Optimización de la regeneración in vitro del olmo utilizando explantes de hoja y evaluación del proceso en experimentos de transformación

We set up a regeneration process for the elm hybrid ‘Sapporo’ resistant to Dutch Elm Disease, using leaf discs from in vitro grown plants and tested it in transformation experiments. Two steps were needed : bud induction (3 weeks) followed by bud elongation (4 weeks). Bud meristems initiated near the cut ribs, from several tissues (phloem, procambium, rib upper parenchyma) except epidermis. Regeneration depended on the use of agarose (6 g/l LSM) and diluted MS medium (1/2). The best results (11-14 buds/explant) were obtained in presence of 0.1 μM TDZ and 0.06 μM IAA and when maltose (55-110 mM) or sorbitol (110 mM) were used as carbohydrate sources. During shoot elongation TDZ should be decreased to 0.01 μM or replaced by 1-2 μM BAP and 1.4 μM of GA3 added. At this stage, a mixture of 55 mM sorbitol and 27.5 mM maltose was required. Up to 7 shoots / explant developed and were easily rooted (96%) and acclimatized when sorbitol (27.5 mM) and active charcoal (2 g/l) were added to the rooting medium. Transformation experiments were performed with Agrobacterium tumefaciens disarmed strain GV3101-pMP90 (pKyGUSintron). Regeneration zones exhibited stable GUS expression. However, all shoots grown in vitro died on a selective rooting medium (50 mg/l kanamycin). When attempts for in vitro selection were made (12.5 mg/l kanamycin), some buds were initiated but elongation was prevented. Susceptibility to neomycin seemed very high, therefore, selection markers and selection steps must be revised carefully.Se ha desarrollado un procedimiento para la regeneración del olmo híbrido «Sapporo» resistente a la grafiosis mediante el uso de discos foliares procedentes de plantas cultivadas in vitro y examinadas en ensayos de transformación. Para ello se requirieron dos pasos: inducción de las yemas (3 semanas), seguido de la elongación de las yemas (4 semanas). Los meristemas que dieron origen a las yemas se formaron en la cercanía de las costillas de corte a partir de diversos tejidos (floema, procámbium, parénquima) excepto la epidermis. La regeneración dependió del uso de agarosa (6 g/l LSM) y de medio MS diluido (1/2). Los mejores resultados (11-14 yemas por explante) se obtuvieron en presencia de 0,1 μM de TDZ y 0,06 μM de IAA y cuando la maltosa (55-110 mM) o el sorbitol (110 mM) se usaron como fuente de carbohidratos. Durante la elongación del tallo, el TDZ hubo de ser disminuido a 0,01 μM o sustituido por 1-2 μM de BAP y 1,4 μM de GA3. En esta fase fue necesaria una mezcla de 55 mM de sorbitol y 27,5 mM de maltosa. Se desarrollaron al menos 7 tallos por explante que fácilmente enraizaron (96%) y se aclimataron cuando se añadió sorbitol (27,5 mM) y carbón activo (2 g/l) al medio de enraizamiento. Los ensayos de transformación se desarrollaron con las cepas GV3101-pMP90 (pKyGUSintron) de Agrobacterium tumefaciens. Las zonas de regeneración presentaron una expresión GUS estable. No obstante, todas las yemas cultivadas in vitro murieron en un medio selectivo de enraizamiento (50 mg/l de kanamicina). Cuando se intentó la selección in vitro (12,5 mg/l de kanamicina), algunas yemas se iniciaron pero la elongación fue impedida. La susceptibilidad a la neomicina parece ser muy alta, por lo que los marcadores y los pasos de selección deben ser cuidadosamente revisados

DETECTING CLASSIFIER-COAL MILL DAMAGE USING A SIGNAL VIBRATION ANALYSIS

A classifier plays a crucial role in the cement industry. It is in charge of separating coal that has been smoothened out and is ready to be burned although the coal is still rough after going through the grinding process. It takes a long time to burn coal that is not perfectly processed with a classifier. Therefore, it will reduce the amount of cement production, and the factories will release more energy. The closed arrangement and the number of components in the unit classifier requires a sophisticated method to detect damage that occurs early. Vibration analysis is a method that has been effectively employed in detecting the initial damage that occurs to the engine, especially the classifier. This study was aimed at detecting the location of the damage occurring in the classifier by using a vibration signal analysis and by measuring the magnitude of vibration and presenting it to the frequency domain (spectrum) form using Fast Fourier Transform. Engine condition assessment referred to ISO 10816-3 standard in velocity and displacement modes. Based on data spectrum analysis, the dominant damage laid in the unbalanced rotor. Spectrum characteristics of the damage appeared to be in the spectrum line worth 438.01 μm at a 3.5-Hz frequency (1X) radially. This analysis proved to be supported by the decrease in vibration value to 18.65 μm after balancing the Classifier rotor

