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1

Wavelength-Scanning Optical Bandpass Filters Based on Optomechatronics for Optical-Frequency Sweepers  

Microsoft Academic Search

We propose and demonstrate a method for improving optical-frequency sweepers that uses a disk-shaped optical bandpass filter operated under the synchro-scan mode. We optimize the filter layer structure to achieve high linearity in optical-frequency tuning with the rotation angle of the disk, while maintaining a constant band-inhibition performance. We introduce an optical system that narrows the bandwidth by using an

Yoshitada Katagiri; Hiroki Takesue; Etsu Hashimoto

2005-01-01

2

Sweepers, Communications and Solar Activity  

Microsoft Academic Search

Sweepers, wide-band noise pulses found in the HF range, have been observed at many locations on the globe. They display a changing frequency vs time characteristic. Two types, described as alpha and beta, have been noted. The duration of the beta type is so short that as it sweeps through 500-kc bandwidth its time rate of change of frequency exceeds

N. C. Gerson; W. H. Gossard

1963-01-01

3

Semi-Active Orbital Debris Sweeper.  

National Technical Information Service (NTIS)

An orbital debris sweeper is provided for removing particles from orbit which otherwise may impact and damage an orbiting spacecraft. The debris sweeper includes a central sweeper core which carries a debris monitoring unit, and a plurality of large area ...

A. J. Petro

1990-01-01

4

Plasma sweeper. [Patents  

DOEpatents

A device is described for coupling RF power (a plasma sweeper) from RF power introducing means to a plasma having a magnetic field associated therewith comprises at least one electrode positioned near the plasma and near the RF power introducing means. Means are described 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.

Motley, R.W.; Glanz, J.

1982-10-25

5

Evaluation of Broom Filaments for Powered Sweepers.  

National Technical Information Service (NTIS)

Tests were conducted to determine the most efficient and economical broom filament and brush construction for industrial and street sweepers. The tests included accelerated wear tests of various kinds of filament materials, sweeping efficiency tests of pi...

J. J. Bayles

1964-01-01

6

An Air Supply System for Operators of Motorized Street Sweepers  

Microsoft Academic Search

A method of protecting operators of motorized street sweepers from the dust cloud created by the sweeper is described, and its effectiveness is discussed in the light of operating conditions encountered.

K. R. SCHRAG

1970-01-01

7

Dust Exposure in Mechanical Street Sweepers  

Microsoft Academic Search

Measurements in three Alberta cities have shown that drivers of mechanical street sweepers can be exposed to excessive concentrations of silica-bearing dust. The provision of an enclosed cab pressurized with a filtered air supply appears to be the best solution to this situation. Care must be taken to specify a filter unit that will efficiently remove particles of respirable size.

Herbert Buchwald; Kenneth R. Schrag

1967-01-01

8

Assessing frequency-dependent seed size selection: a field experiment  

Microsoft Academic Search

Seed size is a life history attribute that affects the probability of seed predation, and therefore affects plant fitness. Compared with smaller seeds, those with large size should be more attractive to predators, as they constitute a more profitable food item because of higher energetic and\\/or nutrient content. However, predator preferences may be frequency-dependent in the sense that they may

JUAN L. CELIS-DIEZ; RAMIRO O. BUSTAMANTE; RODRIGO A. VÁSQUEZ

9

Performance Testing of the DiPerna Sweeper.  

National Technical Information Service (NTIS)

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...

M. K. Breslin

1981-01-01

10

Environment-adaptive Anti-personnel Mine Detection System: Advanced Mine Sweeper  

Microsoft Academic Search

In this chapter, we introduce an environment-adaptive anti-personnel mine detection system called the advanced mine sweeper\\u000a (AMS). The advanced mine sweeper is based on sensing technologies, access-control technologies and system integration technologies\\u000a for safe and effective demining procedures after the Level II survey. advanced mine sweeper consists of a sensing vehicle\\/unit,\\u000a an access vehicle, and an assist vehicle. The sensing

Toshio Fukuda; Yasuhisa Hasegawa; Kazuhiro Kosuge; Kiyoshi Komoriya; Fumihisa Kitagawa; Tomohiro Ikegami

11

Frequency-dependent seed size selection on Cryptocarya alba (Mol.) Looser (Lauraceae): testing the effect of background  

Microsoft Academic Search

Seed size affects the probability of seed predation. Large seeds should be preferred over small seeds but the selective responses of seed predators may also be frequency-dependent. Seed predators may prefer the most common seed sizes (apostatic selection), the rarest ones (antiapostatic selection) or even be unresponsive to the size of seeds. More- over, seed density may further modify the

J. L. CELIS-DIEZ; R. O. BUSTAMANTE

2005-01-01

12

Structural analysis and topology optimization design for a sweeper vehicle frame  

Microsoft Academic Search

To improve the mechanical performance and reduce the weight of a sweeper vehicle frame, a finite element model for a dump sweeper vehicle frame is established to analyze strength stiffness and modal of vehicle. By using Ls-dyna software, displacement and time curve for vehicle rectangular frame under external force incentives is solved. Based on the analysis results, topological optimization is

Zhou Bing; Wu Chonghui; Wei-ping Li

2010-01-01

13

Respiratory morbidity among street sweepers working at Hanumannagar Zone of Nagpur Municipal Corporation, Maharashtra.  

PubMed

Due to the occupational exposure street sweepers are very much vulnerable to develop the chronic diseases of respiratory system. Therefore this study was undertaken to find out the proportion of chronic respiratory morbidity among the street sweepers and the role of various associated risk factors. The study included two groups: study group i.e. street sweepers and comparison group (Class IV workers working in the office buildings). Various risk factors studied were age, sex, socioeconomic status, length of service, smoking habit, type of house, area of residence, cooking fuel and pets. Proportion of chronic respiratory morbidity (chronic bronchitis, asthma and bronchiectasis) was higher (8.1%) among street sweepers compared to comparison group (2.1%), the difference being statistically significant. Unconditional multivariate logistic regression revealed that risk of having chronic respiratory morbidity among street sweepers was 4.24 (95% CI of OR = 1.24 to 14.50) times higher than that in the comparison group and the risk increased significantly with increasing length of service (OR = 1.75, 95 % CI = 1.09 to 2.81). PMID:19189837

Yogesh, Sabde D; Zodpey, Sanjay P

14

Fatality Assessment and Control Evaluation (FACE) Report for Massachusetts: Construction Laborer Crushed by Unattended Rolling Street Sweeper at Asphalt Plant.  

National Technical Information Service (NTIS)

On June 19, 1996 a 13 year old male occasional construction laborer was fatally injured when he was crushed beneath an unattended rolling street sweeper at an asphalt plant, owned by his father. The victim was walking away from the sweeper at the time of ...

1997-01-01

15

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

NASA Astrophysics Data System (ADS)

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 2.36MHz (rms) to 1.07MHz (rms) in 1h by optimizing the voltage of the piezoelectric translator.

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

2011-07-01

16

Single-frequency, injection-seeded Ti:sapphire ring laser with high temporal precision  

Microsoft Academic Search

A three-mirror Ti:sapphire ring laser with a cavity length of 11 cm is injection seeded with a single-mode laser diode operating at 784 nm. The seed beam is injected into the ring cavity through the output coupler. The incident seed power is 11 mW. The ring laser is pumped with a frequency-doubled Nd:YAG laser. An efficiency of 40% is demonstrated.

Charles E. Hamilton

1992-01-01

17

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...

18

Acrorhagi, catch tentacles and sweeper tentacles: a synopsis of ‘aggression’ of actiniarian and scleractinian Cnidaria  

Microsoft Academic Search

Three types of organ (acrorhagi and catch tentacles in sea anemones, and sweeper tentacles in corals) are described with regard to both morphology and ‘aggressive’ function. Species known to possess such organs are listed. Research on the functions of these particular organs is reviewed and some exceptions to their usual behaviour patterns are highlighted. Further research on allogeneic recognition might

R. B. Williams

1991-01-01

19

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

DOEpatents

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.

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

1985-01-01

20

Injection seeded single frequency Nd:YAG MOPA Q-switched laser  

NASA Astrophysics Data System (ADS)

This paper discusses the realization of an injection-seeded single frequency Q-switched Nd:YAG ring laser with pulse width adjustability from several nanoseconds to 20 ns and an output energy in excess of 100 mJ from a ring cavity slave oscillator. In the cavity configuration under study, the slave ring oscillator was injected by a pulse formed from a CW single frequency non-planar ring oscillator (NPRO) Nd:YAG laser with a Pockels cell modulator. The injected pulse duration is slightly shorter than the emission round trip time inside the slave laser cavity. The use of this injection seeding results in unidirectional Q-switched laser oscillation with suppression of bidirectional Q-switched oscillation that otherwise may be initiated from spontaneous emission. The advantage of these regime is in stable laser operation with no need in adjustment of the seeded light wavelength and the mode of the cavity because there are never two waves of the same polarization existing inside the cavity at the same location and the same time. The cavity contains two Pockels-cells, in which the first cell serves to open the oscillator cavity and the second one performs cavity dumping, generating a pulse with optimized characteristics and enables variation of the duration of the Q-switched output pulse. Proper selection of the pump parameters and Pockels-cell gating enables further operation of the system in a mode when the Q-switched pulse can be formed only under the seeding conditions. It is found that the wavelength of the Q-switched laser radiation matches well to the injected seed NPRO laser longitudinal mode. By using two-stage amplifiers, an output energy better than 300 mJ has been achieved in a MOPA configuration without active control of the cavity.

Wu, Frank F.; Khizhnyak, Anatoliy; Markov, Vladimir

2009-02-01

21

On the mechanisms of stimulation and inhibition of wheat seed germination by low-frequency magnetic field  

Microsoft Academic Search

Stimulation of wheat seed germination by brief exposure in a 50-Hz electromagnetic field (EMF) is shown to depend on the extent\\u000a of membrane stretching upon seed swelling in sucrose solutions. This again confirms the effect of low-frequency EMF on the\\u000a release of peripheral proteins from membranes. Prolonged exposure, on the contrary, decreases the germination rate and retards\\u000a seedling growth.

S. I. Aksyonov; T. Yu. Grunina; S. N. Goryachev

2007-01-01

22

Influence of temperature and watering frequencies on seed germination and seedling growth of Ornithogalum longibracteatum and Tulbaghia violacea  

Microsoft Academic Search

The effect of temperature and watering frequencies on seedling growth were investigated in Ornithogalum longibracteatum and Tulbaghia violacea. Temperature had a significant influence on seed germination with low (10°C) and high (40°C) temperatures resulting in poor germination in both species. The optimum temperature for seed germination of O. longibracteatum and T. violacea was 22.9 and 26.8°C, respectively. Seedling survival rate

M. G. Kulkarni; S. G. Sparg; J. van Staden

2005-01-01

23

RADIO-FREQUENCY HEATING OF ALFALFA SEED FOR REDUCING 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 alfalfa seed used in the production of sprouts by dielectric heating was studied by experimental exposure of alfalfa seed arti...

24

Calibration of the Sweeper Chamber Charged-Particle Detectors for the LISA Commissioning Experiment  

NASA Astrophysics Data System (ADS)

The new LISA (Large-area multi-Institutional Scintillator Array) neutron detector array, designed to be used in conjunction with MoNA (Modular Neutron Array) was recently commissioned at the NSCL in an experiment designed to investigate excited states of neutron-rich Oxygen isotopes near the neutron drip-line. Charged fragments resulting from the neutron decays were swept out of the beam direction by the Sweeper Magnet after which they passed through a series of charged-particle detectors for fragment trajectory and energy determination. In order to achieve isotope separation and identification at the focal plane, which is then used to reconstruct the invariant mass of the unbound states, precise determinations of the fragment and neutron energies and trajectories are required. To correct for time-drifts in the charge-particle detectors that develop over the entire length of the experiment, Root C++ macros were developed to analyze and precisely correct for these detector drifts to within few tenths of a nanosecond. Root macros were also developed to position calibrate the ion chamber and CRDC's. Results for the LISA commissioning run will be presented.

Kwiatkowski, J.; Grovom, A.; Rogers, W.

2011-10-01

25

Path optimization for Space Sweeper with Sling-Sat: A method of active space debris removal  

NASA Astrophysics Data System (ADS)

This paper provides a path optimization strategy for space debris removal, focusing on the proposed Space Sweeper with Sling-Sat (4S) mission. 4S captures and ejects debris plastically, exploiting the impulsive momentum exchanges in place of fuel. Ejected debris are sent to lower perigee orbits, or to re-enter the atmosphere. The optimization method searches for the most efficient sequence of events to remove debris of unknown masses. For a fixed time interval and number of debris interactions n, the optimized solution predicts a set of n thrust impulses, n debris captures, and n debris ejections. Optimization is performed using an evolutionary algorithm that solves the combinatory problem of selecting the debris interaction order, ejection velocities, and sequence timing, while optimizing fuel cost and effectiveness towards debris mitigation. The first debris interaction is then applied to the system, and the process is repeated after interacting with each object. In this way, an in-orbit mission is simulated, and the results support the feasibility of 4S mission.

Missel, Jonathan; Mortari, Daniele

2013-10-01

26

Fast resonance-detection technique for single-frequency operation of injection-seeded Nd:YAG lasers  

SciTech Connect

A new technique for maintaining single-frequency output from injection-seeded Nd:YAG lasers is described. It involves quickly sweeping the slave-cavity longitudinal-mode spectrum when the flash lamps have created a maximum population inversion. An interference signal is detected by fast electronics, and the Q switch is opened when the slave cavity is resonant with the injected field.

Henderson, S.W.; Yuen, E.H.; Fry, E.S.

1986-11-01

27

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

PubMed

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

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

2012-02-01

28

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

NASA Astrophysics Data System (ADS)

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 1019 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.

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

2012-02-01

29

Investigation of broadcasting signal overlay using high-frequency filtering characteristics of RSOA in ASE seeded WDM access network  

NASA Astrophysics Data System (ADS)

The simultaneous baseband and broadcasting signal transmission based on wavelength division multiplexing-passive optical network access network are proposed and their experimental verifications are shown. Amplified spontaneous emitting source modulated by broadcasting signal in radio frequency band at reflective semiconductor optical amplifier is provided as seed source for wired signal modulation. The filtered amplified spontaneous emitting source is aligned to each channel and modulated by the downlink baseband signal at RSOA. Simultaneous downstream transmission of baseband and broadcasting signals over 23-km SMF is experimentally verified. Mutual interference between broadcasting and baseband signals, nonlinearity by two tone analysis, and performance variation on temperature are investigated.

Kim, Hyun-Seung; Yang, Se-Hoon; Son, Yong-Hwan; Han, Sang-Kook

2012-02-01

30

Generation of wideband frequency combs by continuous-wave seeding of multistage mixers with synthesized dispersion.  

PubMed

We numerically and experimentally demonstrate efficient generation of an equalized optical comb with 150-nm bandwidth. The comb was generated by low-power, continuous-wave seeds, eliminating the need for pulsed laser sources. The new architecture relies on efficient creation of higher-order mixing tones in phase-matched nonlinear fiber stages separated by a linear compressor. Wideband generation was enabled by precise dispersion engineering of multiple-stage parametric mixers. PMID:22330571

Myslivets, Evgeny; Kuo, Bill P P; Alic, Nikola; Radic, Stojan

2012-01-30

31

Frequency Filter of Seed X-ray by Use of X-ray Laser Medium: Toward the Generation of the Temporally Coherent X-ray Laser  

Microsoft Academic Search

We evaluate the characteristics of a higher-order harmonics light as a seed X-ray amplified through a laser-produced X-ray amplifier. The narrow spectral bandwidth of the X-ray amplifier works as the frequency filter of the seed X-ray, resulting in that only the temporally coherent X-ray is amplified. Experimental investigation using the 29th-order harmonic light of the Ti:sapphire laser at a wavelength

Noboru Hasegawa; Tetsuya Kawachi; Maki Kishimoto; Kouta Sukegawa; Momoko Tanaka; Tai Renzhong; Yoshihiro Ochi; Masaharu Nishikino; Keisuke Nagashima; Yoshiaki Kato

2009-01-01

32

Characterization of frequency-tripled nanosecond pulsed Ti:sapphire laser injection seeded by a frequency-scanning cw Ti:sapphire laser by use of optogalvanic spectroscopy of silicon atoms  

Microsoft Academic Search

The performance of a narrow-linewidth nanosecond pulsed deep-UV coherent light source consisting of a frequency-tripled nanosecond pulsed Ti:sapphire laser injection seeded by a frequency-scanning cw Ti:sapphire laser has been characterized by using optogalvanic spectroscopy of silicon atoms as a diagnostic. The envelope of the optogalvanic spectrum indicates the pure Doppler broadening of silicon atoms, which was estimated to be as

Yasutomo Shiomi; Kuniaki Kyutoku; Hiroshi Kumagai; Ataru Kobayashi

2006-01-01

33

Soliton self-frequency shift controlled by a weak seed laser in tellurite photonic crystal fibers.  

PubMed

We report the first demonstration of soliton self-frequency shift (SSFS) controlled by a weak continuous-wave (CW) laser, from a tellurite photonic crystal fiber pumped by a 1560 nm femtosecond fiber laser. The control of SSFS is performed by the cross-gain modulation of the 1560 nm femtosecond laser. By varying the input power of the weak CW laser (1560 nm) from 0 to 1.17 mW, the soliton generated in the tellurite photonic crystal fiber blue shifts from 1935 to 1591 nm. The dependence of the soliton wavelength on the operation wavelength of the weak CW laser is also measured. The results show the CW laser with a wavelength tunable range of 1530-1592 nm can be used to control the SSFS generation. PMID:23903161

Liu, Lai; Meng, Xiangwei; Yin, Feixiang; Liao, Meisong; Zhao, Dan; Qin, Guanshi; Ohishi, Yasutake; Qin, Weiping

2013-08-01

34

The effects of Fusilade (Fluazifop- p -butyl) on germination, mitotic frequency and ?-amylase activity of lentil ( Lens culinaris Medik.) seeds  

Microsoft Academic Search

In this study, seed germination percentages, effects on phases of mitosis and ?-amylase enzyme activity of lentil seeds treated\\u000a with four different concentrations (0.25, 0.5, 1 and 1.5%) of Fusilade (Fluazifop-p-butyl) were determined. Median EC (effective concentration) values were calculated according to seed germination percentages\\u000a after treatment for 72 h. Germination percentages of primary lentil roots decreased with increasing Fusilade concentrations.

Feruzan Dane; Filiz Ekinci Sanal; Tulin Aktac

2007-01-01

35

ROLE OF GA3 AND KNO3 IN IMPROVING THE FREQUENCY OF SEED GERMINATION IN PLANTAGO LANCEOLATA L  

Microsoft Academic Search

Seeds of Plantago lanceolata L., obtained from crops of 1992- 2001 were treated with 100, 200 and 400 ppm of GA3 and 1000, 2000 and 4000 ppm of KNO3 by incubating them at 20 o C under 16 h light photoperiod, along with control. Highest germination of 97% was obtained from the seed of the crop of 2001, which decreased

ERCUMENT OSMAN SARIHAN; ARIF IPEK; KHALID MAHMOOD; MEHMET ATAK; BILAL GURBUZ

36

[On the mechanisms of stimulation and inhibition during germination of wheat seeds in extremely low frequency electromagnetic fields].  

PubMed

It has been shown that the effects of stimulation of germination of wheat seeds by electromagnetic field depend on the degree of membrane tension during imbibition of seeds in sucrose solutions. This provides further confirmation of the influence of electromagnetic fields on the release of proteins from the bound state on the membranes. The prolonged treatment with electromagnetic fields during the imbibition of seeds leads not only to the inhibition of germination of sprouts but also to a decrease in their germinability, which can be as strong as twofold for seeds with the initial low germinability. This is related to the desynchronization of germination processes, caused by the stimulation of the release of proteins and inhibition of another stage during the cell division, the assembly of complex structures. It is noted that the activation of the release of proteins and inhibition of their binding by the action of electromagnetic fields must elevate the cell excitability. The presumably, the excitability of cells determines the effects of magnetic storms and high solar activity on the physiological state of organisms. PMID:17477063

Aksenov, S I; Grunina, T Iu; Goriachev, S N

37

High power tunable picosecond green laser pulse generation by frequency doubling of an Yb-doped fiber power amplifier seeded by a gain switch laser diode  

NASA Astrophysics Data System (ADS)

A compact tunable high power picosecond green laser pulse source based on frequency doubling of an Yb-doped fiber amplifier seeded by a gain switch laser diode has been developed. The fiber amplifier generates the picosecond infrared pulses with average power of 10.3 W, repetition rate of 1 MHz, pulse duration of 150 ps, and tunable range of 20 nm around 1064 nm. For underwater use, the tunable output infrared pulses are frequency doubled into picosecond green laser pulses, which can be tuned from 527 to 537 nm with average power of more than 1.1 W, corresponding to an overall conversion efficiency of 10.7% by a BBO nonlinear crystal. This kind of laser source will have potential application for underwater optical communication.

Liu, H. J.; Li, X. F.

2011-12-01

38

Multiline short-pulse solid-state seeded carbon dioxide laser for extreme ultraviolet employing multipass radio frequency excited slab amplifier.  

PubMed

In this Letter we describe in more detail a solid-state seeded, nanosecond pulse, multiline CO(2) oscillator designed and built for the extreme ultraviolet (EUV) laser-produced-plasma (LPP) source. Our oscillator featured quantum cascade laser seeders, a diffraction-type seed beam combiner, and a radio-frequency-discharge-excited, diffusion-cooled, slab-waveguide CO(2) gain cell in a compact multipass regenerative amplifier configuration. The oscillator generated pulses of exceptional stability in terms of envelope, energy, and spectrum. Excellent stability of output was achieved without any additional techniques. The output spectrum consisted of two laser lines of a 00(0)1-10(0)0 band of a CO(2) molecule, P20 and P22, with a target of four lines P18-P24. The pulse duration was electronically adjustable between 11 and 35 ns at a repetition frequency from a few hertz to hundreds of kilohertz. Electronic adjustment of the pulse duration was achieved by relative timing offsets of individual seeders, opening an avenue to a range of on-line adjustments of pulse shape and spectral content timing. The jitter-tolerant operation allows for easy synchronization with an external event, such as a droplet target in an EUV LPP source. A resistance to parasitic seeding of more than 40 dB was recorded. The oscillator produced up to 20 W of average output power at a repetition rate of 100 kHz in a near-diffraction-limited beam of M(2)<1.3 and a pointing stability below 50 ?rad. PMID:23503247

Nowak, Krzysztof M; Ohta, Takeshi; Suganuma, Takashi; Fujimoto, Junichi; Mizoguchi, Hakaru

2013-03-15

39

2130.7 nm, Single-Frequency Q-Switched Operation of Tm,Ho:YAlO3 Laser Injection-Seeded by a Microchip Tm,Ho:YAlO3 Laser  

NASA Astrophysics Data System (ADS)

A diode-pumped injection-seeded Q-switched Tm,Ho:YAlO3 (Tm,Ho:YAP) laser was demonstrated in this paper. Using a single-longitudinal-mode Tm,Ho:YAP microchip laser at 2130.7 nm as the seed laser, a single-frequency and nearly transform-limited operation of the frequency-locked pulsed laser was achieved by injection seeding. The frequency-locked pulse laser output energy of 2.8 mJ at 100 Hz with a pulse width of 289 ns was obtained. We measured the pulse spectrum, the full width at half maximum (FWHM) of which was 4.5 MHz, by a heterodyne technique.

Dai, Tong-Yu; Ju, You-Lun; Duan, Xiao-Ming; Shen, Ying-Jie; Yao, Bao-Quan; Wang, Yue-Zhu

2012-08-01

40

Alien dandelion reduces the seed-set of a native congener through frequency-dependent and one-sided effects  

Microsoft Academic Search

In conservation biology, increasing numbers of studies have focused on reproductive interference (RI) between a native species\\u000a and related aliens. However, few studies have examined the frequency dependence of RI, despite of its key importance to invasiveness.\\u000a Here, we report for the first time frequency-dependent RI in a pair of native and alien dandelions: Taraxacum japonicum and T. officinale, respectively.

Koh-Ichi Takakura; Takayoshi Nishida; Takashi Matsumoto; Sachiko Nishida

2009-01-01

41

Effects of radio-frequency driving power, gas pressure, and nitrogen seeding on the transition dynamics in argon inductively coupled plasmas  

SciTech Connect

The influences of rf driving power, neutral gas pressure, and nitrogen seeding on the electrostatic-to-electromagnetic (E-H) mode transition dynamics in radio-frequency argon inductively coupled plasmas (ICPs) in a pressure range of 50-100 kPa are investigated, both experimentally and theoretically. The E-H mode transition dynamics and its characteristic transition time scale are investigated by observing the high-speed imaging (13 500 fps) as well as the temporal change of plasma loading impedance. The experimental results reveal that the E-H mode transition time is not fixed at any operating conditions rather it depends on some important parameters such as the rf driving power, neutral gas pressure, gas type. It is found that the E-H mode transition time depends on the unique parameter E{sub {theta}}/p; the so-called effective induced electric field, rather than the independent parameter: the rf power or neutral gas pressure. It is also found that longer E-H mode transition time is required to ignite the high-pressure Ar-N{sub 2} plasmas with a 2.5%-10% N{sub 2} seeding than that of pure Ar plasmas with the same operating conditions. The experimental results are compared with that of the recently developed theoretical models, and a good agreement is found between them.

Razzak, M. Abdur; Takamura, Shuichi; Uesugi, Yoshihiko [Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Department of Electrical and Electronic Engineering, Kanazawa University 2-40-20 Kodatsuno, Ishikawa 920-8667 (Japan)

2004-11-01

42

Pomegranate seeds  

NSDL National Science Digital Library

This pomegranate has many seeds inside. These seeds are surrounded individually by red fruit. Some fruits also have many seeds, but all of the seeds are surrounded by the fruit instead of individually, like in an apple.

Peter N/A (None;)

2005-01-01

43

Avocado Seeds  

NSDL National Science Digital Library

This Science Update considers the fruit in its natural state -- investigating how the great big avocado seed manages to "get around." This story investigates how the avocado seed is spread, providing an interesting introduction to the larger topic of seed dispersal.

Science Update;

2001-05-15

44

Seed proteomics.  

PubMed

Rather than providing a single specific protocol, the inclusive area of seed proteomics is reviewed; methods are described and compared and primary literature citations are provided. The limitations and challenges of proteomics as an approach to study seed biology are emphasized. The 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 composite? The physiological status of the seeds must be considered; developing, mature, or germinating? If mature, are they quiescent or dormant? If mature and quiescent, then orthodox or recalcitrant? The genetic uniformity of the population of seeds being compared must be considered. Finally, seeds are protein-rich and the extreme abundance of the storage proteins results in a study-subject with a dynamic range that spans several orders of magnitude. This represents a problem that must be dealt with if the study involves analysis of proteins that are of "normal" to low abundance. Several different methods of prefractionation are described and the results compared. PMID:24136535

Miernyk, Ján A

2014-01-01

45

Scattering Seeds  

NSDL National Science Digital Library

In this lesson, students will: 1) Investigate how seeds are dispersed. 2) Understand the variety of seed dispersal that exists in the plant kingdom. 3) Understand how factors in the natural environment can effect how far a seed is dispersed. Included in this one to two day lesson plan are the objectives, needed materials, procedures, adaptations for older students, discussion questions, an evaluation, extensions, suggested reading, links to other sites, vocabulary, and academic standards. Students will collect a variety of seeds and design a wind-dispersed seed mechanism. They can click on a vocabulary word to hear its pronunciation and a sentence using the word. Teachers can purchase the video, The Private Life of Plants 5-Pack (Branching Out) and download comprehension questions and answers. They can link to Teaching Tools to create custom worksheets, puzzles, and quizzes. A printable version of this lesson plan can be downloaded.

Discoveryschool.com; Cahill, Mary

2007-01-01

46

Magnetic-seeding filtration  

SciTech Connect

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.

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

47

Many Seeds: Estimating Hidden Seeds  

NSDL National Science Digital Library

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.

Terc

2010-01-01

48

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

SciTech Connect

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.

John Hansknecht; Benard Poelker

2006-06-01

49

Sock Seeds  

NSDL National Science Digital Library

The experiment demonstrated in this ZOOMSci video segment--wearing an old sock through a grassy or weedy field, planting the sock, and watching what grows--will not only give young scientists a better idea of the kinds of plants growing in their area, but will also help them begin to think about the evolutionary strategies of plants to disperse seeds.

Foundation, Wgbh E.

2009-07-23

50

Seed Bargains  

NSDL National Science Digital Library

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

Konicek-Moran, Richard

2008-04-01

51

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 ...

52

Seed Treatment. Bulletin 760.  

ERIC Educational Resources Information Center

|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)|

Lowery, Harvey C.

53

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.

54

Blind Seed Disease.  

National Technical Information Service (NTIS)

In blind seed disease, infertilized or developing seed of susceptible grasses are colonized by the fungus Gloeotinia temulenta. Infection results in loss of seed germination. About 56 species of grasses are colonized by the fungus Gloeotinia temulenta. In...

S. C. Alderman

2001-01-01

55

The interaction between Cistaceae and a highly specific seed-harvester ant in a Mediterranean scrubland.  

PubMed

We studied the interaction between the ant Goniomma kugleri and Cistaceae in a Cistus ladanifer-dominated scrubland, in southwestern Spain. We monitored seed harvesting, and studied ant preferences among Cistaceae seeds and their capture efficiencies for preferred seeds. For the stand of C. ladanifer, we estimated seed losses due to the ants. Harvesting was restricted to two seasons: mid-autumn to late winter, and late spring. Ant diet relied on Cistaceae seeds: during autumn and winter 90% of seeds returned to nests were of C. ladanifer, and the remaining fraction also comprised Cistaceae seeds. At this time, the ants harvested seeds directly from the plants. In late spring, the ant diet consisted of Tuberaria guttata s.l. seeds. Goniomma kugleri selectively collected Cistaceae seeds. For preferred species, seed removal rates at the colony level and seed capture times invested by individual workers were correlated with seed size. Because of shorter capture time and higher success frequency, capture efficiency in terms of number of seeds captured per unit time was higher for small-seeded species. Although each ant colony collected large numbers (up to 10(5)) of C. ladanifer seeds over the autumn-winter season, the impact of ant removal on the annual seed output was moderate, at around 20%. It is likely that, in C. ladanifer, the staggered seed release period, and the pulsed exposure of seed clumps in capsules through progressive locule dehiscence, effectively minimise seed losses to the ants. PMID:19121113

Bastida, F; Talavera, S; Ortiz, P L; Arista, M

2009-01-01

56

Bean Seed Imbibition.  

ERIC Educational Resources Information Center

|Enables students to examine the time course for seed imbibition and the pressure generated by imbibing seeds. Provides background information, detailed procedures, and ideas for further investigation. (DDR)|

Hershey, David R.

1998-01-01

57

Seed germination as a thermobiological problem.  

PubMed

Thermal effects on seed germination are considered through the changes brought about by temperature in the germination capacity, in the germination rate, and in the distribution of the relative frequency of germination along the incubation times. A number of questions of general thermobiological interest are thus raised, entailing the need of an analysis of the temperature dependence of the seed germination rate. A treatment of these rates by the activation-energy approach cannot be general, for their Arrhenius plots are not always linear. Moreover, it is shown that any process displaying a temperature optimum (as happens in the germination of most seed species) cannot follow one of the fundamental tenets of the collision rate theory. The need of a theoretical treatment stressing the essential role of the partition of energy within the seed system has led to an anlysis using the absolute reaction rate theory. New experimental prospects for the physiology of seed germination are thus raised, concerning the meaning of the temperature cardinal points, the growth pattern of the embryo in germinating seeds, the dual effect of protein thermodenaturation, the effects of high hydrostatic pressures, and a whole pharmacological line of work. The cybernetic counterpart of the thermodynamic view of seed germination appears in the study of the distribution of the relative frequency of germination along the isothermal incubation time. In some species of seeds the thermal communication between the environment and the seed growth effector can be shown to proceed by molecular collisions at all germination isotherms. In the seeds of Dolichos biflorus this communication through random thermal noise prevails only at temperatures close to both extreme limits of germination. Both in this species and in Calotropis procera there is a temperature range (encompassing the optimum) within which a temperature signal is superimposed upon the gaussian noise. An interpretation is proposed according to which the temperature signal is transduced in a protein-conformation code. PMID:756055

Labouriau, L G

1978-12-22

58

Seed health and vigor  

Technology Transfer Automated Retrieval System (TEKTRAN)

The health of lentil and chickpea seed greatly impacts the quality of the crop stand and yield. Healthy seed has a high germination rate, is whole (free of cracks or other damage), is free from foreign matter including weed seed and has limited seedborne pathogens. The health of the seed often dep...

59

Red peach and seed  

NSDL National Science Digital Library

This peach has only one large seed, as compared to the pomegranate that has many seeds. The peach is like an apple in the way that its seed is surrounded by the entire fruit. The fruit can be eaten by humans, but it is actually there as nourishment and food for the peach seed to grow.

Jack Dykinga (USDA;ARS)

1997-08-01

60

Frequency Spectrum.  

National Technical Information Service (NTIS)

Uses a pictorial representation of the frequency spectrum to identify power frequencies, audio frequencies, radio frequencies, VhF, UhF, and microwaves. Given a specific wavelength, calculates the frequency. Given either frequency or wavelength, calculate...

1994-01-01

61

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

62

Rail Impact Test of Rotary Towed Sweeper.  

National Technical Information Service (NTIS)

The U. S. Army Defense Ammunition Center and School (USADACS), Validation Engineering Division (SMCAC-DEV), was tasked by the U. S. Army Tank-Automotive Command to rail impact test per MIL-STD-810D, Military Standard Environmental Test Methods and Enginee...

A. C. McIntosh

1990-01-01

63

DO SMALL-SEEDED SPECIES HAVE HIGHER SURVIVAL THROUGH SEED PREDATION THAN LARGE-SEEDED SPECIES?  

Microsoft Academic Search

Seed ecologists have often stated that they expect larger-seeded species to have lower survivorship through postdispersal seed predation than smaller-seeded species. Similar predictions can be made for the relationship between survivorship through predis- persal seed predation and seed mass. In order to test these predictions, we gathered data regarding survivorship through 24 hours of exposure to postdispersal seed predators for

Angela T. Moles; David I. Warton; Mark Westoby

2003-01-01

64

Mutational effects of space flight on Zea mays seeds  

Microsoft Academic Search

The growth and development of more than 500 Zea mays seeds flown on LDEF were studied. Somatic mutations, including white-yellow stripes on leaves, dwarfing, change of leaf sheath color or seedling color were observed in plants developed from these seeds. When the frequency of white-yellow formation was used as the endpoint and compared with data from ground based studies, the

M. Mei; Y. Qiu; Y. He; H. Bucker; C. H. Yang

1994-01-01

65

Seeds as allelopathic agents  

Microsoft Academic Search

Inhibitors of germination or of growth, highly diversified chemicals are commonly found in higher plants. They occur in vegetative organs as well as in seeds or other dispersal units. Nonprotein amino acids, when present, are mainly found in seeds where they can occur in extremely high concentrations. Density of seeds, rate of emanation of inhibitors, their amount and effectiveness, all

Jacob Friedman; George R. Waller

1983-01-01

66

Pasture seed banks  

Technology Transfer Automated Retrieval System (TEKTRAN)

In our surveys of northeastern pastures, we found the equivalent of more than 8 million seeds per acre in the surface soil (the top four inches) from the seed bank study. These seeds came from 58 species of plants. The annual forbs (all broadleaf plants with the exception of legumes and trees) domin...

67

Needs of Seeds  

ERIC Educational Resources Information Center

|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 students overgeneralize the needs of seeds by assuming they have the same needs as the adult…

Keeley, Page

2011-01-01

68

Frequency Analysis of the Laser Biospeckle  

NASA Astrophysics Data System (ADS)

This research work presents a study of beans seed tissue (Phaseolous vulgaris, L.) optical interactions with laser aiming to contribute to the development of biospeckle techniques applied to the recognition of bean seed tissue vitality when contaminated with fungi, by differentiating the generated frequency spectra. Biospeckle is an interference optic phenomenon occurring when a laser beam reaches a surface exhibiting some dynamic process, due to biological activities or purely physical changes. The technique involves image processing to distinguish each different active material contribution present in the seed, by means of the procedure known as ``Moment of Inertia'' and frequency analysis. Frequency analysis was carried by Fourier Transform preceded by module of convolution. A great challenge in this area is to identify the elements contribution to increase biospeckle activity, such as water, microorganisms, among others. This research work is recognized to provide an important step aiming to characterize the interaction of laser with biological material. Three groups of bean seeds were employed, one represented by healthy seeds and two groups composed of seeds contaminated with Aspergillus spp as well as with Fusarium spp fungi. The biospeckle analysis considered the activity and its frequency spectra. The seeds were each one exposed to laser in a random order. The results reveled differences in the average values of MI of the three seed groups. Also, some different harmonics in the biospeckle pattern in a same group as well as among seed groups had been noticed. These results allow confirming that it is possible to differentiate contaminated seeds from non-contaminated ones by means of biospeckle frequency analysis.

