Leaf Edge Research Articles

TH‐AB‐BRA‐01: A Novel Doubly‐Focused Multileaf Collimator Design for MR‐Guided Radiation Therapy

Purpose:To describe the physical and dosimetric properties of a novel double‐stack multileaf collimator (MLC).Methods:One of the compromises made in the MLC design has been to employ linear‐motion singly‐divergent shapes. Because the MLC leading edge moves linearly, it is rounded to provide a consistent, albeit compromised penumbra. The MLC employed in the new linac‐based MR‐IGRT unit is designed to be doubly focused in that each leaf moves in an arc centered at the source, and the sides of the leaves are machined such that they lie parallel to a line between the leaf edge and the source. The curvature of the MLC keeps motors and encoders in lower magnetic field. However, high spatial‐resolution leaves are difficult to manufacture to sufficiently tight tolerances and difficult to move due to restricted space on the gantry. Wider leaves alleviate this problem with less moving parts but the coarse resolution disallows treating very small lesions. This compromise has been overcome by splitting the MLC leaf bank into two sets, stacked one upon the other and offset half of a leaf width. The dosimetry has been simulated using Monte‐Carlo and a 6 MV linac in a 0.35 T magnetic field.Results:The combined MLC leaf set has a spatial resolution of effectively half of the leaf width, 4mm here. The dosimetry resolution and conformality are consistent with 4mm wide MLC assisted by inverse fluence modulation. Also, because each leaf junction is backed up by the stacked leaf that lies over the junction, the problem of tongue‐and‐groove dosimetry has been greatly reduced. The novel MLC design allows the use of more powerful leaf motors than would be otherwise possible if a single MLC bank is employed.Conclusions:The stacked MLC will provide highly conformal dose distributions suitable for stereotactic radiation therapy of small lesions.The research was funded by ViewRay, Inc.

TU-FG-201-04: Computer Vision in Autonomous Quality Assurance of Linear Accelerators

Purpose: Routine quality assurance (QA) of linear accelerators represents a critical and costly element of a radiation oncology center. Recently, a system was developed to autonomously perform routine quality assurance on linear accelerators. The purpose of this work is to extend this system and contribute computer vision techniques for obtaining quantitative measurements for a monthly multi-leaf collimator (MLC) QA test specified by TG-142, namely leaf position accuracy, and demonstrate extensibility for additional routines. Methods: Grayscale images of a picket fence delivery on a radioluminescent phosphor coated phantom are captured using a CMOS camera. Collected images are processed to correct for camera distortions, rotation and alignment, reduce noise, and enhance contrast. The location of each MLC leaf is determined through logistic fitting and a priori modeling based on knowledge of the delivered beams. Using the data collected and the criteria from TG-142, a decision is made on whether or not the leaf position accuracy of the MLC passes or fails. Results: The locations of all MLC leaf edges are found for three different picket fence images in a picket fence routine to 0.1mm/1pixel precision. The program to correct for image alignment and determination of leaf positions requires a runtime of 21– 25 seconds for a single picket, and 44 – 46 seconds for a group of three pickets on a standard workstation CPU, 2.2 GHz Intel Core i7. Conclusion: MLC leaf edges were successfully found using techniques in computer vision. With the addition of computer vision techniques to the previously described autonomous QA system, the system is able to quickly perform complete QA routines with minimal human contribution.

SU‐F‐T‐493: An Investigation Into the Feasibility of Using PipsPro Software with Film for Linac QA

Purpose:To determine the feasibility of using radiochromic and radiographic film with Pipspro software for quality assurance of linear accelerators with no on‐board imaging.Methods:The linear accelerator being used is a Varian Clinac 21EX. All IGRT is performed using the BrainLab ExacTrac system. Because of the lack of on board imaging, certain monthly and annual TG‐142 quality assurance tests are more difficult to perform and analyze to a high degree of accuracy. Pipspro was not designed to be used with hard film, and to our knowledge its use with film had not been investigated. The film used will be GafChromic EBT3 film and Kodak EDR2 film, scanned with an Epson V700 scanner. The following routine tests will be attempted: MLC picket fence, light vs. radiation field coincidence, starshots, and MLC transmission.Results:The only tests that gave accurate and reliable results were the couch, gantry, and collimator starshots. Typical MV and kV images are acquired with a much higher level of contrast between the irradiated and non‐irradiated areas when compared to film. Pipspro relies on this level of contrast to be able to automatically detect the fiducial points from its phantom devices, leaf edges for picket fence and transmission tests, and jaw edges for light vs. radiation field tests. Because of this, certain tests gave erroneous results and others were not able to be performed in the software at all, with either type of film. The number of monitor units delivered to the film, the experimental setup, and the scan settings was not able to rectify the problem.Conclusion:For linear accelerators with no on‐board imaging, it is not recommended to use hard film with PipsPro to perform TG‐142 quality assurance tests. Other software or methods should instead be investigated.

