29 research outputs found

    The Role of Bio-productivity on Bio-energy Yields

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    The principal photosynthetic pathways convert solar energy differently depending on the environmental conditions and the plant morphotype. Partitioning of energy storage within crops will vary according to environmental and seasonal conditions as well. Highest energy concentration is found in terpens like latex and, to a lesser extent, in lipids. Ideally, we want plant ingredients with high energy content easily amenable to ready-to-use bio-fuel. Generally, these crops are adapted to drier areas and tend to save on eco-volume space. Competition with food crops could be avoided by fetching energy from cheap agricultural by-products or waste products such as bagasse in the sugar cane. This would in fact mean that reducing power of agricultural residues should be extracted from the biomass through non-photosynthetic processes like animal ingestion or industrial bio-fermentation. Conversion and transformation efficiencies in the production chain are illustrated for some relevant crops in the light of the maximum power theorem

    Reception Test of Petals for the End Cap TEC+ of the CMS Silicon Strip Tracker

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    The silicon strip tracker of the CMS experiment has been completed and was inserted into the CMS detector in late 2007. The largest sub system of the tracker are its end caps, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted onto the TEC support structures. Each end cap consists of 144 such petals, which were built and fully qualified by several institutes across Europe. Fro

    Integration of the End Cap TEC+ of the CMS Silicon Strip Tracker

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    The silicon strip tracker of the CMS experiment has been completed and inserted into the CMS detector in late 2007. The largest sub-system of the tracker is its end cap system, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted into the TEC support structures. Each end cap consists of 144 petals, and the insertion of these petals into the end cap structure is referred to as TEC integration. The two end caps were integrated independently in Aachen (TEC+) and at CERN (TEC--). This note deals with the integration of TEC+, describing procedures for end cap integration and for quality control during testing of integrated sections of the end cap and presenting results from the testing

    Establishing an efficient explant superficial sterilization protocol for in vitro micropropagation of bear’s garlic (Allium ursinum L.)

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    Introduction:Allium ursinum L. has a commercial value due to its high contents of bio-active compounds and mild, garlic-like taste. In vitro culture played an important role in obtaining Allium species with the desired characteristics and in the production of healthy reproductive material

    Nutritional and Sensory Quality of Two Types of Cress Microgreens Depending on the Mineral Nutrition

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    The present study addressed the combination of nutritional and sensory quality assessment of radish and garden cress as microgreens cultivated in different amounts of mineral nutrients under conditions that can be realized in a private household. The content of value adding compounds was determined by means of chemical analyses. Total flavor impression and visual appearance were rated by untrained consumer tests. In cotyledons of radish cress (Raphanus sativus L.), carotenoid, total phenols, nitrate contents, and antioxidant capacity decreased significantly with decreasing mineral content in the nutrient solution, whereas, in stems, total phenols and anthocyanin contents rose and nitrate content decreased significantly with decreasing mineral content. In garden cress (Lepidium sativum L.), carotenoid and nitrate contents decreased and anthocyanin content increased significantly with decreasing mineral content, indicating that the response of value adding compounds to changing amounts of minerals in the nutrient solution depends on the compound of interest, plant species, and even the plant organ of a species. The sensory quality of the studied microgreens was generally rated highest when mineral content in the nutrient solution was highest, indicating that sensory quality is not necessarily identical with nutritional quality. Considering the common practice in private households, cultivation with tap water represents an attractive compromise for nutritional and sensory quality in case of garden cress, whereas, for radish cress, the application of 25% modified Hoagland solution is recommended

    The Influence of Phytohormones on the Efficiency of Callus Formation, Its Morphologically Properties and Content of Bioactive Compounds in In Vitro Cultures of <i>Daucus carota</i> L.

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    The significance of cultivar colour (orange and yellow), the application of MgO during field cultivation and chosen phytohormones in the callus cultivation medium are investigated in the present study, with respect to the antioxidative properties of the obtained callus. Callus cultivation are examined as an alternative method for the production of plant antioxidant compounds. Cultivar choice was most significant for callus production and the synthesis of health-promoting metabolites. The best combination, with respect to the induction efficacy and antioxidant properties measured as a synthetic value by Multidimensional Comparative Analysis (MCA), was found in the callus of cultivar ‘Flacoro’, cultivated without MgO fertilization and on a medium with kinetin (KIN) and 1-naphthaleneacetic acid (NAA) (MCA-value 0.465). The worst performance was found for cultivar ‘Yello Mello’, independent of the applied phythormones (averaged MCA-value 0.839) and for the cultivar ‘Flacoro’ fertilized with MgO and independent of growth hormones (averaged MCA-value 0.810)

    <i>Pseudomonas syringae</i> Infection Modifies Chlorophyll Fluorescence in <i>Nicotiana tabacum</i>

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    The system Nicotiana tabacum L.—Pseudomonas syringae VAN HALL pv. tomato (Pto) DC3000 was investigated at a low inoculation level (c. 5 × 105 colony-forming units (CFU) mL–1) such as it occurs in the field. The aim of this study was to test the hypothesis that N. tabacum, a non-host of Pto DC3000, improved the PSII efficiency in inoculated leaves compared with control detached leaves. Visible symptoms at the infected area were not detected within 14 days. Chlorophyll (Chl) a fluorescence was measured 6–7 days after inoculation of detached leaves. Compared with the control, the actual photochemical quantum yield of photosystem (PS) II was higher in the inoculated leaves at the expense of the fraction of heat dissipated by photo-inactivated non-functional centers. In addition, the fraction of open PSII reaction centers (RCs) was higher in inoculated leaves. Maximum fluorescence in the dark-adapted detached inoculated leaves, as a measure of the absorbed energy, was lower than in control leaves. The lower capacity to absorb energy in combination with a higher fraction of open PSII RCs is interpreted as an acclimation to limit over-excitation and to reduce heat dissipation. This should limit the production of reactive oxygen species and reduce the probability of a hypersensitive response (HR), which represents an expensive cell-death program for the plant

    Chlorophyll Fluorescence as a Tool to Assess the Regeneration Potential of African Violet Leaf Explants

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    Micropropagation of many ornamentals has enabled their efficient commercialisation and many problems have been solved by the elaboration of adequate culture protocols. Nevertheless, a non-destructive technique for monitoring the developmental progress of explants would be desirable. The present study focussed on the applicability of chlorophyll fluorescence in leaf explants of African violet (a Saintpaulia ionantha × confusa – hybrid) explanted onto Murashige and Skoog basic medium. The explants that survived on the medium without additional phytohormones had the capacity to develop further into two different kinds of explants: light green explants, characterized by a non-regular size growth and stiffer appearance, and dark green explants capable of organogenesis. Compared to the source leaves of African violet plants, explants were characterized by reduced chlorophyll (Chl) and carotenoid (Car) contents as well as a tendency towards a higher Car/Chl ratio. The Chl a/b ratio decreased significantly in the light green explants. A reduction of maximum quantum efficiency of photosystem II (Fv/Fm) accompanied by a high percentage (&gt; 50%) of thermal energy dissipation as a consequence of an elevated light intensity (800 µmol m-2 s-1 quanta) indicated photoinhibition in the light green explants, whereas in the dark green explants the largest percentage (&gt; 50%) of the light energy was dissipated into the fraction of photon energy trapped by ‘closed’ photosystem II reaction centres. These results suggest that the capacity of organogenesis of leaf explants of African violet can be monitored using chlorophyll fluorescence, because it is related to modifications of the photosynthetic system
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