement & Analysis Service #12;A Complete Solution To All Frequency Measurement & Calibration Problems The NIST Frequency Measurement and Analysis Service makes it easy to measure and calibrate any quartz, rubidium, or cesium frequency standard. All measurements are made automatically

  7. Competition between meiotic and apomictic pathways during ovule and seed development results in clonality.

    PubMed

    Hojsgaard, Diego H; Martínez, Eric J; Quarin, Camilo L

    2013-01-01

    Meiotic and apomictic reproductive pathways develop simultaneously in facultative aposporous species, and compete to form a seed as a final goal. This developmental competition was evaluated in tetraploid genotypes of Paspalum malacophyllum in order to understand the low level of sexuality in facultative apomictic populations. Cyto-embryology on ovules, flow cytometry on seeds and progeny tests by DNA fingerprinting were used to measure the relative incidence of each meiotic or apomictic pathway along four different stages of the plant's life cycle, namely the beginning and end of gametogenesis, seed formation and adult offspring. A high variation in the frequencies of sexual and apomictic pathways occurred at the first two stages. A trend of radical decline in realized sexuality was then observed. Sexual and apomictic seeds were produced, but the efficiency of the sexual pathway dropped drastically, and exclusively clonal offspring remained. Both reproductive pathways are unstable at the beginning of development, and only the apomictic one remains functional. Key factors reducing sexuality are the faster growth and parthenogenetic development in the aposporous pathway, and an (epi)genetically negative background related to the extensive gene de-regulation pattern responsible for apomixis. The effects of inbreeding depression during post-fertilization development may further decrease the frequency of effective sexuality. PMID:23127139

  8. Effects of prolonged exposure of lettuce seeds to HZE particles on orbital stations

    NASA Astrophysics Data System (ADS)

    Nevzgodina, L. V.; Maksimova, E. N.; Kaminskaya, E. V.

    In a study of the biological effects of cosmic HZE particles, lettuce (Lactuca sativa) seeds were flown on the orbital stations Salyut 6 and 7 for varying periods of time (from 40 to 457 days). The dependence of the biological damage on flight duration, physical parameters and the fact of passage of an HZE particle through the seed was estimated using the criterion of the frequency of aberrant cells. The arrangement of the flight biological container Biobloc made it possible to trace the location of tracks of individual HZE particles with Z>=6 and LET 200 keV/um. In seeds hit by HZE particles, for all exposure times, a statistically significant much higher yield of aberrant cells and also of cells containing multiple chromosome aberrations was observed than in the control material. The frequency of aberrant cells is markedly higher (by a factor of 1,5) in seeds hit than in non-hit ones. The changes of the yield of aberrant cells as a function of the absorbed dose (3.2-63.4 mGy) and the fluence (4.8-44.2 particles/cm2) are linear for the exposure duration ranging from 40 to 457 days.

  9. The functional evaluation of waste yuzu (Citrus junos) seeds.

    PubMed

    Minamisawa, Mayumi; Yoshida, Shoichiro; Uzawa, Atsushi

    2014-02-01

    We have succeeded in extracting a large amount of expensive limonoids and the high total antioxidant capability yuzu seed oil from waste yuzu seed by simple methods. Yuzu seeds contain higher amounts of fat-soluble limonoid aglycone (330.6 mg g(-1) of dry seed), water-soluble limonoid glycoside (452.0 mg g(-1) of dry seed), and oil (40 mg g(-1) of green seed) than other citrus fruits. The antioxidant activities of yuzu seed aglycone, glycoside, and seed oil were evaluated in vitro. The potential antioxidant activity in oil solution, diphenylpicrylhydrazyl radical-scavenging activity, and hydrogen peroxide-scavenging activity effects of the seed extracts were also investigated. The antioxidant activity of yuzu seed oil was two times that of grapefruit seed oil, which has high activity. Yuzu glycoside produced the same high antioxidant activity as Luo Han Guo glycoside. PMID:24336775

  10. Using a linearly chirped seed suppresses SBS in high-power fiber amplifiers, allows coherent combination, and enables long delivery fibers

    NASA Astrophysics Data System (ADS)

    White, Jeffrey O.; Petersen, Eliot; Edgecumbe, J.; Rakuljic, George; Satyan, Naresh; Vasilyev, Arseny; Yariv, A.

