Shot Line Research Articles

Asymmetric somatic hybridization between UV-irradiated Citrus unshiu and C. sinensis: regeneration and characterization of hybrid shoots

In the present paper, attempts were made to explore the possibility of employing ultraviolet (UV) irradiation in citrus asymmetric fusion for transfer of limited amount of favorable traits from a desirable cultivar to a target one. Exposure of Satsuma mandarin (Citrus unshiu Marc.) embryogenic protoplasts to UV at an intensity of 300 muW cm(-2) led to reduced viability, especially under long irradiation duration. The protoplasts could not grow during culture when they were irradiated for over 30 s. Terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) assay revealed extensive DNA fragmentation in the UV-irradiated protoplasts compared with those without UV treatment. Electrofusion between UV-irradiated protoplasts of Satsuma mandarin (donor) with those of Jincheng (C. sinensis Osbeck, recipient), a local cultivar of superior quality, gave rise to regeneration of several lines of shoots, which failed to root despite enormous endeavors. Ploidy analysis via flow cytometry and chromosome counting showed that four selected shoots were either diploid, triploid or tetraploid. Random amplified polymorphism DNA (RAPD) and amplified fragment length polymorphism (AFLP) confirmed the shoots, irrespective of their ploidy level, as putative somatic hybrids. Cleaved amplified polymorphism sequences (CAPS) demonstrated that the shoots predominantly got their cytoplasmic components, in terms of chloroplast (cp) and mitochondrion DNA, from Jincheng, along with possible recombination of cpDNA in some shoot lines. The current data indicated that UV-based asymmetric fusion could also be employed in citrus somatic hybridization with the intention of creating novel germplasms, which may provide an alternative approach for cultivar improvement.

Method for Assessing Vulnerability of Aircraft to Spray Fragments of Missile

Abstract A method is proposed for calculating the vulnerability of aircraft to spray fragments of a missile. The input data of aircraft or components for vulnerability assessment is organized by the finite element models. First, the `shot line scanning method' is used to calculate the single-hit vulnerability of aircraft by a fragment of missile. Utilizing Markov-Chain method, the vulnerability of aircraft is obtained at the threat of multiple hits by spray fragments. An example that shows the distributions of probability of kill at the typical missile detonation locations around the aircraft has been provided. In this example, the interaction regions of aircraft with fragments of missile are analyzed and the correctness and feasibility of the proposed method are demonstrated. Application shows that (1) the proposed method is generic and easy to be programmed; (2) to provide a realistic and effective aircraft vulnerability assessment, the method has taken into consideration the factors such as missile velocity, missile detonation location, missile charge ratio, fragment shape, air drag, aircraft altitude, and aircraft velocity; (3) the vulnerability assessment of aircraft to fragments of missile is useful for aircraft survivability enhancement design, missile effectiveness assessment, and optimizing missile fuse design.

Combination of HIFU therapy with contrast-enhanced sonography for quantitative assessment of therapeutic efficiency on tumor grafted mice

The objective was to evaluate treatment efficiency of a new high-intensity focused ultrasound (HIFU) prototype combining a therapeutic transducer with a sonographic probe. The optimal HIFU sequence was defined on ex vivo samples before in vivo evaluation of tumor ablation was performed by perfusion quantification after contrast agent injection. The original feature of this prototype is a 9-MHz sonographic probe in a HIFU device and connected to an Aplio (Toshiba ®) sonograph. Acoustical power and treatment time were determined on ex vivo livers to generate 1-cm-long lesions. Lesion reproducibility was assessed for the power and treatment time selected. The gap between lesions and HIFU displacement shot procedures were optimized to ablate a 1-cm 3 volume. The optimized protocol was applied to five murine tumors in vivo. Tumor ablation was quantified according to (1) contrast uptake (CU) after HIFU using perfusion software (Toshiba ®) in “vascular recognition imaging” mode and Sonovue (Bracco ®) contrast agent, and (2) the percentage of necrosis quantified on histologic slides. Ex vivo results: optimized settings, at 442 W/cm 2 applied during three cycles (3 s on/5 s off) generated 10 identical elementary lesions measuring 9.78 (±0.66) * 2.11 (±0.33) mm 2. A 4-mm gap between adjacent lesions and a 2-min pause between shot lines were found optimal. In vivo results: 60 % (±22) mean reduction in CU after HIFU and tumor necrosis histologically estimated at 58 % (±5.7) were quantified for the five animals. The therapeutic potential of this HIFU prototype was demonstrated in vivo through objective quantification of tumor ablation based on CU. (E-mail: rouffiac@igr.fr)