Association mapping of leaf traits in spinach (Spinacia oleracea L.)

AbstractSpinach (Spinacia oleracea L.) is an important leafy vegetable crop grown worldwide. Leaf traits, surface texture (smooth, savoy or semi‐savoy), petiole colour (different shades of green vs. purple) and edge shape (serrate vs. entire), are important commercial traits of spinach. Association mapping for the three traits was conducted on 323 USDA spinach germplasm accessions, originally collected from 33 countries and representing the entire USDA spinach germplasm collection. The majority of accessions were from Europe (36.3%), Asia (25.3%) and North America (15.8%). The majority of the spinach accessions (82.0%) were smooth (unwrinkled types), whereas the savoy and semi‐savoy types (wrinkled types) accounted for 18.0%. The collection contained 74.9% green petiole types, while the purple petioles consisted of 25.1%. The collection consisted of 27.2% serrated leaf types and 72.8% entire leaf edge types. Genotyping‐by‐sequencing (GBS) was used for single nucleotide polymorphism (SNP) discovery, and SNPs were used as genotypic data to conduct genetic diversity and association mapping of the three leaf traits. Five genetic subpopulations and principal components (PCs) were postulated by structure 2 and JMP Genomics 7 for this association panel. Five, seven and 14 SNPs were identified to be associated with surface texture, edge shape and petiole colour, respectively. This study provides us an approach to identify SNP markers through association analysis in spinach and thus leads to select these three leaf traits through marker‐assisted selection in spinach breeding programme.

Is a leaf life span enough to display changes on developmental instability and nitrogen after simulated herbivory?

Herbivory is a main source of plant damage and injured plants might present decrements in nutrients, delayed growth and low reproductive outputs. Therefore, herbivory can be considered a stressful agent to plants. In this study, we investigated short-term changes in stress and nutrient levels of the invasive plant species Tithonia diversifolia (Asteraceae) after simulated herbivory. Parameters such as leaf fluctuating asymmetry (FA, a measure of plant stress, also known as developmental instability) and nitrogen levels were compared between control and treated plants reared in a greenhouse. We expected high levels of FA and significant changes in nitrogen in injured leaves. FA was assessed by measuring the right and left sides of leaves, from the leaf edge to the midrib, at the middle point of the leaves; nitrogen was evaluated through the Kjeldahl method. Though non-significant, at the end of the study, injured leaves were 22% more asymmetric than control leaves, and before-after comparisons revealed that FA increased by 33% in leaves after leaf damage. In addition, FA was positively and significantly related to leaf area loss. Nitrogen did not present changes after simulated herbivory. The control group showed non-significant changes in FA and nitrogen. FA was concluded to be a rapid estimator of plant stress following leaf damage, as during its short lifespan (45days), leaves displayed tentatively increased developmental instability. We consider that leaf damage is a predictor of plant developmental instability and that FA can be used to detect and compare stress levels in plants after herbivory damage.

Influence of Extracellular Cellulose and Colanic Acid Production on the Survival of Shiga Toxin–Producing Escherichia coli on Spinach and Lettuce after Chlorine Treatment