Enes, Adilson M.; Rabelo, Giovanni F.; Júnior, Roberto A. Braga; Dal Fabbro, Inácio M.; Vilela, Michelle

2008-04-01

69

The seed nuclear proteome  

PubMed Central

Understanding the regulatory networks coordinating seed development will help to manipulate seed traits, such as protein content and seed weight, in order to increase yield and seed nutritional value of important food crops, such as legumes. Because of the cardinal role of the nucleus in gene expression, sub-proteome analyses of nuclei from developing seeds were conducted, taking advantage of the sequences available for model species. In this review, we discuss the strategies used to separate and identify the nuclear proteins at a stage when the seed is preparing for reserve accumulation. We present how these data provide an insight into the complexity and distinctive features of the seed nuclear proteome. We discuss the presence of chromatin-modifying enzymes and proteins that have roles in RNA-directed DNA methylation and which may be involved in modifying genome architecture in preparation for seed filling. Specific features of the seed nuclei at the transition between the stage of cell divisions and that of cell expansion and reserve deposition are described here which may help to manipulate seed quality traits, such as seed weight.

Repetto, Ombretta; Rogniaux, Helene; Larre, Colette; Thompson, Richard; Gallardo, Karine

2012-01-01

70

Anthropogenic fire drives the evolution of seed traits  

PubMed Central

Fire is a major disturbance affecting ecosystems worldwide. Phylogenetic studies have shown that the evolution of seed persistence (fire resistance) is associated with fire frequency or severity. However, the existence of specific seed traits resulting from natural selection mediated by fire remains a key question in plant evolution. We evaluated the role of fire in the evolution of seed traits from a microevolutionary perspective, using as a study system a native forb from the Chilean matorral, where fire is a novel, anthropogenic disturbance. We show that anthropogenic fires are shaping the evolution of seed traits such as pubescence and shape. Among-population variation in seed pubescence, shape, and pericarp thickness was strongly associated with fire frequency, and within a population, fire selected those plants with more pubescent seeds, thicker pericarps, and less rounded seeds. Seed pubescence and shape were shown to be heritable traits. Our findings provide insights into the understanding of the evolution of seed traits in fire-prone environments and demonstrate that human-made fires can be driving evolutionary changes in plant species from ecosystems where fires do not occur naturally.

Gomez-Gonzalez, Susana; Torres-Diaz, Cristian; Bustos-Schindler, Carlos; Gianoli, Ernesto

2011-01-01

71

Mutational effects of space flight on Zea mays seeds  

NASA Astrophysics Data System (ADS)

The growth and development of more than 500 Zea mays seeds flown on LDEF were studied. Somatic mutations, including white-yellow stripes on leaves, dwarfing, change of leaf sheath color or seedling color were observed in plants developed from these seeds. When the frequency of white-yellow formation was used as the endpoint and compared with data from ground based studies, the dose to which maize seeds might be exposed during the flight was estimated to be equivalent to 635 cGy of gamma rays. Seeds from one particular holder gave a high mutation frequency and a wide mutation spectrum. White-yellow stripes on leaves were also found in some of the inbred progenies from plants displayed somatic mutation. Electron microscopy studies showed that the damage of chroloplast development in the white-yellow stripe on leaves was similar between seeds flown on LDEF and that irradiated by accelerated heavy ions on ground.

Mei, M.; Qiu, Y.; He, Y.; Bucker, H.; Yang, C. H.

1994-10-01

72

Fecal Impaction in Adults: Report of 30 Cases of Seed Bezoars in the Rectum  

Microsoft Academic Search

\\u000a Purpose  Seed bezoars in the rectum have been considered an uncommon cause of fecal impaction in adults. Although there have been several\\u000a reports on sunflower seed bezoars, seed bezoars from the fruit of the prickly pear cactus and watermelon have received little\\u000a notice. This study was designed to determine the frequency of fecal impaction by seed bezoars in the rectum and

Arie Eitan; Amitai Bickel; Israel M. Katz

2006-01-01

73

Switchgrass recruitment from broadcast seed vs. seed fed to cattle  

Microsoft Academic Search

Fecal seeding by livestock may be an effective, low-cost means of rangeland restoration. We compared recruitment of switch- grass (Panicum virgatum L.) from seed fed to cattle and deposited in dung to that of broadcast-seeded plots receiving a comparable number of unfed seed. Although germinability of seed passed through livestock (52 to 62%) was reduced relative to that of broadcast

W. R OCUMPAUGH; S. ARCHER; J. W. STUTH

74

Co-evolution of seed size and seed predation  

Microsoft Academic Search

Using the evolutionarily stable strategy (ESS) approach in a model for the co-evolution of seed size and seed predation, I show that seed size variation within individual plants is favoured if there is a trade-off in the predator's attack rate for different seed sizes. A single seed size is not evolutionarily stable because a predator that is optimally adapted to

Stefan a. H. Geritz

1998-01-01

75

Imbibition of Swietenia macrophylla (Meliaceae) Seeds: The Role of Stomata  

PubMed Central

• Background and Aims The occurrence of stomata in seed coats is uncommon and there is limited information about their function(s). The aim of this study was to verify the distribution of stomata in seed coats of Swietenia macrophylla and to relate it to the imbibition process and aspects of the structure of the outer integument layers. • Methods For the structural and ultrastructural studies, the seeds were processed using the usual techniques and studied under light and scanning electron microscopes. Histochemical tests were employed to identify the cell wall composition in the different seed coat portions. To assess the role of the stomata in the imbibition, non-impervious seeds were compared with partially impervious ones, in which only the embryo, median or hilar regions were left free. Further, the apoplastic pathway marker was employed to confirm the role of the stomata as sites of water passage during imbibition. • Key Results A positive relationship was observed between seed coat thickness and stomata density. The stomata were devoid of movement, with a large pore. They occurred in large numbers in the embryo region and extended with lower frequency towards the wing. Imbibition rates were related to stomata density, suggesting that the stomata act as preferential sites for water entry in the S. macrophylla seeds. • Conclusions At maturity, the stomata in the seed coat play a significant role in seed imbibition. The data may also infer that these permanently opened stomata have an important role in gas exchange during seed development, aiding embryo respiration.

PAIVA, ELDER ANTONIO SOUSA; LEMOS-FILHO, JOSE PIRES; OLIVEIRA, DENISE MARIA TROMBERT

2006-01-01

76

Estimation of gene flow into two seed orchards of loblolly pine ( Pinus taeda L.)  

Microsoft Academic Search

Multilocus allozyme markers, which were present in background stands but not in two seed orchards, enabled estimation of gene flow into two seed orchards of loblolly pine. Estimates averaged 36% in two orchards over three years. When pollen pool frequencies in the background stands were used rather than gene frequencies in the non-orchard trees, the estimates averaged 60%. In one

S. T. Friedman; W. T. Adams

1985-01-01

77

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

Microsoft Academic Search

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

Sherel Goodrich; Dustin Rooks

78

Seed Dispersal 101  

NSDL National Science Digital Library

This two-minute radio program introduces listeners to the variety of agents that disperse seeds. The program's guest, a plant biologist, cites examples of nonliving and living dispersal agents that include the wind, water, and such animals as birds and bats. He also explains that a plant's fruits or seeds often offer clues about how they are dispersed. The program, which is available here in audio and text, is the first in a series about seed dispersal. Copyright 2005 Eisenhower National Clearinghouse

Planet, Pulse O.

2007-07-26

79

Water impermeable seed dormancy  

Microsoft Academic Search

Viable seeds that do not imbibe water and thus fail to germinate in an apparently favorable environment are commonly termed\\u000a impermeable or hard seed. This physical, exogenous dormancy is especially common in species of the Fabaceae. The ecological\\u000a significance of hard seed includes the ability to rapidly recolonize burnt areas after fire and to withstand ingestion by\\u000a animals and birds.

M. Philip Rolston

1978-01-01

80

Examining Children's Models of Seed.  

ERIC Educational Resources Information Center

|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)|

Jewell, Natalie

2002-01-01

81

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

SciTech Connect

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.

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

2007-04-01

82

Planting Seeds of Involvement  

ERIC Educational Resources Information Center

|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…

Allyn, David

2004-01-01

83

Sugar-beet Seed  

Microsoft Academic Search

AT a recent meeting of the Sigma Xi Society of the University of Colorado Dr. W. W. Robbins, botanist to the Great Western Sugar Co., read a paper on beet-seed production. Dr. Robbins related that so early as 1909 Mr. Hans Mendelson, a German in the employ of the company, undertook to grow beet-seed in Montana. In those days all

T. D. A. Cockerell

1920-01-01

84

Standardizing seed dormancy research.  

PubMed

Seeds are very attractive and convenient for molecular genetic studies that challenge principal biological phenomena related to the initiation and suppression of growth (e.g., germination and dormancy, respectively). The number of reports in this field is rapidly expanding. Seed dormancy is a widely misinterpreted biological attribute. One of the main reasons is the general neglect of reliable dormancy assays; often, the sole criterion of current dormancy assays is the total germination of a seed population after a defined period of time. This is a very insensitive and inaccurate method, particularly when comparing dormancy levels of seeds from different genotypes, seeds subjected to different treatments, or seeds originating from different environments. Other seed parameters are far more useful. Furthermore, before undertaking comprehensive molecular and biochemical studies to elucidate the underlying mechanisms of dormancy of a given species, it is pivotal to determine the general types or categories of dormancy that are imposed and whether these are influenced by the external environment. Research strategies should be adjusted to this. In order to distinguish dead from dormant seeds, a viability test should be developed. This chapter addresses in a very general way these pitfalls in dormancy research with a focus on current plant model systems in molecular genetics, such as Arabidopsis thaliana and Medicago truncatula. PMID:21898248

Hilhorst, Henk W M

2011-01-01

85

Seeds in Space Experiment.  

National Technical Information Service (NTIS)

Two million seeds of 120 different varieties representing 106 species, 97 genera, and 55 plant families were flown aboard the Long Duration Exposure Facility (LDEF). The seeds were housed in one sealed canister and in two small vented canisters. After bei...

J. A. Alston

1992-01-01

86

Needs of Seeds  

NSDL National Science Digital Library

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.

Eberle, Francis; Tugel, Joyce; Keeley, Page

2007-01-01

87

Imprinting and Seed Development  

Microsoft Academic Search

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

Mary Gehring; Yeonhee Choi; Robert L. Fischer

2004-01-01

88

GROWING SEEDS, TEACHER'S GUIDE.  

ERIC Educational Resources Information Center

THIS TEACHER'S GUIDE IS DESIGNED FOR USE WITH AN ELEMENTARY SCIENCE STUDY UNIT, "GROWING SEEDS," IN WHICH SUCH BASIC SCIENCE SKILLS AND PROCESSES AS MEASUREMENT, OBSERVATION, AND HYPOTHESIS FORMATION ARE INTRODUCED THROUGH STUDENT ACTIVITIES INVOLVING SEEDS, GERMINATION, AND SEEDLING GROWTH. THE MATERIALS WERE DEVELOPED FOR USE IN ELEMENTARY…

Elementary Science Study, Newton, MA.

89

Telomeres and seed banks.  

PubMed

We have found that a progressive loss of telomeric sequences occurs from high molecular weight DNA with an increasing appearance at low molecular weight as the periods of storage in the dry state were extended in time to provide seed germination loss from 98 to 0%. Telomere distribution would appear to follow the general pattern of DNA random fragmentation that occurs in the embryos of seeds stored in the dry state, but there are also indications of an overall telomere loss from DNA as a consequence of storage. There is a need for a convenient "equality marker" for the seeds that can be monitored over time. Reviewing the implications of our results very carefully we believe that there is considerable potential in the use of telomere sequences to mark embryo ageing of seeds held in Seed Banks. PMID:17427414

Boubriak, I; Pouschuk, V; Grodzinsky, A; Osborne, Daphne J

90

The earliest seeds  

USGS Publications Warehouse

Lagenostomalean-type seeds in bifurcating cupule systems have been discovered in the late Devonian Hampshire Formation of Randolph County, West Virginia, USA (Fig. 1). The associated megaflora, plants from coal balls, and vertebrate and invertebrate faunas demonstrate that the material is Famennian; the microflora indicates a more specific Fa2c age. Consequently, these seeds predate Archaeosperma arnoldii1 from the Fa2d of northeastern Pennsylvania, the oldest previously reported seed. By applying precision fracture, transfer, de??gagement, and thin-section techniques to selected cupules from the more than 100 specimens on hand, we have determined the three-dimensional morphology and histology of the seeds (Fig. 2a-h, k) and cupule systems. A comparison with known late Devonian to early Carboniferous seeds reveals that ours are more primitively organized than all except Genomosperma2,3. ?? 1981 Nature Publishing Group.

Gillespie, W. H.; Rothwell, G. W.; Scheckler, S. E.

1981-01-01

91

Frequency curves  

USGS Publications Warehouse

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.

Riggs, H. C.

1968-01-01

92

7 CFR 201.15 - Weed seeds.  

Code of Federal Regulations, 2013 CFR

...Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation or transported and shall include noxious weed...

2013-01-01

93

Corn Seed Germination and Vigor Following Freezing during Seed Development  

Microsoft Academic Search

The potential for an early autumn frost to reduce corn (Zea mays L.) seed quality is a concern for seed producers. This study evaluated the effect of freezing rate, freezing temperature (26, 211C) and duration (4, 6 h), ear attachment, and endosperm composition on seed germination and vigor (accelerated aging (AA) and cold test) during seed development and maturation of

James Woltz; Dennis M. TeKrony; Dennis B. Egli

2006-01-01

94

Seed Dispersal by Ants in the Semi-arid Caatinga of North-east Brazil  

PubMed Central

Background and Aims Myrmecochory is a conspicuous feature of several sclerophyll ecosystems around the world but it has received little attention in the semi-arid areas of South America. This study addresses the importance of seed dispersal by ants in a 2500-km2 area of the Caatinga ecosystem (north-east Brazil) and investigates ant-derived benefits to the plant through myrmecochory. Methods Seed manipulation and dispersal by ants was investigated during a 3-year period in the Xingó region. Both plant and ant assemblages involved in seed dispersal were described and ant behaviour was characterized. True myrmecochorous seeds of seven Euphorbiaceae species (i.e. elaiosome-bearing seeds) were used in experiments designed to: (1) quantify the rates of seed cleaning/removal and the influence of both seed size and elaiosome presence on seed removal; (2) identify the fate of seeds dispersed by ants; and (3) document the benefits of seed dispersal by ants in terms of seed germination and seedling growth. Key Results Seed dispersal by ants involved one-quarter of the woody flora inhabiting the Xingó region, but true myrmecochory was restricted to 12·8 % of the woody plant species. Myrmecochorous seeds manipulated by ants faced high levels of seed removal (38–84 %) and 83 % of removed seeds were discarded on ant nests. Moreover, seed removal positively correlated with the presence of elaiosome, and elaiosome removal increased germination success by at least 30 %. Finally, some Euphorbiaceae species presented both increased germination and seedling growth on ant-nest soils. Conclusions Myrmecochory is a relevant seed dispersal mode in the Caatinga ecosystem, and is particularly frequent among Euphorbiaceae trees and shrubs. The fact that seeds reach micro-sites suitable for establishment (ant nests) supports the directed dispersal hypothesis as a possible force favouring myrmecochory in this ecosystem. Ecosystems with a high frequency of myrmecochorous plants appear not to be restricted to regions of nutrient-impoverished soil or to fire-prone regions.

Leal, Inara R.; Wirth, Rainer; Tabarelli, Marcelo

2007-01-01

95

Photoacoustic Study of Fungal Disease of Acai ( Euterpe oleracea) Seeds  

NASA Astrophysics Data System (ADS)

Photoacoustic spectroscopy is introduced as a promising experimental technique to investigate fungus infected Acai ( Euterpe oleracea) seeds. Photoacoustic spectra of healthy and infected Acai seeds with the fungus Colletotrichum gloeosporioides were recorded firstly in the modulation frequency range of 5Hz to 700 Hz, while keeping the wavelength of excitation radiation of a Xe arc-lamp constant, to ascertain the depth of penetration of infection within the seed and secondly, at variable wavelength (wavelength scanning) in the interval 250nm to 1,000 nm, while keeping the modulation frequency constant. In the former, the photoacoustic signal strength from the infected seed was found higher than that of the healthy one, and has been associated with the appearance of new biomolecules associated with the pathogen infection. In the latter, characteristics peaks and bands were observed in the range from 650 nm to 900 nm ascribed to organic compounds with carboxylates and amines (functional groups) forming the typical metabolic structures of the fungus.

Rezende, Denise V.; Nunes, O. A. C.; Oliveira, A. C.

2009-10-01

96

Genetically Modified Food Seeds: Genetically Modified Food Seeds: Genetically Modified Food Seeds: Genetically Modified Food Seeds: Genetically Modified Food Seeds: Health, Socioeconomic  

Microsoft Academic Search

Although concerns about genetically modified (GM) food seeds are serious and well-founded, the problems which these seeds raise are usually not unique to GM seeds alone. GM organisms are only one example of problematic new varieties or breeds. Large soybean and other monocultural plantations have serious environmental effects which GM seeds exacerbate. Although GM seeds may benefit large scale commercial

Frank J. Leavitt

97

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

Microsoft Academic Search

Commercial oil-yielding seeds (castor, coconut, neem, peanut, pongamia, rubber and sesame) were collected from different places\\u000a in the state of Tamil Nadu (India) from which 1279 endophytic fungi were isolated. The oil-bearing seeds exhibited rich fungal\\u000a diversity. High Shannon-Index H? was observed with pongamia seeds (2.847) while a low Index occurred for coconut kernel-associated\\u000a mycoflora (1.018). Maximum Colonization Frequency (%)

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

98

Seed Dispersal: Lemurs  

NSDL National Science Digital Library

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

Planet, Pulse O.

2007-09-20

99

Molecular Physiology of Seed Maturation and Seed Storage Protein Biosynthesis  

Microsoft Academic Search

\\u000a Recent progress is presented in order to understand seed protein synthesis in the context of seed maturation, with the main\\u000a emphasis on legume and cereal crop seeds. This review highlights the molecular physiology of seed storage protein synthesis\\u000a and deposition, the genetic background, and the regulatory and signal transduction network of seed maturation. Storage protein\\u000a synthesis is tightly connected to

H. Weber; N. Sreenivasulu; W. Weschke

100

Co-evolution of seed size and seed predation  

Microsoft Academic Search

Summary Using the evolutionarily stable strategy (ESS) approach in a model for the co-evolution of seed size and seed predation, I show that seed size variation within individual plants is favoured if there is a trade-oÄ in the predator's attack rate for diÄerent seed sizes. A single seed size is not evolutionarily stable because a predator that is optimally adapted

STEFAN A. H. GERITZ

1998-01-01

101

Hybrid Seed Production in Watermelon  

Microsoft Academic Search

Controlled pollinations are an essential part of watermelon hybrid seed production, and the use of male sterility will reduce labor required. Profitable seed production must employ good cultural practices and timely harvest. Triploid hybrid seed production varies considerably from diploid hybrid seed production. The generation of tetraploid parents has been enhanced considerably with the use of tissue cultural and chromosome

Bill Rhodes; Xingping Zhang

2000-01-01

102

Dielectric characteristics of rape-seed oil  

Microsoft Academic Search

This paper deals with the investigation of fundamental dielectric characteristics of rape-seed oil considered to be a substitute of mineral oil in power transformers. The 50 Hz breakdown voltage is comparable to normal mineral oil, e.g. more than 50 kV\\/2.5 mm. Furthermore, the permittivity εR and the dielectric loss factor tan ? for various temperatures and frequencies were measured. Using

R. Badent; K. Kist; B. Ruggemeier; W. Zierhut; A. J. Schwab

1998-01-01

103

Local seed rain and seed bank in a species-rich grassland: effects of plant abundance and seed size  

Microsoft Academic Search

In this study, we examined the relationship between seed size, seed rain, and seed bank in a species-rich peren- nial grassland in Sweden. The seed rain was monitored by 100 seed traps placed in a 10 m 10 m area for 1 year. The seed bank was sampled by taking 100 soil samples, each in close vicinity to a seed

Anna Jakobsson; Ove Eriksson; Hans Henrik Bruun

2006-01-01

104

Frequency Synthesizer.  

National Technical Information Service (NTIS)

Dual phase lock loops are used to provide a rapid switching, low power, low spurious and fine resolution frequency synthesizer for various radio applications. The first phase lock loop provides for coarse frequency adjustment, and the second phase lock lo...

E. J. Nossen

1978-01-01

105

Operation Weed and Seed.  

National Technical Information Service (NTIS)

Operation Weed and Seed, a U.S. Department of Justice community-based initiative, is an innovative and comprehensive multi-agency approach to law enforcement, crime prevention, and community revitalization.

2008-01-01

106

Seeds in Flight  

ERIC Educational Resources Information Center

|Discussed are the seed dispersal mechanisms of six different plants: big-leaf maple, pincushion tree, tree of heaven, squirting cucumber, digger pine, and bull thistle. Elaborate color and black-and-white drawings illustrate the text. (MA)|

Martin, Willard K.

1978-01-01

107

Fishing for Seeds.  

ERIC Educational Resources Information Center

|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)|

Science and Children, 2001

2001-01-01

108

Tropical Tree Seed Manual.  

National Technical Information Service (NTIS)

The Tropical Tree Seed Manual is a one-volume reference manual for students, technicians, and scientists that provides comprehensive internationally compiled data about tropical trees. The emphasis is on species of the Americas; however, a number of tropi...

J. A. Vozzo

2002-01-01

109

Microencapsulated Cloud Seeding Materials.  

National Technical Information Service (NTIS)

A process was developed for encapsulating hygroscopic, cloud-seeding agents, sodium chloride and urea. The encapsulation process involves depositing the coating polymer, ethylcellulose, onto finely divided powders using a phase separation-coacervation tec...

J. L. Anderson

1971-01-01

110

CloudSeeding  

NSDL National Science Digital Library

This Topic in Depth begins with a Web site from the Oklahoma Weather Modification Program called Cloud Physics - The Basics (1 ). Students are encouraged to initiate a debate on the controversy surrounding the issue of inducing or enhancing precipitation. Next, the Texas Water Resources Institute Web site, Does Weather Modification Really Work? (3 ) provides a more basic description of cloudseeding. The site offers several categories including The Science of Cloud Seeding, A Brief History of Weather Modification in Texas, Legal and Policy Issues, Current and Future Activities, and more. The Western Kansas Weather Modification Program offers the next site, Aircrew Pictures 2001 (4 ). The page contains pictures of the planes and crew involved in the program as well as pictures from the plane during a mission. Other links on the site contain radar, data, and other information. The next site from ABCNEWS.com is an article entitled Weather as a Weapon? (5 ) The piece explorers what might happen "on some battlefield of the future where the US military could gain a tactical advantage by changing the weather." A discussion on the possibilities of changing the weather, an Air Force research paper and several other links are provided to learn more. The 6th site maintained by the North Dakota State Water Commission is entitled Atmospheric Resources-Photos and Videos (6 ). Here, visitors can find more photographs of cloudseeding equipment and most notably three videos of cloudseeding planes in action. Atmospherics Incorporated, an operations and research company in the field of applied meteorology, provides the next site, The Physical Basis for Seeding Clouds (7 ). The page describes techniques for cloud seeding and has a link to photographs of pyrotechnic seeding devices. The last site provided by North American Weather Consultants, Inc. is titled, Cloud Seeding -Frequently Asked Questions (8 ). 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?

2002-01-01

111

Precocious Germination during In Vitro Growth of Soybean Seeds 1  

PubMed Central

Immature Glycine max (L.) Merrill seeds were grown and matured in liquid medium at 25°C under fluorescent light. In standard medium containing minerals, 146 millimolar sucrose and 62.5 millimolar glutamine (osmolality 0.24), precocious germination seldom occurred with a starting seed size of less than 300 milligrams fresh weight. Frequency of precocious germination increased with increased starting seed size. Sucrose concentration strongly affected precocious germination while glutamine concentration had no effect. Starting with 300 to 350 milligrams fresh weight seeds, treatments which reduced the sucrose concentration or lowered the osmolality of the culture medium stimulated precocious germination, and increased the fresh weight growth but not the dry weight growth of seeds. Increasing the osmolality to 0.38 with sucrose or mannitol prevented precocious germination without reducing dry weight accumulation in seeds. In medium with initially low osmolality, precocious germination was inhibited by addition of 1 to 100 micromolar abscisic acid to the medium without a reduction in seed growth. During growth and maturation of large soybean seeds in vitro, precocious germination and other abnormal tissue growth can be prevented by high sucrose or mannitol concentrations in the medium or by addition of abscisic acid.

Obendorf, Ralph L.; Wettlaufer, Scott H.

1984-01-01

112

Seed banks and seed population dynamics of halophytes  

Microsoft Academic Search

In this review I will describe the importance of seed banks and thepopulation dynamics of seeds on the distribution of species in salinehabitats. The main questions being examined in this review include: 1.Does the seed bank represent the flora of the entire salinity gradient or isit restricted to the species in each zonal community? 2. Is the size andspecies composition

Irwin A. Ungar

2001-01-01

113

Seeds of confusion : the impact of policies on seed systems  

Microsoft Academic Search

Seed is basic to crop production. Next to its importance in production, food security and rural development, seed is a key element in many debates about technology development and transfer, biodiversity, globalisation and equity. The sustainable availability of good quality seed is thus an important development issue. This study deals with the impact different types of regulation have on how

N. P. Louwaars

2007-01-01

114

Evolutionary Ecology of Seed Dormancy and Seed Size  

Microsoft Academic Search

The theoretical ideas underpinning the evolution of seed dormancy and seed mass are briefly reviewed. Comparative tests of these theoretical ideas are then presented; all tests use modern comparative methods to allow accurate, meaningful comparisons across species. The comparative analyses of seed dormancy demonstrate that species that average the environment across time, by having long-lived adults or space as a

Mark Rees

1996-01-01

115

Laboratory measurement of seed drill seed spacing and velocity of fall of seeds using high-speed camera system  

Microsoft Academic Search

Due to the individual volumes of fluted wheel metering systems each holding more than one seed, seed drills provide random seed distribution. A prerequisite for the improvement of seed spacing is the fast and reliable evaluation of distribution accuracy in laboratory tests.A high-speed camera system for evaluating seed spacing uniformity and velocity of fall of seeds is described. The performance

D. Karayel; M. Wiesehoff; A. Özmerzi; J. Müller

2006-01-01

116

Physical View of Cloud Seeding  

ERIC Educational Resources Information Center

Reviews experimental data on various aspects of climate control. Includes a discussion of (1) the physics of cloud seeding, (2) the applications of cloud seeding, and (3) the role of statistics in the field of weather modification. Bibliography. (LC)

Tribus, Myron

1970-01-01

117

Physical View of Cloud Seeding  

ERIC Educational Resources Information Center

|Reviews experimental data on various aspects of climate control. Includes a discussion of (1) the physics of cloud seeding, (2) the applications of cloud seeding, and (3) the role of statistics in the field of weather modification. Bibliography. (LC)|

Tribus, Myron

1970-01-01

118

Physiological Basis of Seed Germination.  

National Technical Information Service (NTIS)

This is the first collection of studies on the various aspects of seed germination to be published in Soviet literature. Works of practical significance have been given primary consideration: the presowing treatment of seeds to improve their quality and t...

K. E. Ovcharov

1977-01-01

119

Injection-seeded Tm:YAG laser at room temperature  

NASA Astrophysics Data System (ADS)

The solid-state, tunable, narrowband, high pulse energy and high reliability lasers are attractive source for LIDAR system. In this paper, we demonstrated a diode pumped injection-seeded 2 ?m Tm:YAG laser. By inserting two F-P etalons into the laser cavity, linear-polarized single-frequency seed-laser was achieved at a wavelength of 2013 nm, with a maximum output power of 60 mW. Long-term and short-term frequency stability for the seed-laser were 1.27 × 10- 7 and 97 Hz/?s, respectively. High power Q-switched laser was operated using a bowtie cavity, the bidirectional output of which was favorable for the injection-seeded. After injecting the seed-laser to the power-laser, single-frequency, nearly transform-limited pulsed 2 ?m laser was obtained. As much as 2.0 mJ output energy was achieved at an operating repetition rate of 15 Hz, with a pulse width of 356.2 ns.

Wu, Chunting; Ju, Youlun; Wang, Qiang; Wang, Zhenguo; Yao, Baoquan; Wang, Yuezhu

2011-02-01

120

Seeds of the world : Journey to Forever  

NSDL National Science Digital Library

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.

Addison, Keith

2001-01-01

121

Tree Seed Technology Training Course: Student Outline.  

ERIC Educational Resources Information Center

|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,…

Bonner, F. T.; And Others

122

46 CFR 148.310 - Seed cake.  

Code of Federal Regulations, 2012 CFR

...not apply to solvent-extracted rape seed meal, pellets, soya bean meal, cotton seed meal, or sunflower seed meal thatâ ...content of the seed cake. (e) The seed cake must be kept as dry as practical at all times. (f) If the seed cake is...

2012-10-01

123

46 CFR 148.310 - Seed cake.  

Code of Federal Regulations, 2011 CFR

...not apply to solvent-extracted rape seed meal, pellets, soya bean meal, cotton seed meal, or sunflower seed meal thatâ ...content of the seed cake. (e) The seed cake must be kept as dry as practical at all times. (f) If the seed cake is...

2011-10-01

124

Cloud Seeding Frequently Asked Questions  

NSDL National Science Digital Library

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?"

Griffith, Don; Solak, Mark

2008-01-07

125

SEEDS: Airport Management Database System  

Microsoft Academic Search

. The article describes an airport database management system,which is a part of large simulation environment developed underthe ESPRIT project SEEDS. Airport management database is a distributedcomputing system written entirely in Java and connected tothe rest of the SEEDS system through CORBA interface. The majorityof the SEEDS modules is written in C++ and communicates throughCORBA. The airport management database consists

Tomás Hrúz; Martin Becka; Antonello Pasquarelli

2000-01-01

126

Corridors cause differential seed predation.  

SciTech Connect

Orrock, John, L., and Ellen I. Damschen. 2005. Corridors cause differential seed predation. Ecol. Apps. 15(3):793-798. Abstract. Corridors that connect disjunct populations are heavily debated in conservation, largely because the effects of corridors have rarely been evaluated by replicated, large-scale studies. Using large-scale experimental landscapes, we found that, in addition to documented positive effects, corridors also have negative impacts on bird-dispersed plants by affecting seed predation, and that overall predation is a function of the seeds? primary consumer (rodents or arthropods). Both large-seeded Prunus serotina and small-seeded Rubus allegheniensis experienced greater predation in connected patches. However, P. serotina experienced significantly less seed predation compared to R. allegheniensis in unconnected patches, due to decreased impacts of rodent seed predators on this large-seeded species. Viewed in light of previous evidence that corridors have beneficial impacts by increasing pollination and seed dispersal, this work demonstrates that corridors may have both positive and negative effects for the same plant species at different life stages. Moreover, these effects may differentially affect plant species within the same community: seeds primarily consumed by rodents suffer less predation in unconnected patches. By shifting the impact of rodent and arthropod seed predators, corridors constructed for plant conservation could lead to shifts in the seed bank.

JOHN L. ORROCk; ELLEN I. DAMSCHEN

2005-06-01

127

Seeding Habits of Swamp Tupelo.  

National Technical Information Service (NTIS)

Swamp tupelo (Nyssa sylvatica var. biflora (Walt.) Sarg.) seed production was studied for 4 years by using 1/10-milacre seed traps in a large headwater swamp in South Carolina. Seedfall varied from 0 in 1964 to 833,000 seed per acre in 1966. Peak seedfall...

D. S. DeBell D. D. Hook

1969-01-01

128

Seed Starch Synthesis  

Microsoft Academic Search

Maize plants accumulate starch as a carbohydrate energy reserve in the seed endosperm. Starch is composed of two homopolymers of ? -D-glucose, amylose (Am) and amylopectin (Ap), which are organized to form water insoluble semicrystalline granules. Am comprises ~25% of starch, and is essentially a linear molecule in which glucosyl monomers are joined via ? -(1?4) linkages to form long

Martha James; Alan Myers

129

Teens Parenting. Project Seed.  

ERIC Educational Resources Information Center

One of eight papers from Project Seed, this paper describes Teens Parenting, a program that brings together a group of parenting teenagers for a 20-week learning experience using the "Nurturing Program for Teenage Parents and Their Families." It is noted that the program is open to all teenage parents in the area, whether or not they are currently…

Drasby, Gail; And Others

130

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 ...

131

Seeded Region Growing  

Microsoft Academic Search

We present here a new algorithm for segmentation of intensity images which is robust, rapid, and free of tuning parameters. The method, however, requires the input of a number of seeds, either individual pixels or regions, which will control the formation of regions into which the image will be segmented. In this correspondence, we present the algorithm, discuss briefly its

Rolf Adams; Leanne Bischof

1994-01-01

132

Seed Sectors in Transition  

Microsoft Academic Search

The seed sectors in former Soviet countries that have developed under a centrally planned economy need to respond to the changing business environment following perestroika. In the Soviet times, each step in the process from breeding through multiplication and quality control, and distribution had its own institutions (public) with their assigned task, group of professionals, and in theory all the

Gary Reusché

2002-01-01

133

CHEATGRASS CONTROL AND SEEDING  

Microsoft Academic Search

urrently, there is a rebirth of interest in using herbicides to control the invasive annual cheatgrass in conjunction with seeding perennial grasses, forbs, and shrubs to re - store what once were big sagebrush\\/bunchgrass plant commu- nities. This work is being conducted by a new generation of range scientists who may benefit from knowledge of how some of the basic

James A. Young; Charlie D. Clements

134

Seed dormancy and germination  

Microsoft Academic Search

Seed dormancy and germination are complex adaptive traits of higher plants that are influenced by a large number of genes and environmental factors. Studies of genetics and physiology have shown the important roles of the plant hormones abscisic acid and gibberellin in the regulation of dormancy and germination. More recently, the use of quantitative genetics and mutant approaches has allowed

Maarten Koornneef; Leónie Bentsink; Henk Hilhorst

2002-01-01

135

SEED Software Annotations.  

ERIC Educational Resources Information Center

|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…

Bethke, Dee; And Others

136

Seed mass and mast seeding enhance dispersal by a neotropical scatter-hoarding rodent  

Microsoft Academic Search

Many tree species that depend on scatter-hoarding animals for seed dispersal produce massive crops of large seeds at irregular intervals. Mast seeding and large seed size in these species have been explained as adaptations to increase animal dispersal and reduce predation. We studied how seed size and seed abundance simultaneously influenced seed dispersal and predation by scatter-hoarding rodents in the

Patrick A. Jansen; F. J. J. M. Bongers; Lia Hemerik

2004-01-01

137

Laser Seeding for Biomolecular Crystallization  

NASA Astrophysics Data System (ADS)

Seeding is a powerful tool for biomolecular crystal growth because it permits the decoupling of crystal nucleation and growth. However, its usefulness is limited by the inability of current techniques to manipulate single seeds and it is often considered as a last resort in protein crystal growth trials. Here, a novel seeding technique is described in which a laser beam is used to select and transfer microscopic seed crystals in a growth solution. The technique permits the non-mechanical, in situ manipulation of individual seed crystals as small as one micron. Coupled with a conventional microscope the laser seeding procedure is monitored in real time under high magnification. Crystals of tomato bushy stunt virus have been successfully seeded and grown in test trials.

Bancel, P. A.; Cajipe, V. B.; Rodier, F.; Witz, J.

1998-03-01

138

Construct Arguments: Pumpkin Seeds  

NSDL National Science Digital Library

This professional development video clip shows students engaged in the Common Core Practice Standard #3âConstruct 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.

Boston, Wghb

2013-01-01

139

Universal Seed Skin Segmentation  

Microsoft Academic Search

\\u000a We present a principled approach for general skin segmentation using graph cuts. We present the idea of a highly adaptive\\u000a universal seed thereby exploiting the positive training data only. We model the skin segmentation as a min-cut problem on\\u000a a graph defined by the image color characteristics. The prior graph cuts based approaches for skin segmentation do not provide\\u000a general

Rehanullah Khan; Allan Hanbury; Julian Stöttinger

2010-01-01

140

Proteins of Soybean Seeds  

PubMed Central

Soybean (Glycine max) storage proteins were characterized by sedimentation and by polyacrylamide gel electrophoresis under dissociating (8 m urea) and nondissociating conditions. Three sedimenting classes of proteins were found, with sedimentation coefficients of 2.2S, 7.5S, and 11.8S. The coefficients were related to the bands obtained by electrophoretic separation. The results support the idea that relatively few proteins make up the bulk of the seed protein.

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

1974-01-01

141

Split-seed: a new tool for maize researchers.  