Effect of GA 3 and paclobutrazol on adventitious shoot regeneration of two Pelargonium sp

This study had two aims. The first was to improve the regeneration efficiency of Pelargonium leaf discs by adventitious budding. The second was to test the effect of gibberellic acid (GA 3) and paclobutrazol (PBZ) on callus formation and adventitious shoot regeneration in Pelargonium before using genetic transformation of this species for functional validation of genes involved in the process of GA regulation. GA 3 and paclobutrazol (an inhibitor of GA synthesis pathway) were added (together or separately) in the shoot regeneration media of two Pelargonium species, Pelargonium * hortorum \u27Panache sud\u27 (\u27P.sud\u27) and Pelargonium * domesticum \u27Autumn haze\u27 (\u27 P.dom\u27). In both cases, GA 3 applied alone, completely inhibited the bud regeneration. Moreover, the rate of callus formation decreased drastically when 5 M of GA 3 was applied to \u27 P. dom\u27 explants. Similar result was obtained with \u27P.sud\u27 explants using 20 M GA 3. Paclobutrazol (0.3 M) applied at the same time as GA 3 (10 M) could partially restore regeneration process of \u27 P. dom\u27. For \u27 P. dom\u27, the use of paclobutrazol alone increased callus formation and slightly improved the rate of regeneration. Moreover, initiated buds had a better appearance. For \u27P. sud\u27, which had an abundant callusing, paclobutrazol did not improve regeneration and led to hyperhydric shoots

The Deglaciation of Maine, USA

The glacial geology of Maine records the northward recession of the Late Wisconsinan Laurentide Ice Sheet, followed by development of a residual ice cap in the Maine-Québec border region due to marine transgression of the St. Lawrence Lowland in Canada. The pattern of deglaciation across southern Maine has been reconstructed from numerous end moraines, deltas and submarine fans deposited during marine transgression of the coastal lowland. Inland from the marine limit, a less-detailed sequence of deglaciation is recorded by striation patterns, meltwater channels, scattered moraines and waterlain deposits that constrain the trend of the ice margin. There is no evidence that the northern Maine ice cap extended as far south-west as the Boundary Mountains and New Hampshire border. Newly-obtained radiocarbon ages from marine and terrestrial ice-proximal environments have improved the chronology of glacial recession in Maine. Many of these ages were obtained by coring late-glacial sediments beneath ponds and lakes. Data from this study show that the state was deglaciated between about 14.5 and 11.0 ka BP (14C years). The coastal moraine belt in southern Maine was deposited by oscillatory ice-margin retreat during the cold pre-Bølling time. Rapid ice recession to northern Maine then occurred between 13 and 11 ka BP, during the warmer Bølling/Allerød chronozones. Radiocarbon-dated pond sediments in western and northern Maine show lithologic evidence of Younger Dryas climatic cooling and persistence of the northern ice cap into Younger Dryas time. A large discrepancy still exists between radiocarbon ages of deglaciation in coastal south-western Maine and the timing of ice retreat indicated by New England varve records in areas to the west. Part of this problem may stem from the uncertainty of reservoir corrections applied to the radiocarbon ages of marine organics

Overexpression of RoDELLA impacts the height, branching, and flowering behaviour of Pelargonium × domesticum transgenic plants