Shiga toxin-producing Escherichia coli (STEC) strains produce extracellular cellulose and colanic acid, which may influence stress tolerance. This study investigates the role of these extracellular polymers on the tolerance of STEC to chlorine treatment after attachment to lettuce and spinach. Four STEC strains, two wild-type cellulose-producing and their cellulose-deficient derivatives, were used. One strain pair produced colanic acid in addition to cellulose. Spinach and lettuce with attached cells were treated with chlorinated water (50 and 150 ppm of free chlorine). The production of the extracellular polymers by the planktonic cells had small, but significant, effects on the survival of the attached pathogen when subjected to chlorine treatment. On the lettuce surface, the colanic acid-producing, cellulose-negative mutant (49d) was most susceptible to the treatment, declining significantly (P < 0.05) in population by 0.9 and 1.4 log units after treatment with 50 and 150 ppm of chlorine, respectively. Chlorine treatment reduced populations of cellulose-deficient cells on the intact spinach surface 1.2 log units more than the wild type when treated with 150 ppm of chlorine (P < 0.05). However, populations of cellulose-producing cells were reduced by 1.5 log units more than their mutant counterparts when the cells also produced colanic acid (P < 0.05). A greater proportion of cells attached to the spinach leaf edge were injured by chlorine treatment compared with attached to the leaf surface. These results indicate that extracellular polymers do not generally increase the ability of STEC to survive chlorine treatment and that any effects on survival are influenced by location of attachment, type of leafy green, and concentration of chlorine.

Organic matter-clay interaction along a seawater column of the Eastern Pacific upwelling system (Antofagasta bay, Chile): Implications for source rock organic matter preservation

Natural Organic Matter (OM) preservation and sedimentary burial mechanisms are still poorly understood despite their importance in oil source rock characterization and carbon cycle issues. It is now recognized that mineral sorption contributes significantly to OM preservation by conferring steric protection and preventing enzymatic access. Most of the studies dealing with OM preservation have focused on settled OM, omitting aggregation in the water column. For the first time, we have tested the complexation of natural OM on 3 types of clays in seawater in-situ conditions. Samples of Na exchanged montmorillonite (Na MMt), synthetic montmorillonite (S Na MMt) and natural kaolinite (Kaol) were immersed in an upwelling zone (Antofagasta bay, Chile). Three depths were studied: 15m (photic zone), 40m (oxygen transition zone) and 80m (anoxic zone). The clayey samples were kept immersed for different durations and analyzed after removal, via GC/MS, Py-GC/MS, flash elementary pyrolysis, DOC analyzer and XRD. The main results are: (1) for the shortest immersion times, DOC analyzes performed on clays' proximal water indicated excessive DOC concentrations compared to seawater values. This attraction effect was however temporary, as values tended to rebalance with seawater concentrations for the longest immersion times. (2) Molecular analyses performed on seawater organic extracts indicated that fatty acids, alkanes, alkyl benzenes and methoxy-benzenes were the main dissolved lipid groups. (3) These lipids were also the main sorbed compounds identified on immersed clays, with a predominance of fatty acids. This is due to the higher availability and better affinity of fatty acids with the clayey samples. (4) Because of its higher specific area and CEC, Na MMt exhibited the best sorption rates compared to Kaol and SNa MMt. X ray analyses performed on Na MMt indicated d001spacing growths, but these growths are not attributed to OM intercalation. Sorbed OM is probably located on the external surfaces leaf edges of clays.

Single step direct transgenic plant regeneration from adventive embryos of agro-infected sugarcane (Saccharum spp.) spindle leaf roll segments with assured genetic fidelity

Single step direct transgenic plant regeneration from agro-infected sugarcane (Saccharum spp.) spindle leaf roll segments with assured genetic fidelity is reported. The pre-cultured (96 h) leaf segments of cultivar CoJ 83 were incubated (10 min) with intermittent shaking in Agrobacterium suspension (OD 1.0–1.2) carrying antifungal gene encoding β-1,3-glucanase under the control of CaMV 35S promoter and NOS terminator, in presence of acetosyringone. Thereafter, the segments were co-cultivated (72 h) and transferred for shoot regeneration. The scanning electron micrographs of sectioned leaf segments undergoing in vitro shoot regeneration revealed occurrence of globular structures in clusters near cut leaf edges within 10 days of incubation. In each cluster, two to ten structures of varying sizes occurred concurrently. The sectioning of globular structures confirmed that these were arising directly from pre-embryogenic determined palisade cells, had unicellular origin and were referred to as adventive embryos. The adventive embryos successively expressed their potential for direct shoot regeneration without callus interphase in 3 weeks and transgenic plant formation within a short period of 8 weeks. The integration of β-1,3-glucanase transgene and its expression in T0 plants were determined by reverse transcription-PCR and quantitative real time-PCR, respectively. Simple sequence repeat DNA markers did not detect any polymorphism in the transgenic plants, pointing towards assured genetic fidelity of the plants.