PubMed

Until recently, immature embryos have been a choice tissue for manipulation in culture for regeneration and production of transgenic maize plants. The utility of this explant has been compromised by low output, genotype dependence and time-consuming incubation in tissue culture. We have developed a new explant, the split-seed, which addresses these limitations by formally treating each seed as though it were a "dicot". By splitting maize seed longitudinally, three different tissues: the scutellum, the coleoptilar-ring and the shoot apical meristems are simultaneously exposed. The cells of these tissues can be made competent to enhance the regeneration, given that the molecular networks resulting from exposure of the split-seed to hormones is likely to be different from whole seed and, in turn, affects the in vitro response. Using this explant, callus induction frequency exceeded 92% and the regeneration frequency was 76%. The mean number of shoots regenerated via callus was 11 shoots per callus clump and 28 shoots per explant at first sub-culture. All of the regenerated plants survived and were 95% fertile. The large numbers of fertile plants produced were regenerated in 6-8 weeks. Finally, the incidence of regenerated plants varies as a function of growth regulator profile. PMID:16489455

Al-Abed, Diaa; Rudrabhatla, Sairam; Talla, Reddy; Goldman, Stephen

2006-02-18

142

New genes in traditional seed systems: diffusion, detectability and persistence of transgenes in a maize metapopulation.  

PubMed

Gene flow of transgenes into non-target populations is an important biosafety concern. The case of genetically modified (GM) maize in Mexico has been of particular interest because of the country's status as center of origin and landrace diversity. In contrast to maize in the U.S. and Europe, Mexican landraces form part of an evolving metapopulation in which new genes are subject to evolutionary processes of drift, gene flow and selection. Although these processes are affected by seed management and particularly seed flow, there has been little study into the population genetics of transgenes under traditional seed management. Here, we combine recently compiled data on seed management practices with a spatially explicit population genetic model to evaluate the importance of seed flow as a determinant of the long-term fate of transgenes in traditional seed systems. Seed flow between farmers leads to a much wider diffusion of transgenes than expected by pollen movement alone, but a predominance of seed replacement over seed mixing lowers the probability of detection due to a relative lack of homogenization in spatial frequencies. We find that in spite of the spatial complexities of the modeled system, persistence probabilities under positive selection are estimated quite well by existing theory. Our results have important implications concerning the feasibility of long term transgene monitoring and control in traditional seed systems. PMID:23056246

van Heerwaarden, Joost; Ortega Del Vecchyo, Diego; Alvarez-Buylla, Elena R; Bellon, Mauricio R

2012-10-03

143

Spatial variability in seed predation in Primula farinosa: local population legacy versus patch selection.  

PubMed

Spatio-temporal variation in seed predation may strongly influence both plant population dynamics and selection on plant traits. The intensity of seed predation may depend on a number of factors, but the relative importance of previous predator abundance ("local legacy"), spatial distribution of the host plant, environmental factors and plant characteristics has been explored in few species. We monitored seed predation in the perennial herb Primula farinosa, which is dimorphic for scape length, during 5 consecutive years, in a 10-km x 4-km area comprising 79 P. farinosa populations. A transplant experiment showed that the seed predator, the oligophagous tortricid moth Falseuncaria ruficiliana, was not dispersal limited at the spatial scale corresponding to typical distances between P. farinosa populations. Correlations between population characteristics and incidence and intensity of seed predation varied among years. The incidence of the seed predator was positively correlated with host population size and mean number of flowers, while intensity of seed predation in occupied patches was positively related to the frequency of the long-scaped morph in 2 years and negatively related to host population size in 1 year. In both scape morphs, predation tended to increase with increasing frequency of the long morph. There was no evidence of a local legacy; incidence and intensity of seed predation were not related to the abundance of the seed predator in the population in the previous year. Taken together, the results indicate that among-population variation in seed predation intensity is determined largely by patch selection and that the seed predator's preference for tall and many-flowered inflorescences may not only affect selection on plant traits within host plant populations, but also the overall intensity of seed predation. PMID:19214585

Vanhoenacker, Didrik; Agren, Jon; Ehrlén, Johan

2009-02-12

144

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

Code of Federal Regulations, 2013 CFR

...respective seeds. (b) Seed consigned to a seed cleaning or processing establishment, for cleaning or processing for seeding purposes, need not be labeled to show the information required on each container under sections 201 (a), (b),...

2013-01-01

145

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.  

Code of Federal Regulations, 2010 CFR

...false Certified seed potatoes, and seed corn or maize. 10.57 Section 10.57...ETC. General Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification...

2009-04-01

146

19 CFR 10.57 - Certified seed potatoes, and seed corn or maize.  

Code of Federal Regulations, 2013 CFR

...false Certified seed potatoes, and seed corn or maize. 10.57 Section 10.57...ETC. General Provisions Potatoes, Corn, Or Maize § 10.57 Certified seed potatoes, and seed corn or maize. Claim for classification...

2013-04-01

147

The Seed Scene: An Outdoor Teaching Technique  

ERIC Educational Resources Information Center

|The study of seeds and their dispersal is an excellent way to help students understand basic concepts which will help them in their adult decision-making activities regarding environmental problems. This article discusses the purpose of seeds, aspects of seeds, and collecting seeds. Classroom and outdoor activities with seeds are listed. (NQ)|

Rillo, Thomas J.

1976-01-01

148

Seed Invasion Filters and Forest Fire Severity  

Microsoft Academic Search

Forest seed dispersal is altered after fire. Using seed traps, we studied impacts of fire severity on timing of seed dispersal, total seed rain, and seed rain richness in patches of high and low severity fire and unburned Douglas-fir ( Pseudotsuga menziesii) forests in the Fischer and Tyee fire complexes in the eastern Washington Cascades. Unburned plots had the lowest

Tom R. Cottrell; Paul F. Hessburg; Jonathan A. Betz

2008-01-01

149

Inheritance of Egusi Seed Type in Watermelon  

Microsoft Academic Search

An unusual seed mutant in watermelon (Citrullus lanatus var. lanatus) has seeds with a fleshy pericarp, commonly called egusi seeds. The origin of the phenotype is unknown, but it is widely cultivated in Nigeria for the high protein and carbohydrate content of the edible seeds. Egusi seeds have a thick, fleshy pericarp that appears during the second to third week

G. Gusmini; T. C. WEHNER; R. L. JARRET

2004-01-01

150

Seeded nanosecond optical parametric generator for trace gas measurements  

NASA Astrophysics Data System (ADS)

We report on the development effort of a nanosecond-pulsed seeded optical parametric generator (OPG) for remote trace gas measurements. The seeded OPG output light is single frequency with high spectral purity and is widely tunable both at 1600nm and 3300nm with an optical-optical conversion efficiency of ~40%. We demonstrated simultaneous tuning over the methane (CH4) absorption line at idler wavelength, 3270.4nm, and carbon dioxide (CO2) absorption line at signal wavelength, 1578.2nm. In this paper, we will also discuss open-path atmospheric measurements with this newly developed laser source.

Numata, Kenji; Li, Steve; Riris, Haris; Wu, Stewart; Seas, Antonios; Yu, Anthony; Krainak, Michael; Abshire, James

2010-02-01

151

[Seed aging and survival mechanisms].  

PubMed

Aging and death are universal to living systems. In temperate climate latitudes the mature seeds of higher plants are exposed to aging and have developed resistance mechanisms allowing survival and plant propagation. In addition to the physicochemical properties of the seed that confer stress resistance, the protein metabolism contributes importantly to longevity mechanisms. Recently, genetic studies have demonstrated the occurrence of the Protein L-isoaspartyl methyltransferase repair enzyme in controlling age-related protein damages and seed survival. These protective mechanisms by protein repair are widespread in all kingdoms, so that the use of seeds as models to study these controlling processes offers the prospect of understanding longevity mechanisms better. PMID:18980745

Grappin, Philippe; Bourdais, Gildas; Collet, Boris; Godin, Béatrice; Job, Dominique; Ogé, Laurent; Jullien, Marc; Rajjou, Loïc

2008-11-04

152

Evaluation of a mechanical seed planter for transplanting Zostera marina (eelgrass) seeds  

Microsoft Academic Search

Few seagrass transplant projects worldwide have relied on seeds, and those projects using Zostera marina (eelgrass) seeds have generally found low rates of seedling establishment (<10%). We compared seedling establishment achieved by a mechanical seed planter with seeds broadcast on the sediment surface by hand. The planter injected seeds into the sediment by pumping the seeds, suspended in a gelatin-based

Robert J. Orth; Scott R. Marion; Steven Granger; Michael Traber

2009-01-01

153

INTEGRATING MEASUREMENTS OF SEED AVAILABILITY AND REMOVAL TO ESTIMATE WEED SEED LOSSES DUE TO PREDATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

To fully understand seed predation and as a first step in the search for effective ways to enhance weed seed losses in arable fields, we developed a conceptual model that integrates seed dispersal, seed burial and seed demand, the three processes that describe the dynamics of summer annual weed seed...

154

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

Microsoft Academic Search

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

VIRGINIA E. SHEPHERD; COLIN A. CHAPMAN

1998-01-01

155

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

PubMed

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

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

2008-09-14

156

Wheat Seed System in Ethiopia: Farmers' Varietal Perception, Seed Sources, and Seed Management  

Microsoft Academic Search

Knowledge and information on farmers' perception and its influence on adoption of modern wheat varieties, awareness and source of new wheat production technology, wheat seed sources, and on-farm seed-management practices remain sporadic in Ethiopia. This study was conducted to understand the functioning of the wheat seed system in four major wheat-growing areas of Ethiopia. A total of 304 wheat growers

Zewdie Bishaw; P. C. Struik; A. J. G Van Gastel

2010-01-01

157

Active nursery projects at the Missoula Technology and ... - Treesearch  

Treesearch

... and technology transfer services to Federal, State, and cooperator forest tree ... Current projects at MTDC include a nursery soil moisture meter, remote data ... hardwood cuttings preparation equipment, and seed orchard duff sweeper.

158

Seeds in Space Experiment Results (Abstract Only).  

National Technical Information Service (NTIS)

Two million seeds of 120 different varieties representing 106 species, 97 genera, and 55 plant families were flown aboard the Long Duration Exposure Facility (LDEF). The seeds were housed on the space exposed experiment developed for students (SEEDS) tray...

J. A. Alston

1991-01-01

159

Selecting Random Number Seeds in Practice.  

National Technical Information Service (NTIS)

A pseudorandom number generator, like a multiplicative congruential generator, depends on its initial value or seed. The computer may select a seed using its internal clock. Alternatively the simulation analyst may use Fishman's tables with seeds spaced 1...

J. P. C. Kleijnen

1985-01-01

160

Seed cryopreservation of Halimium and Helianthemum species.  

PubMed

Seed germination of four Halimium species [H. atriplicifolium, H.hHalimifolium, H. ocymoides, H. umbellatum] and eight Helianthemum species [H. almeriense pau, H. appeninum.,H. cinereum, H. hirtum, H. marifolium, H. nummularium, H. syriacum, H. squamatum], all cistaceae species from the mediterranean region, was studied after seed storage in liquid nitrogen (Ln, -196C) for four months. In all samples assayed, mechanical scarification of the seed coat was carried out to enhance seed germination. For most samples studied, final germination percentages were unaffected by storage of seeds in Ln, both for intact seeds and for scarified seeds. The germination rate of cryopreserved seeds, expressed as days to reach 50 percent of the final germination percentage, was lower only for four samples of intact seeds and for three samples of scarified seeds. Therefore, this study shows that seed cryopreservation could be a suitable procedure for the long-term seed conservation of several Halimium and Helianthemum species. PMID:19137189

Pérez-García, Félix; González-Benito, M Elena

161

A guide to forest seed handling  

SciTech Connect

This guide to forest seed handling focuses on seed quality, i.e., the physiological viability and vigor of the seeds. Seed and fruit development, germination, and dormancy and the fundamentals of planning seed collections are covered. The guide includes discussions on seed collection of fallen fruits or seeds from the forest floor from the crowns of felled trees, and from standing trees with access from the ground and with other means of access. Also considered are precautions to be followed during fruit and seed handling between collection and processing. The different stages in seed processing are detailed, including extraction, depulping, drying, tumbling and threshing, dewinging, cleaning, grading, and mixing. Factors affecting seed longevity in storage and the choice of storage methods are reviewed. Different forms of seed pretreatment and seed testing methods are described.

Willan, R.L.

1986-01-01

162

A preliminary investigation of pre-dispersal seed predation by Acanthoscelides schrankiae Horn (Coleoptera: Bruchidae) in Mimosa bimucronata (DC.) Kuntze trees.  

PubMed

This is the first record of Acanthoscelides schrankiae Horn. feeding in seeds of Mimosa bimucronata (DC.) Kuntze. We investigated the pattern of oviposition and seed exploitation by A. schrankiae, and the distribution of mature fruits and seed predation in the inflorescences. We also compared the percentage of predated seeds, the total dry weight of fruits and non-predated seeds, the percentage of aborted seeds, and the percentage of non-emergent insects, among different quadrants of the M. bimucronata canopy. To determine the occurring species, the emergence of bruchids and parasitoids was observed in the laboratory, resulting altogether, only in individuals of A. schrankiae and Horismenus sp. (Hymenoptera: Eulophidae) species, respectively. Mean number of fruits produced in the median region of inflorescence was significantly higher than in the inferior and superior regions, and the frequencies (observed and expected) of predated and non-predated seeds differed among the different regions of inflorescence. Females of A. schrankiae laid their eggs on fruits, and larvae, after emergence, perforated the exocarp to reach the seeds. Most fruits presented one to three eggs and only one bruchid larva was observed in each seed. The highest value of the rate "number of eggs/fruit" and the highest percentage of predated seeds were recorded in April. Dry weight of fruits (total) and seeds (non-predated), proportions of predated seeds, seed abortions, and non-emergent seed predators, were evenly distributed in the canopy. PMID:17607452

Silva, Laura A; Maimoni-Rodella, Rita C S; Rossi, Marcelo N

163

Simulation of free-electron lasers seeded with broadband radiation  

SciTech Connect

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.

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

2011-03-10

164

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...

165

Training for Certification: Seed Treatment.  

ERIC Educational Resources Information Center

|This Cooperative Extension Service publication from Mississippi State University is a training guide for commercial pesticide applicators. Focusing specifically on the treatment of seeds with pesticides, this publication is meant to prepare one to take the written examination for Environmental Protection Agency Seed Treatment certification.…

Mississippi State Univ., State College. Cooperative Extension Service.

166

STUDY OF A SEEDED PLASMA  

Microsoft Academic Search

A method for increasing the electrical conductivity of a gas by ; introducing a foreign element into the gas flow, and the properties of the ; resulting plasma were studied. The important chemical reactions which take place ; when a fluid is seeded were analyzed as a function of temperature and pressure. ; The seeding elements considered were the alkali

1962-01-01

167

Seed that Apple RND Generator!  

ERIC Educational Resources Information Center

|Provides instructions for "seeding" the random number generator (RND) in Apple computer programs. If RND is not seeded, students would see the same examples, questions, graphics features, or other information each time they turn on the microcomputer and run a program. (JN)|

Salyer, Darnell

1984-01-01

168

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...

169

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...

170

Efficient computation of spaced seeds  

PubMed Central

Background The most frequently used tools in bioinformatics are those searching for similarities, or local alignments, between biological sequences. Since the exact dynamic programming algorithm is quadratic, linear-time heuristics such as BLAST are used. Spaced seeds are much more sensitive than the consecutive seed of BLAST and using several seeds represents the current state of the art in approximate search for biological sequences. The most important aspect is computing highly sensitive seeds. Since the problem seems hard, heuristic algorithms are used. The leading software in the common Bernoulli model is the SpEED program. Findings SpEED uses a hill climbing method based on the overlap complexity heuristic. We propose a new algorithm for this heuristic that improves its speed by over one order of magnitude. We use the new implementation to compute improved seeds for several software programs. We compute as well multiple seeds of the same weight as MegaBLAST, that greatly improve its sensitivity. Conclusion Multiple spaced seeds are being successfully used in bioinformatics software programs. Enabling researchers to compute very fast high quality seeds will help expanding the range of their applications.

2012-01-01

171

Ripening events in seeded watermelons  

Technology Transfer Automated Retrieval System (TEKTRAN)

Seeded watermelons generally start color development in the locule (seed cavity), with color progressing to the center of the fruit during the ripening process. Soluble solids content (SSR) is thought to be highest at the blossom end. In large-fruited watermelon where only a portion of the fruit is...

172

Singular spectrum analysis applied to ultrasonic detection and imaging of brachytherapy seeds.  

PubMed

Ultrasound-guided brachytherapy using titanium-shelled radioactive seeds is a popular, effective means of treating prostate cancer. Unfortunately, implantation using needles inserted transperitoneally causes gland movement and distortion, which often results in seed misplacement and dosimetry errors. If actual seed locations could be determined in the operating room, then corrections to dosimetry errors could be made immediately. However, seed specularity, shadowing, and tissue clutter make imaging seeds difficult using conventional ultrasound. Singular spectrum analysis (SSA) shows promise for reliably imaging radioactive seeds implanted in the prostate and enabling additional corrective implantations to be made in the operating room. SSA utilizes eigenvalues derived from the diagonalized correlation matrix of envelope-detected radio-frequency echo signals to yield a P value indicative of the likelihood of a seed-specific repetitive signal. We demonstrated the potential of SSA for seed detection and imaging and illustrated the trade-off considerations for optimization of SSA in clinical applications using simulations assessing performance as a function of different levels of noise and the presence of repetitive signals with various repetition periods; experiments in an ideal scattering environment; and experiments using seeds implanted in beef. PMID:17407916

Mamou, Jonathan; Feleppa, Ernest J

2007-03-01

173

Implications of nonrandom seed abscission and global stilling for migration of wind-dispersed plant species.  

PubMed

Migration of plant populations is a potential survival response to climate change that depends critically on seed dispersal. Biological and physical factors determine dispersal and migration of wind-dispersed species. Recent field and wind tunnel studies demonstrate biological adaptations that bias seed release toward conditions of higher wind velocity, promoting longer dispersal distances and faster migration. However, another suite of international studies also recently highlighted a global decrease in near-surface wind speeds, or 'global stilling'. This study assessed the implications of both factors on potential plant population migration rates, using a mechanistic modeling framework. Nonrandom abscission was investigated using models of three seed release mechanisms: (i) a simple drag model; (ii) a seed deflection model; and (iii) a 'wear and tear' model. The models generated a single functional relationship between the frequency of seed release and statistics of the near-surface wind environment, independent of the abscission mechanism. An Inertial-Particle, Coupled Eulerian-Lagrangian Closure model (IP-CELC) was used to investigate abscission effects on seed dispersal kernels and plant population migration rates under contemporary and potential future wind conditions (based on reported global stilling trends). The results confirm that nonrandom seed abscission increased dispersal distances, particularly for light seeds. The increases were mitigated by two physical feedbacks: (i) although nonrandom abscission increased the initial acceleration of seeds from rest, the sensitivity of the seed dispersal to this initial condition declined as the wind speed increased; and (ii) while nonrandom abscission increased the mean dispersal length, it reduced the kurtosis of seasonal dispersal kernels, and thus the chance of long-distance dispersal. Wind stilling greatly reduced the modeled migration rates under biased seed release conditions. Thus, species that require high wind velocities for seed abscission could experience threshold-like reductions in dispersal and migration potential if near-surface wind speeds continue to decline. PMID:23505130

Thompson, Sally E; Katul, Gabriel G

2013-03-25

174

Heat shock effects on seed germination of five Brazilian savanna species.  

PubMed

Fire is considered an important factor in influencing the physiognomy, dynamics and composition of Neotropical savannas. Species of diverse physiognomies exhibit different responses to fire, such as population persistence and seed mortality, according to the fire frequency to which they are submitted. The aim of this study is to investigate the effects of heat shocks on seed germination of Anadenanthera macrocarpa (Benth.) Brenan, Dalbergia miscolobium Benth., Aristolochia galeata Mart. & Zucc., Kielmeyera coriacea (Spreng.) Mart. and Guazuma ulmifolia Lam., which are native species of the Brazilian savanna. The temperatures and exposure times to which the seeds were submitted were established according to data obtained in the field during a prescribed fire: 60 °C (10, 20 and 40 min), 80 °C (5, 10 and 20 min) and 100 °C (2, 5 and 10 min). Untreated seeds were used as controls. Seeds of A. galeata and K. coriacea showed high tolerance to most heat treatments, and seeds of A. macrocarpa showed a significant reduction in germination percentage after treatments of 80 °C and 100 °C. Treatments of 100 °C for 10 min reduced germination percentage for all species except G. ulmifolia, which has dormant seeds. For this species, germination was accelerated by heat treatments. The high temperatures applied did not interfere with the time to 50% germination (T(50) ) of the tolerant seeds. Seeds of the savanna species K. coriacea and A. galeata were more tolerant to heat shocks than seeds of the forest species A. macrocarpa. Guazuma ulmifolia, the forest species with seeds that germinate after heat shock, also occurs in savanna physiognomies. Overall, the high temperatures applied did not affect the germination rate of the tolerant seeds. PMID:22672775

Ribeiro, L C; Pedrosa, M; Borghetti, F

2012-06-05

175

Effect of seed mass on germination and growth in three dominant species in southern Brazilian coastal dunes.  

PubMed

The effect of seed mass on germination and growth was tested in fresh-seeds of Blutaparon portulacoides, Panicum racemosum, and Spartina ciliata, selected at random in southern Brazilian populations. The seed mass varied within a population of the three species. Both B. portulacoides and P. racemosum showed normal frequency distribution of seed mass, while S. ciliata did not. Significant differences were observed in seed germination between large and small seeds of all species. In all species the capacity of seedling elongation was greater in seedlings of large seeds than those of small ones. Relative growth rate of seedlings of P. racemosum and S. ciliata decreased with time in all seed mass size-classes. On the other hand, the relative growth rate of B. portulacoides seedlings increased during the first 40 days. Seed mass is an important biological factor, affecting seed germination, seedling elongation, and growth of these species, and favoring large seeds, specially in areas of active sand accretion like coastal dunes. PMID:12530178

Cordazzo, C V

2002-11-05

176

Wet deposition of the seeding agent after weather modification activities.  

PubMed

Weather modification activities are performed mostly by cloud seeding. Some operational projects have been conducted for more than a half century and cover planetary scales. These activities have led to large amounts of seeding agents being deposited on the ground in precipitation. The main intent of this paper is to identify the spatial pattern of silver iodide deposits after hail suppression. The spatial pattern of silver iodide deposits is determined using the weather modification project measurements from seeding agent reports, two weather radars and 316 launching sites during a 5-year period. The estimated spatial distribution of the deposits is not uniform, with the maximum silver iodide amount located in the southern part of the study area (up to 140 ?g m(-2)). Our results are comparable with the measurements performed by chemical analyses during other cloud seeding experiments. The maximum location coincides well with that of the maximum seeded hailstorm precipitation frequency. A new method for identifying the spatial pattern of wet-deposited material has been established. The location with the maximum amount is found. This method would be important as a means of placing samplers and monitoring at the representative sites because those are where most weather modification projects would be performed in the future. PMID:23589275

Curi?, Mladjen; Janc, Dejan

2013-04-16

177

[Experiment on seeding induction from seed of Demdrobium candidum].  

PubMed

Demdrobium candidum seed should be used as the explant to induce a great deal of seedings. The optimal medium for seeds germination was VW + NAA 0. 18 mg/L + 6-BA 0. 53 mg/L + GA 0. 28 mg/L + sucrose 20 g/L + banana mud 100 g/L + active carbon 10 g/L. The VW + NAA 0.18 mg/L + 6-BA 0.53 mg/L + GA 0.28 mg/L + sucrose 20 g/l + banana mud 100 g/L + active carbon 10 g/L was best for rooting of the plantlets. PMID:18300485

Du, Gang; Yang, Hai-ying; Zhu, Shao-lin; Zhang, Guang-qiu

2007-10-01

178

Sesame seed food allergy.  

PubMed

The number of reports regarding sesame seed food allergy (SFA) has increased significantly worldwide over the past two decades, either due to a genuine increase in SFA or merely an increase in its awareness. Its prevalence is difficult to estimate due to the lack of well designed prospective population-based studies. Based on the available data, we estimate that SFA affects 0.1-0.2 % of the population, in areas where the food is available. Albeit this prevalence appears to be relatively low, it is approximately one-half of that of persistent cow's milk allergy. While only one fatality has been reported, the significant number of SFA patients presenting as anaphylaxis indicates the potential risk. Many reports based the diagnosis of SFA on sensitization criteria alone, particularly amongst atopic dermatitis patients. Elimination of sesame from the diet of these children utilizing such criteria is not justified, and may even increase the risk for developing SFA. PMID:22610362

Dalal, Ilan; Goldberg, Michael; Katz, Yitzhak

2012-08-01

179

Laser Seeding of the Storage-Ring Microbunching Instability for High-Power Coherent Terahertz Radiation  

NASA Astrophysics Data System (ADS)

We report the first observation of laser seeding of the storage-ring microbunching instability. Above a threshold bunch current, the interaction of the beam and its radiation results in a coherent instability, observed as a series of stochastic bursts of coherent synchrotron radiation (CSR) at terahertz frequencies initiated by fluctuations in the beam density. We have observed that this effect can be seeded by imprinting an initial density modulation on the beam by means of laser “slicing.” In such a situation, most of the bursts of CSR become synchronous with the pulses of the modulating laser and their average intensity scales exponentially with the current per bunch. We present detailed experimental observations of the seeding effect and a model of the phenomenon. This seeding mechanism also creates potential applications as a high-power source of CSR at terahertz frequencies.

Byrd, J. M.; Hao, Z.; Martin, M. C.; Robin, D. S.; Sannibale, F.; Schoenlein, R. W.; Zholents, A. A.; Zolotorev, M. S.

2006-08-01

180

Laser Seeding of the Storage-Ring Microbunching Instability for High-Power Coherent Terahertz Radiation  

SciTech Connect

We report the first observation of laser seeding of the storage-ring microbunching instability. Above a threshold bunch current, the interaction of the beam and its radiation results in a coherent instability, observed as a series of stochastic bursts of coherent synchrotron radiation (CSR) at terahertz frequencies initiated by fluctuations in the beam density. We have observed that this effect can be seeded by imprinting an initial density modulation on the beam by means of laser ''slicing.'' In such a situation, most of the bursts of CSR become synchronous with the pulses of the modulating laser and their average intensity scales exponentially with the current per bunch. We present detailed experimental observations of the seeding effect and a model of the phenomenon. This seeding mechanism also creates potential applications as a high-power source of CSR at terahertz frequencies.

Byrd, J. M.; Hao, Z.; Martin, M. C.; Robin, D. S.; Sannibale, F.; Schoenlein, R. W.; Zholents, A. A.; Zolotorev, M. S. [Ernest Orlando Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720 (United States)

2006-08-18

181

Indirectly-seeded optical parametric generation in periodically poled lithium niobate  

NASA Astrophysics Data System (ADS)

We report a technique for injection-seeding optical parametric generation (OPG) in periodically poled lithium niobate in which the wavelength of the seed is neither that of the signal nor of the idler waves; instead, it is the wavelength resulting from the sum-frequency mixing of the pump and signal waves. We show that pulsed OPG can be appropriately seeded in this way even if the sum-frequency process is not quasi-phasematched if a pulsed laser is used as a seed, and if it is quasi-phase-matched even a low power (15 mW) HeNe beam can substantially reduce the bandwidth of the generated signal wave.

Orozco-Arellanes, M. J.; Cudney, R. S.

2003-01-01

182

Self-seeding of a pulsed double-grating Ti:sapphire laser oscillator  

SciTech Connect

A self-seeded pulsed double-grating Ti:sapphire laser oscillator consisting of a grazing incidence cavity geometry with a pair of gratings and a standing-wave cavity pumped by a frequency-doubled Nd:YAG laser was developed and characterized. With self-seeding, narrow-linewidth single-longitudinal-mode (SLM) operation and SLM scanning were possible with a reduced lasing threshold, which was desirable for the intended applications.

Tamura, Koji

2008-04-01

183

Self-seeding of a pulsed double-grating Ti:sapphire laser oscillator  

Microsoft Academic Search

A self-seeded pulsed double-grating Ti:sapphire laser oscillator consisting of a grazing incidence cavity geometry with a pair of gratings and a standing-wave cavity pumped by a frequency-doubled Nd:YAG laser was developed and characterized. With self-seeding, narrow-linewidth single-longitudinal-mode (SLM) operation and SLM scanning were possible with a reduced lasing threshold, which was desirable for the intended applications.

Koji Tamura; Koji

2008-01-01

184

Hypoxia and Imbibition Injuries to Aging Seeds  

Microsoft Academic Search

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%

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

2003-01-01

185

7 CFR 201.50 - Weed seed.  

Code of Federal Regulations, 2013 CFR

...REGULATIONS Purity Analysis in the Administration of the Act § 201.50 Weed seed. Seeds (including bulblets or tubers) of plants shall be considered weed seeds when recognized as weed seeds by the law or rules and regulations of the...

2013-01-01

186

Improvements on a Reliable Oak Seed Trap.  

National Technical Information Service (NTIS)

The need for seed trap longevity, capture of heavy seed, and protection from predation in several forest types for long-term studies of seed production prompted seed trap design improvements. Critical improvements were achieved by painting the trap with a...

C. N. Phillips M. K. Burke T. B. Hunnicutt

1995-01-01

187

THz generation by DFG from two seeded PPLN-OPGs  

Microsoft Academic Search

A continuous and tunable operation from 1.6 to 4.5 THz has been demonstrated using a difference frequency generation (DFG) scheme by using the nonlinear optical crystal 4-dimethylamino-N-methyl-4-stilbazolium-tosylate (DAST) as the DFG crystal. The scheme was based on DFG between two seeded optical parametric generators. The THz bandwidth was 2.4 GHz. A high-resolution transmission spectrum of water vapor in air was

Rashid Alkuwari; Peter E. Powers; Joseph W. Haus; Koji Suizu; Hiromasa Ito

2005-01-01

188

Terahertz generation with tandem seeded optical parametric generators  

Microsoft Academic Search

A simple difference frequency generation (DFG) scheme based on two seeded optical parametric generators is presented as a tunable terahertz (THz) source. Using the nonlinear optical crystal 4-dimethylamino-N-methyl-4-stilbazolium-tosylate (DAST) as the DFG crystal, our system has demonstrated continuous and seamless tunable operation from 1.6 to 4.5 THz. The output bandwidth of the THz source is 2.4 GHz. The utility of

P. E. Powers; R. A. Alkuwari; J. W. Haus; K. Suizu; H. Ito

2005-01-01

189

The role of variable weather for the dynamics of a seed-seed predator system  

Microsoft Academic Search

A simple model is presented describing the interaction between weather conditions, seed production of a longlived herb, Vincetoxicum hirundinaria (Asclepiadaceae), and abundance of a predispersal seed predator, Euphranta connexa (Diptera, Tephritidae). The model is used to investigate the role of weather-induced fluctuations in seed set on the interaction between plant and seed predator and the resulting longterm production of seeds

Christer Solbreck; Birgitta Sillén-Tullberg

1986-01-01

190

INCORPORATING ANIMAL BEHAVIOR INTO SEED DISPERSAL MODELS: IMPLICATIONS FOR SEED SHADOWS  

Microsoft Academic Search

Seed dispersal fundamentally influences plant population and community dynamics but is difficult to quantify directly. Consequently, models are frequently used to describe the seed shadow (the seed deposition pattern of a plant population). For vertebrate- dispersed plants, animal behavior is known to influence seed shadows but is poorly integrated in seed dispersal models. Here, we illustrate a modeling approach that

Sabrina E. Russo; Stephen Portnoy; Carol K. Augspurger

2006-01-01

191

Echo-Enabled Harmonic Generation for Seeded FELs  

SciTech Connect

In the x-ray wavelengths, the two leading FEL concepts are the self-amplified spontaneous emission (SASE) configuration and the high-gain harmonic generation (HGHG) scheme. While the radiation from a SASE FEL is coherent transversely, it typically has rather limited temporal coherence. Alternatively, the HGHG scheme allows generation of fully coherent radiation by up-converting the frequency of a high-power seed laser. However, due to the relatively low up-frequency conversion efficiency, multiple stages of HGHG FEL are needed in order to generate x-rays from a UV laser. The up-frequency conversion efficiency can be greatly improved with the recently proposed echo-enabled harmonic generation (EEHG) technique. In this work we will present the concept of EEHG, and address some practically important issues that affect the performance of the seeding. We show how the EEHG can be incorporated in the FEL scheme and what is the expected performance of the EEHG seeded FEL. We will then briefly describe the first proof-of-principle EEHG experiment carried out at the Next Linear Collider Test Accelerator (NLCTA) at SLAC. We will also discuss latest advances in the echo-scheme approach, and refer to subsequent modifications of the original concept.

Stupakov, G.; /SLAC

2011-05-19

192

Synthetic clonal reproduction through seeds.  

PubMed

Cloning through seeds has potential revolutionary applications in agriculture, because it would allow vigorous hybrids to be propagated indefinitely. However, asexual seed formation or apomixis, avoiding meiosis and fertilization, is not found in the major food crops. To develop de novo synthesis of apomixis, we crossed Arabidopsis MiMe and dyad mutants that produce diploid clonal gametes to a strain whose chromosomes are engineered to be eliminated after fertilization. Up to 34% of the progeny were clones of their parent, demonstrating the conversion of clonal female or male gametes into seeds. We also show that first-generation cloned plants can be cloned again. Clonal reproduction through seeds can therefore be achieved in a sexual plant by manipulating two to four conserved genes. PMID:21330535

Marimuthu, Mohan P A; Jolivet, Sylvie; Ravi, Maruthachalam; Pereira, Lucie; Davda, Jayeshkumar N; Cromer, Laurence; Wang, Lili; Nogué, Fabien; Chan, Simon W L; Siddiqi, Imran; Mercier, Raphaël

2011-02-18

193

Seeding for pervasively overlapping communities.  

PubMed

In some social and biological networks, the majority of nodes belong to multiple communities. It has recently been shown that a number of the algorithms specifically designed to detect overlapping communities do not perform well in such highly overlapping settings. Here, we consider one class of these algorithms, those which optimize a local fitness measure, typically by using a greedy heuristic to expand a seed into a community. We perform synthetic benchmarks which indicate that an appropriate seeding strategy becomes more important as the extent of community overlap increases. We find that distinct cliques provide the best seeds. We find further support for this seeding strategy with benchmarks on a Facebook network and the yeast interactome. PMID:21797441

Lee, Conrad; Reid, Fergal; McDaid, Aaron; Hurley, Neil

2011-06-15

194

Seed dormancy and ABA signaling  

PubMed Central

The seed is an important organ in higher plants, it is an important organ for plant survival and species dispersion. The transition between seed dormancy and germination represents a critical stage in the plant life cycle and it is an important ecological and commercial trait. A dynamic balance of synthesis and catabolism of two antagonistic hormones, abscisic acid (ABA) and giberellins (GAs), controls the equilibrium between seed dormancy and germination. Embryonic ABA plays a central role in induction and maintenance of seed dormancy and also inhibits the transition from embryonic to germination growth. Therefore, the ABA metabolism must be highly regulated at both temporal and spatial levels during phase of dessication tolerance. On the other hand, the ABA levels do not depend exclusively on the seeds because sometimes it becomes a strong sink and imports it from the roots and rhizosphere through the xylem and/or phloem. These events are discussed in depth here. Likewise, the role of some recently characterized genes belonging to seeds of woody species and related to ABA signaling are also included. Finally, although four possible ABA receptors have been reported, not much is known about how they mediate ABA signaling transduction. However, new publications seem to show that almost all these receptors lack several properties to consider them as such.

del Carmen Rodriguez-Gacio, Maria; Matilla-Vazquez, Miguel A

2009-01-01

195

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

PubMed Central

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.

Mandak, Bohumil; Zakravsky, Petr; Mahelka, Vaclav; Plackova, Ivana

2012-01-01

196

Can soil seed banks serve as genetic memory? A study of three species with contrasting life history strategies.  

PubMed

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

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

2012-11-21

197

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

NSDL National Science Digital Library

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.

Program, The W.

198

Effect of seed predation on seed bank size and seedling recruitment of bush lupine ( Lupinus arboreus )  

Microsoft Academic Search

Whether seed consumers affect plant establishment is an important unresolved question in plant population biology. Seed consumption\\u000a is ubiquitous; at issue is whether seedling recruitment is limited by safe-sites or seeds. If most seeds inhabit sites unsuitable\\u000a for germination, post-dispersal seed consumption primarily removes seeds that would otherwise never contribute to the population\\u000a and granivory has minimal impacts on plant

John L. Maron; Ellen L. Simms

1997-01-01

199

Laser Phase Errors in Seeded FELs  

SciTech Connect

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.

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

2012-03-28

200

Unique Method for Generating Design Earthquake Time History Seeds  

SciTech Connect

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.

R. E. Spears

2008-07-01

201

Seed Mucilage Improves Seedling Emergence of a Sand Desert Shrub  

PubMed Central

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.

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

2012-01-01

202

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

SciTech Connect

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.