Technology Update: Technique for Full Modeling of the Multiple Wavefield

Three-dimensional Surface-Related Multiple Elimination (SRME) has proved a powerful method to address the seismic problem of either reconstructing missing data or reconstructing missing multiple contributions. The specific problems of diffracted multiple energy and out-of-plane (shifted-apex) 3D multiple energy have responded well. Typically, these multiples are caused by rugose or structured seafloors and have proved to be particularly difficult to remove. Cie. Générale de Géophysique (CGG) has applied the 3D SRME method on projects worldwide with significant benefits. With the approach being based on full modeling of the multiple wavefield, this method is also independent of acquisition geometry, whether 3D streamer with conventional or sparse separation, multi-azimuth, or ocean-bottom cable. The problem of multiples is approached by use of model-based prediction techniques rather than a data-driven method. The result is a multiple-attenuation technique that fully models the multiple arrivals. The strength of this method lies in its ability to cope with any kind of acquisition geometry. 3D SRME by Surface-Consistent Convolution Data-driven SRME techniques have recently represented attractive solutions to the multiple problem because they do not require a priori knowledge of the subsurface (reflectivity, structures, and velocities). However, these methods require one shot location for each receiver position, and this is not the case for most 3D acquisition geometries. The most common solution requires interpolation of the input data, thus creating the missing streamers and shot lines for the required prestack convolutional process. The strengths of this approach are that it is fully data driven and models all the multiples at once. However, the surface-consistent convolutions require sampling of identical source/receiver sets; in 3D, this requires significant acquisition and/or data regularization and extrapolation effort (typically, closer sail lines). 3D SRME by Wavefield Modeling The modeling of the primaries is obtained by prestack demigration of the migrated section (either time or depth). The ringing of the primaries and multiples through the target volume is modeled using the one-way wave equation; as there is a propagated wavefield all along the acquisition surface, the method addresses problems of cable feathering. Because the shot gathers are modeled separately, the method is suited for parallel implementation. It is currently optimized to run on large personal-computer clusters. For the ocean-bottom-cable environment, each receiver gather is processed separately, and there is no need for sail-line interpolation (or receiver-gather interpolation).

Improvement of Surface Layer Characteristics by Shot Lining

In the present study, lining of the metal with foils using shot peening was investigated to improve the surface layer characteristics. In the shot peening experiment, the foils set on the metal are pelted with hard particles traveling at a high velocity. The foils are bonded to the metal surface due to plastic deformation induced by the collision of the particles. The foils and the metal are heated to heighten the bondability because of the reduction of flow stress. Lining the metal with the hard powder sandwiched between two aluminum foil sheets was also attempted. In this experiment, a centrifugal shot peening machine wite an electrical heater was employed. The metals are commercially aluminium alloys and magnesium alloys, and the foils are commercially aluminum, titanium and nickel. The effects of shot speed and the heating temperature on the bondability were examined. Wear resistance was also evaluated by grinding. The foils were successfully bonded to the metal surface. It was found that the present method is effective in improving of surface layer characteristics.