    2014-03-01

    When seeding a high power fiber amplifier with a frequency-chirped seed, the backward Brillouin scattering can be kept at the spontaneous level because the coherent laser/Stokes interaction is interrupted. Operating a conventional vertical cavity surface-emitting diode laser in an optoelectronic feedback loop can yield a linear frequency chirp of ~1016 Hz/s at a constant output power. The simple and deterministic variation of phase with time preserves temporal coherence, in the sense that it is straightforward to coherently combine multiple amplifiers despite a large length mismatch. The seed bandwidth as seen by the counter-propagating SBS is large, and also increases linearly with fiber length, resulting in a nearly-length-independent SBS threshold. Experimental results at the 600W level will be presented. The impact of a chirped seed on multimode instability is also addressed theoretically.

  11. Physical dormancy in seeds: a game of hide and seek?

    PubMed

    Paulsen, Torbjørn Rage; Colville, Louise; Kranner, Ilse; Daws, Matthew I; Högstedt, Göran; Vandvik, Vigdis; Thompson, Ken

    2013-04-01

    Historically, 'physical dormancy', or 'hard seededness', where seeds are prevented from germinating by a water-impermeable seed coat, is viewed as a dormancy mechanism. However, upon water uptake, resumption of metabolism leads to the unavoidable release of volatile by-products, olfactory cues that are perceived by seed predators. Here, we examine the hypothesis that hard seeds are an anti-predator trait that evolved in response to powerful selection by small mammal seed predators. Seeds of two legume species with dimorphic seeds ('hard' and 'soft'), Robinia pseudoacacia and Vicia sativa, were offered to desert hamsters (Phodopus roborovskii) in a series of seed removal studies examining the differences in seed harvest between hard and soft seeds. Volatile compounds emitted by dry and imbibed soft seeds were identified by headspace gas chromatography-mass spectrometry (GC-MS). Fourteen main volatile compounds were identified, and hamsters readily detected both buried imbibed seeds and an artificial 'volatile cocktail' that mimicked the scent of imbibed seeds, but could not detect buried hard or dry soft seeds. We argue that physical dormancy has evolved to hide seeds from mammalian predators. This hypothesis also helps to explain some otherwise puzzling features of hard seeds and has implications for seed dispersal. PMID:23421728

  12. Do seed mass and family affect germination and juvenile performance in Knautia arvensis? A study using failure-time methods

    NASA Astrophysics Data System (ADS)

    Vange, Vibekke; Heuch, Ivar; Vandvik, Vigdis

    2004-05-01

    Germination and seedling establishment are vulnerable stages in the plant life cycle. We investigated how seed mass and family (progeny origin) affect germination and juvenile performance in the grassland herb Knautia arvensis. Seeds were produced by cross-pollination by hand. The fate of 15 individually weighed seeds from each of 15 plants was followed during a 3-month growth chamber experiment. Progeny origin affected germination, both through seed mass and as an independent factor. Two groups of progenies could be distinguished by having rapid or delayed germination. The two groups had similar mean seed masses, but a positive relationship between seed mass and germination rate could be established only among the rapidly germinating progenies. These biologically relevant patterns were revealed because timing of germination was taken into account in the analyses, not only frequencies. Time-to-event data were analysed with failure-time methods, which gave more stable estimates for the relation between germination and seed mass than the commonly applied logistic regression. Progeny origin and seed mass exerted less impact on later characters like juvenile survival, juvenile biomass, and rosette number. These characters were not affected by the timing of germination under the competition-free study conditions. The decrease in the effect of progeny origin from the seed and germination to the juvenile stages suggests that parental effects other than those contributing to the offspring genotype strongly influenced the offspring phenotype at the earliest life stages. Further, the division of progeny germination patterns into two fairly distinct groups indicates that there was a genetic basis for the variation in stratification requirements among parental plants. Field studies are needed to elucidate effects of different timing of germination in the seasonal grasslands that K. arvensis inhabits.