功能性核磁成像技术在脊髓型颈椎病患者中应用及其临床意义

目的：探究功能性核磁成像技术在脊髓型颈椎病患者中应用及其临床意义。方法：选择2014年1月至2014年6月我院骨科收治的脊髓型颈椎病患者为观察对象，选择同期10例健康志愿者为对照组对象。在术前、术后6周、3月及其6月分别进行一次fMRI脑功能成像并根据日本骨科学会评分系统(JOA scores)对术后恢复情况进行评估。对照组对象同期行脑fMRI功能成像。比较两组不同时间点脑fMRI功能成像、JOA 评分和术后恢复(步长，动作完成时间)。结果：对照组健康对象在完成指定动作时，在对侧脑部主要运动区都有局部有限的皮质激活区域。脊髓型颈椎病患者fMRI图像表明激活的皮质映射区域与健康对照组相比有所扩大。脊髓减压术后皮质激活映射区有所缩小并接近健康组激活区域范围。与对照组比较，枕叶、额叶及其边缘系统是观察组患者ReHo显著降低的脑区；小脑及其边缘叶是观察组ReHo显著升高的脑区。JOA评分和术后恢复观察组患者明显(P < 0.05)。结论：fMRI可作为脊髓型颈椎病患者术前和术后皮质投射区变化的有效评定方法，通过此FMRI的评估可以有效的进行患者术后评估和术后恢复指导。 Objective: To explore the functional magnetic resonance imaging application and its clinical significance in the spondylotic myelopathy. Methods: 10 cases spondylotic myelopathy patients treated in the orthopaedic department of our hospital from January 2014 to June 2014 were selected as the observation objects, and 10 cases healthy volunteers were selected as the control objects in the same period. Functional magnetic resonance imaging and the Japanese orthopaedic society of scoring system (JOA scores) evaluating the postoperative recovery were measured in the preoperative and postoperative 6 weeks, 3 months and 6 months, respectively. The control objects in the same period were measured by functional magnetic resonance imaging. Functional magnetic resonance imaging and JOA score and postoperative recovery (time step, action) were compared between two groups at different time points. Results: The limited areas of the cortex were activated at main motor areas on the side of the brain after completing the action in the control objects. Activation of cortical map area in functional magnetic resonance imaging of the spondylotic myelopathy patients widened compared with the healthy controls. Cortical activation mapping area reduced activation area and close to the healthy group after the spinal cord decompression. Compared with the control group, the occipital lobe, the frontal lobe and the limbic system were the areas of the brain that ReHo of the observation group patients significantly reduced. The cerebellum and the edge of leaf were the areas of the brain that ReHo of the observation group patients significantly increased. The JOA score and post-operation of the observation group are more significant than those of the control group (P < 0.05). Conclusion: Functional magnetic resonance imaging can be effective evaluation methods for the preoperative and postoperative cortical projection area changes in the spondylotic myelopathy patients’ cerebral cortex. We can evaluate the postoperative recovery and give positive postoperative rehabilitation guidance effectively with the functional magnetic resonance imaging assessment.

チャノホソガ（チョウ目：ホソガ科）の異なる発育ステージに対する各種薬剤の効果

The effects of 28 insecticides of 11 types on different life stages of the tea leaf roller, Caloptilia theivora（Walsingham）were investigated in our laboratory. The following life stages were examined: egg stage, early leaf-mining stage, late leaf-mining stage, and leaf edge rolling stage. We compared the effects of the different insecticides and examined which life stages were most sensitive to each agent. Insect growth regulators（IGR）were found to be highly effective from the egg stage to the early leaf-mining stage. Neonicotinoid was highly effective in inhibiting egg hatching. Pyrethroid•pyrethrin, avermectin, spinosyn, nereistoxin, and diamide were all highly effective against all of the life stages tested. Application of BT and some IGRs during leaf edge rolling allowed the creation of triangular-shaped leaves, however, it killed the larvae in these leaves, reducing the excretion of the larval feces that is responsible for discoloration of green tea extracts. Organophosphate and METI were comparatively less effective against all of the life stages tested. These results revealed the importance of considering life stage when selecting insecticides for control of the tea leaf roller.