Transformation of persimmon with a pear fruit polygalacturonase inhibiting protein (PGIP) gene

Persimmon ( Diospyros kaki cv. Jiro) was transformed with the gene encoding the pear fruit ( Pyrus communis) polygalacturonase inhibiting protein (PGIP) using Agrobacterium tumefaciens EHA101. Two plasmid constructions were used for transformation; pDU94.0928 containing chimeric genes of PGIP, GUS and NPTII in its T-DNA region, and pYS95.091 containing only the GUS and NPTII sequences (control transformations). Among 165 callus lines obtained from infection by A. tumefaciens with pDU94.0928, 15 showed GUS activity. A PGIP gene fragment of 132 bp was amplified by PCR in nine of 15 callus lines. Shoots were regenerated from three of the nine PGIP-containing callus lines. The transformation of the regenerated shoots was confirmed by PCR and Southern blot analyses using NTPII, GUS and pear PGIP probes. PGIP expression in shoot tissues was analyzed by western blot analysis. The protein expression was observed in all three shoot lines regenerated from transformed calli with the PGIP gene. Fungal PG activity was inhibited by crude extracts from shoots transformed with the PGIP gene substantially more than by those from the control transformants obtained from the transformation with pYS95.091.

3D geometry for demultiple and noise cancellation

The simple process of CMP stack can act as a powerful mechanism for suppression of multiples and attenuation of many types of linear shot noise (air waves, ground roll, backscatter). In any 3D acquisition geometry, each CMP bin will have a variety of traces that have different shot-receiver offsets and azimuths. These recorded traces will be processed through various algorithms such as scaling, NMO, statics corrections, and so forth prior to summing them into CMP stack traces. The act of summing or stacking will increase coherent signal content and reduce incoherent (uncorrelated) noise—noise such as linear shot noise and multiples (whether surface or interbed). The offset and azimuth distribution of the traces in a CMP bin plays a critical role in determining the effectiveness of attenuating multiples and other noise. Thus, the CMP stack of the noise component of the recorded seismic data varies from bin to bin according to the offset distribution. Different geometries lead to different attenuation characteristics. It is instructive to investigate some key factors in 3D geometries to see their effect on noise attenuation in general. These key factors are: aspect ratio (width versus length of the recording patch), ratio of shot line interval to receiver line interval, and angle of shot lines to receiver lines (slanted geometries). Synthetic linear noise and multiples can be generated to investigate the effects of these key factors. By knowing the levels of input noise, the level of output noise can be established (through CMP stacking) at various points throughout the CMP bins of a particular 3D geometry. Hence, a range of noise attenuation may be assigned to a 3D geometry. In creating different geometries for analysis, it is important that the main parameters should be the same. In other words the geometries will have: different aspect ratio, same fold, …

Processing the Hod 3D multicomponent OBS survey, comparing parallel and orthogonal acquisition geometries

The Hod 3D multicomponent ocean-bottom seismic (OBS) survey was acquired to image the reservoir through a gas cloud. Data were acquired with shot lines both along the receiver cables (in-line or parallel shooting) and orthogonal to the receiver cables (cross-line shooting).

New evidence of Tasmania's tectonic history from a novel seismic experiment

In March 1995, 44 land‐based recorders were deployed throughout Tasmania, SE Australia, to record seismic energy from an encircling array of marine normal‐incidence reflection shot lines. We invert refraction and wide‐angle reflection traveltimes for crustal structure, with the principal outcome being a map of the Tasmanian Moho. Key tectonic inferences from this map include: (1) the Arthur Lineament metamorphic belt in NW Tasmania overlies a major change in crustal thickness (over 5 km) and probably represents the NW limit of deformation in Tasmania during the Mid‐Late Cambrian Tyennan Orogeny, (2) thickening of the crust beneath central northern Tasmania may be associated with the juxtaposition of the Eastern and Western Tasmania Terranes during the Mid‐Devonian Tabberabberan Orogeny, and (3) the difference in crustal thickness between the east and west coasts reflects the presence of differing strain regimes during the Cretaceous break‐up of Gondwana.

Protocol for transformation of the apple rootstock Jork 9 with the rolB gene and its influence on rooting

A suitable protocol for transformation has been developed for the apple rootstock Jork 9 using Agrobacterium tumefaciens strain EHA101A(pEHA101A)(pSCV1.6). Root formation was increased by transforming the rootstock with A. tumefaciens strain C58C1(pGV3850)(pB-B:GUS), which contains the nptII, rolB and gus genes on the T-DNA. Transformation for all of the introduced genes was confirmed by polymerase chain reaction and Southern blot analyses. Of the 18 independent shoot lines obtained after transformation only ten contained at least one copy of intact T-DNA, while six lines were missing the gus gene and two lines were missing both the gus and rolB genes. The rooting experiments showed that introduction of the rolB gene increased root percentage and root number, giving 13.8 roots per shoot compared to 2.3 for untransformed shoots. More than two copies of the rolB gene decreased the number of roots and percentage of rooted shoots.