  13. Seed supply, recruitment, and assembly: quantifying relative seed and establishment limitation in a plant community context.

    PubMed

    Aicher, Rebecca J; Larios, Loralee; Suding, Katharine N

    2011-10-01

    There is a growing consensus that the relative constraints of seed limitation and establishment limitation in recruitment strongly influence abundance patterns in plant communities. Although these constraints have direct relevance to coexistence, most investigations utilize a seed addition approach that offers limited insight into these dynamics. Here we report the results of an assembly experiment with annual plant species from California grasslands to examine how propagule pool characteristics (dominant species abundance, functional diversity) influence establishment and seed limitation (density independence and density dependence across a gradient of seed supply) for each species, as well as how these constraints affect community diversity. Species were predominantly colimited by seed and establishment constraints, exhibiting saturating recruitment functions with increased seed supply. Consistent with competition-colonization trade-off predictions, recruitment constraints often depended on the degree of seed limitation of the competitive dominant, Brassica nigra; diversity was greatest in communities where Brassica was seed limited. Functional similarity within the propagule pool did not affect recruitment across a range of seed supply; likewise, functional diversity of the propagule pool was not related to community diversity. We conclude that seed limitation of the dominant species rather than niche similarity influences interspecific competition for safe sites and scales up to affect community-level diversity. PMID:21956025

  14. A seed predator drives the evolution of a seed dispersal mutualism.

    PubMed

    Siepielski, Adam M; Benkman, Craig W

    2008-08-22

    Although antagonists are hypothesized to impede the evolution of mutualisms, they may simultaneously exert selection favouring the evolution of alternative mutualistic interactions. We found that increases in limber pine (Pinus flexilis) seed defences arising from selection exerted by a pre-dispersal seed predator (red squirrel Tamiasciurus hudsonicus) reduced the efficacy of limber pine's primary seed disperser (Clark's nutcracker Nucifraga columbiana) while enhancing seed dispersal by ground-foraging scatter-hoarding rodents (Peromyscus). Thus, there is a shift from relying on primary seed dispersal by birds in areas without red squirrels, to an increasing reliance on secondary seed dispersal by scatter-hoarding rodents in areas with red squirrels. Seed predators can therefore drive the evolution of seed defences, which in turn favour alternative seed dispersal mutualisms that lead to major changes in the mode of seed dispersal. Given that adaptive evolution in response to antagonists frequently impedes one kind of mutualistic interaction, the evolution of alternative mutualistic interactions may be a common by-product. PMID:18460433

  15. A seed predator drives the evolution of a seed dispersal mutualism

    PubMed Central

    Siepielski, Adam M; Benkman, Craig W

    2008-01-01

    Although antagonists are hypothesized to impede the evolution of mutualisms, they may simultaneously exert selection favouring the evolution of alternative mutualistic interactions. We found that increases in limber pine (Pinus flexilis) seed defences arising from selection exerted by a pre-dispersal seed predator (red squirrel Tamiasciurus hudsonicus) reduced the efficacy of limber pine's primary seed disperser (Clark's nutcracker Nucifraga columbiana) while enhancing seed dispersal by ground-foraging scatter-hoarding rodents (Peromyscus). Thus, there is a shift from relying on primary seed dispersal by birds in areas without red squirrels, to an increasing reliance on secondary seed dispersal by scatter-hoarding rodents in areas with red squirrels. Seed predators can therefore drive the evolution of seed defences, which in turn favour alternative seed dispersal mutualisms that lead to major changes in the mode of seed dispersal. Given that adaptive evolution in response to antagonists frequently impedes one kind of mutualistic interaction, the evolution of alternative mutualistic interactions may be a common by-product. PMID:18460433

  16. Cell cycle control and seed development

    PubMed Central

    Dante, Ricardo A.; Larkins, Brian A.; Sabelli, Paolo A.