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

203

A comparison of the precision of seeds deposited as loose seeds versus suture embedded seeds: a randomized trial  

Microsoft Academic Search

PurposeBrachytherapy for prostate cancer with permanent low–dose-rate seeds has been shown to be an effective treatment for early stage prostate cancer. Due to the rapid falloff of dose, accurate seed placement is critical for optimal dosimetry. One approach to achieve optimal dosimetry is the use of seeds embedded in suture material. Seeds embedded in suture may not move after implantation

Irving D. Kaplan; Paul M. Meskell; Marshal Lieberfarb; Brian Saltzman; Solomon Berg; Edward J. Holupka

2004-01-01

204

Frequency signature of water activity by biospeckle laser  

NASA Astrophysics Data System (ADS)

Biospeckle laser technique has become an important tool to investigate biological activity in several areas of science. However, due to the complexity of biological materials it is necessary to develop research processes that ensure greater efficiency in isolating areas of different activities in the same material using the biospeckle. Thus, alternative techniques, such as those related to spectral domain, allow approaches that provide a means for frequency and isolation marking of various observed phenomena. The possibility of creating frequency markers related to physical or chemical phenomena under biospeckle laser monitoring opens the way for important applications in the analysis of biological materials. In seeds, for example, one research challenge is the creation of a methodology to analyze their vigor undermining the influence of water activity. This study aimed to use wavelet transform to create maps in frequency of biological material, particularly from maize and bean seeds, seeking to isolate water activity. Wavelet transform was used in conjunction with traditional biospeckle laser methods, Fujii, Generalized Differences and Time History Speckle Patterns. The data analysis allowed access of information in different frequencies, making it possible to map activities that only occur at certain frequencies in the seeds associated to particular areas they operate, as in the case of activities present in the embryo as well as those present in the endosperm. Thus the work enabled the identification of frequency bands where water activity may be operating creating a signature useful in further works.

Cardoso, Rafael Rodrigues; Costa, Anderson Gomide; Nobre, Cassia Marques Batista; Braga, Roberto Alves

2011-04-01

205

Provisional tree seed zones and transfer guidelines for Alaska.  

Treesearch

... (128,130,000 acres) Seed transfer guidelines and standard labeling of seed ... Keywords: alaska, seed zone, seed transfer and labeling guidelines, tree distribution, tree limit, forest area, genetic diversity, climate ... Last Modified: July 21, 2013.

206

Seed Potato Systems in the Philippines: A Case Study.  

National Technical Information Service (NTIS)

Seeds and seed systems provide a vital link between cropping seasons. While systems of botanical seed reproduction have been extensively studied, the seed systems of vegetatively reproduced crops are relatively undocumented although vegetatively reproduce...

C. C. Crissman

1989-01-01

207

7 CFR 201.49 - Other crop seed.  

Code of Federal Regulations, 2013 CFR

...Administration of the Act § 201.49 Other crop seed. (a) Seeds of plants grown as crops (other than the kind(s) and variety(ies) included in the pure seed) shall be considered other crop seeds, unless...

2013-01-01

208

7 CFR 201.54 - Number of seeds for germination.  

Code of Federal Regulations, 2010 CFR

... false Number of seeds for germination. 201.54 Section 201.54...FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of...201.54 Number of seeds for germination. At least 400 seeds shall...

2009-01-01

209

7 CFR 201.54 - Number of seeds for germination.  

Code of Federal Regulations, 2010 CFR

... false Number of seeds for germination. 201.54 Section 201.54...FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of...201.54 Number of seeds for germination. At least 400 seeds shall...

2010-01-01

210

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 ...

211

Epoxy oils from plant seeds  

Microsoft Academic Search

Epoxy acids have been reported in seed oils from more than 60 species in 12 plant families. The discovery of 9,10-epoxyoctadec-12-ynoic\\u000a and 9,10-epoxy-trans-3,cis-12-octadecadienoic acids brings to six the number of natural epoxy acids now known to occur in seed oils. These latest epoxy\\u000a acids and 15,16-epoxy-cis-9,cis-12-octadecadienoic acid have been found in only one species each and at levels lower than

F. R. Earle

1970-01-01

212

Technique and interpretation in tree seed radiography  

Treesearch

Title: Technique and interpretation in tree seed radiography ... suggest how radiographs can contribute to an understanding of the biology of seed formation. ... Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows ...

213

We're Having a Seed Sale.  

ERIC Educational Resources Information Center

|Botany meets computer science in this activity, which challenges students to create a computerized seed catalog. Class members work together to develop a database of plants, much like the major seed companies do. (PR)|

Riss, Pam Helfers

1994-01-01

214

Methods for Collecting Ash (Fraxinus spp.) Seeds.  

National Technical Information Service (NTIS)

The threat of emerald ash borer (Agrilus planipennis) has necessitated ash seed collection to preserve the ash genetic resource. For ash species found only in natural areas, we have developed seed collection methods that require no special training or cer...

K. S. Knight M. E. Mason R. P. Karrfalt

2010-01-01

215

We're Having a Seed Sale.  

ERIC Educational Resources Information Center

Botany meets computer science in this activity, which challenges students to create a computerized seed catalog. Class members work together to develop a database of plants, much like the major seed companies do. (PR)

Riss, Pam Helfers

1994-01-01

216

Guide to Southern Pine Seed Sources.  

National Technical Information Service (NTIS)

The selection of an appropriate seed source is critical for successful southern pine plantations. Guides for selection of seed sources are presented for loblolly, slash, longleaf, Virginia, shortleaf, and sand pines. Separate recommendations are given for...

C. W. Lantz J. F. Kraus

1987-01-01

217

7 CFR 948.6 - Seed potatoes.  

Code of Federal Regulations, 2013 CFR

...NUTS), DEPARTMENT OF AGRICULTURE IRISH POTATOES GROWN IN COLORADO Order Regulating Handling Definitions § 948.6 Seed...certified by the official seed certification agency of the State of Colorado and bear the official tags, seals, or other appropriate...

2013-01-01

218

Inheritance of egusi seed type in watermelon.  

PubMed

An unusual seed mutant in watermelon (Citrullus lanatus var. lanatus) has seeds with a fleshy pericarp, commonly called egusi seeds. The origin of the phenotype is unknown, but it is widely cultivated in Nigeria for the high protein and carbohydrate content of the edible seeds. Egusi seeds have a thick, fleshy pericarp that appears during the second to third week of fruit development. We studied the inheritance of this phenotype in crosses of normal seeded Charleston Gray and Calhoun Gray with two plant introduction accessions, PI 490383w and PI 560006, having the egusi seed type. We found that the egusi seed type is controlled by a single recessive gene, and the symbol eg was assigned. PMID:15220396

Gusmini, G; Wehner, T C; Jarret, R L

219

Guidelines for Producing Quality Longleaf Pine Seeds.  

National Technical Information Service (NTIS)

Longleaf pine (Pinus palustris Mill.) seeds are sensitive to damage during collection, processing, treatment, and storage. High-quality seeds are essential for successfully producing nursery crops that meet management goals and perform well in the field. ...

J. M. McGilvray J. P. Barnett

2002-01-01

220

Stimulation of Lettuce Seed Germination by Ethylene.  

National Technical Information Service (NTIS)

Ethylene increased the germination of freshly imbibed lettuce (Lactuca sativa L. var. Grand Rapids) seeds. Seeds receiving either red or far-red light or darkness all responded positively to the gas. However, ethylene was apparently without effect on dorm...

F. B. Abeles J. Lonski

1968-01-01

221

Effects of bird ingestion on seed germination of Sorbus commixta  

Microsoft Academic Search

To determine the effects of ingestion by birds on seed germination, we performed germination experiments in the field and\\u000a laboratory with Sorbus commixta. The germination of four groups of seeds was compared: ingested seeds, seeds defecated in feces after feeding of fruits to\\u000a birds; extracted seeds, seeds deliberately extracted from the fruit pulp; juiced seeds, seeds plus the juice of

Tsutomu Yagihashi; Mitsuhiro Hayashida; Toshizumi Miyamoto

1998-01-01

222

Genetic and Environmental Effects on Seed Weight and Seed Yield in Switchgrass  

Microsoft Academic Search

have received little attention (Boe and Johnson, 1987; Bortnem and Boe, 1993). A positive correlation exists between seed weight and seedling The advantage of large seed on seedling growth of vigor. The objective of this study was to determine genetic and envi- switchgrass has been shown to last only up to about 10 ronmental effects on seed weight and seed

A. Boe

2003-01-01

223

Masting, seed dispersal and seed predation in the cycad Macrozamia communis  

Microsoft Academic Search

Little is known about the adaptive value of mast seeding, a common phenomenon in temperate trees and shrubs. Masting is likely to affect both seed dispersal and seed predation. In systems where similar taxa of animals are involved in these two processes, the consequences of mast seeding are likely to be particularly complicated. This study examined the effects of mast

Ruth T. Ballardie; Robert J. Whelan

1986-01-01

224

INFLUENCE OF CHEMICAL FUNGICIDE TREATMENT OF OAT SEED ON SEEDLING EMERGENCE, SEED YIELD, AND KERNEL WEIGHT  

Microsoft Academic Search

Treating sound seed of five oat (Avena sativa) varieties with six fungicide chemicals in field trials over a sdn years resulted in seed yields and kernel weights not significantly different from those of the untreated controls. Seedling emergence was increased slightly. Average seed yields were significantly different over the 3-year period but kernel weights were not. Varietal seed yields and

R. V. Clark

1971-01-01

225

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...

226

Seed size as an indicator of seed quality: a case study of Primula veris  

Microsoft Academic Search

Seed size is a widely accepted measure of seed quality, because many earlier studies have shown that large seeds have high seedling survival, growth and establishment. We tested whether ovule loss increases size of the remaining seeds and whether such size increase affects seedling establishment. We removed all except one flower from inflorescences of Primula veris L. (Primulaceae), a perennial

Kari Lehtilä; Johan Ehrlén

2005-01-01

227

[Genetic polymorphism of clones and their seed progeny in the scotch pine clone plantation].  

PubMed

Genetic variation at 12 allozyme loci (10 of them being polymorphic ones) has been studied in the archive-clone plantation of 23 Pinus sylvestris plus-trees and their seed progeny in the south-east of Ukraine. More than a half of clones had 4-8 heterozygous loci, whereas their seed progeny was marked by a lower variation than maternal trees. Seed progeny was obtained at a high outcrossing rate (t(m) = 95%). The clone progeny was characterized by a high percentage of abnormal allele segregation in megagametophytes. There was also a high frequency of significant deviation in distribution of seed embryo genotypes from the theoretically expected one according to the Hardy-Weinberg law. PMID:20201411

Korshikov, I I; Demkovich, A E

228

Laser seeding of the storage-ring microbunching instability forhigh-power coherent terahertz radiation  

SciTech Connect

We report the rst observation of laser seeding of thestorage ring microbunching instability. Above a threshold bunch current,the interaction of the beam and its radiation results in a coherentinstability, observed as a series of stochastic bursts of coherentsynchrotron radiation (CSR) at terahertz frequencies initiated byfluctuations in the beam density. We have observed that this effect canbe seeded by imprinting an initial density modulation on the beam bymeans of laser 'slicing'. In such a situation, most of the bursts of CSRbecome synchronous with the pulses of the modulating laser and theiraverage intensity scales exponentially with the current per bunch. Wepresent detailed experimental observations of the seeding effect and amodel of the phenomenon. This seeding mechanism also creates potentialapplications as a high power source of CSR at terahertzfrequencies.

Byrd, John M.; Hao, Zhao; Martin, Michael C.; Robin, David S.; Sannibale, Fernando; Schoenlein, Robert W.; Zholents, Alexander A.; Zolotorev, Max S.

2006-05-26

229

MHD heat and seed recovery technology project  

NASA Astrophysics Data System (ADS)

Heat and Seed Recovery Technology Project is discussed, including NOx behavior in the radiant boiler and secondary combustor, radiant boiler design to meet the multiple requirements of steam generation, NOx decomposition, and seed-slag separating, effects of solid or liquid seed deposits on heat transfer and gas flow in the steam and air heaters, formation, growth, and deposition of seed-slag particles, character of the combustion gas effluents, and the corrosion and erosion of ceramic and metallic materials of construction.

Petrick, M.; Johnson, T. R.

1980-08-01

230

Laser Initiation and Radiofrequency Sustainment of Seeded Air Plasmas  

NASA Astrophysics Data System (ADS)

Seeded gas plasmas and air constituents have been created by a 193 nm laser and radiofrequency sources. We have obtained 10^14/cm^3 plasma densities with initial electron temperatures of 0.3 eV in TMAE (tetrakis (dimethylamino) ethylene) by laser photoionization. We developed a fast Langmuir probe analysis of plasma decay independent of ion species mix. Langmuir probe and optical emission data illustrating the density and temperature decay with TMAE mixed with nitrogen is presented. Simulations of antenna coupling, wave frequencies, wave propagation, and power absorption are compared with experimental observations for radiofrequency plasma sources. The source produces plasma densities of 2 × 10^13/cm^3in an 8500 cm^3 volume at electron temperatures of 5 eV in 10 mTorr Ar in a nonuniform magnetic field. Radiofrequency plasma production at pressures from 2-760 Torr using Ar and laser initiated TMAE plasmas as seeds will be discussed.

Scharer, J.; Ding, G.; Gui, H.; Kelly, K.; Paller, E.

1999-11-01

231

Exudation of an allelopathic substance lepidimoide from seeds during germination  

Microsoft Academic Search

Lepidimoide promotes growth of the cockscomb hypocotyl. It is exuded from germinating seeds of various plant species into their culture environment. The mode of exudation of lepidimoide from seeds into the culture solution, using sunflower and buckwheat seeds, was studied in relation to seed germination. In the dry seeds, about 75% of the lepidimoide was found in the seed coat

Kosumi Yamada; Seiji Kosemura; Shosuke Yamamura; Koji Hasegawa

1997-01-01

232

Seed Scarification Requirement in Doum (Hyphaene thebaica Mart.)  

Microsoft Academic Search

Seed dormancy is a means to allow seeds to initiate germination when conditions are normally favorable for germination and survival of the seedlings. Dormancy can be regulated by the environment or by the seed itself. The seed dormancy may be due to unfavorable environmental conditions or sometimes, some seeds may not germinate because of some inhibitory factor of the seed

Mohammed A. Al-Fredan; Yusef S. S. Ali

2008-01-01

233

Abscisic acid and assimilate partitioning during seed development  

Microsoft Academic Search

This thesis describes the influence of abscisic acid (ABA) on the transport of assimilates to seeds and the deposition of reserves in seeds. It is well-known from literature that ABA accumulates in seeds during development, and that ABA concentrations in seeds correlate rather well with seed size and seed growth rates. However, since ABA is at least partly synthesized in

Bruijn de S. M

1993-01-01

234

Isolation of protein from tomato seed meal  

Microsoft Academic Search

The results are given of a study of the extraction and precipitation of tomato seed protein. Some physicochemical properties\\u000a and the amino acid composition of tomato seed protein has been studied. Under laboratory conditions 11% of protein on the\\u000a weight of the initial seeds was obtained.

M. T. Turakhozhaev; R. A. Alibekova; S. R. Rakhmetova; L. P. Zubkova; T. T. Shakirov

1979-01-01

235

DIPLOCHORY AND THE EVOLUTION OF SEED DISPERSAL  

Technology Transfer Automated Retrieval System (TEKTRAN)

Seeds often arrive at a suitable site for germination via two or more distinct means of dispersal. We define primary dispersal as the initial movement of a seed away from the parent plant and secondary dispersal as subsequent movements of that seed by a distinctly different mechanism. For example, ...

236

7 CFR 947.12 - Seed potatoes.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 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...

2009-01-01

237

Rodent Depredation-A Direct Seeding Problem.  

National Technical Information Service (NTIS)

Foresters have known for a long time that seed-eating rodents, birds, and insects must be circumvented before direct seeding can be successful. Advances have been made in reducing losses in the direct seeding of pine by the use of chemical repellents, and...

1965-01-01

238

A Brief History of Seed Size  

Microsoft Academic Search

Improved phylogenies and the accumulation of broad comparative data sets have opened the way for phylogenetic analyses to trace trait evolution in major groups of organisms. We arrayed seed mass data for 12,987 species on the seed plant phylogeny and show the history of seed size from the emergence of the angiosperms through to the present day. The largest single

Angela T. Moles; David D. Ackerly; Campbell O. Webb; John C. Tweddle; John B. Dickie; Mark Westoby

2005-01-01

239

Forward genetics studies of seed phytic acid  

Technology Transfer Automated Retrieval System (TEKTRAN)

Both the chemical composition and total amount of seed phosphorus (P) are important to the end-use quality of cereal and legume seed crops. The chemistry of seed total P largely revolves around the synthesis and storage of phytic acid (myo-inositol hexaphosphate). Forward genetics research, beginnin...

240

Resistance to Phomopsis Seed Decay in soybean  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phomopsis seed decay (PSD) of soybean is caused primarily by the fungal pathogen, Phomopsis longicolla T.W. Hobbs along with other Phomopsis and Diaporthe spp. This disease causes poor seed quality and suppresses yield in most soybean-growing countries. Infected soybean seeds can be symptomless, but...

241

Some engineering properties of locust bean seed  

Microsoft Academic Search

Locust bean was found to be a protein rich crop whose seed is processed into local food condiment ‘iru’ in Nigeria. To explore the possibility of developing handling and processing equipment for the seed, some engineering properties namely: size, 1000 seed weight, true density, bulk density, porosity, static coefficient of friction on wood, angle of repose, specific heat and cracking

L. A. O. Ogunjimi; N. A. Aviara; O. A. Aregbesola

2002-01-01

242

Nutritional Evaluation of Dried Tomato Seeds  

Microsoft Academic Search

Two samples of tomato seeds, a by-prod- uct of the tomato canning industry were evaluated to determine proximate analysis, amino acid content, and digestibility, TMEn, and protein efficiency ratio. Tomato seeds were also used to replace corn and soybean meal (SBM) in a chick diet on an equal true amino acid digest- ibility and TMEn basis. Tomato seeds were found

M. E. Persia; C. M. Parsons; M. Schang; J. Azcona

243

Concentrations of Gibberellin in Chilled Hazel Seeds  

Microsoft Academic Search

Frankland and Wareing1 reported that chilling treatments which break the dormancy of hazel (Corylus avellana L.) seeds were also accompanied by an increase in the gibberellin content of the seeds, but that the resultant concentrations of gibberellin appeared to be much too low to account for the subsequent germination of the chilled seeds. On the basis of germination experiments in

J. D. Ross; J. W. Bradbeer

1968-01-01

244

Seeds and weeds [From the Editor  

Microsoft Academic Search

It's sad to realize that there may very well be a need for a seed vault, a facility that stores thousands of different types of plant seeds so that a species can be reestablished if it becomes extinct in its natural environment. Such a vault now exists. Sitting on a remote Arctic island, the frozen contents of the Svalbard Seed

Dennis Bernstein

2008-01-01

245

Weed seeds identification by machine vision  

Microsoft Academic Search

The implementation of new methods for reliable and fast identification and classification of seeds is of major technical and economical importance in the agricultural industry. As in ocular inspection, the automatic classification of seeds should be based on knowledge of seed size, shape, color and texture. In this work, we assess the discriminating power of these characteristics for the unique

Pablo M Granitto; Hugo D Navone; Pablo F Verdes; H. A Ceccatto

2002-01-01

246

PRODUCTION AND SEED YIELDS OF LESQUERELLA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Seed yields are critical in determining the economic success of lesquerella. There have been reports of yield potential based on individual plants and on small-plot estimates. A decade ago attempts were made to produce lesquerella on farmers¿ fields to increase seed to measure seed yields. The objec...

247

Quartz Growth on X-Seeds.  

National Technical Information Service (NTIS)

This invention concerns itself with a method for producing single crystal, seed material for use in growing synthetic quartz crystals. This seed material comprises a Z-faced seed crystal cut or sliced from the X-plus growing region of a synthetic quartz, ...

A. F. Armington

1983-01-01

248

Hemp Seed Production in Finland  

Microsoft Academic Search

This is the third in a series of “Hemp production notes,” which focuses on the unique challenge of growing hemp at high latitudes in the European Community. This paper briefly reviews the historical considerations of hemp in Finland, addresses some of the problems inherent at high latitudes and identifies specific market potentials for the Nordic production of hemp seed as

J. C. Callaway

2004-01-01

249

Seed Mapping of Sugar Beet  

Microsoft Academic Search

Individual plant care may well become embodied in precision farming in the future and will lead to new opportunities in agricultural crop management. The objective of this project was to develop and evaluate a data logging system attached to a precision seeder to enable high accuracy seed position mapping of a field of sugar beet. A Real Time Kinematic Global

H. W. Griepentrog; M. Nørremark; H. Nielsen; B. S. Blackmore

2005-01-01

250

Spatial Joins Using Seeded Trees  

Microsoft Academic Search

Existing methods for spatial joins assume the existence of indices for the participating data sets. This assumption is not realistic for applications involving multiple map layer overlays or for queries involving non-spatial selections. In this paper, we explore a spatiaJ join method that dynamically constructs index trees called seeded trees at join time. This method uses knowledge of thedata sets

Ming-Ling Lo; Chinya V. Ravishankar

1994-01-01

251

Experiments with solid particle seeding  

Microsoft Academic Search

Kaoline, a hydrated aluminum silicate clay, is investigated as a seeding material for laser velocimetry. It is inexpensive but is polydispersed with some of the fineparticles being too large to follow wind tunnel flow and is in the form of nonspherical platelets having an aspect ratio of approximately 4\\/1. Gravity sedimentation experiments as a means of narrowing the fineparticle sizes

C. E. Nichols Jr.

1985-01-01

252

Advanced backward Raman amplification seeding  

NASA Astrophysics Data System (ADS)

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.

Malkin, Vladimir; Fisch, Nathaniel

2010-11-01

253

The Seed Is the Law  

ERIC Educational Resources Information Center

|Since humanities arise from a specific place and from the people of that place, this article will focus on Peacemaker's revolutionary teachings about the seed of law. Long before the people from across the ocean arrived here on Turtle Island (North America) there was much warfare happening. According to John Mohawk (2001, para. 1), an Iroquoian…

Antone, Eileen M.

2005-01-01

254

ELASTOHYDRODYNAMIC PROPERTIES OF SEED OILS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The film-forming properties of canola (CAN), soybean (SBO), and jojoba (JO) seed oils under elastohydrodynamic (EHD) conditions were investigated to determine if differences in their chemical and physical properties affect their EHD properties. Polyalphaolefin (PAO), whose EHD properties have been ...

255

Reversible Seeding in Storage Rings  

SciTech Connect

We propose to generate steady-state microbunching in a storage ring with a reversible seeding scheme. High gain harmonic generation (HGHG) and echo-enabled harmonic generation (EEHG) are two promising methods for microbunching linac electron beams. Because both schemes increase the energy spread of the seeded beam, they cannot drive a coherent radiator turn-by-turn in a storage ring. However, reversing the seeding process following the radiator minimizes the impact on the electron beam and may allow coherent radiation at or near the storage ring repetition rate. In this paper we describe the general idea and outline a proof-of-principle experiment. Electron storage rings can drive high average power light sources, and free-electron lasers (FELs) are now producing coherent light sources of unprecedented peak brightness While there is active research towards high repetition rate FELs (for example, using energy recovery linacs), at present there are still no convenient accelerator-based sources of high repetition rate, coherent radiation. As an alternative avenue, we recently proposed to establish steady-state microbunching (SSMB) in a storage ring. By maintaining steady-state coherent microbunching at one point in the storage ring, the beam generates coherent radiation at or close to the repetition rate of the storage ring. In this paper, we propose a method of generating a microbunched beam in a storage ring by using reversible versions of linac seeding schemes.

Ratner, Daniel; Chao, Alex; /SLAC

2011-12-14

256

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...

257

[Seed rain, soil seed bank, and natural regeneration of natural Toona ciliata var. pubescens forest].  

PubMed

Taking the natural Toona ciliata var. pubescens forest in the Jiujiangshan National Nature Reserve in Jiangxi Province of China as test object, an investigation was conducted on the seed rain, soil seed bank, and seedlings number in 2008-2011. The seed rain of the forest was dispersed from late October to the end of December. In 2010, the seed rain intensity in different sampling plots was in the order of Xiagongtang observatory (320.3 +/- 23.5 seeds x m(-2)) > Xiagongtang protection station (284.7 +/- 24.2 seeds x m(-2)) > Daqiutian protection station (251.6 +/- 24.7 seeds x m(-2)), and the quantity of the intact seeds in soil supplied for seed germination and regeneration was 222.0, 34.3, and 22.6 seeds x m(-2), respectively. The seed bank reserves was affected by the seed production amount, bird feeding, and seed viability, etc., of which, bird feeding was the prime factor for the substantial drop of the seed bank reserves. Due to the low resistance against storage and a large number of rot during storage, the seeds in soil could hardly be effectively stored beyond one month. The seedlings germinated in December were averagely less than 2 stands x m(-2), and the soil seed reserves in the next January was the least (6.7-11.8 seeds x m(-2)), with the germinated seedlings averagely 0.4-0.6 stands x m(-2), which was consistent with the rare distribution of natural seedlings in the forest. It was concluded that the small seed rain reserves, low seed vigor of soil seed bank, and low seedling establishment were the important factors impacting the natural regeneration of T. ciliata var. pubescens. PMID:22803462

Huang, Hong-Lan; Zhang, Lu; Liao, Cheng-Kai

2012-04-01

258

Reducing seed damage by soybean bugs by growing small-seeded soybeans and delaying sowing time  

Microsoft Academic Search

We evaluated the effects of seed size and planting time on seed damage by soybean bugs in the field over 2 years. Kyushu-143, a small-seeded soybean with many pods, suffered less damage at harvest by soybean bugs than the large-seeded cultivars Fukuyutaka and Sachiyutaka. We attributed the field tolerance of Kyushu-143 to large numbers of “spare” seeds that could compensate

Takashi Wada; Nobuyuki Endo; Masakazu Takahashi

2006-01-01

259

Satiation of predispersal seed predators: the importance of considering both plant and seed levels  

Microsoft Academic Search

Plants can reduce the fitness costs of granivory by satiating seed predators. The most common satiation mechanism is the production\\u000a of large crops, which ensures that a proportion of the seeds survive predation. Nevertheless, satiation of small granivores\\u000a at the seed level may also exist. Larger seeds would satiate more efficiently, enhancing the probability of seed survival\\u000a after having been

Raul Bonal; Alberto Muñoz; Mario Díaz

2007-01-01

260

Effects of APETALA2 on embryo, endosperm, and seed coat development determine seed size in Arabidopsis  

Microsoft Academic Search

Arabidopsis APETALA2 (AP2) controls seed mass maternally, with ap2 mutants producing larger seeds than wild type. Here, we show that AP2 influences development of the three major seed compartments:\\u000a embryo, endosperm, and seed coat. AP2 appears to have a significant effect on endosperm development. ap2 mutant seeds undergo an extended period of rapid endosperm growth early in development relative to

Masa-aki Ohto; Sandra K. Floyd; Robert L. Fischer; Robert B. Goldberg; John J. Harada

2009-01-01

261

Evaluation fo frost damage in seed corn (Zea mays): with special emphasis on seed composition and moisture content  

Microsoft Academic Search

Fall frost is a serious concern to seed corn (Zea mays L.) producers in the Midwest. A frost event that happens prior to seed maturity can cause physical, biochemical, and physiological changes in the seed. These changes lead to decreased vigor and viability resulting in revenue loss for seed corn producers. Genetics and seed maturity greatly influence seed tolerance to

Heather Ann Hall

2009-01-01

262

Seed size and seed growth rate in relation to cotyledon cell volume and number in common bean  

Microsoft Academic Search

Seed yield is negatively associated with cultivar seed size in common bean (Phaseolus vulgaris L.). Large-seeded cultivars are predominantly from the Andean center of origin while small-seeded cultivars are from the Mesoamerican center. The objective of this study was to determine the relationship of cotyledon cell number and individual cell volume to seed size and seed growth rate (SGR) in

P. J. Sexton; K. J. Boote; J. W. White; C. M. Peterson

1997-01-01

263

Variability in post-dispersal seed predation in deciduous woodland: relative importance of location, seed species, burial and density  

Microsoft Academic Search

The considerable variability found in post-dispersal seed predation and the absence of consistent directional trends (e.g., with reference to seed size) has made it difficult to predict accurately the impact of seed predators on plant communities. We examined the variation attributable to location, seed density and seed burial on the removal of seeds of three tree species: Fraxinus excelsior, Taxus

Philip E. Hulme; Teresa Borelli

1999-01-01

264

Myrmecochory and short-term seed fate in Rhamnus alaternus: Ant species and seed characteristics  

NASA Astrophysics Data System (ADS)

Benefits conferred on plants in ant-mediated seed dispersal mutualisms (myrmecochory) depend on the fate of transported seeds. We studied the effects of elaiosome presence, seed size and seed treatment (with and without passage through a bird's digestive tract) on short-term seed fate in Rhamnus alaternus. In our study, we define short-term seed, or initial, seed fate, as the location where ants release the seeds after ant contact with it. The elaiosomes had the most influence on short-term fate, i.e. whether or not seeds were transported to the nest. The workers usually transported big seeds more often than small ones, but small ants did not transport large seeds. Effect of seed size on transport depended on the ant species and on the treatment of the seed (manual extraction simulating a direct fall from the parent plant vs. bird deposition corresponding to preliminary primary dispersal). Probability of removal of elaiosome-bearing seeds to the nest by Aphaenogaster senilis increased with increasing seed weight.

Bas, J. M.; Oliveras, J.; Gómez, C.

2009-05-01

265

Radio frequency interference  

Microsoft Academic Search

The article consists of a Powerpoint presentation on radio frequency interference. The areas discussed include: radio frequency interference; electromagnetic interference; mobile Internet device and wireless sensitivity requirement.

H. Skinner; K. Slattery

2008-01-01

266

The role of local species pool, soil seed bank and seedling pool in natural vegetation restoration on abandoned slope land  

NASA Astrophysics Data System (ADS)

Theory and empirical evidence suggest that natural vegetation restoration depends on both the availability of seed resources and on successful seedling establishment. In the hill-gully Loess Plateau region, it remains unclear whether a rich diversity of species persists in the fragmented landscape in spite of intensive human activities and whether the distribution of the soil seed bank and the establishment of seedlings are threatened by serious soil erosion. We investigated vegetation composition in a series of plots with different slope aspects and degrees in a watershed of 8.26 km2 in Shaanxi Provence, China to determine the local species pool. The soil seed bank and seedling recruitment on typical eroded slopes over varied erosion zones were simultaneously studied to characterise soil seed bank resources and seedling establishment. In this study, 133 species were identified in the local species pool. The species' frequency within the soil seed bank, seedling and standing vegetation was positively correlated with the frequency of matched species in the local species pool. The soil seed bank density and species richness had no significantly decreasing with the soil erosion intensity increasing on the hill slope. However, the seedling density and species composition showed significant difference among the investigative times and different erosion zones. Furthermore, the species frequency declined with increasing seed mass. Results of this study indicate that the seeds of widely distributed species always have small size, persist in soil under eroded conditions and have stable seedling density over the growing season. Therefore, these species can successfully recolonise in abandoned slope land. However, late-successional species with large seeds that lack dispersal vectors are less able to disperse and recolonise in areas that need to be restored.

Wang, Ning; Jiao, Juying; Du, Huadong; Wang, Dongli; Jia, Yanfeng; Chen, Yu

2013-04-01

267

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...

268

Statistical Tests of the Apple IIe Random Number Generator Yield Suggestions from Generator Seeding.  

ERIC Educational Resources Information Center

|Discusses flaws in the Apple IIe Applesoft random number generator, RND, and reports results of frequency and serial correlation tests of the generator. Suggestions of seeds that yield sequences of numbers which pass fundamental screening tests for randomness are presented. (Author/LRW)|

Gleason, John M.

1988-01-01

269

TEMPERATURE-DEPENDENT BEHAVIOR OF MICROWAVE DIELECTRIC PROPERTIES OF BOUND WATER IN GRAIN AND SEED  

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 –70 degrees Celsius and +21 degrees Celsius. Samples of wheat and soybeans were cooled to –70 degrees Celsius and the...

270

Conventional and in situ transesterification of sunflower seed oil for the production of biodiesel  

Microsoft Academic Search

In the present work the alkaline transesterification of sunflower seed oil with methanol and ethanol, for the production of biodiesel fuel was studied. Both conventional and in situ transesterification were investigated using low frequency ultrasonication (24 kHz) and mechanical stirring (600 rpm). Use of ultrasonication in conventional transesterification with methanol gave high yields of methyl esters (95%) after a short reaction time

K. G. Georgogianni; M. G. Kontominas; P. J. Pomonis; D. Avlonitis; V. Gergis

2008-01-01

271

Diatom response to extremely low-frequency magnetic fields  

SciTech Connect

Reports that extremely low-frequency magnetic fields can interfere with normal biological cell function continue to stimulate experimental activity as well as investigations into the possible mechanism of the interaction. The cyclotron resonance' model of Liboff has been tested by Smith et al. using as the biological test system the diatom Amphora coffeiformis. They report enhanced motility of the diatom in response to a low-frequency electromagnetic field tuned to the cyclotron resonance condition for calcium ions. We report here an attempt to reproduce their results. Following their protocol diatoms were seeded onto agar plates containing varying amounts of calcium and exposed to colinear DC and AC magnetic fields tuned to the cyclotron resonant condition for frequencies of 16, 30, and 60 Hz. The fractional motility was compared with that of control plates seeded at the same time from the same culture. We find no evidence of a cyclotron resonance effect.

Parkinson, W.C.; Sulik, G.L. (Department of Physics, University of Michigan, Ann Arbor (United States))

1992-06-01

272

Total annual seed loss on a perennial legume through predation by insects: The importance of within-season seed and seed feeder dynamics  

Microsoft Academic Search

Determining total annual seed loss from seed predators is an important step in quantifying the role they have in modifying plant populations. Total seed loss is typically estimated with a single, well-timed survey. However, this overlooks the potential importance of within-season patterns of seed availability and insect activity, particularly where seed gain and loss are not synchronous and where insects

RIEKS D. VAN KLINKEN

2005-01-01

273

Comparative study of spectral narrowing of a pulsed Ti:Sapphire laser using pulsed and CW injection seeding  

Microsoft Academic Search

We report a comparative study of a pulsed as well as continuous-wave (cw) injection seeding of a Ti:Sapphire laser pumped by aQ-switched frequency-doubled Nd3+:YAG laser for achieving narrow spectral bandwidth. The results have indicated that the Ti:Sapphire laser using either a pulsed or a cw injection seeding could achieve efficient energy extraction in a narrow spectral bandwidth. In the case

N. J. Vasa; M. Tanaka; T. Okada; M. Maeda; O. Uchino

1996-01-01

274

Influence of Ca 2+ in biological stimulating effects of AC magnetic fields on germination of bean seeds  

Microsoft Academic Search

This study reports an attempt to investigate the effects of AC magnetic field on the seed germination and seedling growth of beans, at different concentrations of CaCl2, since Ca2+ is an essential plant nutrient. Bean seeds were exposed to a combination of local geomagnetic field (DC field) and sinusoidal time-varying extremely low frequency (ELF) magnetic field (AC field) 28.3Hz, 20?T

Lama Sakhnini

2007-01-01

275

Terahertz generation with tandem seeded optical parametric generators.  

PubMed

A simple difference frequency generation (DFG) scheme based on two seeded optical parametric generators is presented as a tunable terahertz (THz) source. Using the nonlinear optical crystal 4-dimethylamino-N-methyl-4-stilbazolium-tosylate (DAST) as the DFG crystal, our system has demonstrated continuous and seamless tunable operation from 1.6 to 4.5 THz. The output bandwidth of the THz source is 2.4 GHz. The utility of the source over this spectral range is demonstrated by measuring a high-resolution transmission spectrum of water vapor in air. PMID:15792002

Powers, P E; Alkuwari, R A; Haus, J W; Suizu, K; Ito, H

2005-03-15

276

Thermal properties of cumin seed  

Microsoft Academic Search

This paper describes the measurement of thermal properties, namely specific heat, thermal conductivity and thermal diffusivity of cumin seed. The specific heat increased from 1330 to 3090 J\\/kgK with increase in temperature from ?70°C to 50°C and moisture content from 1.8% to 20.5% dry basis. The thermal conductivity increased from 0.046 to 0.223 W\\/mK with the increase in temperature from

K. K Singh; T. K Goswami

2000-01-01

277

Seed localization in ultrasound and registration to C-arm fluoroscopy using matched needle tracks for prostate brachytherapy.  