Inversion of seismic refraction and wide-angle reflection traveltimes for three-dimensional layered crustal structure

We present a method for the determination of crustal structure by simultaneous inversion of seismic refraction and wide-angle reflection traveltimes for 3-D interface geometry and layer velocity. Crustal structure is represented by layers in which velocity varies linearly with depth, separated by smooth interfaces with a cubic B-spline parametrization. Lateral variations in structure are therefore represented by variations in interface depth only. The model parametrization we have chosen means that ray paths consist of piecewise circular arc segments for which analytic expressions of trajectory and traveltime are calculated. The two-point problem of finding the first-arrival ray path and traveltime of a specified phase between a given source and receiver is solved using a shooting technique. A subspace inversion method is used to solve the inverse problem, which is formulated as a non-linear optimization problem in which we seek to minimize an objective function that consists of a data residual term and a regularization term. Before performing the inversion, each data pick must be assigned as a refraction or reflection from a particular layer or interface. Since our method represents structure in terms of interfaces, fewer parameters would generally be used in a reconstruction compared to an equivalent 3-D variable-velocity inversion. The method is well suited to wide-angle surveys that consist of many sources and relatively few receivers (or vice versa), such as marine shot lines used in conjunction with land-based receivers. Data coverage in this kind of survey is often sparse and, especially if near-offset ray paths are unavailable, highly variable. A 3-D synthetic test with an array consisting of eight sources lying within a three-sided square of 79 receivers is described. The test model consists of a three-interface structure that includes a layer pinch-out, and the synthetic data set comprises 987 refraction and 930 reflection travel times contaminated with 75 ms of data noise. Six iterations of an 18-D subspace method demonstrate that the method can produce an accurate reconstruction that satisfies the data from a 1-D starting model. We also find that estimates of a posteriori model covariance and resolution obtained from linear theory are useful in analysing solution reliability despite the non-linear nature of the problem. Application of the method to data collected as part of the 1995 TASGO project in Tasmania shows that the method can satisfy 1345 refraction and reflection traveltime picks with a geologically reasonable and robust 254-parameter three-interface model. The inversion results indicate that the Moho beneath NW Tasmania varies in depth from 27 km near the coast to 37 km near central Tasmania, with the major increase in depth occurring across the Arthur Lineament.

Effects of ipt gene expression on the physiological and chemical characteristics of Artemisia annua L.

An isopentenyl transferase gene ( ipt) from T-DNA was transferred into Artemisia annua L. via Agrobacterium tumefaciens. The ipt gene was placed in a binary vector under the control of the CaMV 35S promoter. Leaf explants were infected with A. tumefaciens LBA4404 containing pBIipt to induce the buds. Nineteen shoot lines were selected, which were resistant to kanamycin. Polymerase chain reactions and Southern blotting confirmed that at least five shoot lines contained the foreign gene. The results of RT-PCR and Northern blotting analyses suggested that the foreign ipt gene of the transgenic shoot was expressed. Cytokinins, chlorophyll and artemisinin contents were found increased at different degree. Content of cytokinins (iPA and iP) was elevated 2- to 3-fold, chlorophyll increased 20–60% and artemisinin increased 30–70% compared with the control plants, respectively. A direct correlation was found between the contents of cytokinins, chlorophyll and artemisinin. This may be the first report on the relationship between endogenous cytokinin content and the production of secondary metabolites in plants.

Transgenic apple (Malus x domestica) shoot showing low browning potential.

Transgenic apple shoots were prepared from leaf disks by using Agrobacterium tumefaciens carrying the kanamycin (KM) resistance gene and antisense polyphenol oxidase (PPO) DNA. Four transgenic apple lines that grew on the medium containing 50 microgram/mL KM were obtained. They contained the KM resistance gene and grew stably on the medium for >3 years. Two transgenic shoot lines containing antisense PPO DNA in which PPO activity was repressed showed a lower browning potential than a control shoot.