    2014-01-01

    Seed development is a complex process that requires coordinated integration of many genetic, metabolic, and physiological pathways and environmental cues. Different cell cycle types, such as asymmetric cell division, acytokinetic mitosis, mitotic cell division, and endoreduplication, frequently occur in sequential yet overlapping manner during the development of the embryo and the endosperm, seed structures that are both products of double fertilization. Asymmetric cell divisions in the embryo generate polarized daughter cells with different cell fates. While nuclear and cell division cycles play a key role in determining final seed cell numbers, endoreduplication is often associated with processes such as cell enlargement and accumulation of storage metabolites that underlie cell differentiation and growth of the different seed compartments. This review focuses on recent advances in our understanding of different cell cycle mechanisms operating during seed development and their impact on the growth, development, and function of seed tissues. Particularly, the roles of core cell cycle regulators, such as cyclin-dependent-kinases and their inhibitors, the Retinoblastoma-Related/E2F pathway and the proteasome-ubiquitin system, are discussed in the contexts of different cell cycle types that characterize seed development. The contributions of nuclear and cellular proliferative cycles and endoreduplication to cereal endosperm development are also discussed. PMID:25295050

  17. Oxygen requirement of germinating flax seeds.

    PubMed

    Kuznetsov, Oleg A; Hasenstein, K H

    2003-01-01

    Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume=14 mL) and after 36 h measured the root length. At 90 microliters O2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O2 we determined the lower limit of reliable germination to be 10 vol. % O2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination. PMID:14686434

  18. Studies in Wild Oat Seed Dormancy

    PubMed Central

    Adkins, Stephen W.; Ross, James D.

    1981-01-01

    Seed of Avena fatua were shown to exhibit a characteristic loss of dormancy during dry storage at 25 C, whereas similar seed stored at 5 C maintained dormancy. 2-Chloroethylphosphonic acid was shown to increase germination of partly dormant seed imbibed under certain temperature regimes; a similar effect could not be established for fully dormant or fully nondormant seed. Using gas-liquid chromatography, natural ethylene levels were followed during imbibition of fully dormant and nondormant seed. A large peak in production was observed in the period prior to radicle emergence in the case of the nondormant seed. Measurements of ethylene production taken at 15 C, following periods of after-ripening in moist soil at either 5 or 25 C, indicated that endogenous production was unlikely to be a main cause of dormancy breakage in this species. The possibility that endogenous ethylene could play a role in natural dormancy breakage in aged seeds is discussed. The practical possibilities of 2-chloroethylphosphonic acid as a dormancy breaking agent in a field situation are outlined. PMID:16661675

  19. Oxygen requirement of germinating flax seeds

    NASA Technical Reports Server (NTRS)

    Kuznetsov, Oleg A.; Hasenstein, K. H.; Hasentein, K. H. (Principal Investigator)

    2003-01-01

    Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume=14 mL) and after 36 h measured the root length. At 90 microliters O2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O2 we determined the lower limit of reliable germination to be 10 vol. % O2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination. c2003 Published by Elsevier Ltd on behalf of COSPAR.

  20. Oxygen requirement of germinating flax seeds

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Oleg A.; Hasenstein, K. H.

    2003-05-01

    Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax ( Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume = 14 mL) and after 36 h measured the root length. At 90 ?l O 2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O 2 we determined the lower limit of reliable germination to be 10 vol. % O 2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination.