PubMed

We propose a novel fiducial-free approach for the registration of C-arm fluoroscopy to 3-D ultrasound images of prostate brachytherapy implants to enable dosimetry. The approach involves the reliable detection of a subset of radioactive seeds from 3-D ultrasound, and the use of needle tracks in both ultrasound and fluoroscopy for registration. Seed detection in ultrasound is achieved through template matching in 3-D radio frequency ultrasound signals, followed by thresholding and spatial filtering. The resulting subset of seeds is registered to the complete reconstruction of the brachytherapy implant from multiple C-arm fluoroscopy views. To compensate for the deformation caused by the ultrasound probe, simulated warping is applied to the seed cloud from fluoroscopy. The magnitude of the applied warping is optimized within the registration process. The registration is performed in two stages. First, the needle track projections from fluoroscopy and ultrasound are matched. Only the seeds in the matched needles are then used as fiducials for point-based registration. We report results from a physical phantom with a realistic implant (average postregistration seed distance of 1.6 ± 1.2 mm) and from five clinical patient datasets (average error: 2.8 ± 1.5 mm over 128 detected seeds). We conclude that it is feasible to use RF ultrasound data, template matching, and spatial filtering to detect a reliable subset of brachytherapy seeds from ultrasound to enable registration to fluoroscopy for dosimetry. PMID:22759435

Moradi, Mehdi; Mahdavi, S Sara; Dehghan, Ehsan; Lobo, Julio R; Deshmukh, Sanchit; Morris, William James; Fichtinger, Gabor; Salcudean, Septimiu Tim E

2012-06-29

278

Proteomics of rice seed germination.  

PubMed

Seed is a condensed form of plant. Under suitable environmental conditions, it can resume the metabolic activity from physiological quiescent status, and mobilize the reserves, biosynthesize new proteins, regenerate organelles, and cell membrane, eventually protrude the radicle and enter into seedling establishment. So far, how these activities are regulated in a coordinated and sequential manner is largely unknown. With the availability of more and more genome sequence information and the development of mass spectrometry (MS) technology, proteomics has been widely applied in analyzing the mechanisms of different biological processes, and proved to be very powerful. Regulation of rice seed germination is critical for rice cultivation. In recent years, a lot of proteomic studies have been conducted in exploring the gene expression regulation, reserves mobilization and metabolisms reactivation, which brings us new insights on the mechanisms of metabolism regulation during this process. Nevertheless, it also invokes a lot of questions. In this mini-review, we summarized the progress in the proteomic studies of rice seed germination. The current challenges and future perspectives were also discussed, which might be helpful for the following studies. PMID:23847647

He, Dongli; Yang, Pingfang

2013-07-09

279

Apparatus for depositing seed and fertilizer  

US Patent & Trademark Office Database

Apparatus for depositing seed and fertilizer in the ground comprises, a sectional frame, a seed supply and a fertilizer supply mounted on the frame, a multiplicity of unique fluid controlled seed row assemblies pivotally mounted on the frame to receive seed and fertilizer from their supplies, a fluid pressure source, a first control means for controlling fluid flowing from the source to the seed row assemblies, an identical second control means for controlling fluid flowing from the source to fluid controlled pivotal sections of the sectioned frame. The unique seed row assemblies including a frame assembly mounting, an elongated draw arm pivotally connected to the frame assembly mounting, a ground engaging assembly fixed to the elongated draw arm, the ground engaging assembly including a mounting arm, a ground engaging fertilizer dispenser pivotally mounted on the arm, a ground engaging seed dispenser adjustably mounted on the arm and a packing/depth gauge wheel rotatably mounted and laterally adjustable on the arm, a two way seed row assembly biasing cylinder and piston assembly pivotally connected to the frame assembly mounting and to the ground engaging fertilizer dispenser to bias the seed row assembly in a working position or to bias the seed row assembly in a transport position.

1994-07-26

280

Post-hypoxic Oxidative Stress in Aging Pea Seeds: I. Hypoxia Development during Imbibition  

Microsoft Academic Search

During seed transition from quiescence to metabolic activity and subsequent germination, orthodox seeds become sensitive to stress. Aging seeds become particularly sensitive to stress conditions and during storage, seeds undergo aging that deteriorates their quality. Each seed lot contains strong seeds, weak seeds, and dead seeds, but dry seed quality cannot be assessed prior to germination. Nevertheless, air- dry pea

Tatiana V. Veselova; Vladimir A. Veselovsky

2009-01-01

281

Allometric scaling of long-distance seed dispersal by migratory birds.  

PubMed

Migratory birds are often suggested to be important vectors for long-distance dispersal (LDD) of plant and animal propagules. The scale of such dispersal events (hundreds to thousands of kilometers) can influence landscape-level biological processes and species distributions. However, the few vector species studied and the lack of proper integration of their migratory movement in models of LDD has precluded the study of their potential as long-distance biotic dispersers. By means of a mechanistic model parameterized with empirical data, we first investigated the properties of seed dispersal curves generated by migratory birds and then analyzed the effect of bird size on model parameters and consequent seed dispersal patterns. Seed dispersal curves showed in most cases large and heavy tails, resulting in relatively frequent LDD (up to 3.5% of dispersal distances longer than 100 km). Bird size mediated trade-offs between bird movement and seed retention time that, in turn, determined seed dispersal patterns and the potential of each bird species as an LDD vector. Our modeling framework builds on a mechanistic understanding of seed dispersal by migratory birds and may thus be a useful tool to estimate the scale and frequency of bird-mediated, large-scale transport of native, invasive, and pathogenic organisms. PMID:23594548

Viana, Duarte S; Santamaría, Luis; Michot, Thomas C; Figuerola, Jordi

2013-03-15

282

Laser Initiation and Radiofrequency Sustainment of Seeded Air Plasmas  

NASA Astrophysics Data System (ADS)

Seeded gas plasmas and air constituents have been created by a 193 nm laser and radiofrequency sources. We have obtained 1014/cm3 plasma densities with initial electron temperatures of 0.3 eV in TMAE (tetrakis (dimethylamino) ethylene) by laser photoionization. We developed a fast Langmuir probe analysis of plasma decay independent of ion species mix. Langmuir probe and optical emission data illustrating the density and temperature decay with TMAE mixed with nitrogen is presented showing the existence of superexcited seed gas states which reduce the effective recombination rate. Simulations of antenna coupling, wave frequencies, wave propagation, and power absorption are compared with experimental observations for radiofrequency plasma sources. The source produces plasma densities of 2 x 1013/cm3 in an 8500 cm cm3 volume at electron temperatures of 5 eV in 10 mTorr Ar in a nonuniform magnetic field. Radiofrequency plasma sustainment at pressures from 2-760 Torr using Ar and laser initiated TMAE plasmas as seeds will be discussed.

Kelly, K.; Scharer, J.; Cao, R.; Ding, G.; Paller, E.

2000-10-01

283

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

NASA Astrophysics Data System (ADS)

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.

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

2011-07-01

284

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

USGS Publications Warehouse

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.

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

2006-01-01

285

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

NASA Astrophysics Data System (ADS)

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.

Wang, Bo; Chen, Jin

2008-11-01

286

Insect-Caused Cone and Seed Losses in Treated and Untreated Loblolly Pine Seed Orchards.  

National Technical Information Service (NTIS)

Differences in strobilus survival and yields of viable seed were estimated between ramets of the same four clones of loblolly pine, Pinus taeda, in two differently managed seed orchards. One orchard had been treated with insecticides, fertilizers, and var...

C. W. Fatzinger H. O. Yates W. J. Hammond R. Hutto

1985-01-01

287

Barley Stripe Mosaic Virus and the Frequency of Triploids and Aneuploids in Barley  

PubMed Central

BSMV infection caused a pronounced increase in the frequency of triploid and aneuploid seeds in eleven barley varieties, but with considerable variation in frequency among varieties. In some of the varieties triploids exceeded three per cent. In virus-free material a few triploids were found in most of the varieties, but the frequency was very low. There was, however, a significant variation among varieties.

Sandfaer, Jens

1973-01-01

288

Plants as seed traps: inter-specific interference with dispersal  

Microsoft Academic Search

Established plants may disrupt patterns of seed deposition by physically trapping dispersing seed. In this study we quantified seed trapping at very fine spatial scales, by measuring seed fall of two ericaceous dwarf shrub species at a range of distances from allospecific shrubs within a matrix of short grass vegetation. Next to allospecific bushes, seed deposition densities of Calluna vulgaris

James M. Bullock; Ibby L. Moy

2004-01-01

289

Conyza canadensis seed ascent in the lower atmosphere  

Microsoft Academic Search

Long-distance dispersal of wind dispersed plant seed is dependent on seeds ascending in the atmosphere's surface boundary layer (SL). However, seed dispersal research often focuses on the near-surface dynamics of abscission and deposition, with little attention paid to seed ascent and transport beyond the surface boundary layer. Our research sought to estimate the vertical seed density flux of Conyza canadensis,

Joseph T. Dauer; David A. Mortensen; Edward C. Luschei; Scott A. Isard; Elson Shields; Mark J. Van-Gessel

2009-01-01

290

Conyza canadensis seed ascent in the lower atmosphere  

Microsoft Academic Search

Long-distance dispersal of wind dispersed plant seed is dependent on seeds ascending in the atmosphere's surface boundary layer (SL). However, seed dispersal research often focuses on the near-surface dynamics of abscission and deposition, with little attention paid to seed ascent and transport beyond the surface boundary layer. Our research sought to estimate the vertical seed density flux of Conyza canadensis,

Joseph T. Dauer; David A. Mortensen; Edward C. Luschei; Scott A. Isard; Elson Shields; Mark J. Van-Gessel

2008-01-01

291

Seed dynamics during forest succession in Costa Rica  

Microsoft Academic Search

Soil seed banks and current seed inputs each play a role in tropical succession. We compared the abundance and floristic composition of seeds from these two sources at a Costa Rican site by germinating seeds from the soil, measuring seed inputs for 3 yr, and monitoring the earliest colonists in a forest clearing.

K. R. Young; J. J. Ewel; B. J. Brown

1987-01-01

292

Seed Germination and Seedling Survival of Spartina alterniflora Loisel  

Microsoft Academic Search

Spartina alterniflora (smooth cordgrass) is a widespread intertidal salt marsh plant that is frequently used in coastal restoration projects. Seeds collected in 2004 were tested for seed germination and seedling survival after 6 months of cold seed storage to determine differences among collection locations (experiment 1). Seeds collected in 2005, after Hurricane Katrina, were tested for seed germination and seedling

Patrick D. Biber; John D. Caldwell

293

The evolution of radar echo in a seeded cloud  

Microsoft Academic Search

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

Marianne English; John D. Marwitz

1982-01-01

294

Biophysical Approaches to Measure and Predict Seed Longevity  

Technology Transfer Automated Retrieval System (TEKTRAN)

Reliable predictions of seed longevity would allow seed companies and seed bank managers to economize on processing, handling and monitoring of stored seeds and select lots that require regeneration or immediate sale. Seed longevity is difficult to predict because early symptoms of deterioration ar...

295

Diseases and Disease Management in Seed Garlic: Problems and Prospects  

Technology Transfer Automated Retrieval System (TEKTRAN)

Although garlic is occasionally propagated via true seed, routine planting of garlic uses seed cloves as vegetative propagules. The size of seed cloves (large relative to seed of most agronomic crops), their vegetative habit, and routine storage conditions for seed cloves (permissive for most fungi...

296

Applicator Training Manual for: Seed Treatment Pest Control.  

ERIC Educational Resources Information Center

|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…

TeKrony, Dennis M.

297

Developmental Genetic Analysis of Seed Size in Soybean ( Glycine max)  

Microsoft Academic Search

Seed size is one of the important factors of soybean [Glycine max (L.) Merrill] yield. There have been lots of reports about genetic effects and physiology—ecological researches on seed size, but the genetic behaviors of genes during seeds development were rarely discussed. Analysis of main genetic effects for fresh seed size (FSS) and dry seed size (DSS) of soybean was

Wen-Xia LI; Hai-Long NING; Wen-Bin LI; Wen-He LÜ

2006-01-01

298

Micro-SEED and its application  

Microsoft Academic Search

Micro-SEED is the first complete database management system for microcomputers. This paper reviews the development of Micro-SEED and then describes two applications that have been developed to use Micro-SEED: general ledger and bill-of-material processor. A final section evaluates the performance in terms of the transaction rate of general ledger applications that can be supported and calculates the cost per transaction.

Rob Gerritsen; Richard Hackathorn

1979-01-01

299

Hæmagglutinin Anti-N in Plant Seeds  

Microsoft Academic Search

SOME plant seeds contain specific antibodies for the antigens A, B and O (or H) of human blood1,2. Rh, M and N antibodies have been sought, but with negative results2. Through the courtesy of Prof. K. Mohrdiek (Porto Alegre), we received seeds of four species of Vicia from southern Brazil. Seed extracts were made and tested in the usual manner1,

F. Ottensooser; K. Silberschmidt

1953-01-01

300

Photoacoustic imaging of prostate brachytherapy seeds  

PubMed Central

Brachytherapy seed therapy is an increasingly common way to treat prostate cancer through localized radiation. The current standard of care relies on transrectal ultrasound (TRUS) for imaging guidance during the seed placement procedure. As visualization of individual metallic seeds tends to be difficult or inaccurate under TRUS guidance, guide needles are generally tracked to infer seed placement. In an effort to improve seed visualization and placement accuracy, the use of photoacoustic (PA) imaging, which is highly sensitive to metallic objects in soft tissue, was investigated for this clinical application. The PA imaging properties of bare (i.e., embedded in pure gelatin) and tissue-embedded (at depths of up to 13 mm) seeds were investigated with a multi-wavelength (750 to 1090 nm) PA imaging technique. Results indicate that, much like ultrasonic (US) imaging, an angular dependence (i.e., seed orientation relative to imaging transducer) of the PA signal exists. Despite this shortcoming, however, PA imaging offers improved contrast, over US imaging, of a seed in prostate tissue if sufficient local fluence is achieved. Additionally, although the PA signal of a bare seed is greatest for lower laser wavelengths (e.g., 750 nm), the scattering that results from tissue tends to favor the use of higher wavelengths (e.g., 1064 nm, which is the primary wavelength of Nd:YAG lasers) when the seed is located in tissue. A combined PA and US imaging approach (i.e., PAUS imaging) shows strong potential to visualize both the seed and the surrounding anatomical environment of the prostate during brachytherapy seed placement procedures.

Su, Jimmy L.; Bouchard, Richard R.; Karpiouk, Andrei B.; Hazle, John D.; Emelianov, Stanislav Y.

2011-01-01

301

Seed storage and seed storage reserves in Chatham Island forget?me?not (Myosotidium hortensia, Boraginaceae)  

Microsoft Academic Search

Chatham Island forget?me?not is endemic to the Chatham Islands, New Zealand, where it is mainly confined to the outer islands. The conditions required to maintain seed viability during storage are not well understood and there are conflicting reports as to whether the seed will retain viability in storage. Seed of M. hortensia stored at 7.5% seed moisture content showed no

C. R. McGill; J. C. McIntosh; H. A. Outred; D. W. Fountain

2002-01-01

302

Seed longevity: survival and maintenance of high germination ability of dry seeds.  

PubMed

The seed constitutes the main vector of plant propagation and it is a critical development stage with many specificities. Seed longevity is a major challenge for the conservation of plant biodiversity and for crop success. Seeds possess a wide range of systems (protection, detoxification, repair) allowing them to survive in the dry state and to preserve a high germination ability. Therefore, the seed system provides an appropriate model to study longevity and aging. PMID:18926494

Rajjou, Loïc; Debeaujon, Isabelle

2008-09-02

303

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

Microsoft Academic Search

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

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

2012-01-01

304

Studies on palms: Fruits, seeds and seed germination in the genus Phoenix L  

Microsoft Academic Search

The paper gives an account of the morphology and anatomy of fruits, seeds and their germination in the genusPhoenix. The fruit is an oblong, 1-seeded berry, yellowish-black to dark purple in colour. The seed is hard and stony, grooved on\\u000a ventral side. Embryo lies dorsally opposite the groove. Germination is hypogeal, eligulate and remotive.\\u000a \\u000a Many palm fruits and seeds are

N. V. Biradar; T. S. Mahabale

1969-01-01

305

Theoretical Basis of Protocols for Seed Storage  

PubMed Central

The protocols presently established for optimum seed storage do not account for the chemical composition of different seed species, the physiological status of the seed, and the physical status of water within the seed. The physiological status of seeds from five species with varying chemical compositions was determined by measurements of rates of oxygen uptake and seed deterioration. The physical status of water was determined by water sorption characteristics. For each species studied, there was a specific moisture content for the onset of respiration, chemical reactions, and accelerated aging rates. The moisture contents at which these physiological levels were observed varied among the species and correlated with the lipid content of the seed. However, the changes in physiological activities and the physical status of water occurred at specific relative humidities: 91% for the onset of respiration, 27% for the increased rates of thermal-chemical reactions, and 19% for optimum longevity. Based on these observations, we propose that equilibrating seeds between 19 and 27% relative humidity provides the optimum moisture level for maintaining seed longevity during longterm storage.

Vertucci, Christina W.; Roos, Eric E.

1990-01-01

306

Efficient Chaining of Seeds in Ordered Trees  

NASA Astrophysics Data System (ADS)

We consider here the problem of chaining seeds in ordered trees. Seeds are mappings between two trees Q and T and a chain is a subset of non overlapping seeds that is consistent with respect to postfix order and ancestrality. This problem is a natural extension of a similar problem for sequences, and has applications in computational biology, such as mining a database of RNA secondary structures. For the chaining problem with a set of m constant size seeds, we describe an algorithm with complexity O(m 2 log(m)) in time and O(m 2) in space.

Allali, Julien; Chauve, Cédric; Ferraro, Pascal; Gaillard, Anne-Laure

307

Seed size, shape and vertical distribution in the soil: indicators of seed longevity  

Microsoft Academic Search

Summary 1. We investigated the vertical distribution of seeds in the soil, using data from nine studies in five European countries. We discovered significant correlations between seed shape and distribution in the soil. 2. The classification of the longevity of seeds of plant species has been improved by the introduction of a 'longevity index', expressing on a continuous scale the

R. M. BEKKER; J. P. BAKKER; U. GRANDIN; R. KALAMEES; P. MILBERG; P. POSCHLOD; Ken Thompson; J. H. WILLEMS

1998-01-01

308

CONTROL ROD DRIVE MECHANISM TESTING DURING SEED 3 OPERATION AND SEED 3-4 REFUELING  

Microsoft Academic Search

The test data reported for the periodic testing during Seed 3 and for ; the precritical and initial critical testing after the third refueling indicate ; that the mechanisms operated satisfactorily during Seed 3, have sufficient wear ; life remaining for Seed 4 operation, and were operating satisfactorily as ; installed at the completion of the third refueling period. Several

Secrist

1963-01-01

309

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

Microsoft Academic Search

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

DEMEL TEKETAY

2005-01-01

310

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...

311

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

Microsoft Academic Search

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

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

2001-01-01

312

``From seed-to-seed'' experiment with wheat plants under space-flight conditions  

Microsoft Academic Search

An important goal with plant experiments in microgravity is to achieve a complete life cycle, the ``seed-to-seed experiment''. Some Soviet attempts to reach this goal are described, notably an experiment with the tiny mustard, Arabidopsis thaliana, in the Phyton 3 device on Salyut 7. Normal seeds were produced although yields were reduced and development was delayed. Several other experiments have

A. Mashinsky; I. Ivanova; T. Derendyaeva; G. Nechitailo; F. Salisbury

1994-01-01

313

Seed Size and Seeding Depth Influence on Canola Emergence and Performance in the Northern Great Plains  

Microsoft Academic Search

size are known to be major factors influencing seedling emergence, stand establishment, and crop performance. Dramatic increases in canola (Brassica napus L.) production in Ahmed and Zuberi (1973) screened large- and small- the Northern Great Plains and lack of regional research prompted evaluating seeding depth and seed size effects on crop performance. seed categories for each of four strains of

Kenneth E. Lamb; Burton L. Johnson

2004-01-01

314

Long-term survival and seed transmission of Acidovorax avenae ssp. citrulli in melon and watermelon seed  

Technology Transfer Automated Retrieval System (TEKTRAN)

Seed transmission of Acidovorax avenae ssp. citrulli (Aac) is a key factor in the dissemination of bacterial fruit blotch of cucurbits. In this study, we report seed transmission of Aac from 34-year-old watermelon seed (Citrullus lanatus) and from 40-year-old melon seed (Cucumis melo). The seed lo...

315

The potential of seed-eating birds to spread viable seeds of weeds and other undesirable plants  

Microsoft Academic Search

The potential for seed-eating birds to spread viable seeds was investigated using captive-feeding trials to determine seed preference, passage time through the gut, and viability of passed seeds for bronzewing pigeons (Phaps chalcoptera), peaceful doves (Geopelia striata), crested pigeons (Ocyphaps lophotes), Senegal doves (Streptopelia senegalensis), zebra finches (Taeniopygia guttata), black ducks (Anas superciliosa) and wood ducks (Chenonetta jubata). Test seeds

LAURIE E. TWIGG; TIM J. LOWE; CATHERINE M. TAYLOR; MIKE C. CALVER; GARY R. MARTIN; CLAIRE STEVENSON; RIC HOW

2009-01-01

316

Long-term Survival and Seed Transmission of Acidovorax avenae subsp. citrulli in Melon and Watermelon Seed  

Technology Transfer Automated Retrieval System (TEKTRAN)

Seed transmission of Acidovorax avenae ssp. citrulli (Aac) is a key factor in the dissemination of bacterial fruit blotch of cucurbits. In this study, we report seed transmission of Aac from 34-year-old watermelon seed (Citrullus lanatus) and from 40-year-old melon seed (Cucumis melo). The seed lo...

317

Temperature and seed weight affect the germination of peach rootstock seeds and the growth of rootstock seedlings  

Microsoft Academic Search

Seeds of five cultivars of peach rootstocks were assessed to determine the effect of seed quality and temperature on germination and seedling growth. The weight of each seed and its surrounding endocarp was determined. Based on weight, the seeds were divided into four quartiles, stratified, and grown at 23°C with a 16h photoperiod. The percentage of seeds germinating over an

P. J Malcolm; P Holford; W. B McGlasson; S Newman

2003-01-01

318

High Frequency Via.  

National Technical Information Service (NTIS)

Techniques that enable the transitioning of high frequency signals on a printed wiring board processed in accordance with industry standards (such as the IPC specifications) are disclosed. One embodiment provides a high frequency via structure for a print...

J. S. Greeley

2004-01-01

319

Direct SAW Frequency Synthesizer.  

National Technical Information Service (NTIS)

A frequency synthesizer utilizing three elementary direct synthesizers to achieve fast frequency hopping among 219 tones is described. The elementary synthesizers used for the two 9-channel sets of tones consist of a comb generator followed by a surface a...

A. J. Budreau P. H. Carr

1978-01-01

320

Sterols in pumpkin seed oil  

Microsoft Academic Search

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

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

1977-01-01

321

Minimax frequency invariant beamforming  

Microsoft Academic Search

Introduction: The frequency invariant beamformer (FIB) is a beam-former of which the response is approximately invariant for a designed frequency range. The technique mostly used for the design of an FIB is FIR or IIR filter coefficient optimisation that employs some analytical relations between frequency responses of filters located on different antenna array elements of the FIB, with utilisation of

I. D. Dotlic?

2004-01-01

322

Laser frequency standards  

Microsoft Academic Search

This paper gives a brief review of the present status of the problem of developing optical frequency standards. The basic principles of laser-frequency stabilization based on narrow nonlinear optical resonances are presented. The basic physical factors determining the shape and the shift of narrow resonances are discussed. The design of the modern laser frequency standard, based on the use of

Sergei N Bagaev; V P Chebotaev

1986-01-01

323

Mast seeding under increasing drought: results from a long-term data set and from a rainfall exclusion experiment.  

PubMed

Mast seeding, the synchronous, highly variable seed production among years, is very common in tree species, but there is no consensus about its main causes and the main environmental factors affecting it. In this study, we first analyze a long-term data set on reproductive and vegetative growth of Quercus ilex in a mediterranean woodland in order to identify the main environmental drivers of interannual variation in flower and seed production and contrast the impact of climate vs. adaptive factors as main causes of masting. Second, we conducted an experiment of rainfall exclusion to evaluate the effects of an increasing drought (simulating predictions of global change models) on both reproductive processes. The annual seed crop was always affected by environmental factors related to the precipitation pattern, these abiotic factors disrupting the fruiting process at different periods of time. Seed production was strongly dependent upon water availability for the plant at initial (spring) and advanced (summer) stages of the acorn maturation cycle, whereas the final step of seed development was negatively affected by the frequency of torrential-rain events. We also found clear evidence that seed masting in the study species is not only regulated by selective endogenous rhythms, but is mainly a physiological response to the variable environment. Our results from the rainfall exclusion experiment corroborated the conclusions obtained from the 26-year fruiting record and demonstrated that the high interannual variation in seed crop was mainly determined by the success in seed development rather than by the flowering effort. Under a global change scenario, it could be expected that the drier conditions predicted by climate models reinforce the negative effects of summer drought on seed production, leading to negative consequences for tree recruitment and forest dynamics. PMID:21058565

Pérez-Ramos, I M; Ourcival, J M; Limousin, J M; Rambal, S

2010-10-01

324

Occurrence of Physical Dormancy in Seeds of Australian Sapindaceae: A Survey of 14 Species in Nine Genera  

PubMed Central

Background and Aims Sapindaceae is one of 16 angiosperm families whose seeds have physical dormancy (PY). However, the extent and nature of PY within this family is poorly known. The primary aims of this study were: (1) to evaluate seed characteristics and determine presence (or not) of PY within nine genera of Australian Sapindaceae; and (2) to compare the frequency of PY across the phylogenetic tree within Australian Sapindaceae. Methods Viability, imbibition and seed characteristics were assessed for 14 taxa from nine genera of Sapindaceae. For five species of Dodonaea, optimal conditions for germination and dormancy break were evaluated. An in situ burial experiment was performed on D. hackettiana seeds to identify the factor(s) responsible for overcoming PY. Classes of dormancy and of non-dormancy for 26 genera of Sapindaceae were mapped onto a phylogenetic tree for the family. Key Results Mean seed viability across all taxa was 69·7 %. Embryos were fully developed and folded (seven genera) or bent (two genera); no endosperm was present. Seeds of all five Dodonaea spp. and of Distichostemon hispidulus had PY. Hot-water treatment released PY in these six species. Optimal germination temperature for seeds of the four Dodonaea spp. that germinated was 15–20 °C. Following 5 months burial in soil, 36·4 % of D. hackettiana seeds had lost PY and germinated by the beginning of the winter wet season (May). Laboratory and field data indicate that dormancy was broken by warm, moist temperatures (?50 °C) during summer. Conclusions PY occurs infrequently in genera of Sapindaceae native to Australia. Seeds of Dodonaea and Distichostemon had PY, whereas those of the other seven genera did not. Seeds of these two genera and of Diplopeltis (a previous study) are the only three of the 20 native Australian genera of Sapindaceae for which germination has been studied that have PY; all three belong to subfamily Dodonaeoideae.

Cook, A.; Turner, S. R.; Baskin, J. M.; Baskin, C. C.; Steadman, K. J.; Dixon, K. W.

2008-01-01

325

7 CFR 945.7 - Certified seed potatoes.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 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...

2009-01-01

326

7 CFR 361.5 - Sampling of seeds.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Sampling of seeds. 361.5 Section 361...Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE...AGRICULTURE IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.5 Sampling...

2013-01-01

327

Optimum Size for Planting Hatchery Produced Oyster Seed.  

National Technical Information Service (NTIS)

The ability of hatcheries to produce oyster seed for stocking a variety of oyster culture operations is well established. Hatchery produced seed has not gained acceptance along the Gulf Coast primarily because survival of seed is poorly understood, partic...

R. K. Wallace F. S. Rikard J. C. Howe D. B. Rouse

2001-01-01

328

7 CFR 1427.165 - Eligible seed cotton.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 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....

2012-01-01

329

7 CFR 1427.165 - Eligible seed cotton.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 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....

2013-01-01

330

Seed production and establishment of western Oregon native grasses  

Treesearch

However, unfavorable economics, low seed yields for some species, genetic issues ... It has also conducted studies involving the effects of fertilization, row spacing, ... These include dormancy, seed appendages, seed quality, slow growth, and ...

331

7 CFR 810.1801 - Definition of sunflower seed.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Definition of sunflower seed. 810.1801 Section 810.1801...FOR GRAIN United States Standards for Sunflower Seed Terms Defined § 810.1801 Definition of sunflower seed. Grain that, before the...

2009-01-01

332

7 CFR 810.1801 - Definition of sunflower seed.  

Code of Federal Regulations, 2010 CFR

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

2010-01-01

333

7 CFR 457.108 - Sunflower seed crop insurance provisions.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Sunflower seed crop insurance provisions. 457...CROP INSURANCE REGULATIONS § 457.108 Sunflower seed crop insurance provisions. The sunflower seed crop insurance provisions for...

2009-01-01

334

7 CFR 457.108 - Sunflower seed crop insurance provisions.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Sunflower seed crop insurance provisions. 457...CROP INSURANCE REGULATIONS § 457.108 Sunflower seed crop insurance provisions. The sunflower seed crop insurance provisions for...

2010-01-01

335

7 CFR 201.53 - Source of seeds for germination.  

Code of Federal Regulations, 2010 CFR

... false Source of seeds for germination. 201.53 Section 201.53...FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of...201.53 Source of seeds for germination. (a) When both purity...

2009-01-01

336

7 CFR 201.53 - Source of seeds for germination.  

Code of Federal Regulations, 2010 CFR

... false Source of seeds for germination. 201.53 Section 201.53...FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of...201.53 Source of seeds for germination. (a) When both purity...

2010-01-01

337

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

PubMed Central

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.

Orozco-Segovia, A.; Marquez-Guzman, J.; Sanchez-Coronado, M. E.; Gamboa de Buen, A.; Baskin, J. M.; Baskin, C. C.

2007-01-01

338

Femtosecond Optical Frequency Combs  

NASA Astrophysics Data System (ADS)

A laser frequency comb allows the conversion of the very rapid oscillations of visible light down to frequencies that can be handled with conventional electronics. This has enabled the most precise laser spectroscopy experiments yet, to determine fundamental constants and to limit their possible slow drift. Using an optical frequency reference in combination with a laser frequency comb has made it possible to construct all optical atomic clocks. Frequency combs are also used to calibrate astronomical spectrographs and might reach an accuracy that is sufficient to observe the change of the expansion rate of the universe in real time.

Udem, Thomas; Holzwarth, Ronald; Hänsch, Theodor

339

Allelopathy due to purine alkaloids in tea seeds during germination  

Microsoft Academic Search

Summary  During imbibition of whole tea seeds (6 days) two purine alkaloids, caffeine and theobromine, did not decrease in the seed\\u000a coats and there was no increase in the seeds. In parallel with and after the breaking of seed coats there was a gradual release\\u000a of caffeine from coats of germinating seeds. By contrast, when the seed was freed from the

T. Suzuki; G. R. Waller

1987-01-01

340

Seeded attosecond-pulse generation in structured media: A road for attosecond optics  

SciTech Connect

We present an approach for controlling attosecond pulses just like one controls femtosecond pulses nowadays. Using an adequate medium constituted of aligned and pre-dissociated molecules associated with a ''seed'' attosecond pulse and a control ir field, we propose a scheme for generating secondary attosecond pulses with a high degree of control of their characteristics. By solving the time-dependent Schroedinger equation for a model pre-dissociated molecule (H{sub 2}{sup +}) irradiated by the control ir field and seed xuv pulse, we demonstrate that one can generate such well-controlled secondary attosecond pulses by achieving frequency tuning and up-shifting and control on the chirp of the secondary pulses, which can even be significantly shorter than the seed. We also show that their characteristics can be accurately predicted with a simple classical approach.

Foerre, Morten [Department of Physics and Technology, University of Bergen, N-5007 Bergen (Norway); Centre Lasers Intenses et Applications, Universite Bordeaux-CNRS-CEA, F-33405 Talence Cedex (France); Mevel, Eric; Constant, Eric [Centre Lasers Intenses et Applications, Universite Bordeaux-CNRS-CEA, F-33405 Talence Cedex (France)

2011-02-15

341

VARIATIONS IN THE COMPOSITION OF AVOCADO SEED  

Microsoft Academic Search

SUMMARY Avocado seed are usually considered as waste or as a source of seedlings suitable for use as rootstocks. This paper emphasizes the changing composition of avocado seed and how as a storage organ certain constituents are translocated from it to other portions of the fruit or tree. The fresh and dry weight and some of the inorganic constituents were

R. C. Haas

342

First off the mark: early seed germination.  

PubMed

Most plant seeds are dispersed in a dry, mature state. If these seeds are non-dormant and the environmental conditions are favourable, they will pass through the complex process of germination. In this review, recent progress made with state-of-the-art techniques including genome-wide gene expression analyses that provided deeper insight into the early phase of seed germination, which includes imbibition and the subsequent plateau phase of water uptake in which metabolism is reactivated, is summarized. The physiological state of a seed is determined, at least in part, by the stored mRNAs that are translated upon imbibition. Very early upon imbibition massive transcriptome changes occur, which are regulated by ambient temperature, light conditions, and plant hormones. The hormones abscisic acid and gibberellins play a major role in regulating early seed germination. The early germination phase of Arabidopsis thaliana culminates in testa rupture, which is followed by the late germination phase and endosperm rupture. An integrated view on the early phase of seed germination is provided and it is shown that it is characterized by dynamic biomechanical changes together with very early alterations in transcript, protein, and hormone levels that set the stage for the later events. Early seed germination thereby contributes to seed and seedling performance important for plant establishment in the natural and agricultural ecosystem. PMID:21430292

Weitbrecht, Karin; Müller, Kerstin; Leubner-Metzger, Gerhard

2011-03-23

343

9 CFR 101.7 - Seed organisms.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Seed organisms. 101.7 Section 101.7 Animals...SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS DEFINITIONS § 101.7 Seed organisms. When used in conjunction with or...

2009-01-01

344

9 CFR 101.7 - Seed organisms.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Seed organisms. 101.7 Section 101.7 Animals...SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS DEFINITIONS § 101.7 Seed organisms. When used in conjunction with or...

2010-01-01

345

Finding influential seed successors in social networks  

Microsoft Academic Search

In a dynamic social network, nodes can be removed from the network for some reasons, and consequently affect the behaviors of the network. In this paper, we tackle the challenge of finding a successor node for each removed seed node to maintain the influence spread in the network. Given a social network and a set of seed nodes for influence

Cheng-Te Li; Hsun-Ping Hsieh; Shou-De Lin; Man-Kwan Shan

2012-01-01

346

Lipid biosynthesis in developing perilla seeds  

Microsoft Academic Search

In developing seeds of Perilla frutescens var. crispa, the triacylglycerol fraction was found to accumulate between 15 and 19 days after flowering. Of this, 65% of the total fatty acids was ?-linolenic acid in the mature seeds, with the latter being esterified in comparable amounts at all positions (sn-1, 2 and 3) of the glycerol residue. It was also demonstrated

Ken'ichi Ichihara; Yasumasa Suda

2003-01-01

347

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.

348

Chapter 12. Seedbed preparation and seeding practices  

Treesearch

... Fire and Aviation, International Forestry, Just for Kids, Maps and Brochures, Passes and Permits ... Science.gov - We Participate ... The selection of species to be planted in any restoration program usually takes place after the ... Seeding and planting involves an introduction of seeds and plants to a site that alters existing ...

349

76 FR 31790 - Federal Seed Act Regulations  

Federal Register 2010, 2011, 2012, 2013

...September for germination. Germination labeling is required for all...label all kinds of seed for germination prior to shipment and sale...require labeling of all seed for germination, removing this exemption...Ciferri and Giacom.'', ``Alfalfa--Medicago sativa...

2011-06-02

350

75 FR 78932 - Federal Seed Act Regulations  

Federal Register 2010, 2011, 2012, 2013

...September for germination. Germination labeling is required for all...label all kinds of seed for germination prior to shipment and sale...require labeling of all seed for germination, removing this exemption...Ciferri and Giacom.'', ``Alfalfa--Medicago sativa...

2010-12-17

351

Spatiotemporal variation in predispersal seed predation intensity  

Microsoft Academic Search

The effect of predispersal seed predation by Bruchus atomarius (Bruchidae, Coleoptera) on individual performance and population dynamics of the perennial forest herb, Lathyrus vernus (Leguminosae), was investigated in 11 permanent plots over 4 years. Seed predation and parameters describing intra-specific neighbour distance, plant size, inflorescence size, flowering phenology and current and previous herbivore damage were measured on all plants. In

Johan Ehrlén

1996-01-01

352

Seed predation in the legume Crotalaria  

Microsoft Academic Search

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

L. R. Moore

1978-01-01

353

7 CFR 947.12 - Seed potatoes.  

Code of Federal Regulations, 2010 CFR

means and includes all potatoes officially certified and tagged, marked or otherwise appropriately identified under the supervision of the official seed potato certifying agency of the State from which the potatoes are shipped, or other seed certification agencies which the Secretary may...