Host Phenology and Leaf Effects on Susceptibility of California Bay Laurel to Phytophthora ramorum.

Spread of the plant pathogen Phytophthora ramorum, causal agent of the forest disease sudden oak death, is driven by a few competent hosts that support spore production from foliar lesions. The relationship between traits of a principal foliar host, California bay laurel (Umbellularia californica), and susceptibility to P. ramorum infection were investigated with multiple P. ramorum isolates and leaves collected from multiple trees in leaf-droplet assays. We examined whether susceptibility varies with season, leaf age, or inoculum position. Bay laurel susceptibility was highest during spring and summer and lowest in winter. Older leaves (>1 year) were more susceptible than younger ones (8 to 11 months). Susceptibility was greater at leaf tips and edges than the middle of the leaf. Leaf surfaces wiped with 70% ethanol were more susceptible to P. ramorum infection than untreated leaf surfaces. Our results indicate that seasonal changes in susceptibility of U. californica significantly influence P. ramorum infection levels. Thus, in addition to environmental variables such as temperature and moisture, variability in host plant susceptibility contributes to disease establishment of P. ramorum.

Graphs with multiplicative vertex-coloring 2-edge-weightings

A k-weighting w of a graph is an assignment of an integer weight w(e)in {1,...k} to each edge e. Such an edge weighting induces a vertex coloring c defined by c(v)=mathop {displaystyle {prod }}limits _{vin e}w(e). A k-weighting of a graph G is multiplicative vertex-coloring if the induced coloring c is proper, i.e., c(u)ne c(v) for any edge uvin E(G). This paper studies the parameter mu (G), which is the minimum k for which G has a multiplicative vertex-coloring k-weighting. Chang, Lu, Wu, Yu investigated graphs with additive vertex-coloring 2-weightings (they considered sums instead of products of incident edge weights). In particular, they proved that 3-connected bipartite graphs, bipartite graphs with the minimum degree 1, and r-regular bipartite graphs with rge 3 permit an additive vertex-coloring 2-weighting. In this paper, the multiplicative version of the problem is considered. It was shown in Skowronek-Kaziów (Inf Process Lett 112:191–194, 2012) that mu (G)le 4 for every graph G. It was also proved that every 3-colorable graph admits a multiplicative vertex-coloring 3 -weighting. A natural problem to consider is whether every 2-colorable graph (i.e., a bipartite graph) has a multiplicative vertex-coloring 2-weighting. But the answer is no, since the cycle C_{6} and the path P_{6} do not admit a multiplicative vertex-coloring 2-weighting. The paper presents several classes of 2-colorable graphs for which mu (G)=2, including trees with at least two adjacent leaf edges, bipartite graphs with the minimum degree 3 and bipartite graphs G=(A,B,E) with even left| Aright| or left| Bright| .

Euclidean Networks with a Backbone and a Limit Theorem for Minimum Spanning Caterpillars

A caterpillar network (or graph) G is a tree with the property that removal of the leaf edges of G leaves one with a path. Here we focus on minimum weight spanning caterpillars where the vertices are points in the Euclidean plane and the costs of the path edges and the leaf edges are multiples of their corresponding Euclidean lengths. The flexibility in choosing the weight for path edges versus the weight for leaf edges gives some useful flexibility in modeling. In particular, one can accommodate problems motivated by communications theory such as the “last mile problem.” Geometric and probabilistic inequalities are developed that lead to a limit theorem that is analogous to the well-known Beardwood, Halton, and Hammersley theorem for the length of the shortest tour through a random sample, but the minimal spanning caterpillars fall outside the scope of the theory of subadditive Euclidean functionals.

Exploiting affine invariant regions and leaf edge shapes for weed detection

In this article, local features extracted from field images are evaluated for weed detection. Several scale and affine invariant detectors from computer vision literature along with high performance descriptors were applied. Field dataset contained a total of 474 plant images of sugar beet and creeping thistle, divided into six groups based on illumination, age, and camera to plant distance. To establish a performance baseline, leaf image retrieval potential of the selected features was first assessed on a publicly available leaf database containing flatbed scanned images of 15 tree species. Then a comparison with the field data retrieval highlighted the trade-off due to the field challenges. Adopting a comprehensive approach, edge shape detectors and homogeneous surface detecting affine invariant regions were fused. In order to integrate vegetation indices as local features, a new local vegetation color descriptor was introduced which used various combinations of color indices and offered a very high precision. Retrieval in the field data was evaluated group-wise. Although, the impact of the sunlight was found to be very low on shape features, but relatively higher precisions were obtained for younger plants under a shade (overall more than 80%). The weed detection accuracy was assessed using the Bag-of-Visual-Word scheme with KNN and SVM classifiers. The assessment showed that with an SVM classifier, a fusion of surface color and edge shapes boosted the overall classification accuracy to as high as 99.07% with a very low false negative rate (2%).