  1. 38 High Frequency Electronics High Frequency Design

    E-print Network

    Popovic, Zoya

    38 High Frequency Electronics High Frequency Design RF POWER AMPLIFIERS RF and Microwave Power, and predistortion. 8a. FEEDBACK Feedback linearization can be applied either directly around the RF amplifier (RF the amplifier is fed back to, and subtracted from, the RF-input signal without detection or down- conversion

  2. SUPERMASSIVE SEEDS FOR SUPERMASSIVE BLACK HOLES

    SciTech Connect

    Johnson, Jarrett L.; Whalen, Daniel J.; Li Hui [Nuclear and Particle Physics, Astrophysics and Cosmology Group (T-2), Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Holz, Daniel E., E-mail: jlj@lanl.gov [Enrico Fermi Institute, Department of Physics, and Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States)

    2013-07-10

    Recent observations of quasars powered by supermassive black holes (SMBHs) out to z {approx}> 7 constrain both the initial seed masses and the growth of the most massive black holes (BHs) in the early universe. Here we elucidate the implications of the radiative feedback from early generations of stars and from BH accretion for popular models for the formation and growth of seed BHs. We show that by properly accounting for (1) the limited role of mergers in growing seed BHs as inferred from cosmological simulations of early star formation and radiative feedback, (2) the sub-Eddington accretion rates of BHs expected at the earliest times, and (3) the large radiative efficiencies {epsilon} of the most massive BHs inferred from observations of active galactic nuclei at high redshift ({epsilon} {approx}> 0.1), we are led to the conclusion that the initial BH seeds may have been as massive as {approx}> 10{sup 5} M{sub Sun }. This presents a strong challenge to the Population III seed model, which calls for seed masses of {approx}100 M{sub Sun} and, even with constant Eddington-limited accretion, requires {epsilon} {approx}< 0.09 to explain the highest-z SMBHs in today's standard {Lambda}CDM cosmological model. It is, however, consistent with the prediction of the direct collapse scenario of SMBH seed formation, in which a supermassive primordial star forms in a region of the universe with a high molecule-dissociating background radiation field, and collapses directly into a 10{sup 4}-10{sup 6} M{sub Sun} seed BH. These results corroborate recent cosmological simulations and observational campaigns which suggest that these massive BHs were the seeds of a large fraction of the SMBHs residing in the centers of galaxies today.

  3. Localization of seed protein genes on metaphase chromosomes of Vicia faba via fluorescence in situ hybridization

    Microsoft Academic Search

    J. Fuchs; I. Schubert

    1995-01-01

    Using fluorescencein situ hybridization (FISH), four different seed protein genes were physically mapped on metaphase chromosomes ofVicia faba L. dropped on slides. FISH with a 2.8 kb genomic probe of a legumin B4 gene resulted in reproducible signals on the long arm of chromosome III near the centromere. The same clone cross-hybridized at a lower frequency to the short arm

  4. Low Distortion Multicasting of an Analog Signal by Self-Seeded Parametric Mixer

    Microsoft Academic Search

    Camille-Sophie Brès; Andreas O. J. Wiberg; B. P.-P. Kuo; E. Myslivets; N. Alic; B. Stossel; S. Radic

    2010-01-01

    We present a linear multicast of an analog signal in a two-pump self-seeded parametric device. The linearity of the parametric multicasting is assessed by two-tone measurements of the third-order intermodulation products and radio-frequency spectral analysis. Experimental results show the linear behavior of a four-photon mixer over a wide range of input signal power.