Key message We reported the cloning of a rose DELLA gene. We obtained transgenic Pelargonium lines overexpressing this gene which presented several phenotypes in plant growth, root growth, flowering time and number of inflorescences. Abstract Control of development is an important issue for production of ornamental plant. The plant growth regulator, gibberellins (GAs), plays a pivotal role in regulating plant growth and development. DELLA proteins are nuclear negative regulator of GA signalling. Our objective was to study the role of GA in the plant architecture and in the blooming of ornamentals. We cloned a rose DELLA homologous gene, RoDELLA, and studied its function by genetic transformation of pelargonium. Several transgenic pelargonium (Pelargonium × domesticum ‘Autum Haze’) lines were produced that ectopically expressed RoDELLA under the control of the 35S promoter. These transgenic plants exhibited a range of phenotypes which could be related to the reduction in GA response. Most of transgenic plants showed reduced growth associated to an increase of the node and branch number. Moreover, overexpression of RoDELLA blocked or delayed flowering in transgenic pelargonium and exhibited defects in the root formation. We demonstrated that pelargonium could be used to validate ornamental gene as the rose DELLA gene. RoDELLA overexpression modified many aspects of plant developmental pathways, as the plant growth, the transition of vegetative to floral stage and the ability of rooting

Segmentation of corpus callosum using diffusion tensor imaging: validation in patients with glioblastoma

Abstract Background This paper presents a three-dimensional (3D) method for segmenting corpus callosum in normal subjects and brain cancer patients with glioblastoma. Methods Nineteen patients with histologically confirmed treatment naïve glioblastoma and eleven normal control subjects underwent DTI on a 3T scanner. Based on the information inherent in diffusion tensors, a similarity measure was proposed and used in the proposed algorithm. In this algorithm, diffusion pattern of corpus callosum was used as prior information. Subsequently, corpus callosum was automatically divided into Witelson subdivisions. We simulated the potential rotation of corpus callosum under tumor pressure and studied the reproducibility of the proposed segmentation method in such cases. Results Dice coefficients, estimated to compare automatic and manual segmentation results for Witelson subdivisions, ranged from 94% to 98% for control subjects and from 81% to 95% for tumor patients, illustrating closeness of automatic and manual segmentations. Studying the effect of corpus callosum rotation by different Euler angles showed that although segmentation results were more sensitive to azimuth and elevation than skew, rotations caused by brain tumors do not have major effects on the segmentation results. Conclusions The proposed method and similarity measure segment corpus callosum by propagating a hyper-surface inside the structure (resulting in high sensitivity), without penetrating into neighboring fiber bundles (resulting in high specificity)

Mutation analysis of the Fanconi anaemia A gene in breast tumours with loss of heterozygosity at 16q24.3

The recently identified Fanconi anaemia A (FAA) gene is located on chromosomal band 16q24.3 within a region that has been frequently reported to show loss of heterozygosity (LOH) in breast cancer. FAA mutation analysis of 19 breast tumours with specific LOH at 16q24.3 was performed. Single-stranded conformational polymorphism (SSCP) analysis on cDNA and genomic DNA, and Southern blotting failed to identify any tumour-specific mutations. Five polymorphisms were identified, but frequencies of occurrence did not deviate from those in a normal control population. Therefore, the FAA gene is not the gene targeted by LOH at 16q24.3 in breast cancer. Another tumour suppressor gene in this chromosomal region remains to be identified. © 1999 Cancer Research Campaig

Topography of the Chimpanzee Corpus Callosum

The corpus callosum (CC) is the largest commissural white matter tract in mammalian brains, connecting homotopic and heterotopic regions of the cerebral cortex. Knowledge of the distribution of callosal fibers projecting into specific cortical regions has important implications for understanding the evolution of lateralized structures and functions of the cerebral cortex. No comparisons of CC topography in humans and great apes have yet been conducted. We investigated the topography of the CC in 21 chimpanzees using high-resolution magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). Tractography was conducted based on fiber assignment by continuous tracking (FACT) algorithm. We expected chimpanzees to display topographical organization similar to humans, especially concerning projections into the frontal cortical regions. Similar to recent studies in humans, tractography identified five clusters of CC fibers projecting into defined cortical regions: prefrontal; premotor and supplementary motor; motor; sensory; parietal, temporal and occipital. Significant differences in fractional anisotropy (FA) were found in callosal regions, with highest FA values in regions projecting to higher-association areas of posterior cortical (including parietal, temporal and occipital cortices) and prefrontal cortical regions (p<0.001). The lowest FA values were seen in regions projecting into motor and sensory cortical areas. Our results indicate chimpanzees display similar topography of the CC as humans, in terms of distribution of callosal projections and microstructure of fibers as determined by anisotropy measures