Silk Gland Gene Expression during Larval-Pupal Transition in the Cotton Leaf Roller Sylepta derogata (Lepidoptera: Pyralidae).

The cotton leaf roller, Sylepta derogata, is a silk-producing insect pest. While young larvae feed on the underside of leaves, the older ones roll cotton leaves and feed on the leaf edges, which defoliates cotton plants. The larvae produce silk to stabilize the rolled leaf and to balloon from used to new leaves. Despite the significance of silk in the biology of pest insect species, there is virtually no information on the genes involved in their silk production. This is a substantial knowledge gap because some of these genes may be valuable targets for developing molecular pest management technologies. We addressed the gap by posing the hypothesis that silk gland gene expression changes during the transition from larvae to pupae. We tested our hypothesis using RNA-seq to investigate changes in silk gland gene expression at three developmental stages, 5th instar larvae (silk producing; 15,445,926 clean reads), prepupae (reduced silk producing; 13,758,154) and pupae (beyond silk producing; 16,787,792). We recorded 60,298 unigenes and mapped 50,158 (larvae), 48,415 (prepupae) and 46,623 (pupae) of them to the NCBI database. Most differentially expressed genes in the 5th instar larvae/prepupae libraries were relevant to nucleotide synthesis and maintenance of silk gland function. We identified down-regulated transcriptional factors and several genes involved in silk formation in the three libraries and verified the expression pattern of eight genes by qPCR. The developmental- and tissue-specific expression patterns of the fibroin light chain gene showed it was highly expressed during the larval silk-producing stage. We recorded highest expression of this gene in the larval silk gland, compared to other tissues, including midgut, hindgut, epidermis, Malpighian tubes, hemolymph and fat body. These data are a genetic resource to guide selection of key genes that may be targeted for in planta and other gene-silencing technologies for sustainable cotton agriculture.

Microsatellite mapping of the mutant gene conferring interrupted development of leaf blade in Triticum aestivum L.

The growth of the leaf blade is one of the limiting factors of the life cycle of a plant. The leaf elongation rate in early plant growth stages is important for plant establishment. The rlb (reduction of leaf blade) mutation in Triticum aestivum L. (2n = 6x = 42, BBAADD genome) caused a severe interruption of leaf blade development, a reduction of spike length and spikelet number, and decreased plant height. The heterozygous plants of the hybrid ‘ANK-31’ (rlb near-isogenic line of T. aestivum ‘Novosibirskaya 67’)/Novosibirskaya 67 was used to conserve the rlb trait, since the heterozygous plants were fertile and were characterized by incisions on the leaf edge. The F2 of ANK-31/T. aestivum ‘Chinese Spring’ segregated 559 normal leaf: 162 reduction of leaf blade, fitting a 3:1 ratio. This results confirmed that the recessive allele at a single locus controlled the rlb phenotype. Using microsatellite probes, the rlb gene was mapped between Xgwm133 and Xgwm582 in chromosome arm 6DL. We discussed possible use of ANK-31 to find the negative determinants of leaf development.

Morphoanatomic characterization of the stem and the leaf of Tabernaemontana catharinensis A.DC (Apocynaceae) and antimutagenic activity of its leaves