  5. High-frequency transformation of Arabidopsis thaliana by Agrobacterium tumefaciens

    Microsoft Academic Search

    Michael C. Clarke; Wenbin Wei; Keith Lindsey

    1992-01-01

    Incorporation of 5 mg\\/L silver thiosulphate into media for seed germination and callus induction, as used in the transformation\\u000a protocol originally described by Valvekens et al. (1988), was found to increase the frequency of regeneration of transformants\\u000a ofArabidopsis thaliana ecotypes C24 and Landsbergerecta by at least 10- to 100-fold. Other factors, such as density of the bacterial inoculation culture, density

  6. Genomic Data and Annotation from the SEED

    DOE Data Explorer

    Fonstein, Michael; Kogan, Yakov; Osterman, Andrei; Overbeek, Ross; Vonstein, Veronika The Fellowship for Interpretation of Genomes (FIG)

    The SEED Project has been extended to support metagenomic samples and concomitant analytical tools. Moreover, the number of genomes being introduced into SEED is growing very rapidly. Building a framework to support this growth while providing highly accurate annotations is centrally important to SEED. The project’s subsystem-based annotation strategy has become the technological foundation for addressing these challenges.(copied from Appendix 7 of Systems Biology Knowledgebase for a New Era in Biology, A Genomics:GTL Report from the May 2008 Workshop, DOE/SC-0113, Grequrick, S; Fredrickson, J.K.; Stevens, R., Pub March 1, 2009.)

  7. Some Physical Properties of Lentil Seeds

    Microsoft Academic Search

    K. Çarman

    1996-01-01

    Several physical properties of lentil seed were evaluated as a function of moisture content. The average diameter, thickness, unit mass and volume of seed were 6·64 mm, 2·65 mm, 0·070 g and 49·08 mm3respectively at 6·5% m.c.d.b. Studies on rewetted seed showed that as moisture content increased from 6·5 to 32·6% d.b., bulk density decreased from 1190 to 935 kg\\/m3,

  8. Copyright (C) 2007 Seed-Project All Rights Reserved 01

    E-print Network

    Nakamura, Iku

    Copyright (C) 2007 Seed-Project All Rights Reserved 01 #12;Copyright (C) 2007 Seed-Project All Rights Reserved 03 FM #12;Copyright (C) 2007 Seed-Project All Rights Reserved 04 FM #12;Copyright (C) 2007 Seed-Project All Rights Reserved 05 112 http

  9. Seed and spore banks of two boreal mires

    Microsoft Academic Search

    Sinikka Jauhiainen

    1998-01-01

    The importance of the seed bank as a regenerative strategy in disturbed mires and the viability of seeds and spores in peat stratigraphy on two drained mires were studied prior to restoration. Most of the seedlings developed from the surface sample but still viable seeds occurred in the deepest layer sampled (50 cm). Germination from seeds, however, remained low. Six

  10. Burial increases seed longevity of two Artemisia tridentata (Asteraceae) subspecies

    USGS Publications Warehouse

    Wijayratne, Upekala C.; Pyke, David A.

    2012-01-01

    Premise of the study: Seed longevity and persistence in soil seed banks may be especially important for population persistence in ecosystems where opportunities for seedling establishment and disturbance are unpredictable. The fire regime, an important driver of population dynamics in sagebrush steppe ecosystems, has been altered by exotic annual grass invasion. Soil seed banks may play an active role in postfire recovery of the foundation shrub Artemisia tridentata, yet conditions under which seeds persist are largely unknown. Methods: We investigated seed longevity of two Artemisia tridentata subspecies in situ by retrieving seed bags that were placed at varying depths over a 2 yr period. We also sampled naturally dispersed seeds in litter and soil immediately after seed dispersal and before flowering in subsequent seasons to estimate seed persistence. Key results: After 24 mo, seeds buried at least 3 cm below the soil surface retained 30–40% viability whereas viability of seeds on the surface and under litter declined to 0 and Artemisia tridentata has the potential to form a short-term soil seed bank that persists longer than has been commonly assumed, and that burial is necessary for seed longevity. Use of seeding techniques that promote burial of some seeds to aid in formation of a soil seed bank may increase restoration potential.

  11. Radish (Raphanus sativus) seed size affects germination response to coumarin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The inhibition of seed germination by an allelochemical is generally greater in small seeds than in large seeds. Studies reporting these results used a large number of plant species that varied in seed size, which might have introduced differences in germination characteristics or various parameter...