Expression of a chimeric farnesyl diphosphate synthase gene in Artemisia annua L. transgenic plants via Agrobacterium tumefaciens-mediated transformation

An Agrobacterium tumefaciens-mediated transformation system was developed for Artemisia annua L. Using this system a cDNA encoding farnesyl diphosphate synthase (FDS placed under a CaMV 35S promoter) was transferred into A. annua via A. tumefaciens strain LB4404. Leaf or leaf discs were used as explants to be infected with A. tumefaciens and an optimal concentration of 20 mg/l kanamycin was applied to select kanamycin resistant shoots. Forty-five lines of resistance kanamycin shoots transformed with FDS were established. Analysis of PCR showed that at least 20 shoots transformed with the FDS gene were PCR positive. Southern blot analysis suggested the foreign FDS gene had been integrated into the A. annua genome, and Northern blot analysis revealed that the foreign FDS gene expressed at the transcriptional level in five shoot lines (F-1, F-4, F-61, F-62 and F-73 shoot lines). Analysis of artemisinin demonstrated that about 8∼10 mg/g DW of artemisinin were then detected in transgenic plants regenerated from five shoot lines, this is about 2–3 times higher than that in the control.

Anatomical and Biochemical Events duringin vitroRooting of Microcuttings from Juvenile and Mature Phases of Chestnut

A comparative study of thein vitrorooting process of chestnut (Castanea sativa)shoots of the same genotype exhibiting juvenile (easy-to-root) and mature (difficult-to-root) characteristics is described. The two culture lines originated from shoots collected from the base (juvenile) and crown (mature) of an 80-year-old tree. Anatomically, juvenile and mature shoots had a similar stem structure at the time of excision, the main difference being that secondary phloem and xylem were more developed in mature than in juvenile shoots. A substantial reactivation of cell division was observed in both shoot lines 48 h after the root inductive treatment with indole-3-butyric acid. Meristemoids and root primordia developed only in juvenile shoots, beginning 3 d after the inductive treatment, and the first adventitious roots emerged 10 d after treatment. However, in mature shoots periclinal divisions of cambial cells occurred, especially on the phloem side, maintaining the normal orientation of the cambial derivatives. No meristemoids formed in this proliferating tissue. During the time course of the rooting process, more endogenous indole-3-acetic acid (IAA) was detected in mature than in juvenile shoots, indicating that the level of IAA is not the limiting factor accounting for the lack of rooting capacity in mature shoots. The levels of polyamines (putrescine, spermine and spermidine) were also higher in mature than in juvenile shoots.

3-D symmetric sampling in theory and practice

In brief, 3-D symmetric sampling criteria are: shot station interval = receiver station interval, shot line interval = receiver line interval, maximum in‐line offset = maximum cross‐line offset, center‐spread acquisition for shots and receivers, and shot arrays required as much as receiver arrays.

Production of somatic hybrids between Diospyros glandulosa and D. kaki by protoplast fusion

Interspecific somatic hybrids between Diospyros glandulosa (2n=2x=30) and D. kaki cv. Jiro (2n=6x=90) were produced by electrofusion of protoplasts. Protoplasts were isolated from calli derived from leaf primordia, fused electrically, and cultured by agarose-bead culture using a modified KM8p medium. Flow cytometry revealed that the nuclear DNA content was the sum of those of D. glandulosa and D. kaki cv. Jiro in 149 of the 166 calli obtained. RAPD analysis showed that the 149 callus lines yielded specific bands for both D. glandulosa and D. kaki cv. Jiro and further confirmed that they were interspecific somatic hybrid calluses. Shoots were regenerated from 63 of the 149 interspecific hybrid calluses. Chloroplast DNA analysis by PCR-RFLP, flow cytometric determination of nuclear DNA content, and RAPD analysis revealed that the 63 interspecific hybrid shoot lines contained the nuclear genomes from both parents but only the chloroplast genome from D. glandulosa. Microscopic observation of root tip cells demonstrated that somatic chromosome number of the interspecific hybrids was 2n=8x=120.