ABSTRACT Tabernaemontana catharinensis A. DC (Apocynaceae) is used as a medicinal plant by the population. In order to contribute to the safe use of the plant as herbal medicine, this study aimed to morphoanatomically characterize the aereal vegetative organs of T. catharinensis and to evaluate the leaves’ mutagenic and antimutagenic activities. Histological blades of leaves and stem of T. catharinensis were performed; the methionine system (methG1) and Aspergillusnidulans conidia germination analysis were employed for mutagenic and antimutagenic evaluation. The morphoanatomic analysis did not show trichomes in the stem, petiole and leaf. Besides, it was observed both the presence of bi-collateral bundles - except in the foliar apex where the bundles were from the collateral type - as well as anamphistomatic leaf with paracyte stomata and sub-epidermal layer in the region of the leaf edges. The mutagenicity/antimutagenicity trial indicated a significant decrease of mutation frequency in comparison with the control group and showed that the T. catharinensis had antimutagenic activity within the type, time and form of treatment. Since the germination test showed that the conidia germination was accelerated from the bud phase, activities at the cell cycle level and polarized growth proved to be possible. The morphoanatomic analysis of the leaf and stem associated with the mutagenic and antimutagenic analyses contributes to the safe use of the plant by humans and also for the quality control of a possible phytotherapeutic drug.

Optimization of the rounded leaf offset table in modeling the multileaf collimator leaf edge in a commercial treatment planning system.

An editable rounded leaf offset (RLO) table is provided in the Pinnacle3 treatment planning software. Default tables are provided for major linear accelerator manufacturers, but it is not clear how the default table values should be adjusted by the user to optimize agreement between the calculated leaf tip value and the actual measured value. Since we wish for the calculated MLC‐defined field edge to closely match the actual delivered field edge, optimal RLO table values are crucial. This is especially true for IMRT fields containing a large number of segments, since any errors would add together. A method based on the calculated MLC‐defined field edge was developed for optimizing and modifying the default RLO table values. Modified RLO tables were developed and evaluated for both dosimetric and light field‐based MLC leaf calibrations. It was shown, using a Picket Fence type test, that the optimized RLO table better modeled the calculated leaf tip than the Pinnacle3 default table. This was demonstrated for both an Elekta Synergy 80‐leaf and a Varian 120‐leaf MLC.PACS numbers: 87.55.D‐, 87.55.de, 87.55.Qr

BraLTP1, a lipid transfer protein gene involved in epicuticular wax deposition, cell proliferation and flower development in Brassica napus.

Plant non-specific lipid transfer proteins (nsLTPs) constitute large multigene families that possess complex physiological functions, many of which remain unclear. This study isolated and characterized the function of a lipid transfer protein gene, BraLTP1 from Brassica rapa, in the important oilseed crops Brassica napus. BraLTP1 encodes a predicted secretory protein, in the little known VI Class of nsLTP families. Overexpression of BnaLTP1 in B. napus caused abnormal green coloration and reduced wax deposition on leaves and detailed wax analysis revealed 17–80% reduction in various major wax components, which resulted in significant water-loss relative to wild type. BnaLTP1 overexpressing leaves exhibited morphological disfiguration and abaxially curled leaf edges, and leaf cross-sections revealed cell overproliferation that was correlated to increased cytokinin levels (tZ, tZR, iP, and iPR) in leaves and high expression of the cytokinin biosynthsis gene IPT3. BnaLTP1-overexpressing plants also displayed morphological disfiguration of flowers, with early-onset and elongated carpel development and outwardly curled stamen. This was consistent with altered expression of a a number of ABC model genes related to flower development. Together, these results suggest that BraLTP1 is a new nsLTP gene involved in wax production or deposition, with additional direct or indirect effects on cell division and flower development.

Construction of Hevea brasiliensis Genetic Linkage Map and Identification of Quantitative Trait Loci Using RAPD Markers

Rubber breeding program so far have constraints especially in selection process which need very wide area and very long time. The use molecular markers in breeding program could simplify the selection procedure. The objectives of research were to get the linkage map especially for PB 260 as female parent, and to get RAPD markers and morphology markers which associated with QTL controlling production component. Construction of genetic linkage map on rubber tree (2n=36) was conducted by using RAPD markers data through pseudo-testcross. First generation progenies of crossing between PB 260 and PN were used as mapping populations: 22 progenies of A population (PB 260 x PN 7111), 20 progenies of C population (PB 260 x PN7). Construction of linkage map was conducted using MAPMAKER/EXP 3.0. Linkage map of PB 260 was constructed on LOD 3.0 yielded 1 linkage group, on LOD 2.5 yielded 2 linkage group. Based on single marker analysis through t-test was known that marker C13-2000 linked with yield character and number of latex vessel character. Character of leaf shape linked with girth, bark thickness, and number of latex vessel. Character of leaf edge linked with plugging index.