  12. Mustard Seed Meal suppresses Weeds in Potato and Peppermint

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed meal is a co-product remaining after pressing mustard seed to remove the oil. Seed meals containing high glucosinolates have been reported to have herbicidal activity. Weed suppression with seed meal of Sinapis alba, variety Ida Gold was evaluated in field trials on potatoes and peppermint in ...

  13. Performing local similarity searches with variable length seeds

    E-print Network

    Csürös, Miklós

    Performing local similarity searches with variable length seeds Mikl´os Csur¨os D´epartement d with the seed-and-extend paradigm employed by many search algorithms, including BLAST. We introduce the concept of a seed tree, and provide a seed tree-pruning algorithm that affects the specificity in a predictable

  14. HORTSCIENCE 42(6):14361439. 2007. Primed Lettuce Seeds Exhibit

    E-print Network

    Bradford, Kent

    HORTSCIENCE 42(6):1436­1439. 2007. Primed Lettuce Seeds Exhibit Increased Sensitivity to Moisture Content During Controlled Deterioration H.J. Hill and Jesse D. Cunningham Seed Dynamics, Inc., 1081-B. Lactuca sativa, seed priming, aging, viability equation, germination Abstract. The Ellis-Roberts seed

  15. Designing Seeds for Similarity Search in Genomic DNA Jeremy Buhler

    E-print Network

    Lonardi, Stefano

    Designing Seeds for Similarity Search in Genomic DNA Jeremy Buhler jbuhler@cse.wustl.edu Department tools use seeded alignment, which com- pares only sequences that can be shown to share a common pattern or "seed" of matching bases. The literature suggests that the choice of seed substantially affects

  16. Seed Science Research http://journals.cambridge.org/SSR

    E-print Network

    Abella, Scott R.

    Seed Science Research http://journals.cambridge.org/SSR Additional services for Seed Science : Click here Soil seed banks in a mature coniferous forest landscape: dominance of native perennials and low spatial variability Scott R. Abella and Judith D. Springer Seed Science Research / Volume 22

  17. SEEDING ELEMENT POLARITY ARRANGEMENT ON DRUM-TYPE MAGNETIC

    E-print Network

    Boyer, Edmond

    SEEDING ELEMENT POLARITY ARRANGEMENT ON DRUM-TYPE MAGNETIC PRECISION SEEDER Qirui Wang *1 of magnetic seeding element on the magnetic induction intensity of seeding element end and magnetic field distribution in the seeding air gap. As a result of the different electromagnetic coil current direction

  18. Seed surface gums content using the Dubois carbohydrate analysis

    Microsoft Academic Search

    Thomas P. Abbott; Terry C. Nelsen; Robert Kleiman

    1995-01-01

    The Dubois total carbohydrate method was applied to quantitative analysis of seed surface gums removed from Lesquerella seed by ultrasound. Between 20 and 30 seed samples could be tested in triplicate in a normal 8-h day. The analyses were repeatable with a coefficient of variation of 4%. Germination rates of seeds were unaffected by the sonic treatment. Of 16 Lesquerella

  19. Semi-supervised Document Clustering with Dual Supervision through Seeding

    E-print Network

    Milios, Evangelos E.

    , Features Keywords User Supervision, Feature Supervision, Seeding, Text Cloud 1. INTRODUCTION TraditionalSemi-supervised Document Clustering with Dual Supervision through Seeding Yeming Hu Dalhousie labeled features to gen- erate cluster seeds to seed the unsupervised clustering. In this paper, we

  20. Report on the Polarimetric Cloud Analysis and Seeding Test 2

    E-print Network

    Delene, David J.

    Report on the Polarimetric Cloud Analysis and Seeding Test 2 (POLCAST2 ) David Delene1 , Paul seeding of convective clouds in North Dakota. · Determine identifiable signatures of hygroscopic seeding by aerosol and CCN concentrations. · Characterization of the cloud droplet size distributions for seeded