Engineering Genetic Resistance against Insects in Japanese Persimmon Using the cryIA(c) Gene of Bacillus thuringiensis

Japanese persimmon (Diospyros kaki L. `Jiro') was transformed using a disarmed strain of Agrobacterium tumefaciens, EHA101, carrying the binary plasmid vector, pDU92.710. The T-DNA region of pDU92.710 contained the kanamycin resistance gene (nptII), the β-glucuronidase gene (uidA), and a synthetic reconstruct of cryIA(c) encoding the insecticidal crystal protein fragment of Bacillus thuringiensis subsp. kurstaki HD-73. Leaf discs made from leaves of shoot cultures were cocultivated with Agrobacterium and cultured on a callus-induction medium containing kanamycin and cefotaxime. Among 720 infected leaf discs, 17 putative transformed callus lines showing kanamycin resistance were obtained after 8 weeks of culture. When these were cultured on a regeneration medium containing kanamycin, 15 formed adventitious buds. Of the 15 shoot lines, 11 grew well on a shoot-proliferation medium containing kanamycin, while 4 lines did not grow well. Of the 11 shoot lines, 10 showed GUS activities by fluorometric assay and were subjected to polymerase chain reaction (PCR) and Southern analyses. Except for two lines, all results were consistent with a stable integration of T-DNA into the persimmon genome. The production of CryIA(c) protein in transformed shoot lines was confirmed with Western analysis using anti-CryIA(c) serum. Insect bioassays were conducted with 10 lines showing GUS activity. Many of these lines showed high significant mortality of the test insects, Plodia interpunctella Hüber and Monema flavescens Walker, when compared to nontransformed controls.

Production of Interspecific Hybrids of Persimmon by Protoplast Fusion

Interspecific hybrids between Diospyros glandulosa (2n = 2x = 30) and D. kaki cv. Jiro (2n = 6x = 90) were produced by electrofusion of protoplasts. Protoplasts were isolated from calli derived from leaf primordia, fused electrically, and cultured by agarose-bead culture using modified KM8p medium. Relative nuclear DNA contents of calli derived from fusion-treated protoplasts were determined by flow cytometry. One-hundred-forty-nine of 166 calli obtained had the nuclear DNA content of the sum of those of D. glandulosa and D. kaki cv. Jiro. RAPD analysis showed that the 149 callus lines yielded specific bands for both D. glandulosa and D. kaki cv. Jiro and they appeared to be interspecific somatic hybrid calli. Shoots were regenerated from 63 of the 149 interspecific hybrid calli. PCR-RFLP of chloroplast DNA analysis, flow cytometric determination of nuclear DNA content, and RAPD analysis revealed that the 63 interspecific hybrid shoot lines contained nuclear genome from both the parents but only chloroplast genome from D. glandulosa. Microscopic observation of root tip cells confirmed that somatic chromosome numbers of the interspecific hybrids were 2n = 8x = 120.

Regeneration of somatic hybrids from electrofused protoplasts of Japanese persimmon ( Diospyros kaki L.)

Somatic hybrids of Japanese persimmon ( Diospyros kaki L.) were obtained by electrofusion of protoplasts. Callus protoplasts of cvs. Jiro and Suruga were fused electrically and cultured in modified KM8p medium using agarose-bead culture. Relative nuclear DNA contents of calli recovered from the fused protoplasts were determined by flow cytometry. About 20% of the callus lines (22 of 127) regenerated from protoplasts had twice the nuclear DNA content of the parental calli. When the 22 callus lines were transferred to regeneration medium, nine of them formed adventitious buds. RAPD analysis of nine shoot lines showed that they were somatic hybrids between Jiro and Suruga. Neither Jiro + Jiro nor Suruga + Suruga was regenerated. Chromosome number of the somatic hybrids was counted by microscopic observation of root tip cells. They had the dodecaploid chromosome number of around 2n = 180, which is twice the number of parental plants (2n = 90, x = 15).