2004-01-01

354

An improved seeded region growing algorithm  

Microsoft Academic Search

Recently Adams and Bischof (1994) proposed a novel region growing algorithm for segmenting intensity images. The inputs to the algorithm are the intensity image and a set of seeds — individual points or connected components — that identify the individual regions to be segmented. The algorithm grows these seed regions until all of the image pixels have been assimilated. Unfortunately

Andrew Mehnert; Paul T. Jackway

1997-01-01

355

A flow-guided streamline seeding strategy  

Microsoft Academic Search

This paper presents a seed placement strategy for streamlines based on ow features in thedata set. The primary goal of our seeding strategy is to capture ow patterns in the vicinity ofcritical points in the ow eld, even as the density of streamlines is reduced. Secondary goalsare to place streamlines such that there is sucient coverage in non-critical regions, and

Vivek Verma; David T. Kao; Alex Pang

2000-01-01

356

Seed island formation by forced magnetic reconnection  

Microsoft Academic Search

Neoclassical tearing modes observed in experiments often grow from seed magnetic islands induced by triggers like sawteeth. The formation of seed islands is studied in this paper using both the reduced MHD and two-fluid equations, with the trigger being modelled by externally applied resonant magnetic perturbations. In the linear phase the growth rate of the driven mode is found to

Q. Yu; S. Günter; K. Lackner; M. Maraschek

2012-01-01

357

Method of Removing Pigment from Annatto Seed.  

National Technical Information Service (NTIS)

This invention relates to and has among its objects the provision of novel methods for extracting pigment from seeds containing the same, e.g., seeds of Bixa orellana L. (Lipstick Pod). It is a particular object of the invention to realize a high yield of...

W. G. Schultz

1978-01-01

358

EFFECTS OF X IRRADIATION ON CORN SEED  

Microsoft Academic Search

Corn seed was irradiated with eight dosages of x rays ranging from 0 to ; 1000 kr. Generally, all the seeds germinated and grew at uniform reduced rates ; for any given dose. Both hard and soft x rays greatly suppressed seedling ; growth, however. The range of x-ray treatments did not give a linear effect on ; growth. Hard

JOE H. CHERRY; R. H. Hageman; FLOYD I. COLLINS; DONNA FLESHER

1961-01-01

359

Have Biotech Seeds Increased Maize Yields?  

Microsoft Academic Search

Corn yield is determined by soils, weather, seed used and other technology choices. Global population and per capita income growth trends as well as demand from the energy sector have placed great stress on cropland use. Global cropland acres and\\/or yield per acre will need to increase. Whether new seed technologies have enhanced corn yield is a controversial issue. We

Zheng Xu; David A. Hennessy; GianCarlo Moschini

2010-01-01

360

Seeding Native Grasses in the Arid Southwest.  

National Technical Information Service (NTIS)

Grass seeding is an uncertain endeavor even in the best of circumstances, but in the arid Southwest it is an extremely risky venture. This technical note is intended to present the important factors that influence the success of seeding native grasses in ...

D. R. Dreesen

2013-01-01

361

Chemical characterization of Achyranthes bidentata seed  

Microsoft Academic Search

The chemical compositions of seeds of Achyranthes bidentata (AB) were determined and compared to those commonly found within the same Amaranthaceae family, i.e. genus Amaranthus and to those of more common cereal grains. The study revealed that AB seeds were substantially higher in nutritionally important minerals, such as phosporus, potassium, calcium, magnesium and iron, as well as being substantially higher

Massimo F. Marcone; Firouz Jahaniaval; Hamid Aliee; Yukio Kakuda

2003-01-01

362

Primordial magnetic seeds from string cosmology  

Microsoft Academic Search

After a discussion of the inflationary production of primordial magnetic seeds and a brief review of various possible mechanisms, we concentrate on the analysis of the photon-dilaton coupling typical of string theory models. Particular attention is paid to the constraints to be imposed on the primordial seed spectrum and to the possibility of obtaining phenomenological signatures of heterotic and Type

M. Gasperini

2006-01-01

363

Primordial magnetic seeds from string cosmology  

Microsoft Academic Search

After a discussion of the inflationary production of primordial magnetic seeds, and a short review of various possible mechanisms, we concentrate on the analysis of the photon-dilaton coupling typical of string theory models. Particular attention is paid to the constraints to be imposed on the primordial seed spectrum, and to the possibility of obtaining phenomenological signatures of heterotic and Type

M Gasperini

2005-01-01

364

Sucrose metabolism in lima bean seeds  

Microsoft Academic Search

Developing and germinating lima bean (Phaseolus lunatus var Cangreen) seeds were used for testing the sucrose synthase pathway, to examine the competition for uridine diphosphate (UDP) and pyrophosphate (PPi), and to identify adaptive and maintenance-type enzymes in glycolysis and gluconeogenesis. In developing seeds, sucrose breakdown was dominated by the sucrose synthase pathway; but in the seedling embryos, both the sucrose

Dianpeng Xu; S.-J. S. Sung; S. Shijean; C. C. Black

1989-01-01

365

Improving photoacoustic imaging contrast of brachytherapy seeds  

NASA Astrophysics Data System (ADS)

Prostate brachytherapy is a form of radiotherapy for treating prostate cancer where the radiation sources are seeds inserted into the prostate. Accurate localization of seeds during prostate brachytherapy is essential to the success of intraoperative treatment planning. The current standard modality used in intraoperative seeds localization is transrectal ultrasound. Transrectal ultrasound, however, suffers in image quality due to several factors such speckle, shadowing, and off-axis seed orientation. Photoacoustic imaging, based on the photoacoustic phenomenon, is an emerging imaging modality. The contrast generating mechanism in photoacoustic imaging is optical absorption that is fundamentally different from conventional B-mode ultrasound which depicts changes in acoustic impedance. A photoacoustic imaging system is developed using a commercial ultrasound system. To improve imaging contrast and depth penetration, absorption enhancing coating is applied to the seeds. In comparison to bare seeds, approximately 18.5 dB increase in signal-to-noise ratio as well as a doubling of imaging depth are achieved. Our results demonstrate that the coating of the seeds can further improve the discernibility of the seeds.

Pan, Leo; Baghani, Ali; Rohling, Robert; Abolmaesumi, Purang; Salcudean, Septimiu; Tang, Shuo

2013-03-01

366

Physicochemical changes of oat seeds during germination  

Microsoft Academic Search

The physicochemical properties of native and germinated oat seeds cultivated in China and their correlations were investigated. The growth curve during germination of oat seeds was described. The malt yield was 84% at the end of malting. The losses by removing of shoots and rootlets were the major cause of the total dry matter losses in the last 24h of

Binqiang Tian; Bijun Xie; John Shi; Jia Wu; Yan Cai; Tuoming Xu; Sophia Xue; Qianchun Deng

2010-01-01

367

Effect of oat seed treatment with microelements  

Microsoft Academic Search

Summary A field experiment was carried out to study the effect of treating oats seeds with the microelements boron, cobalt and copper. Treatment with microelements had no marked effect on seed germination. Tillering rate was increased by B- and Co-treatments. Boron and cobalt had positive effect on panicle length, and cobalt positively influenced plant height. The most beneficial effect of

T. Saric; B. Saciragic

1969-01-01

368

Detection of drechslera avenae in oat seeds  

Microsoft Academic Search

The fungus Drechslera avenae, the causal agent of Helminthosporium leaf spot on oats (Avena sativa), survives as mycelium in crop residues and in infected seeds. In trials carried out in the laboratory, ten methods were evaluated for their efficiency to detect D. avenae in oat seeds. In each experiment, groups of two or three methods were compared to a standard

NADIA C. LÂNGARO; ERLEI M. REIS; ELMAR L. FLOSS

2001-01-01

369

Antidiabetic oligocyclitols in seeds of Mucuna pruriens.  

PubMed

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

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

2005-12-01

370

Sativa seeds against Schistosoma mansoni different stages  

Microsoft Academic Search

The schistosomicidal properties of Nigella sativa seeds were tested in vitro against Schistosoma mansoni mira- cidia, cercariae, and adult worms. Results indicate its strong biocidal effects against all stages of the parasite and also showed an inhibitory effect on egg-laying of adult female worms. In the present work we also studied the effects of crushed seeds on some antioxidant enzymes;

Azza M Mohamed; Nadia M Metwally; Sohair S Mahmoud

2005-01-01

371

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....

372

Alterations in seed development gene expression affect size and oil content of Arabidopsis seeds.  

PubMed

Seed endosperm development in Arabidopsis (Arabidopsis thaliana) is under control of the polycomb group complex, which includes Fertilization Independent Endosperm (FIE). The polycomb group complex regulates downstream factors, e.g. Pheres1 (PHE1), by genomic imprinting. In heterozygous fie mutants, an endosperm develops in ovules carrying a maternal fie allele without fertilization, finally leading to abortion. Another endosperm development pathway depends on MINISEED3 (a WRKY10 transcription factor) and HAIKU2 (a leucine-rich repeat kinase). While the role of seed development genes in the embryo and endosperm establishment has been studied in detail, their impact on metabolism and oil accumulation remained unclear. Analysis of oil, protein, and sucrose accumulation in mutants and overexpression plants of the four seed development genes revealed that (1) seeds carrying a maternal fie allele accumulate low oil with an altered composition of triacylglycerol molecular species; (2) homozygous mutant seeds of phe1, mini3, and iku2, which are smaller, accumulate less oil and slightly less protein, and starch, which accumulates early during seed development, remains elevated in mutant seeds; (3) embryo-specific overexpression of FIE, PHE1, and MINI3 has no influence on seed size and weight, nor on oil, protein, or sucrose content; and (4) overexpression of IKU2 results in seeds with increased size and weight, and oil content of overexpressed IKU2 seeds is increased by 35%. Thus, IKU2 overexpression represents a novel strategy for the genetic manipulation of the oil content in seeds. PMID:24014578

Fatihi, Abdelhak; Zbierzak, Anna Maria; Dörmann, Peter

2013-09-06

373

Frequency-guided windowed Fourier ridges technique for automatic demodulation of a single closed fringe pattern  

SciTech Connect

A frequency-guided windowed Fourier ridges (FG-WFR) technique for phase extraction from a single closed fringe pattern is proposed. The algorithm begins with a selected seed point and is then guided by the local frequency of the computed pixels. For the seed point, the whole spectral range is examined with WFR to provide reliable local frequency and phase estimation. However, for the rest of the pixels, the WFR algorithm is performed in a more narrow spectral range centered at the determined frequency of its computed neighboring pixel, which not only enforces the continuity of the local frequency between adjacent pixels but also reduces computation consumption significantly. Besides, since phase unwrapping can be readily implemented after demodulation of each pixel, the algorithm directly offers a continuous phase map. The proposed FG-WFR algorithm is verified by successfully demodulating two computer simulated fringe patterns and one noisy experimental fringe pattern.

Li Kai; Pan Bing

2010-01-01

374

Seed Aging: Chromosome Stability and Extended Viability of Seeds Stored Fully Imbided 1  

PubMed Central

Increase in moisture content of seeds of Lactuca sativa L. and Fraxinus americana L. in air-dry storage caused a rapid decline in longevity and an increase in the rate of accumulation of chromosome aberrations. Storage of seeds fully imbibed but unable to germinate allowed a high germination capacity to be maintained for long periods, together with a very low incidence of chromosome aberrations. Seedlings grown from dry-stored seeds showed an increase in morphological abnormalities with length of storage, whereas seedlings from imbibed-stored seeds appeared normal. It is suggested that in dry tissues, enzyme-controlled turnover and repair may be temporarily suspended, and that this may be an important factor in the loss of seed viability in storage. The effect of increasing seed longevity by lowering the moisture content of dry-stored seeds is discussed in relation to this hypothesis. The relevance of the proposal is also discussed in relation to ecological studies. Images

Villiers, T. A.

1974-01-01

375

Mitomycin C induced leaf mosaicism in Glycine max (L.) Merrill in relation to the post-germination age of the seed  

Microsoft Academic Search

The frequency of mitomycin C induced somatic crossing over in variety L65-1237 of Glycine max is shown to be dependent upon the (physiological) age of the seed during post germination period. Effect of mitomycin C during the first four hr of germination is significantly lower than during later periods. This increase in the frequency of somatic crossing over is observed

B. K. Vig

1973-01-01

376

Seed-less iodine-125 ophthalmic applicator.  

PubMed

A method of preparation a seed-less active insert of iodine-125 ophthalmic applicator is described. Internal electrolysis was applied for fixing iodine-125 on the concave surface of the silver shell which is afterwards hermetically sealed inside a spherically shaped acrylic insert. The current-voltage characteristics of the galvanic cell used for deposition of silver iodide were determined. The results of the measurements of the energy spectra of the radiation emitted by a seed-less and seed-containing applicator are presented. The iodine-125 surface distribution uniformity on a silver shell was measured. The depth dose rate measurements indicate that the total activity incorporated in a seed-less applicator can be lower than that in seed-containing, while simultaneously assuring the desired dose rate. PMID:12485658

Puchalska, Izabela; Mielcarski, Mieczyslaw

2003-01-01

377

Protein profile of rice (Oryza sativa) seeds  

PubMed Central

Seeds are the most important plant storage organ and play a central role in the life cycle of plants. Since little is known about the protein composition of rice (Oryza sativa) seeds, in this work we used proteomic methods to obtain a reference map of rice seed proteins and identify important molecules. Overall, 480 reproducible protein spots were detected by two-dimensional electrophoresis on pH 4–7 gels and 302 proteins were identified by MALDI-TOF MS and database searches. Together, these proteins represented 252 gene products and were classified into 12 functional categories, most of which were involved in metabolic pathways. Database searches combined with hydropathy plots and gene ontology analysis showed that most rice seed proteins were hydrophilic and were related to binding, catalytic, cellular or metabolic processes. These results expand our knowledge of the rice proteome and improve our understanding of the cellular biology of rice seeds.

Yang, Yanhua; Dai, Li; Xia, Hengchuan; Zhu, Keming; Liu, Haijun; Chen, Keping

2013-01-01

378

Alfalfa Seed Decontamination in Salmonella Outbreak  

PubMed Central

Based on in vitro data, the U.S. Food and Drug Administration recommends chemical disinfection of raw sprout seeds to reduce enteric pathogens contaminating the seed coats. However, little is known about the effectiveness of decontamination at preventing human disease. In 1999, an outbreak of Salmonella enterica serotype Mbandaka occurred in Oregon, Washington, Idaho, and California. Based on epidemiologic and pulsed-field gel electrophoresis evidence from 87 confirmed cases, the outbreak was linked to contaminated alfalfa seeds grown in California’s Imperial Valley. Trace-back and trace-forward investigations identified a single lot of seeds used by five sprout growers during the outbreak period. Cases of salmonellosis were linked with two sprout growers who had not employed chemical disinfection; no cases were linked to three sprout growers who used disinfection. This natural experiment provides empiric evidence that chemical disinfection can reduce the human risk for disease posed by contaminated seed sprouts.

Gill, Christopher J.; Mohle-Boetani, Janet C.; Farrar, Jeff A.; Waller, Patti L.; Hahn, Christine G.; Cieslak, Paul R.

2003-01-01

379

Amino Acid Composition of Germinating Cotton Seeds  

PubMed Central

Total and free amino acid composition of germinating cotton seeds (Gossypium hirsutum L.) was determined. The germinating seeds were separated into cotyledon and developing axis fractions daily and the composition of each tissue was summed to get the whole seed composition. By separating the developing seeds into these two tissue fractions, and determining total and free amino acids, a balance sheet was developed for each amino acid. This technique allowed changes in distribution with time of each amino acid to be followed in each tissue. Data for total content and amount in protein of each amino acid are presented. Asparagine increased in the whole seed, and most of this increase was found in the free pool of the developing axis. Other amino acids (e.g. arginine, glutamic acid) increased in the free pool but showed an over-all decrease, indicating that they were being metabolized. Amino acid contents of storage and nonstorage protein isolates were determined.

Elmore, C. Dennis; King, Earl E.

1978-01-01

380

????????????????????????????? ????? ???? ??? ??????????????????????? Genetic Control of Seed Weight, Size and Germination in Amoora polystachya  

Microsoft Academic Search

The study on seed morphology and genetic control of seed weight seed size and seed germination in Amoora polystachya was conducted using seeds collected from 10 seed trees each in natural forest in Kamphangphet and Tak provinces. The results showed that in one fruit contained 1-3 seeds whereas 1-2 seeds per 1 fruis was highest (77%) and in 100 fruits,

Suksan Saiwa; Prapai Kannark; Bundit Ponoy

381

[Evaluation of the consequences of stress factors on plant seeds growing in a 30-km zone of Balakovo AES].  

PubMed

The effect of stress factors (small doses of radiation and maximum temperatures in the econiche of the tested plants (tmax)) as well as aging on pea seeds, both acting independently and in combination, is estimated. Here we evaluate the influence of oxidizing stress on pea seeds in the laboratory (gamma-irradiated with 7 cGy at 0.3-19.1 cGy/h, tmax approximately 30-32 degrees C) and on natural plantain seeds collected in a 30-km zone of NPP (radiation exposure approximately 15 R/h, tmax approximately 38-40 degrees C). We have mathematically modeled CAs frequencies in root seedlings meristeme by invoking an enhancing factor transmitted from cell to cell. It is shown under the stress conditions: 1) CA frequency decreases whereas the fraction of inviable seeds (IS) increases, the dependence of IS on CA frequency being inversed; 2) a stimulation of proliferation of cell was observed; 3) a bystander effect appears; 4) antioxidative status (AOS) of seeds influences on adaptation on the all levels of the organization; 5) IS increases up to 73-80% under the combined effect of radiation and heat stresses. PMID:15060947

Korogodina, V L; Bamblevski?, V P; Grishina, I V; Gustova, M V; Dzhavadova, V; Zueva, M V; Korogodin, V I; Lozovskaia, E L; Malikov, A N; Maslov, O D; Mel'nikova, L A; Stepanchuk, V P; Florko, B V; Shliakhtin, G V

382

Seed banks in a degraded desert shrubland: Influence of soil surface condition and harvester ant activity on seed abundance  

Microsoft Academic Search

We compared seed banks between two contrasting anthropogenic surface disturbances (compacted, trenched) and adjacent undisturbed controls to determine whether site condition influences viable seed densities of perennial and annual Mojave Desert species. Viable seeds of perennials were rare in undisturbed areas (3–4 seeds\\/m2) and declined to <1 seed\\/m2 within disturbed sites. Annual seed densities were an order of magnitude greater

L. A. DeFalco; T. C. Esque; J. M. Kane; M. B. Nicklas

2009-01-01

383

Seed and microsite limitations of recruitment and the impacts of post-dispersal seed predation at the within population level  

Microsoft Academic Search

Seed predation may cause important seed losses in plant populations, but its impact on the dynamics of populations will depend\\u000a on the degree of seed or microsite limitations for recruitment. Seed losses will only affect recruitment if it is seed limited.\\u000a The nature of recruitment limitation (seeds or microsites) is usually ascribed to whole plant populations but it may vary

María Calviño-Cancela

2007-01-01

384

Seed treatment with Trichoderma harzianum alleviates biotic, abiotic, and physiological stresses in germinating seeds and seedlings.  

PubMed

Trichoderma spp. are endophytic plant symbionts that are widely used as seed treatments to control diseases and to enhance plant growth and yield. Although some recent work has been published on their abilities to alleviate abiotic stresses, specific knowledge of mechanisms, abilities to control multiple plant stress factors, their effects on seed and seedlings is lacking. We examined the effects of seed treatment with T. harzianum strain T22 on germination of seed exposed to biotic stress (seed and seedling disease caused by Pythium ultimum) and abiotic stresses (osmotic, salinity, chilling, or heat stress). We also evaluated the ability of the beneficial fungus to overcome physiological stress (poor seed quality induced by seed aging). If seed were not under any of the stresses noted above, T22 generally had little effect upon seedling performance. However, under stress, treated seed germinated consistently faster and more uniformly than untreated seeds whether the stress was osmotic, salt, or suboptimal temperatures. The consistent response to varying stresses suggests a common mechanism through which the plant-fungus association enhances tolerance to a wide range of abiotic stresses as well as biotic stress. A common factor that negatively affects plants under these stress conditions is accumulation of toxic reactive oxygen species (ROS), and we tested the hypothesis that T22 reduced damages resulting from accumulation of ROS in stressed plants. Treatment of seeds reduced accumulation of lipid peroxides in seedlings under osmotic stress or in aged seeds. In addition, we showed that the effect of exogenous application of an antioxidant, glutathione, or application of T22, resulted in a similar positive effect on seed germination under osmotic stress or in aged seed. This evidence supports the model that T. harzianum strain T22 increases seedling vigor and ameliorates stress by inducing physiological protection in plants against oxidative damage. PMID:20649416

Mastouri, Fatemeh; Björkman, Thomas; Harman, Gary E

2010-11-01

385

Effects of seed abundance on seed scatter-hoarding of Edward's rat (Leopoldamys edwardsi Muridae) at the individual level.  

PubMed

Mast seeding is a common phenomenon, and has important effects on seed dispersal and hoarding by animals. At population level, the predator satiation hypothesis proposes that the satiating effect of a large amount of seeds on a relatively small number of predators benefits seed survival in mast-seeding years. However, the effect of mast seeding on the scatter-hoarding of rodents at the individual level is largely unknown. In this study, we investigated the effects of seed abundance (by simulating mast seeding and non-mast seeding) on the removal, consumption and scatter-hoarding of seeds of Camellia oleifera (Theaceae) by Edward's rat Leopoldamys edwardsi (Muridae) in seminatural enclosures in southwest China. We wanted to test the masting-enhanced hoarding hypothesis, which suggests that rodents tend to scatter-hoard more seeds in mast-seeding years in order to occupy more food resources. Our results indicate that L. edwardsi tended to disperse and scatter-hoard more seeds of C. oleifera per night with increasing seed abundance, and to eat less seeds per night when there was a high level of seed abundance in the enclosure experiments. These results support the masting-enhanced hoarding hypothesis. This capacity of rodents may be an evolutionary adaptation to the mast-seeding phenomenon. Our results suggest that mast seeding benefits forest regeneration not only through the predator satiation effect at the population level, but also through increased hoarding by animals at the individual level. PMID:18661155

Zhang, Hongmao; Cheng, Jinrui; Xiao, Zhishu; Zhang, Zhibin

2008-07-26

386

Detection and elimination of Salmonella mbandaka from naturally contaminated alfalfa seed by treatment with heat or calcium hypochlorite.  

PubMed

In 1999, consumption of alfalfa sprouts contaminated with Salmonella Mbandaka led to a multistate outbreak of salmonellosis. In this study, the implicated alfalfa seed lot (no. 8,119) was confirmed to be contaminated with Salmonella Mbandaka at a detection frequency of approximately 72% per replicated 100 g of seed. The sensitivity of detection was improved by a combination of nonselective and selective enrichment of 5.0 ml of germination effluent, followed by immunomagnetic separation. Detection of low levels of viable cells with nonselective enrichment, employed to enhance the recovery of stressed or injured cells, was facilitated by the application of Salmonella-specific polymerase chain reaction (PCR). With PCR assays, Salmonella Mbandaka was detectable on seed stored at 5 degrees C for at least 11 months, but at an increasingly diminishing frequency. Using conventional techniques, viable populations were detected in the seed germination effluent from seeds stored for up to 8 months. Seed treatments with buffered (to pH 7) and unbuffered solutions of calcium hypochlorite, providing approximately 2,000 and 20,000 ppm of free chlorine, for 10 min were equally effective in eliminating viable populations of Salmonella Mbandaka. However, aqueous heat treatments at up to 85 degrees C for 1 min did not eliminate the naturally occurring contaminant from the seed. Reductions of > 15% in germination were observed following heat treatments of 65 degrees C for > or = 6 min or 70 degrees C for > or = 4 min. On the basis of these results, aqueous heat treatments alone do not appear to be a viable alternative to hyperchlorination as an effective method to eliminate Salmonella from alfalfa seed. PMID:11899042

Suslow, Trevor V; Wu, Jiangchun; Fett, William F; Harris, Linda J

2002-03-01

387

SEED QUALITY OF A SET OF INBREDS AND THEIR CORRESPONDING HYBRIDS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Seed composition and genetic background influence seed quality. The standard germination test evaluates seed viability, but many times overestimates field performance. Thus, vigor tests are used to predict seed germination under more stressful environments. Seed scientists have combined several v...

388

Dielectric and conductivity studies of the hydration mechanisms in plant seeds.  

PubMed Central

The hydration mechanism of various plant seeds has been investigated by a) sorption-desorption isotherms, b) ac-dielectric spectroscopy in the 10 Hz to 1 GHz frequency range and the -80 to + 40 degrees C temperature range, and c) thermally stimulated depolarization current techniques in the -170 to + 23 degrees C temperature range. Seeds of different chemical composition were studied at water contents varying between 0 and 40% w/w (dry weight basis). Our experimental results permitted us to determine i) the diffusion constant of water in the samples, found to be between 1.4 x 10(-11) and 3.7 x 10(-11) m2/s; ii) a critical water content corresponding to the completion of the primary hydration layer, which is in the range 0.11-0.17 w/w, depending on the seed nature; and iii) the activation energy of the main relaxation mechanism, found to be equal to 0.54 +/- 0.05 eV. Moreover, they make it possible to investigate the dependence of various parameters (conductivity, molecular mobility, plasticizing effect of water) on the water content of the sample, to follow the crystallization of water in the seeds as a function of temperature and confirm that it is not a reversible process, to study the dehydration process as a function of temperature and time, and to propose an alternative technique for the determination of the moisture content in seeds.

Konsta, A A; Pissis, P; Kanapitsas, A; Ratkovic, S

1996-01-01

389

Frequency Selective Buildings Through Frequency Selective Surfaces  

Microsoft Academic Search

This paper proposes the deployment of frequency selective surfaces (FSS) in indoor wireless environments and investigates their effect on radio wave propagation. FSS can be deployed to selectively confine radio propagation in indoor areas, by artificially increasing the radio transmission loss naturally caused by building walls. FSS can also be used to channel radio signals into other areas of interest.

Marios Raspopoulos; Stavros Stavrou

2011-01-01

390

Differential effect of sodium azide on the frequency of radiation-induced chromosome aberrations vs. the frequency of radiation-induced chlorophyll mutations in Hordeum vulgare  

Microsoft Academic Search

A considerable synergistic increase of the frequency of cells carrying ; chromosome aberrations was observed in seeds of Hordeum vulgare, variety ; Himalaya, irradiated dry with gamma rays and hydrated in sodium azide solutions ; buffered at pH 3, 7, and 11. This effect, which was most evident at pH 3, was ; detected throughout development up to the formation

E. G. Sideris; R. A. Nilan; T. P. Bogyo

1973-01-01

391

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

PubMed

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

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

2013-02-20

392

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

PubMed

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

Siepielski, Adam M; Benkman, Craig W

2008-08-22

393

Frequency Dependence of Vibrothermography  

NASA Astrophysics Data System (ADS)

It has long been postulated that vibrothermographic heating-the heating of cracks due to sound or vibration-induced rubbing-may be frequency dependent. It has been difficult to factor out the innate frequency dependence of the heat-generation process from the geometry-dependent mode structure. We present experiments showing the heating of cracks in slender Inconel/Titanium specimens at transverse resonance. Different resonant modes vibrate at different frequencies but load the crack in the same way (Mode I). The results show a clear increase of heating with vibration frequency.

Zhang, Wenjun; Holland, Stephen D.; Renshaw, Jeremy

2010-02-01

394

Colonization of citrus seed coats by 'Candidatus Liberibacter asiaticus': implications for seed transmission of the bacterium.  

PubMed

Huanglongbing is an economically damaging disease of citrus associated with infection by 'Candidatus Liberibacter asiaticus'. Transmission of the organism via infection of seeds has not been demonstrated but is a concern since some citrus varieties, particularly those used as rootstocks in commercial plantings are propagated from seed. We compared the incidence of detection of 'Ca. Liberibacter asiaticus' DNA in individual fruit peduncles, seed coats, seeds, and in germinated seedlings from 'Sanguenelli' sweet orange and 'Conners' grapefruit fruits sampled from infected trees. Using real-time quantitative PCR (qPCR) we detected pathogen DNA in nucleic acid extracts of 36 and 100% of peduncles from 'Sanguenelli' and from 'Conners' fruits, respectively. We also detected pathogen DNA in extracts of 37 and 98% of seed coats and in 1.6 and 4% of extracts from the corresponding seeds of 'Sanguenelli' and 'Conners', respectively. Small amounts of pathogen DNA were detected in 10% of 'Sanguenelli' seedlings grown in the greenhouse, but in none of 204 extracts from 'Conners' seedlings. Pathogen DNA was detected in 4.9% and in 89% of seed coats peeled from seeds of 'Sanguenelli' and 'Conners' which were germinated on agar, and in 5% of 'Sanguenelli' but in none of 164 'Conners' seedlings which grew from these seeds on agar. No pathogen DNA was detected in 'Ridge Pineapple' tissue at 3 months post-grafting onto 'Sanguenelli' seedlings, even when pathogen DNA had been detected initially in the 'Sanguenelli' seedling. Though the apparent colonization of 'Conners' seeds was more extensive and nearly uniform compared with 'Sanguenelli' seeds, no pathogen DNA was detected in 'Conners' seedlings grown from these seeds. For either variety, no association was established between the presence of pathogen DNA in fruit peduncles and seed coats and in seedlings. PMID:21714779

Hilf, Mark E

2011-10-01

395

Sucrose metabolism in lima bean seeds  

SciTech Connect

Developing and germinating lima bean (Phaseolus lunatus var Cangreen) seeds were used for testing the sucrose synthase pathway, to examine the competition for uridine diphosphate (UDP) and pyrophosphate (PPi), and to identify adaptive and maintenance-type enzymes in glycolysis and gluconeogenesis. In developing seeds, sucrose breakdown was dominated by the sucrose synthase pathway; but in the seedling embryos, both the sucrose synthase pathway and acid invertase were active. UDPase activity was low and seemingly insufficient to compete for UDP during sucrose metabolism in seed development or germination. In contrast, both an acid and alkaline pyrophosphatase were active in seed development and germination. The set of adaptive enzymes identified in developing seeds were sucrose synthase, PPi-dependent phosphofructokinase, plus acid and alkaline pyrophosphatase; and, the adaptive enzymes identified in germinating seeds included the same set of enzymes plus acid invertase. The set of maintenance enzymes identified during development, in the dry seed, and during germination were UDP-glucopyrophosphorylase, neutral invertase, ATP and UTP-dependent fructokinase, glucokinase, phosphoglucomutase, ATP and UTP-dependent phosphofructokinase and sucrose-P synthase.

Xu, Dianpeng; Sung, Shijean, S.; Black, C.C. (Univ. of Georgia, Athens (USA))

1989-04-01

396

Injection-seeded pulsed Ti:sapphire laser with novel stabilization scheme and capability of dual-wavelength operation  

Microsoft Academic Search

A gain-switched, single-frequency titanium-sapphire laser for atmospheric humidity measurements using the differential absorption lidar technique operating in the 820 nm wavelength region is described. The laser is pumped by a frequency-doubled, flashlamp-pumped Nd:YAG laser at a repetition rate of 50 Hz and injection seeded by two external-cavity-diode lasers. The system yields pulses with an energy of 15 mJ and high

Klaus Ertel; Holger Linné; Jens Bösenberg

2005-01-01

397

Using a 1.2 GHz bandwidth reflective semiconductor optical amplifier with seeding light by 64-quadrature amplitude modulation orthogonal frequency division multiplexing modulation to achieve a 10-gbits/s upstream rate in long-reach passive optical network access  

NASA Astrophysics Data System (ADS)

We use a commercially available 1.2 GHz bandwidth reflective semiconductor optical amplifier (RSOA)--based optical network unit (ONU) to achieve 10-gbits/s upstream traffic for an optical orthogonal frequency division multiplexing (OFDM) long-reach passive optical network (LR-PON). This is the first time the 64--quadrature amplitude modulation (QAM) OFDM format has been applied to RSOA-ONU to achieve a 75 km fiber transmission length. In the proposed LR-PON, the upstream power penalty of 5.2 dB at the bit error rate of 3.8×10-3 is measured by using a 64-QAM OFDM modulation after the 75 km fiber transmission without dispersion compensation.

Yeh, Chien-Hung; Chen, Hsing-Yu; Chow, Chi-Wai; Wu, Yu-Fu

2012-01-01

398

Riparian seed dispersal: transport and depositional processes  

NASA Astrophysics Data System (ADS)

Riparian tree population dynamics are linked to the physical processes controlled by the hydrogeomorphic setting. In particular, fluvial seed dispersal is influenced by a combination of factors including the hydrology, fluvial geomorphology, and seed dispersal traits. This study examines the influence of stream flow patterns on the transportation and deposition of buoyant seeds by applying a one dimensional transport model. Conceptually, the model separates the stream into two components: the main channel and transient storage /deposition zones. The hydrologic processes are governed by an advection-dispersion equation and numerically solved using the Crank-Nicolson method. Additional terms in the equation allow for model variation in the flow regime (lateral inflow and outflow) and the incorporation of a transient storage/deposition component where seeds may be detained. The model parameters are based on a bedrock-gravel bed river with pool-riffle morphology where we conducted field experimentation in Coastal Northern California. The riparian zone of the study reach is inhabited by White Alder (Alnus rhombifolia) which disperses buoyant seeds in late winter/early spring coinciding with the latter part of the wet, Mediterranean climate. Artificial seeds with similar characteristic traits of buoyancy, density and Bond Number to White Alder seeds were used to quantify transport times and identify storage areas. The model output captures a greater number of seeds during a receding hydrograph due to the increase in transient storage. Typically, this is found in shallow stream margins where the flow is divergent such as areas with back-eddies. In the field, this is associated with the ends of gravel bars or riffles where flow expansion causes secondary flows. The results demonstrate the importance of transient storage for seed transport and depositional processes and emphasize the need for improved measurement techniques, in lieu of empirical coefficients, to advance the mechanistic understanding of the complex hydraulic processes.

Cunnings, A.; Johnson, E. A.; Martin, Y. E.

2012-04-01

399

Some physical properties of the watermelon seeds  

Microsoft Academic Search

& Ball's method, changed from 2.004 to 2.125, 0.446 to 0.513, 149.68 to 225.03 mm2, 128.09 to 198.01 mm2, respectively. The values of the seed volume, true density, bulk density and porosity of watermelon seeds were between 179.53-311.62 mm3, 861.75-866.66 kg\\/m3, 416.33-527.265 kg\\/m3 and 39.14-51.68% respectively. The study over the coefficient of friction of watermelon seeds on some materials such

Seyed M. A. Razaviand; Elnaz Milani

2006-01-01

400

Interaction of microwaves and germinating seeds  

SciTech Connect

The preliminary investigation measured the internal metabolic process by ATP production. Leakage of ions and organic material from germinating seeds indicated that membranes are a target of microwaves and heat. Electron photo-micrographs showed an increase in damage to membranes as heat and microwave treatments were increased. The second phase of this investigation was concerned with determining some of the biological activity at the initiation of germination of wheat seed, Triticum aestivum L., using a resonating microwave cavity oscillating at 9.3 GHz as a probe. Direct current conductivity measurements were also made on the seeds as a means of confirming the observations made with the microwave cavity.

Shafer, F.L.

1987-01-01

401

Genomic Data and Annotation from the SEED  

DOE Data Explorer

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.)

Fonstein, Michael; Kogan, Yakov; Osterman, Andrei; Overbeek, Ross; Vonstein, Veronika The Fellowship for Interpretation of Genomes (FIG)

402

Optical frequency metrology  

Microsoft Academic Search

Extremely narrow optical resonances in cold atoms or single trapped ions can be measured with high resolution. A laser locked to such a narrow optical resonance could serve as a highly stable oscillator for an all-optical atomic clock. However, until recently there was no reliable clockwork mechanism that could count optical frequencies of hundreds of terahertz. Techniques using femtosecond-laser frequency

Th. Udem; R. Holzwarth; T. W. Hänsch

2002-01-01

403

Improving Food Frequency Questionnaires  

Microsoft Academic Search

In an attempt to improve data quality and ease of administration of standard self-administered food frequency questionnaires, various alternative approaches were tried for inquiring about frequency of consumption, portion size, seasonal intake, and food preparation. Evaluation consisted of a cognitive interviewing method in which respondents verbalize their thought process while completing several variations of a questionnaire. Interviewers observed and asked

AMY F SUBAR; FRANCES E THOMPSON; ALBERT F SMITH; JARED B JOBE; REGINA G ZIEGLER; NANCY POTISCHMAN; ARTHUR SCHATZKIN; ANNE HARTMAN; CHRISTINE SWANSON; LAURA KRUSE; RICHARD B HAYES; DENISE RIEDEL LEWIS; LINDA C HARLAN

1995-01-01

404

Master International Frequency List.  

National Technical Information Service (NTIS)

The International Frequency List, in magnetic tape format, contains particulars of radio frequency assignments between 10 kHz and 40,000 gHz and of assignments to broadcasting stations in Regions 1, 2 and 3, as recorded in the Master International Frequen...

1971-01-01

405

IGBT high frequency operation  

Microsoft Academic Search

IGBT (insulated gate bipolar transistor) devices have been designed into low frequency (<20 kHz) power controls for many types of equipment. This equipment includes: high voltage applications such as 120 V to 440 V motor controls; AC power line conditioning; and automotive ignition systems. It can be quite disconcerting to have an IGBT power control design that generates radio frequency

R. J. Valentine

1996-01-01

406

Genetic Influences on the Seed Yielding Ability of Carrot Hybrids  

Technology Transfer Automated Retrieval System (TEKTRAN)

Carrot seed production characteristics of four different threeway carrot hybrids were evaluated over three years during seed production from transplanted roots in Madison, Wisconsin. Components of seed yielding ability and plant architecture were measured. Both the male sterile seed parent and inbr...

407

Secondary dispersal of bigcone Douglas-fir ( Pseudotsuga macrocarpa ) seeds  

NASA Astrophysics Data System (ADS)

Large-seeded pines ( Pinus spp.) are known to be dispersed by seed-caching corvids (i.e. jays and nutcrackers) and rodents (e.g. chipmunks and mice), with a concomitant decrease in seed dispersability by wind. We tested the idea that seeds of bigcone Douglas-fir ( Pseudotsuga macrocarpa), which are winged but larger than the seeds of other members of Pseudotsuga, are dispersed by a combination of wind and seed-caching rodents. We compared characteristics of seeds from P. macrocarpa in southern California (mean seed mass 132.6 mg) to seeds of a population of Pseudotsuga menziesii (Douglas-fir) in northern California (24.8 mg). We also tested whether rodents would cache seeds of P. macrocarpa. Seeds of P. macrocarpa had greater wing loadings (1.37 mg/mm 2) and descent velocities (2.47 m/s) than those of P. menziesii (0.52 mg/mm 2 and 1.28 m/s, respectively). These data indicate that the wind dispersability of P. macrocarpa is likely to be less than that of P. menziesii, but this loss of wind dispersability is partially compensated for by secondary dispersal of seeds by rodents, which readily gathered and cached the larger seeds of P. macrocarpa up to 34 m from source trees. Large seed size confers several advantages to P. macrocarpa, most importantly attracting seed-caching animals that effectively bury seeds.

Vander Wall, Stephen B.; Borchert, Mark I.; Gworek, Jennifer R.

2006-07-01

408

Development of Seeded and Seedless Avocado Fruits1  

Microsoft Academic Search

The seed influences rate of growth, size, shape and maturation of avocado fruits. Seeded fruits are 8-10 times larger than seedless ones and contain more and larger cells. The growth pattern of seeded and seedless fruits is similar from June until maturation, when growth rate of seeded fruits decreases. Fruit maturation is characterized by rapid accumulation of oil in the

Amos Blumenfeld; Shmuel Gazit

409

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 ...

410

Yield and Quality of Seed from Yellow Birch Progenies.  

National Technical Information Service (NTIS)

Seed yield in 8- and 9-year-old yellow birch varied among families and years but averaged more than 1,500 seeds per tree. Long catkins contained more seed than short ones. Seed quality was poor due to insufficient pollination and to differences among tree...

K. E. Clausen

1980-01-01

411

7 CFR 361.5 - Sampling of seeds.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Sampling of seeds. 361.5 Section 361.5 Agriculture ...SERVICE, DEPARTMENT OF AGRICULTURE IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.5 Sampling of seeds....

2009-01-01

412

7 CFR 361.5 - Sampling of seeds.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Sampling of seeds. 361.5 Section 361.5 Agriculture ...SERVICE, DEPARTMENT OF AGRICULTURE IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.5 Sampling of seeds....

2010-01-01

413

A repellent to reduce mouse damage to longleaf pine seed  

Microsoft Academic Search

Direct seeding is a potential method for reforestation of pines on many southern sites. The success of direct seeding, however, depends, at least in part, in reducing seed predation by birds and rodents. We conducted a series of tests to assess the efficacy of capsicum and thiram in reducing mouse damage to longleaf pine (Pinus palustris) seeds. House mice (Mus

Dale L. Nolte; James P. Barnett

2000-01-01

414

Directed Seed Dispersal by Bellbirds in a Tropical Cloud Forest  

Microsoft Academic Search

A fundamental goal of plant population ecology is to understand the consequences for plant fitness of seed dispersal by animals. Theories of seed dispersal and tropical forest regeneration suggest that the advantages of seed dispersal for most plants are escape from seed predation near the parent tree and colonization of vacant sites, the locations of which are unpredictable in space

Daniel G. Wenny; Douglas J. Levey

1998-01-01

415

Directed seed dispersal by bellbirds in a tropical cloud forest  

Microsoft Academic Search

A fundamental goal of plant population ecol- ogy is to understand the consequences for plant fitness of seed dispersal by animals. Theories of seed dispersal and tropical forest regeneration suggest that the advantages of seed dis- persal for most plants are escape from seed predation near the parent tree and colonization of vacant sites, the locations of which are unpredictable

DANIEL G. WENNY; DOUGLAS J. LEVEY

1998-01-01

416

Anti-diabetic and cholesterol lowering preparation from fenugreek seeds  

US Patent & Trademark Office Database

The invention relates to a composition having blood glucose-lowering and cholesterol-lowering activity that can be obtained from seeds of the Papilinaceae Leguminosae family, for example, fenugreek seed. Methods of obtaining the composition from seed and seed parts are provided. Therapeutic methods of using the composition, such as for treating diabetes and hypercholesterolemia, are also a part of the invention.

2010-10-19

417

Thieving rodents as substitute dispersers of megafaunal seeds  

PubMed Central

The Neotropics have many plant species that seem to be adapted for seed dispersal by megafauna that went extinct in the late Pleistocene. Given the crucial importance of seed dispersal for plant persistence, it remains a mystery how these plants have survived more than 10,000 y without their mutualist dispersers. Here we present support for the hypothesis that secondary seed dispersal by scatter-hoarding rodents has facilitated the persistence of these large-seeded species. We used miniature radio transmitters to track the dispersal of reputedly megafaunal seeds by Central American agoutis, which scatter-hoard seeds in shallow caches in the soil throughout the forest. We found that seeds were initially cached at mostly short distances and then quickly dug up again. However, rather than eating the recovered seeds, agoutis continued to move and recache the seeds, up to 36 times. Agoutis dispersed an estimated 35% of seeds for >100 m. An estimated 14% of the cached seeds survived to the next year, when a new fruit crop became available to the rodents. Serial video-monitoring of cached seeds revealed that the stepwise dispersal was caused by agoutis repeatedly stealing and recaching each other’s buried seeds. Although previous studies suggest that rodents are poor dispersers, we demonstrate that communities of rodents can in fact provide highly effective long-distance seed dispersal. Our findings suggest that thieving scatter-hoarding rodents could substitute for extinct megafaunal seed dispersers of tropical large-seeded trees.

Jansen, Patrick A.; Hirsch, Ben T.; Emsens, Willem-Jan; Zamora-Gutierrez, Veronica; Wikelski, Martin; Kays, Roland

2012-01-01

418

Whole Sunflower Seeds for High Producing Dairy Cows1  

Microsoft Academic Search

Nine Holstein cows in 3 × 3 Latin squares were used to determine the feed- ing value of whole sunflower seeds. Com- plete rations (dry matter) of 45% corn silage, 10% alfalfa hay, and 45% concen- trate were fed. Concentrates contained mostly corn and soybean meal, 22% whole rolled sunflower seeds, and 22% extruded whole sunflower seeds. Sun- flower seeds

R. K. McGuffey; D. J. Schingoethe

1982-01-01

419

Bean Seed Dissemination Systems in Malawi: A Strategy  

Microsoft Academic Search

Farmers have shown considerable interest in purchasing seed of newly released dry bean (Phaseolus vulgaris L.) varieties in Malawi. However, this seed is not available on a large scale to farmers at present. The private seed sector in the country is not interested in bean seed production due to low profit margins. As a self-pollinating crop, once farmers have obtained

Rowland M. Chirwa; Vas D. Aggarwal

2000-01-01

420

USE OF SWITCHGRASS SEED AS WILD BIRD FEED  

Microsoft Academic Search

To date, switchgrass (Panicum virgatum L.) seed is only used for planting new fields. However, the highly anticipated widespread planting of switchgrass as biomass for biofuel production prompted this investigation into whether switchgrass seed could be used as wild bird feed. We compared the consump- tion of switchgrass seed to proso millet (Panicum miliaceum) seed by birds from ground trays

Travis J. Runia; Daniel E. Hubbard; Arvid Boe

2007-01-01

421

Longitudinal Coherence Preservation and Chirp Evolution in a High Gain Laser Seeded Free Electron Laser Amplifier  

SciTech Connect

In this letter we examine the start-up of a high gain free electron laser in which a frequency-chirped coherent seed laser pulse interacts with a relativistic electron beam. A Green function formalism is used to evaluate the initial value problem. We have fully characterized the startup and evolution through the exponential growth regime. We obtain explicit expressions for the pulse duration, bandwidth and chirp of the amplified light and show that the FEL light remains fully longitudinally coherent.

Murphy, J.B.; /BNL, NSLS; Wu, Juhao; /SLAC; Wang, X.J.; Watanabe, T.; /BNL, NSLS

2006-06-07

422

Variation in relation to geographical distribution of wild oats-seed traits  

Microsoft Academic Search

A sample of 457 wild oats (Avena sterilis L.) from the world collection maintained at the Germplasm Laboratory, Beltsville, Maryland, USA, was studied for variation of six seed characters via means, ranges, variances, and frequencies from various geographical areas. It was concuded that region-specific adaptations are responsible for occurrence of certain trait(s) in specific geographical regions; e.g., Libyan and Iraqi

A. Rezai; K. J. Frey

1988-01-01

423

A comparison of androgenetic doubled-haploid, and single seed descent lines in Triticale  

Microsoft Academic Search

Sixty single seed descent (SSD) lines and about 25 anther-derived doubled-haploid (DH) lines were obtained from two triticale crosses. The frequency distributions of 10 quantitative agronomic traits were compared using parametric and non-parametric tests. A multivariate discriminant analysis was subsequently carried out. Gliadin patterns obtained from each line by polyacrylamide gel electrophoresis were used to calculate intra- and inter-population diversities

G. Charmet; G. Branlard

1985-01-01

424

Optical parametric amplifier by a narrow linewidth pulse Ti:sapphire laser on injection seeding  

Microsoft Academic Search

We constructed a computer controlled high stability wide tunable parametric amplifier, and reported on a (beta) - borium borate (BBO) optical parametric amplifier of injection-seeded with a narrow linewidth pulsed Ti:sapphire laser. The pump source of Ti:sapphire laser is the residual second harmonic (532 nm) in frequency tripling (355 nm) of the Nd:YAG laser. We obtained the linewidth interferograph of

Li Wang; Jian Yang; Jinfeng Zhou; Liu Huang

2002-01-01

425

Gastropod seed dispersal: an invasive slug destroys far more seeds in its gut than native gastropods.  

PubMed

Seed dispersal is one of the most important mechanisms shaping biodiversity, and animals are one of the key dispersal vectors. Animal seed dispersal can directly or indirectly be altered by invasive organisms through the establishment of new or the disruption of existing seed dispersal interactions. So far it is known for a few gastropod species that they ingest and defecate viable plant seeds and consequently act as seed dispersers, referred to as gastropodochory. In a multi-species experiment, consisting of five different plant species and four different gastropod species, we tested with a fully crossed design whether gastropodochory is a general mechanism across native gastropod species, and whether it is altered by the invasive alien slug species Arion lusitanicus. Specifically, we hypothesized that a) native gastropod species consume the seeds from all tested plant species in equal numbers (have no preference), b) the voracious invasive alien slug A. lusitanicus - similarly to its herbivore behaviour - consumes a higher amount of seeds than native gastropods, and that c) seed viability is equal among different gastropod species after gut passage. As expected all tested gastropod species consumed all tested plant species. Against our expectation there was a difference in the amount of consumed seeds, with the largest and native mollusk Helix pomatia consuming most seeds, followed by the invasive slug and the other gastropods. Seed damage and germination rates did not differ after gut passage through different native species, but seed damage was significantly higher after gut passage through the invasive slug A. lusitanicus, and their germination rates were significantly reduced. PMID:24086477

Blattmann, Tamara; Boch, Steffen; Türke, Manfred; Knop, Eva

2013-09-25

426

Seed Systems and Farmers’ Seed Choices: The Case of Maizein the Peruvian Amazon  

Microsoft Academic Search

This paper analyzes how local seed system institutions support seed diversity, itself a requirement for agrobiodiversity maintained\\u000a on-farm. The paper focuses on maize seed diversity in the central Peruvian Amazon. Using household and community level data\\u000a from three different cultural groups from the central Peruvian Amazon, empirical results show the importance of collective\\u000a action and the mediating role of ethnicity

Per M. Stromberg; Unai Pascual; Mauricio R. Bellon

2010-01-01

427

Naturalising transgenics: Official seeds, loose seeds and risk in the decision matrix of Gujarati cotton farmers  

Microsoft Academic Search

Cotton farmers in Gujarat, western India, faced a novel decision matrix when Delhi gave provisional approval, in March 2002, to Mahyco–Monsanto Biotech Ltd. to release three Bt-cotton varieties. These varieties represented India's first legally commercialised transgenics: official seeds. Unofficial transgenic seeds were also available to farmers both as unpackaged, unbranded ‘loose seeds’ – mostly F2 progeny of a popular but banned transgenic

Devparna Roy; Ronald J. Herring; Charles C. Geisler

2007-01-01

428

Gastropod Seed Dispersal: An Invasive Slug Destroys Far More Seeds in Its Gut than Native Gastropods  

PubMed Central

Seed dispersal is one of the most important mechanisms shaping biodiversity, and animals are one of the key dispersal vectors. Animal seed dispersal can directly or indirectly be altered by invasive organisms through the establishment of new or the disruption of existing seed dispersal interactions. So far it is known for a few gastropod species that they ingest and defecate viable plant seeds and consequently act as seed dispersers, referred to as gastropodochory. In a multi-species experiment, consisting of five different plant species and four different gastropod species, we tested with a fully crossed design whether gastropodochory is a general mechanism across native gastropod species, and whether it is altered by the invasive alien slug species Arion lusitanicus. Specifically, we hypothesized that a) native gastropod species consume the seeds from all tested plant species in equal numbers (have no preference), b) the voracious invasive alien slug A. lusitanicus – similarly to its herbivore behaviour – consumes a higher amount of seeds than native gastropods, and that c) seed viability is equal among different gastropod species after gut passage. As expected all tested gastropod species consumed all tested plant species. Against our expectation there was a difference in the amount of consumed seeds, with the largest and native mollusk Helix pomatia consuming most seeds, followed by the invasive slug and the other gastropods. Seed damage and germination rates did not differ after gut passage through different native species, but seed damage was significantly higher after gut passage through the invasive slug A. lusitanicus, and their germination rates were significantly reduced.

Blattmann, Tamara; Boch, Steffen; Turke, Manfred; Knop, Eva

2013-01-01

429

Effects of Seed Predators of Different Body Size on Seed Mortality in Bornean Logged Forest  

Microsoft Academic Search

BackgroundThe Janzen-Connell hypothesis proposes that seed and seedling enemies play a major role in maintaining high levels of tree diversity in tropical forests. However, human disturbance may alter guilds of seed predators including their body size distribution. These changes have the potential to affect seedling survival in logged forest and may alter forest composition and diversity.Methodology\\/Principal FindingsWe manipulated seed density

Yann Hautier; Philippe Saner; Christopher Philipson; Robert Bagchi; Robert C. Ong; Andy Hector; Jerome Chave

2010-01-01

430

Role of Seed Coat in Imbibing Soybean Seeds Observed by Micro-magnetic Resonance Imaging  

PubMed Central

Background and Aims Imbibition of Japanese soybean (Glycine max) cultivars was studied using micro-magnetic resonance imaging (MRI) in order to elucidate the mechanism of soaking injury and the protective role of the seed coat. Methods Time-lapse images during water uptake were acquired by the single-point imaging (SPI) method at 15-min intervals, for 20 h in the dry seed with seed coat, and for 2 h in seeds with the seed coat removed. The technique visualized water migration within the testa and demonstrated the distortion associated with cotyledon swelling during the very early stages of water uptake. Key Results Water soon appeared in the testa and went around the dorsal surface of the seed from near the raphe, then migrated to the hilum region. An obvious protrusion was noted when water reached the hypocotyl and the radicle, followed by swelling of the cotyledons. A convex area was observed around the raphe with the enlargement of the seed. Water was always incorporated into the cotyledons from the abaxial surfaces, leading to swelling and generating a large air space between the adaxial surfaces. Water uptake greatly slowed, and the internal structures, veins and oil-accumulating tissues in the cotyledons developed after the seed stopped expanding. When the testa was removed from the dry seeds before imbibition, the cotyledons were severely damaged within 1·5 h of water uptake. Conclusions The activation of the water channel seemed unnecessary for water entry into soybean seeds, and the testa rapidly swelled with steeping in water. However, the testa did not regulate the water incorporation in itself, but rather the rate at which water encountered the hypocotyl, the radicle, and the cotyledons through the inner layer of the seed coat, and thus prevented the destruction of the seed tissues at the beginning of imbibition.

Koizumi, Mika; Kikuchi, Kaori; Isobe, Seiichiro; Ishida, Nobuaki; Naito, Shigehiro; Kano, Hiromi

2008-01-01

431

Pesticide-laden dust emission and drift from treated seeds during seed drilling: a review.  

PubMed

Dressing seeds with pesticides to control pests is a widespread practice with important advantages. Recent incidents of bee losses, however, have directed attention to the emission of abraded pesticide-coated seed particles to the environment during sowing. This phenomenon of drift of pesticide dust can lead to pesticide contamination of air, water and other natural resources in crop-growing areas. This review article presents the state of the art of the phenomenon of dust emission and drift from pesticide seed dressing during sowing and its consequences. Firstly, pesticide seed treatment is defined and its pros and cons are set out, with the focus on dust, dust emission and dust drift from pesticide-coated seed. The factors affecting emission of pesticide dust (e.g. seed treatment quality, seed drilling technology and environmental conditions) are considered, along with its possible effects. The measuring techniques and protocols and models currently in use for calculating the behaviour of dust are reviewed, together with their features and limitations. Finally, possible mitigation measures are discussed, such as improving the seed quality and the use of modified seed drilling technology, and an overview of regulations and stewardship activities is given. PMID:23456984

Nuyttens, David; Devarrewaere, Wouter; Verboven, Pieter; Foqué, Dieter

2013-03-01

432

Induction of 9-cis-epoxycarotenoid dioxygenase in Arabidopsis thaliana seeds enhances seed dormancy  

PubMed Central

Full understanding of mechanisms that control seed dormancy and germination remains elusive. Whereas it has been proposed that translational control plays a predominant role in germination, other studies suggest the importance of specific gene expression patterns in imbibed seeds. Transgenic plants were developed to permit conditional expression of a gene encoding 9-cis-epoxycarotenoid dioxygenase 6 (NCED6), a rate-limiting enzyme in abscisic acid (ABA) biosynthesis, using the ecdysone receptor-based plant gene switch system and the ligand methoxyfenozide. Induction of NCED6 during imbibition increased ABA levels more than 20-fold and was sufficient to prevent seed germination. Germination suppression was prevented by fluridone, an inhibitor of ABA biosynthesis. In another study, induction of the NCED6 gene in transgenic seeds of nondormant mutants tt3 and tt4 reestablished seed dormancy. Furthermore, inducing expression of NCED6 during seed development suppressed vivipary, precocious germination of developing seeds. These results indicate that expression of a hormone metabolism gene in seeds can be a sole determinant of dormancy. This study opens the possibility of developing a robust technology to suppress or promote seed germination through engineering pathways of hormone metabolism.

Martinez-Andujar, Cristina; Ordiz, M. Isabel; Huang, Zhonglian; Nonogaki, Mariko; Beachy, Roger N.; Nonogaki, Hiroyuki

2011-01-01

433

The functional response of a hoarding seed predator to mast seeding.  

PubMed

Mast seeding involves the episodic and synchronous production of large seed crops by perennial plants. The predator satiation hypothesis proposes that mast seeding maximizes seed escape because seed predators consume a decreasing proportion of available seeds with increasing seed production. However, the seed escape benefits of masting depend not only on whether predators are satiated at high levels of seed production, but also on the shape of their functional response (type II vs. type III), and the actual proportion of available seeds that they consume at different levels of seed production. North American red squirrels (Tamiasciurus hudsonicus) are the primary vertebrate predator of white spruce (Picea glauca) mast seed crops in many boreal regions because they hoard unopened cones in underground locations, preempting the normal sequence of cone opening, seed dispersal, and seed germination. We document the functional response of cone-hoarding by red squirrels across three non-mast years and one mast year by estimating the number of cones present in the territories of individual red squirrels and the proportion of these cones that they hoarded each autumn. Even though red squirrels are not constrained by the ingestive and on-body (fat reserves) energy reserve limitations experienced by animals that consume seeds directly, most squirrels hoarded < 10% of the cones present on their territories under mast conditions. Cone availability during non-mast years also reached levels that satiated the hoarding activity of red squirrels; however, this occurred only on the highest-quality territories. Squirrels switched to mushroom-hoarding when cone production was low and mushrooms were abundant. This resulted in type III functional response whereby the proportional harvest of cones was highest at levels of cone availability that were intermediate within non-mast years. Overall, more cones escaped squirrel cone-hoarding during a mast event than when cone production was low in non-mast years, which supports the predator satiation hypothesis. However, the highly variable seed escape in non-mast years may help to explain why all spruce cone production is not concentrated into fewer, larger, mast years. PMID:20957961

Fletcher, Quinn E; Boutin, Stan; Lane, Jeffrey E; LaMontagne, Jalene M; McAdam, Andrew G; Krebs, Charles J; Humphries, Murray M

2010-09-01

434

Seed island formation by forced magnetic reconnection  

NASA Astrophysics Data System (ADS)

Neoclassical tearing modes observed in experiments often grow from seed magnetic islands induced by triggers like sawteeth. The formation of seed islands is studied in this paper using both the reduced MHD and two-fluid equations, with the trigger being modelled by externally applied resonant magnetic perturbations. In the linear phase the growth rate of the driven mode is found to be the same as that of the trigger. A slowly growing trigger drives a tearing mode, while a fast one drives a kink-like mode, which becomes a tearing mode later when the trigger's growth slows down. A finite ion sound Larmor radius (ion Larmor radius by using electron temperature) and electron inertia are found to lead to a larger seed island for a given external perturbation. The electron diamagnetic drift and plasma rotation, if increasing the relative rotation between the trigger and the driven mode, decrease the seed island width.

Yu, Q.; Günter, S.; Lackner, K.; Maraschek, M.

2012-06-01

435

Shaping metal nanocrystals through epitaxial seeded growth  

SciTech Connect

Morphological control of nanocrystals has becomeincreasingly important, as many of their physical and chemical propertiesare highly shape-dependent. Nanocrystal shape control for both single andmultiple material systems, however, remains fairly empirical andchallenging. New methods need to be explored for the rational syntheticdesign of heterostructures with controlled morphology. Overgrowth of adifferent material on well-faceted seeds, for example, allows for the useof the defined seed morphology to control nucleation and growth of thesecondary structure. Here, we have used highly faceted cubic Pt seeds todirect the epitaxial overgrowth of a secondary metal. We demonstrate thisconcept with lattice matched Pd to produce conformal shape-controlledcore-shell particles, and then extend it to lattice mismatched Au to giveanisotropic growth. Seeding with faceted nanocrystals may havesignificant potential towards the development of shape-controlledheterostructures with defined interfaces.

Habas, Susan E.; Lee, Hyunjoo; Radmilovic, Velimir; Somorjai,Gabor A.; Yang, Peidong

2008-02-17

436

The Flying Sunflower: A Seed Dispersal Project.  

ERIC Educational Resources Information Center

|Describes an open-ended activity in which students build a "plant" that launches its seeds as far as possible to study the dispersal strategies of various plants. Recommends extension activities for elementary- and secondary-level students. (WRM)|

Buege, Douglas J.

1999-01-01

437

Seed size variability: from carob to carats.  

PubMed

The seeds of various plants were used as weights because their mass reputedly varies so little. Carob (Ceratonia siliqua), which has given its name to the carat, is particularly famous in this regard. But are carob seeds unusually constant in weight and, if not, how did the myth arise? The variability of seeds sampled from a collection of carob trees (CV=23%) was close to the average of 63 species reviewed from the literature (CV=25%). However, in a perception experiment observers could discriminate differences in carob seed weight of around 5% by eye demonstrating the potential for humans to greatly reduce natural variation. Interestingly, the variability of pre-metrication carat weight standards is also around 5% suggesting that human rather than natural selection gave rise to the carob myth. PMID:17148413

Turnbull, Lindsay A; Santamaria, Luis; Martorell, Toni; Rallo, Joan; Hector, Andy

2006-09-22

438

Thermophysical properties of fodder grass seeds  

NASA Astrophysics Data System (ADS)

The article presents the values of critical heat in the range -50 to +200°C, thermal conductivities at 25°C, and pressures of 100.641 kPa, and an equation for determining the thermotolerance of fodder grass seeds.

Korolik, T. K.; Golubev, V. A.; Kharitonov, V. V.

1985-06-01

439

Effects of Herbicides on Submerged Seed Plants.  

National Technical Information Service (NTIS)

The effect of various concentrations of three herbicides on underwater seed plants was investigated. The herbicides used were atrazine, glyphosate, and metribuzin. The plants exposed to one or more of these herbicides were elodea (Elodea canadensis), wild...

D. E. Davis

1980-01-01

440

The Flying Sunflower: A Seed Dispersal Project.  

ERIC Educational Resources Information Center

Describes an open-ended activity in which students build a "plant" that launches its seeds as far as possible to study the dispersal strategies of various plants. Recommends extension activities for elementary- and secondary-level students. (WRM)

Buege, Douglas J.

1999-01-01

441

MHD seed recovery/regeneration, Phase 2  

SciTech Connect

This report is divided into the following tasks: design, refurbish, operate potassium formate ( backend'') system; design, construct, operate the calcium formate production POC ( Frontend'') unit; and Western seed (K carbonate, sulfate) studies. 5 figs.

Not Available

1993-01-01

442

9 CFR 101.7 - Seed organisms.  

Code of Federal Regulations, 2013 CFR

...101.7 Section 101.7 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE...TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS DEFINITIONS...the producer from which all other seed passages are derived...

2013-01-01

443

Automatic Brachytherapy Seed Placement Under MRI Guidance  

PubMed Central

The paper presents a robotic method of performing low dose rate prostate brachytherapy under magnetic resonance imaging (MRI) guidance. The design and operation of a fully automated MR compatible seed injector is presented. This is used with the MrBot robot for transperineal percutaneous prostate access. A new image-registration marker and algorithms are also presented. The system is integrated and tested with a 3T MRI scanner. Tests compare three different registration methods, assess the precision of performing automated seed deployment, and use the seeds to assess the accuracy of needle targeting under image guidance. Under the ideal conditions of the in vitro experiments, results show outstanding image-guided needle and seed placement accuracy.

Patriciu, Alexandru; Petrisor, Doru; Muntener, Michael; Mazilu, Dumitru; Schar, Michael; Stoianovici, Dan

2011-01-01

444

Limonoids from the seeds of Azadirachta indica  

Microsoft Academic Search

Four new compounds, 11-hydroxyazadirachtin-B, 1-tigloyl-3-acetylazadirachtinin, 1,2-diacetyl-7-tigloyl-12-hydroxyvilasinin and 23-desmethyllimocin-B from neem seeds have been isolated and characterized using spectral studies

Ch. S. S. R. Kumar; Malladi Srinivas; Shirish Yakkundi

1996-01-01

445

Alkaloid Changes in Tobacco Seeds during Germination.  

PubMed

Nicotine, nornicotine, anabasine, and anatabine, normally found in growing and mature tobacco (Nicotiana tabacum L.) plants, were extracted and quantified from mature tobacco seeds and young tobacco seedlings. The rate of net alkaloid disappearance and accumulation in tobacco seedlings was related to phases of germination.In general, the increased rate of germination associated with higher temperatures also increased the rate of initial loss of alkaloids and the subsequent rate of accumulation of alkaloids. Maximum alkaloid accumulation in 144-hour-old seedlings cultured with 10-hour day occurred at 27 C. Following an 8-hour photoinduction period, seeds germinated in darkness accumulated greater amounts of alkaloids than seeds exposed to light each day. Seeds germinated in darkness for 96 hours, following the 8-hour photoinduction period, and then exposed to light each day accumulated the greatest amounts of alkaloids. PMID:16658655

Weeks, W W; Bush, L P

1974-01-01

446

Efficiency of endozoochorous seed dispersal in six dry-fruited species (Cistaceae): from seed ingestion to early seedling establishment  

Microsoft Academic Search

We combined laboratory and nursery experiments to analyse the effectiveness of sheep as endozoochorous seed dispersers of six native shrubby Cistaceae species collected in SE Spain (Helianthemum apenninum (L.) Mill., H. violaceum (Cav.) Pers., Fumana ericoides (Cav.) Grand., F. thymifolia (L.) Spach, Cistus monspeliensis L. and C. laurifolius L.), considering the main stages after seed ingestion, i.e. seed recovery, seed

María E. Ramos; Ana B. Robles; Jorge Castro

2006-01-01

447

Assessment of organic seed treatments in a pea disease nursery to manage seed and root rot on peas, 2008.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Twenty-one organic seed treatments consisting of biological, non-biological and a combination of each were evaluated in a pea root rot field nursery in Prosser, WA for their potential to manage seed and root rot pathogens of processed peas. Non-treated seed and a commercial seed treatment (Capta...

448

Ecosystem services from keystone species: diversionary seeding and seed-caching desert rodents can enhance Indian ricegrass seedling establishment  

Technology Transfer Automated Retrieval System (TEKTRAN)

Seeds of Achnatherum hymenoides (Indian ricegrass), a native bunchgrass on arid western rangelands, are naturally dispersed by seed-caching rodent species, particularly Dipodomys spp. (kangaroo rats). These animals cache large quantities of seeds when mature seeds are available and recover most of t...

449

Seed production, pre-dispersal seed predation and germination of Nothofagus glauca (Nothofagaceae) in a temperate fragmented forest in Chile  

Microsoft Academic Search

The ecological processes and interactions that involve plants at the seed level may be altered in a fragmented forest, with consequences on plant recruitment and forest structure. We studied seed production, pre-dispersal seed predation and germination of non-damaged and damaged seeds of the endemic and vulnerable Nothofagus glauca tree, in small fragments and in a continuous area of the Maulino

Aracely Burgos; Audrey A. Grez; Ramiro O. Bustamante

2008-01-01

450

Evaluation of seed treatments for the eradication of Acidovorax avenae subsp. citrulli from melon and watermelon seeds  

Microsoft Academic Search

Acidovorax avenae subsp. citrulli, the causal agent of bacterial fruit blotch of watermelon (Citrullus lanatus), is a serious seed-borne pathogen. To determine the effectiveness of several treatments to eradicate it from seeds, healthy triploid watermelon seed lots were spiked with naturally infected watermelon and melon seeds harvested from three separate diseased fruits. Of the eight treatments studied, only the use

Jianjun Feng; Jianqiang Li; Parmjit Randhawa; Morris Bonde; Norman W. Schaad

2009-01-01

451

Relationships between seed yield and growth characters, yield components, seed quality of summer-type oilseed rape (Brassica napus L.)  

Microsoft Academic Search

Five genotypes of rapeseed were observed in the field on a single plant and plot basis to evaluate growth characteristics, yield, yield components and seed quality. Observations were made in two years at two locations on three seeding date and three seeding rate treatments. Correlation of seed yield with growth characters demonstrated no consistent trend, indicating that an early maturity

D. F. Degenhart; Z. P. Kondra

1984-01-01

452

Seed size, more than nutrient or tannin content, affects seed caching behavior of a common genus of Old World rodents  

Microsoft Academic Search

Scatter-hoarding rodents play an important dispersal role for many large- seeded plants. Seed traits affect their foraging behavior; however, it is difficult to isolate their effects because of the covariance among traits. Here, we used artificial seeds to partition the effects of seed size, tannin and nutrient content on scatter-hoarding rodents in a natural pine forest in Northwest Yunnan, China.

BO WANG; JIN CHEN

453

Laser and Radiofrequency Production of Seeded Air Plasmas  

NASA Astrophysics Data System (ADS)

Seeded gas plasmas and air constituents have been created by a 193 nm laser and by a radiofrequency source. We have obtained 10^14/cm^3 plasma densities with initial electron temperatures of 0.3 eV in TMAE (tetrakis (dimethylamino) ethylene) by laser photoionization. We developed a fast Langmuir probe analysis of plasma decay independent of ion species mix. Langmuir probe and optical emission data illustrating the density and temperature decay with TMAE mixed with nitrogen is presented. Simulations of antenna coupling, wave frequencies, wave propagation, and power absorption are compared with experimental observations for radiofrequency plasma sources. The source produces plasma densities of 2 × 10^13/cm^3in an 8500 cm^3 volume at electron temperatures of 5 eV in 10 mTorr Ar with 1 kW coupled power levels in a nonuniform magnetic field. Plasmas production at pressures from 2-760 Torr using Ar and laser initiated TMAE plasmas as seeds will be discussed.

Scharer, J.; Ding, G.; Gui, H.; Kelly, K.; Paller, E.

1999-10-01

454

Comparing seed removal of 16 pine species differing in invasiveness  

Microsoft Academic Search

Small seed mass is regarded as a robust trait related to invasion success, especially in pines. However, few studies have\\u000a explored whether invasiveness related to small seed mass is also associated to low levels of seed predation in the recipient\\u000a community. We conducted field cafeteria seed removal experiments comparing 16 Pinus species that differ in seed mass to test if

M. A. Carrillo-Gavilán; H. Lalagüe; M. Vilà

2010-01-01

455

Uniformity, performance and seed quality of soybean (Glycine max (L.) Merrill) seed crops grown from sub-samples of one seed lot obtained after selection for physical seed attributes  

Microsoft Academic Search

In a glasshouse experiment it was examined whether narrow grading and selection from a commercial soybean seed lot cultivar ‘IAS-5’, could improve the uniformity of the seed crop grown from it and thereby enhance yield, quality and uniformity of seeds produced. The classes created were: Control (original seed lot); Size-graded seeds (projected area measured by image analysis 37–46 mm2); Non-cracked

R. A. Illipronti; C. J. Langerak; W. J. M. Lommen; P. C. Struik

2000-01-01

456

Switchgrass Seedling Development as Affected by Seed Size  

Microsoft Academic Search

Seed size has been associated with early seedling vigor (i.e., germination rate, emergence rate, and growth) in grasses. This study was conducted to compare seedling development over a 60-d period in the field as affected by heavy seed (HS) (0.19 to 0.21 g 100 seed-1) and light seed (LS) (0.13 to 0.16 g 100 seed-1) of 'Blackwell' and 'Trailblazer' switchgrass

Alexander J. Smart; Lowell E. Moser

1999-01-01

457

Landscape-scale eco-evolutionary dynamics: selection by seed predators and fire determine a major reproductive strategy.  

PubMed

Recent work in model systems has demonstrated significant effects of rapid evolutionary change on ecological processes (eco-evolutionary dynamics). Fewer studies have addressed whether eco-evolutionary dynamics structure natural ecosystems. We investigated variation in the frequency of serotiny in lodgepole pine (Pinus contorta), a widespread species in which postfire seedling density and ecosystem structure are largely determined by serotiny. Serotiny, the retention of mature seeds in cones in a canopy seed bank, is thought to be an adaptation for stand-replacing fire, but less attention has been paid to the potential selective effects of seed predation on serotiny. We hypothesized that spatial variation in percentage serotiny in lodgepole pine forests results from an eco-evolutionary dynamic where the local level of serotiny depends on the relative strengths of conflicting directional selection from fire (favoring serotiny) and seed predation (favoring cones that open at maturity). We measured percentage serotiny, the abundance of American red squirrels (Tamiasciurus hudsonicus; the primary pre-dispersal seed predator of lodgepole pine), and several measures of forest structure in Yellowstone National Park, USA. Fire frequency strongly predicted the frequency of serotiny, a pattern that is well-supported in the literature. At sites with high fire frequency (return intervals of -135-185 years) where fire favors increased serotiny, squirrel abundance was negatively associated with serotiny, suggesting that selection from predation can overwhelm selection from fire when squirrels are abundant. At sites with low fire frequency (return intervals of -280-310 years), serotiny was nearly universally uncommon (< 10%). Finally, forest structure strongly predicted squirrel density independently of serotiny, and serotiny provided no additional explanatory power, suggesting that the correlation is caused by selection against serotiny exerted by squirrels, rather than squirrels responding to variation in percentage serotiny. PMID:23923494

Talluto, Matt V; Benkman, Craig W

2013-06-01

458

The clinical outcome of adjuvant therapy with black seed oil on intractable paediatric seizures: a pilot study.  

PubMed

Aim. To evaluate the effect of black seed oil, as add-on treatment to antiepileptic drugs (AEDs), on seizure frequency and severity as well as oxidative stress in intractable epilepsy patients. Methods. A prospective, randomised, single-blinded, controlled, crossover pilot study. Five healthy children were included as controls. Thirty intractable epileptic children were randomly assigned to either Group I or II. Group I received placebo for four weeks, followed by a two-week washout period, and subsequently black seed oil for four weeks. Group II received the same intervention but in the reverse order. All patients received AEDs throughout the study period. Prior to allocation, all patients underwent a neurological assessment and evaluation of oxidative stress markers; total antioxidant capacity (TAC) and malondialehyde (MDA). Patients were assessed at Weeks 4 and 10 for oxidative stress markers and seizure frequency and severity. Results. At baseline, both groups (I, II) had significantly lower serum TAC levels relative to healthy controls (p=0.007), while MDA levels were unchanged. After the 4-week period of black seed oil administration, there was no significant difference between the two groups with regards to seizure frequency, severity, or oxidative stress markers (TAC and MDA; p>0.05). Eight patients had >50% reduction in seizure frequency/severity after black seed oil versus placebo. Conclusion. Children with intractable epilepsy show evidence of oxidative stress. Administration of 40-80 mg/kg/day of black seed oil as add-on therapy did not alter either oxidative stress markers or seizure frequency or severity in intractable epileptic patients. PMID:23981722

Shawki, May; El Wakeel, Lamia; Shatla, Rania; El-Saeed, Gamila; Ibrahim, Samira; Badary, Osama

2013-09-01

459

Fatty acid content of selected seed oils.  

PubMed

Fatty acid content of selected seed oils from world-wide edible fruits, Ceratonia ciliqua (carob) from Caesalpiniaceae family, Diospyros kaki (persimmon) from Ebenaceae family, Zizyphus jujuba (jujube) from Rhamnaceae family, and Persea gratissima (avocado pear) from Lauraceae family, were determined by capillary gas chromatography- mass spectrometry (GC-MS) to find new natural sources for essential fatty acids. Among the seed oils analyzed, Ceratonia ciliqua has been found to have the highest essential fatty acid content. PMID:15277087

Orhan, Ilkay; Sener, Bilge

2002-01-01

460

Some Physical Properties of Hemp Seed  

Microsoft Academic Search

Various physical properties of hemp seed were determined as a function of moisture content. As the moisture content increased from 8·62 to 20·88% dry basis (d.b.), the dimensions of the major, medium and minor axes varied from 3·79 to 4·11mm, 2·92 to 3·11mm and 2·47 to 2·82mm, respectively. In the same moisture range, studies on rewetted hemp seed showed that

K. Sacilik; R. Öztürk; R. Keskin

2003-01-01

461

Phosphorus accumulation in Proteaceae seeds: a synthesis  

Microsoft Academic Search

The family Proteaceae dominates the nutrient-poor, Mediterranean-climate floristic regions of southwestern Australia (SWA)\\u000a and the Cape of South Africa. It is well-recognised that mediterranean Proteaceae have comparatively large seeds that are\\u000a enriched with phosphorus (P), stored mainly as salts of phytic acid in protein globoids. Seed P can contribute up to 48% of\\u000a the total aboveground P, with the fraction

Philip K. Groom; Byron B. Lamont

2010-01-01

462

Seed germination ecology in southwestern Western Australia  

Microsoft Academic Search

Germination responses of species from the native plant communities of southwestern Western Australia can be related to syndromes\\u000a of life history, fire response, and seed storage, and also to factors related to environmental stress. The Mediterranean-type\\u000a climate of the region with periodic drought and recurrent fires affects the production of viable seeds in plants of limited\\u000a stature and rooting depth.

David T. Bell; Julie A. Plummer; Susan K. Taylor

1993-01-01

463

Seed germination characteristics of Halogeton glomeratus  

Microsoft Academic Search

Halogeton glomeratus (Bieb.) C.A. Mey, an annual forb in the family Chenopodiaceae, is widely distributed in the inland salt deserts of western North America. Experiments were conducted to determine the effects of NaCl and temperature on seed germination and the recovery of germination responses after transfer to distilled water. Seeds of H. glomeratus were germinated at various temperature regimes (5-15°C,

M. Ajmal Khan; Bilquees Gul; Darrell J. Weber

2001-01-01

464

Canopy seed storage in woody plants  

Microsoft Academic Search

The retention of seeds in the plant canopy for one to 30 years or more is termed serotiny. It is well represented floristically\\u000a and physiognomically in fire-prone, nutrient-poor and seasonally-dry sclerophyll vegetation in Australia, and to a lesser\\u000a extent, South Africa followed by North America. While the seed-storing structures vary greatly, all will release their propagules\\u000a following exposure to the

Byron B. Lamont; D. C. Le Maitre; R. M. Cowling; N. J. Enright

1991-01-01

465

Calibration procedures for seeds preloaded in cartridges  

SciTech Connect

Radioactive seeds preloaded in sterilized cartridges or needles are commonly obtainable from manufacturers. Under the US regulations for control of radioactive materials, seed users are required to account for all seeds and independently verify their air kerma strength (S{sub K}). As a result, the viability of inspection schemes that rely on measurement of aggregate seeds is of interest. In this paper we consider the conditions (if any) under which cartridge inspection can satisfy regulatory requirements and still provide practical benefit (i.e., time savings) against the regular single-seed assay. The standards for comparison are the recommendations of AAPM TG40, AAPM TG56, and ACR's 'Standard for the Performance of Manually Loaded Brachytherapy Sources'. The practical benefit is judged in comparison to the effort required to apply the 10% assay recommendation of TG40 to seeds in cartridges. Two specific cartridge inspection schemes are considered: (a) measuring the S{sub K} of each cartridge in a batch; (b) measuring a single cartridge sampled at random from the batch. Unlike the 10% assay, which is defined (imperfectly, in our view) without reference to the prevalence of in-calibration seeds, the estimation of the relative merits of cartridge inspection methods must necessarily include such information and, as such, is manufacturer specific. In this paper results are provided for Oncura model 6711 {sup 125}I seeds in shielded and unshielded Mick cartridges. We show that the only practically useful cartridge inspection scheme is the batch scheme applied to unshielded cartridges. The false positive rates associated with the other schemes are such that we expect to open a cartridge (and perform the 10% assay) at least 80% of the time. While anything less than 100% of the time is theoretically an improvement, this neglects the additional effort required to assay the cartridges.

Brame, Ryan S.; Cohen, Gil'ad N.; Zaider, Marco [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10021 (United States)

2006-08-15

466

Some Physical Properties of Locust Bean Seed  

Microsoft Academic Search

To design equipment and facilities to process “Iru”, an important food-flavouring condiment made from locust bean seeds, some of the physical properties of the seeds were determined. At a moisture content of 6·42% d.b., the average length, width and thickness of locust bean were 10·80, 8·42 and 4·64 mm, respectively. The average geometric mean diameter, sphericity and density were 7·47

J. O. Olajide; B. I. O. Ade-Omowaye

1999-01-01

467

Lignans in seeds of Linum species.  

PubMed

Mature seeds of 20 Linum species were analyzed for their content of lignans. The seeds of common flax (Linum usitatissimum L.) are known to contain as characteristic lignan sesoisolariciresinol diglucoside (SDG), whose presence in seeds of some other Linum species has also been reported. In order to investigate the material for the presence of such very polar lignans as well as for less polar non-glycosidic lignans as frequently found in aerial parts of Linum species, polar and non-polar extracts of each sample were analyzed by HPLC/ESI-MSMS. SDG was detected in 15 of 16 investigated seed samples of taxa representing sections Linum and Dasylinum. None of eight samples of taxa from sections Syllinum and Linopsis contained detectable amounts of SDG. Quite interestingly, most of the SDG-positive samples contained the 8R,8'R-isomer exclusively while only three (including L. usitatissimum) contained the 8S,8'S-stereoisomer as the predominant form. As a most noteworthy finding, the dichloromethane extracts obtained from seeds of several Linum species were found to contain significant concentrations of non-polar cyclolignans of the arylnaphthalene/-dihydronaphthalene lactone type or, alternatively of the aryltetralin lactone type. Thus, seeds of Linum perenne L. as well as those of several other representatives of sections Linum and Dasylinum were found to contain significant concentrations of the arylnaphthalene justicidin B along with further compounds of this type and some aryldihydronaphthalene-type lignans. On the other hand, seeds of Linum flavum and further representatives of section Syllinum were found to contain aryltetralin-type lignans, mainly in the form of esters with aliphatic carboxylic acids, such as 6-methoxypodophyllotoxin-7-O-n-hexanoate, whose occurrence in L. flavum seeds has very recently been reported by us for the first time. Various chemosystematic and biogenetic aspects are discussed in the light of these results. PMID:22854497

Schmidt, Thomas J; Klaes, Michael; Sendker, Jandirk

2012-07-31

468

Seed extracts inhibiting protein synthesis in vitro.  

PubMed Central

Of 33 seed extracts examined, 12 inhibited protein synthesis in a rabbit reticulocyte lysate. This activity seems to be due to a protein, since (i) it was recovered with the (NH4)2SO4 precipitate, (ii) it was retained by dialysis membranes, and (iii) in all cases but one was destroyed by boiling. Only the extracts from the seeds of Adenia digitata and, to a lower extent, of Euonymus europaeus inhibited protein synthesis in intact cells.

Gasperi-Campani, A; Barbieri, L; Morelli, P; Stirpe, F

1980-01-01

469

Solvent winterization of sunflower seed oil  

Microsoft Academic Search

Samples of oil from whole and dehulled sunflower seed were solvent winterized. The solvent mixture, 85% acetone, 15% hexane\\u000a (v\\/v), was used at solvent-in-oil concentrations of 20, 40, and 70% by wt and the samples winterized at 0, ?5, ?10, and ?15\\u000a .01 C for 4 hr. Generally, sunflower oils from whole seed remained free from cloud formation longer on

W. Herbert Morrison; James A. Robertson

1975-01-01

470

Some Physical Properties of Triploid Watermelon Seed  

Microsoft Academic Search

In order to improve the germination via physical method, the physical properties of triploid watermelon seed were measured. Watermelon seeds of three varieties, Heiniu, Mihong and Huapi, at the moisture content of 7.02, 6.55 & 6.75 % (w.b.), were selected to study the physical properties using standard methods, respectively. Experimental results obtained the physical properties' parameters, length, width, thickness, arithmetic

Dai Sihui; Xiong Xingyao; Sun Xiaowu; Yao Jun; Deng Ping; Li Ming

2012-01-01

471

A CW seeded femtosecond optical parametric amplifer  

NASA Astrophysics Data System (ADS)

A CW seeded femtosecond optical parametric amplifier, a compromise between OPG/OPA and strongly seeded OPA configurations, has been demonstrated. An independent CW Nd: YAG laser with sub-watt power decreases the pump threshold of the OPA and improves the stability of the output pulses considerably. Output signal energies as high as 30 ?J with pulse durations less than 250 fs near 1 ?m are reported. from this two-stage device.

Zhu, Heyuan; Xu, Guang; Wang, Tao; Qian, Liejia; Fan, Dianyuan

2004-11-01

472

The Arabidopsis SeedGenes Project  

Microsoft Academic Search

The SeedGenes database (http:\\/\\/www.seedgenes.org) presents molecular and phenotypic information on essential, non-redundant genes of Arabidopsis that give a seed phenotype when disrupted by mutation. Experimental details are synthesized for efficient use by the community and organized into two major sections in the database, one dealing with genes and the other with mutant alleles. The database can be queried for detailed

Iris Tzafrir; Allan Dickerman; Olga Brazhnik; Quoc Nguyen; John Mcelver; Catherine Frye; David Patton; David Meinke

2003-01-01

473

Investigating Seed Longevity of Big Sagebrush (Artemisia tridentata)  

USGS Publications Warehouse

The Intermountain West is dominated by big sagebrush communities (Artemisia tridentata subspecies) that provide habitat and forage for wildlife, prevent erosion, and are economically important to recreation and livestock industries. The two most prominent subspecies of big sagebrush in this region are Wyoming big sagebrush (A. t. ssp. wyomingensis) and mountain big sagebrush (A. t. ssp. vaseyana). Increased understanding of seed bank dynamics will assist with sustainable management and persistence of sagebrush communities. For example, mountain big sagebrush may be subjected to shorter fire return intervals and prescribed fire is a tool used often to rejuvenate stands and reduce tree (Juniperus sp. or Pinus sp.) encroachment into these communities. A persistent seed bank for mountain big sagebrush would be advantageous under these circumstances. Laboratory germination trials indicate that seed dormancy in big sagebrush may be habitat-specific, with collections from colder sites being more dormant. Our objective was to investigate seed longevity of both subspecies by evaluating viability of seeds in the field with a seed retrieval experiment and sampling for seeds in situ. We chose six study sites for each subspecies. These sites were dispersed across eastern Oregon, southern Idaho, northwestern Utah, and eastern Nevada. Ninety-six polyester mesh bags, each containing 100 seeds of a subspecies, were placed at each site during November 2006. Seed bags were placed in three locations: (1) at the soil surface above litter, (2) on the soil surface beneath litter, and (3) 3 cm below the soil surface to determine whether dormancy is affected by continued darkness or environmental conditions. Subsets of seeds were examined in April and November in both 2007 and 2008 to determine seed viability dynamics. Seed bank samples were taken at each site, separated into litter and soil fractions, and assessed for number of germinable seeds in a greenhouse. Community composition data from each site, as well as several environmental variables, were used to evaluate seed viability within the context of habitat variation. Initial viability of seeds used in the seed retrieval experiment was 81 and 92 percent for mountain and Wyoming big sagebrush, respectively. After remaining in the field for 24 months, buried Wyoming big sagebrush seeds retained 28-58 percent viability,11-23 percent of seeds under litter remained viable, and no seeds remained viable on the surface (estimates are 95-percent confidence intervals). The odds of remaining viable did not change from 12 to 24 months. However, after 24 months the odds of seeds beneath litter being viable decreased to 75 percent of the odds of viability at 12 months. Similar to Wyoming big sagebrush, buried seeds of mountain big sagebrush were 31-68 percent viable, seeds under litter retained 10-22 percent of their viability, and no surface seeds were viable after 24 months. Both subspecies of big sagebrush had some portion of seed that remained viable for more than one growing season provided they were buried or under litter. Although seeds beneath litter may remain viable in intact communities, seeds are susceptible to incineration during fires. Nine months after seed dispersal, seed bank estimates for Wyoming big sagebrush ranged from 19 to 49 viable seeds/m2 in litter samples and 19-57 viable seeds/m2 in soil samples (95-percent confidence interval). For mountain big sagebrush, estimates were 27-75 viable seeds/m2 in litter samples and 54-139 viable seeds/m2 in soil (95-percent confidence interval). The number of viable seeds present in the seed bank 9 months after seed dispersal was not significantly different from the number present immediately after seed dispersal. Seed viability was highest in mountain big sagebrush sites for seeds on the surface and beneath litter, but decreased after one season. Buried seeds of both subspecies were in equal abundances and may be insulated from the effect

Wijayratne, Upekala C.; Pyke, David A.

2009-01-01

474

Injection-seeded optical parametric amplifier for generating chirped nanosecond pulses.  

PubMed

We constructed an optical parametric amplifier with BiBO crystals, which was injection seeded by a phase-modulated cw beam in the 1,040-1,070 nm region. Two-stage pre-amplification by Yb-doped fibers were implemented for stable injection to the OPA. The frequency chirp in the OPA pulse was actively controlled by adjusting the RF wave for the phase modulation and its synchronization to the OPA firing. Down/up chirps with up to 500 MHz shift were demonstrated. The output pulse energy was ~40 mJ, which is sufficient for future application of frequency conversion and coherent population transfer. PMID:23482098

Miyake, Shinichirou; Ohshima, Yasuhiro

2013-03-11

475

Oxidative Processes in Soybean and Pea Seeds  

PubMed Central

Oxidative processes are probable determinants of longevity of seeds in storage. Measurements of actual oxygen uptake rates were made for soybean and pea seeds as a comparison of short and long lived seeds when light, temperature, and moisture contents were varied. In both peas and soybeans, the oxygen uptake was depressed at low temperatures (<16°C) and low water contents (<0.25 gram H2O per gram dry weight). Apparent activation energies under these conditions are very high, while apparent activation energies of seeds at higher water contents and at temperatures greater than 22°C are much less. Light enhances the level of oxygen uptake in pea, but reduces the level of oxygen uptake in soybean. The complexities of the interactions of oxygen uptake with environmental conditions in soybean compared to pea suggest that oxidative processes occur in soybean at low water contents, but are essentially absent in pea. It is suggested that the additional oxidative processes in soybean with moisture contents between 0.10 and 0.24 gram per gram may contribute to the poorer longevity of soybean seed compared to pea seed.

Vertucci, Christina W.; Leopold, A. Carl

1987-01-01

476

Survival of seeds in hypervelocity impacts  

NASA Astrophysics Data System (ADS)

Panspermia (‘seeds everywhere’) postulates that life naturally migrates through space. Laboratory studies of Panspermia often examine the survival of Earth's species under the conditions thought to occur during transfer through space. Much of this research has centred on bacteria, but here we consider seeds themselves. We simulated the extreme accelerations necessary for their hypothetical ejection from a planetary surface and the impacts associated with their arrival on another planet. Seeds of tobacco, alfalfa and cress were fired into water at speeds in the range 1 3 km s-1, corresponding to impact shock pressures of circa 0.24 2.4 GPa. No seeds remained intact and able to germinate, even at the lowest speeds. Although fragmentation occurred, even at 3 km s-1 the size of some of the fragments was about 25% that of the seeds. Thus, whilst the seeds themselves did not survive extreme shocks, a substantial fraction of their mass did and might successfully deliver complex organic materials after impact. These results are discussed with respect to ancient Panspermia and the potential of contemporary impacts to eject living organisms into space.

Jerling, Aaron; Burchell, Mark J.; Tepfer, David

2008-10-01

477

Protein syntehsis during soybean seed maturation  

SciTech Connect

The authors previous work has demonstrated that physiological and biochemical changes specifically associated with soybean seed maturation can be separated from events associated with seed development. The objective of this study was to determine if soybean seed metabolism is altered during maturation drying at the level of protein synthesis. Seed harvested 35 days after flowering (0% seedling growth) were induced to mature (100% seedling growth) through controlled dehydration. Proteins labeled with (/sup 35/S)-methionine were extracted and analyzed by 1-D PAGE coupled with autoradiography and densitometry. Results show a 31 kD and 128 kD polypeptide synthesized de novo during dehydration and precocious maturation. The same two polypeptides are synthesized during natural dehydration and maturation (>60 days after flowering). Furthermore, these polypeptides persist during rehydration and germination of both precociously and naturally matured seed, but specifically disappear during early seedling growth. The authors are currently investigating the role of protein synthesis during soybean seed maturation and if it is required for establishment of a soybean seedling.

Rosenberg, L.A.; Rinne, R.W.

1987-04-01

478

Development capacity of artemia cysts and lettuce seeds flown in Cosmos 936 and directly exposed to cosmic rays.  

PubMed

Developmental capacity of Artemia cysts and chromosomal aberration frequency in lettuce seeds, flown aboard Cosmos 936 have been investigated. Biological objects were located inside or outside the spacecraft. Lettuce seeds were stuck on plastic plates and sandwiched in cellulose sheets in order to discriminate the objects hit by the cosmic heavy ions from the ones not hit. The absorbed dose inside the spacecraft was about 650 mrad. Biological objects were located at different levels in the "outside" container; absorbed doses were 1.5 rad for lettuce seeds and 30 rad for Artemia cysts. There was no change in hatch-ability of Artemia cysts located inside or outside the spacecraft when eggs were tested 2-4 months after recovery, but a marked decrease was observed in eggs 9 months after the space flight. Survival of larvae and adults was normal in "inside" eggs, but decreased in "outside" eggs. Space flight also resulted in a higher frequency of single chromosomal aberrations in cells developed from "inside and outside", hit and non-hit seeds. This highest percentage of multiple chromosomal aberrations occurred in seeds hit by the heavy ions. PMID:571717

Gaubin, Y; Kovalev, E E; Planel, H; Nevzgodina, L V; Gasset, G; Pianezzi, B

1979-02-01

479

Co-pumped 130 W monolithic single frequency fiber amplifier with an optically induced thermal gradient  

NASA Astrophysics Data System (ADS)

We present theoretical and experimental results of a 130 W continuous-wave (CW), single-frequency, 7 m, polarizationmaintaining (PM) Yb:doped fiber (25/400) ?m amplifier simultaneously seeded with a combination of broadband and narrow-line signals. Experiments were performed for two thermal configurations and the SBS threshold of the doubly seeded amplifier is compared to the singly seeded case. In the first configuration, the fiber was wrapped around a cold spool held at 12° C to diminish thermally induced shifts in the acoustic resonance of the fiber, which is known to suppress stimulated Brillouin scattering (SBS). In this case, over 80 W of single-frequency output was obtained demonstrating an enhancement of 3 dB in the SBS threshold compared to the single-tone case whereby the SBS threshold was 40 W. In the second thermal configuration, 6 m of the fiber is wrapped around the same cold spool, but approximately 1 m of the fiber is left to cool in ambient conditions. In this case, an optically induced thermal gradient was formed due to the quantum defect heating associated with power transfer from the pump and broadband seed signals into the single-frequency signal at the output end of the fiber. Over 130 W of single-frequency output was demonstrated yielding an effective increase of ~5 dB in the SBS threshold when compared to the single-tone case.

Zeringue, Clint; Vergien, Chris; Dajani, Iyad

2011-05-01

480

Noise Suppression and Enhanced Focusability in Plasma Raman Amplifier with Multi-frequency Pump  

SciTech Connect

Laser pulse compression/amplification through Raman backscattering in plasmas can be facilitated by using multi-frequency pump laser beams. The efficiency of amplification is increased by suppressing the Raman instability of thermal fluctuations and seed precursors. Also the focusability of the amplified radiation is enhanced due to the suppression of large-scale longitudinal speckles in the pump wave structure.

A.A. Balakin; G.M. Fraiman; N.J. Fisch; V.M. Malkin

2003-06-16

481

Uncoupling the effects of seed predation and seed dispersal by granivorous ants on plant population dynamics.  

PubMed

Secondary seed dispersal is an important plant-animal interaction, which is central to understanding plant population and community dynamics. Very little information is still available on the effects of dispersal on plant demography and, particularly, for ant-seed dispersal interactions. As many other interactions, seed dispersal by animals involves costs (seed predation) and benefits (seed dispersal), the balance of which determines the outcome of the interaction. Separate quantification of each of them is essential in order to understand the effects of this interaction. To address this issue, we have successfully separated and analyzed the costs and benefits of seed dispersal by seed-harvesting ants on the plant population dynamics of three shrub species with different traits. To that aim a stochastic, spatially-explicit individually-based simulation model has been implemented based on actual data sets. The results from our simulation model agree with theoretical models of plant response dependent on seed dispersal, for one plant species, and ant-mediated seed predation, for another one. In these cases, model predictions were close to the observed values at field. Nonetheless, these ecological processes did not affect in anyway a third species, for which the model predictions were far from the observed values. This indicates that the balance between costs and benefits associated to secondary seed dispersal is clearly related to specific traits. This study is one of the first works that analyze tradeoffs of secondary seed dispersal on plant population dynamics, by disentangling the effects of related costs and benefits. We suggest analyzing the effects of interactions on population dynamics as opposed to merely analyzing the partners and their interaction strength. PMID:22880125

Arnan, Xavier; Molowny-Horas, Roberto; Rodrigo, Anselm; Retana, Javier

2012-08-07

482

Comparison Between High and Low Source Activity Seeds for I-125 Permanent Seed Prostate Brachytherapy  

SciTech Connect

Purpose: To compare low (mean 0.44, SD {+-} 0.0163 mCi) with high source activity (0.61 {+-} 0.0178 mCi) in I{sup 125} permanent seed brachytherapy regarding seed loss, dosimetric outcome, and toxicity. Methods and Materials: The study included 199 patients with prostate cancer treated by permanent seed brachytherapy alone: the first 105 with seeds of lower activity (first cohort), the following 94 with higher seed activity (second cohort). The V100, V150, V200, and D90 were analyzed on the CT scan 30 days after implantation (CTD30). The V100, V150, and D2 of the rectum were also calculated on CTD30. Seed loss was determined 30 days after implantation. Urinary toxicity was measured with the International Prostate Symptom Score (IPSS) questionnaire. Results: Lower seed activity was associated with lower V150 and V200 (p = 0.01 and p {<=} 0.001, respectively) on CTD30. More patients had a V100 <90% and D90 <140 Gy in the lower activity cohort (p = 0.098 for D90 and p = 0.029 for V100) on CTD30. There was no difference between cohorts in dose to the rectum (p = 0.325-0.516) or difference in patients' IPSS score from baseline (p = 0.0.117-0.618), although there was a trend toward more urinary toxicity at 4 and 8 months for high activity seeds. Seed loss as a percentage of implanted seeds was not different (p = 0.324). Conclusions: Higher seed activity (I{sup 125} {>=} 0.6 mCi) results in at least equal V100 and D90 on CTD30. However, dose inhomogeneity and a trend toward more urinary toxicity at 4 and 8 months after treatment may lead to a higher long-term urinary complications.

Masucci, Giuseppina Laura; Donath, David; Tetreault-Laflamme, Audrey; Carrier, Jean-Francois; Hervieux, Yannick; Larouche, Renee Xaviere; Bahary, Jean-Paul [Department of Radiation Oncology Centre Hospitalier de l'Universite de Montreal, Montreal (Canada); Taussky, Daniel, E-mail: daniel.taussky.chum@ssss.gouv.qc.c [Department of Radiation Oncology Centre Hospitalier de l'Universite de Montreal, Montreal (Canada)

2010-11-01

483

Seasonal Variation in Seed Dispersal by Tamarins Alters Seed Rain in a Secondary Rain Forest  

PubMed Central

Reduced dispersal of large seeds into degraded areas is one of the major factors limiting rain forest regeneration, as many seed dispersers capable of transporting large seeds avoid these sites with a limited forest cover. However, the small size of tamarins allows them to use small trees, and hence to disperse seeds into young secondary forests. Seasonal variations in diet and home range use might modify their contribution to forest regeneration through an impact on the seed rain. For a 2-yr period, we followed a mixed-species group of tamarins in Peru to determine how their role as seed dispersers in a 9-yr-old secondary-growth forest varied across seasons. These tamarins dispersed small to large seeds of 166 tree species, 63 of which were into a degraded area. Tamarins’ efficiency in dispersing seeds from primary to secondary forest varied across seasons. During the late wet season, high dietary diversity and long forays in secondary forest allowed them to disperse large seeds involved in later stages of regeneration. This occurred precisely when tamarins spent a more equal amount of time eating a high diversity of fruit species in primary forest and pioneer species in secondary forest. We hypothesized that well-balanced fruit availability induced the movement of seed dispersers between these 2 habitats. The noteworthy number of large-seeded plant species dispersed by such small primates suggests that tamarins play an important, but previously neglected, role in the regeneration and maintenance of forest structure. Electronic supplementary material The online version of this article (doi:10.1007/s10764-010-9413-7) contains supplementary material, which is available to authorized users.

Munoz Lazo, Fernando Julio Joao; Huynen, Marie-Claude; Poncin, Pascal; Heymann, Eckhard W.

2010-01-01

484

Accumulation of a Brazil nut albumin in seeds of transgenic canola results in enhanced levels of seed protein methionine  

Microsoft Academic Search

We have increased the methionine content of the seed proteins of a commercial winter variety of canola by expressing a chimeric gene encoding a methionine-rich seed protein from Brazil nut in the seeds of transgenic plants. Transgenic canola seeds accumulate the heterologous methionine-rich protein at levels which range from 1.7% to 4.0% of the total seed protein and contain up

Susan B. Altenbach; Chiung-Chi Kuo; Lisa C. Staraci; Karen W. Pearson; Connie Wainwright; Anca Georgescu; Jeffrey Townsend

1992-01-01

485

Frequency Control Devices.  

National Technical Information Service (NTIS)

The objective of the program was to explore advanced concepts in the design and manufacture of frequency control devices. The program was designed to lead to low cost mass production, high performance components, increased levels of communication system c...

K. M. Lakin

1995-01-01

486

Radio Frequency Radiation Hazards.  

National Technical Information Service (NTIS)

Explains the biological (personnel) and non-biological (feed and fuel) effects of RF radiation. The frequency spectrum is explained and the difference between ionizing and non-ionizing radiation is illustrated.

1994-01-01

487

Effective Frequency Technique.  

National Technical Information Service (NTIS)

An effective monochromatic frequency technique is described to represent the effects of finite spectral bandwidth for active and passive measurements centered on an absorption line, a trough region, or a slowly varying spectral feature. For Gaussian and r...

C. L. Korb C. Y. Weng

2003-01-01

488

Homodyne Frequency Multiplier Concept.  

National Technical Information Service (NTIS)

The technical note describes experiments conducted with broadband single ended, single balanced and double balanced mixers connected through a hybrid device to allow both the Radio Frequency (RF) and Local Oscillator (LO) ports to be driven by the same si...

G. J. Rast T. A. Barley

1971-01-01

489

Association Studies and Legume Synteny Reveal Haplotypes Determining Seed Size in Vigna unguiculata  

PubMed Central

Highly specific seed market classes for cowpea and other grain legumes exist because grain is most commonly cooked and consumed whole. Size, shape, color, and texture are critical features of these market classes and breeders target development of cultivars for market acceptance. Resistance to biotic and abiotic stresses that are absent from elite breeding material are often introgressed through crosses to landraces or wild relatives. When crosses are made between parents with different grain quality characteristics, recovery of progeny with acceptable or enhanced grain quality is problematic. Thus genetic markers for grain quality traits can help in pyramiding genes needed for specific market classes. Allelic variation dictating the inheritance of seed size can be tagged and used to assist the selection of large seeded lines. In this work we applied 1,536-plex SNP genotyping and knowledge of legume synteny to characterize regions of the cowpea genome associated with seed size. These marker-trait associations will enable breeders to use marker-based selection approaches to increase the frequency of progeny with large seed. For 804 individuals derived from eight bi-parental populations, QTL analysis was used to identify markers linked to 10 trait determinants. In addition, the population structure of 171 samples from the USDA core collection was identified and incorporated into a genome-wide association study which supported more than half of the trait-associated regions important in the bi-parental populations. Seven of the total 10 QTLs were supported based on synteny to seed size associated regions identified in the related legume soybean. In addition to delivering markers linked to major trait determinants in the context of modern breeding, we provide an analysis of the diversity of the USDA core collection of cowpea to identify genepools, migrants, admixture, and duplicates.

Lucas, Mitchell R.; Huynh, Bao-Lam; da Silva Vinholes, Patricia; Cisse, Ndiaga; Drabo, Issa; Ehlers, Jeffrey D.; Roberts, Philip A.; Close, Timothy J.

2013-01-01

490

A digital frequency synthesizer  

Microsoft Academic Search

A digital frequency synthesizer has been designed and constructed based on generating digital samples ofexp [j(2^{pi}nk\\/N)]at timenT. The real and imaginary parts of this exponential form samples of quadrature sinusoids where the frequency indexkis allowed to vary(-N\\/4) leq K < (N\\/4). The digital samples drive digital to analog converters followed by low-pass interpolating filters to produce analog sinusoids. The method

JOSEPH TIERNEY; CHARLES M. RADER; B. Gold

1971-01-01

491

Evaluation of several seed treatments for eradication of Acidovorax avenae subsp. citrulli from watermelon seed  

Technology Transfer Automated Retrieval System (TEKTRAN)

Acidovorax avenae subsp. citrulli (Aac), the causal agent of bacterial fruit blotch of watermelon (Citrullus lanatus), is a serious seedborne pathogen. To determine the effectiveness of several seed treatments for eradication of Aac from seed, healthy triploid watermelon seedlots were spiked with n...

492

Drift Seeds And Drift Fruits : Seeds That Ride The Ocean Currents  

NSDL National Science Digital Library

This essay explores seed dispersal by water and describes some of the physical adaptations that evolution has produced in the seeds and fruits that travel this way. There is a background essay, discussion questions, state and national standards, and links to related Teacher's Domain resources.

2007-01-01

493

AN ATLAS OF GENE EXPRESSION FROM SEED TO SEED THROUGH BARLEY DEVELOPMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

We assessed the global regulation of gene expression from seed to seed during barley (Hordeum vulgare L.) development by quantifying transcript abundance in key tissues and developmental stages of two diverse genotypes using the Barley1 GeneChip. Differential abundance was observed both between tis...

494

Are Plant Populations Seed Limited? A Critique and Meta?Analysis of Seed Addition Experiments  

Microsoft Academic Search

We examine the relative importance of processes that underlie plant population abundance and distribution. Two opposing views dominate the field. One posits that the ability to establish at a site is determined by the availability of suitable microsites (estab- lishment limitation), while the second asserts that recruitment is limited by the availability of seeds (seed limitation). An underlying problem is

2007-01-01

495

Poachers Alter Mammal Abundance, Seed Dispersal, and Seed Predation in a Neotropical Forest  

Microsoft Academic Search

We evaluated the hypothesis that poachers reduce the abundance of herbivorous mammals, and that this, in turn, alters seed dispersal, seed predation, and seedling recruitment for two palms ( Attalea bu- tyraceae and Astrocaryum standleyanum ) in central Panama. Using physical evidence left by poachers and in- terviews with forest guards, we quantified poaching intensity for eight forest sites. We

S. Joseph Wright; Horacio Zeballos; Iván Domínguez; Marina M. Gallardo; Marta C. Moreno; Roberto Ibáñez

2000-01-01

496

Performance of HGMS filter and recycling of magnetic seeding material on magnetic seeding method  

SciTech Connect

The optimum conditions for the recovery of nonmagnetic particles were obtained using a HGMS (high gradient magnetic separation) filter on the magnetic seeding method. The performance of the filter was given by the magnetic separator equations. In addition, it was found from the experimental results that the recycling of 95% magnetic seeding material was practicable.

Kurinobu, Shuntaro; Uesugi, Jun; Utumi, Yasusi; Kasahara, Hiroshi

1999-09-01

497

Chitosan treatment of wheat seeds induces resistance to Fusarium graminearum and improves seed quality.  

PubMed

Chitosan treatment (2-8 mg/mL) of wheat seeds significantly improved seed germination to recommended seed certification standards (>85%) and vigor at concentrations >4 mg/mL, in two cultivars of spring wheat (Norseman and Max), by controlling seed-borne Fusarium graminearum infection. The germination was <80% in the control and >85% in benomyl- and chitosan-treated seeds. Seed-borne F. graminearum was reduced to >50% at higher chitosan treatments compared to the control. Synthesis of phenolic acids was stimulated in primary leaves following chitosan treatment, and levels of these phenolic acids, especially ferulic acid, increased significantly with increasing chitosan concentration. Lignin content of primary leaves also showed a similar pattern. The synthesis of precursors of lignin such as p-coumaric, ferulic, and sinapic acids and phenolic acids having antimicrobial activity such as benzoic, p-coumaric, caffeic, protocatechuic, chlorogenic, ferulic, and gallic acids was also stimulated by chitosan treatment. The induction of phenolic acids and lignin was significantly lower in cv. Max compared to Norseman. Chitosan also inhibited fungal transmission to the primary roots of germinating seedlings. Results suggest that chitosan controlled seed-borne F. graminearum infection and increased the resistance in seedlings by stimulating the accumulation of phenolics and lignin. Thus, chitosan has a potential for improvement of seed quality and enhancement of crop yields as well as increased value of stored grains for food and feed. PMID:10552439

Bhaskara Reddy, M V; Arul, J; Angers, P; Couture, L

1999-03-01

498

Percent Moisture and Seed Coat Characteristics of Alfalfa Seeds After Artificial Inoculation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vegetable sprouts can be a vehicle for food borne illness and the seeds used for sprouts are considered the probable source of the pathogen contamination. Since naturally contaminated seeds have a very low pathogen level, most reports on the efficacy of sanitizing decontamination methods use artifi...

499

Seeding in the NCAA Men's Basketball Tournament: When is a Higher Seed Better?  

Microsoft Academic Search

A number of methods have been proposed for predicting game winners in the National Collegiate Athletic Association's (NCAA) annual men's college basketball championship tournament. Since 1985, more than 70% of the teams in the fourth, fifth, and sixth rounds of the tournament have been high-seeded teams (i.e., teams assigned seeds of one, two, or three); a method that can accurately

Sheldon H. Jacobson; Douglas M. King

2009-01-01

500

Population ecology of wild sunflowers: effects of seed density and post-dispersal vertebrate seed predators  

Microsoft Academic Search

Assessing the effects of seed density on the population dynamics of wild plant species with crop relatives will be vital in determining the potential effects of introducing traits into wild populations as a result of crop-to-wild gene flow. We examined experimental sunflower (Helianthus annuus) patches in eastern Kansas to determine the effects of seed density and predation on seedling recruitment

Charity L. Cummings; Helen M. Alexander

2002-01-01