59 research outputs found

    Embryogenesis in microspore culture of Vitis subspecies

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    Embryoid structures showing epidermal layers have been regenerated from isolated Vitis microspores. Experiments were carried out on 8 genotypes of Vitis including different donor plant growth conditions, chilling of microspores (4 °C), heat shock (35 °C) and colchicine exposure (10, 25 and 50 mg/l) as induction treatments and incubation of the cultures on 87 different solid and liquid NN and LS media. The reactions of the cultured microspores included enlargement and thickening of the exine, formation of microcalli, calli, globular proembryos and embryoid structures displaying cell differentiation. Callus formation took place mainly on solid LS media with 3 % or 12 % sucrose, whereas most of the embryoids developed on NN media with 3 % sucrose. Both, callus and embryoid formation, were promoted by colchicine treatment. 8 months after transfer of calli and embryoids to subculture media, 4 embryoids still showed cell proliferation

    Excited-State Electronic Structure with Configuration Interaction Singles and Tamm–Dancoff Time-Dependent Density Functional Theory on Graphical Processing Units

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    Excited-state calculations are implemented in a development version of the GPU-based TeraChem software package using the configuration interaction singles (CIS) and adiabatic linear response Tamm–Dancoff time-dependent density functional theory (TDA-TDDFT) methods. The speedup of the CIS and TDDFT methods using GPU-based electron repulsion integrals and density functional quadrature integration allows full ab initio excited-state calculations on molecules of unprecedented size. CIS/6-31G and TD-BLYP/6-31G benchmark timings are presented for a range of systems, including four generations of oligothiophene dendrimers, photoactive yellow protein (PYP), and the PYP chromophore solvated with 900 quantum mechanical water molecules. The effects of double and single precision integration are discussed, and mixed precision GPU integration is shown to give extremely good numerical accuracy for both CIS and TDDFT excitation energies (excitation energies within 0.0005 eV of extended double precision CPU results)

    REMARKS TO THE CURRENT DISCUSSION ABOUT BIOENERGY –BIOENERGY FOR THE PUBLIC AND/ OR FOR THE AGRICULTURAL OR RURAL AREAS ONLY ?

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    An energy system that is based on the use of renewable energy resources must be service –oriented and should be able to cover the varying energy demands. Moreover it must be flexible and cost effective by using on optimal mix of predominantly renewable energy sources. Agriculture will play an important role in the future if an optimal mix between food/feed production and energy plant production could be found. The present examples in the world to gain agricultural land for energy plants on the expenses of forests is going into the wrong direction. The cost intensive investments at present performed in Europe for biofuel and bioenergy production will certainly influence prices for crops and biomass supply. In this paper, strategies are questioned and discussed if the goals of the EU-commission to replace substantial parts of the fossile energy demands by bioenergy supply is feasible and can be realistic. As an example for a national agricultural situation, Austria, as am member of the PBBA, has elaborated a study about the timely development how much of the arable land can be utilized in the period between 2005 and 2020 for various bioenergy sources .The results demonstrate that, at the maximum , agriculture can only supply about 22 % of the total arable land for additional bioenergy as biofuel and biogas without interfering the national self food/feed supply and the protection of the sensible environment and emission situation. Finally, recent University research studies are presented about new processes to achieve a better and more efficient use of cereal and maize straw for biogas production already performed in the present 358 local biogas plants in Austria

    Breeding objectives and the relative importance of traits in plant and animal breeding: a comparative review

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    Breeding objectives always involve consideration of multiple traits, even in situations where output of a single trait is dominant. We review literature dealing with formal definition of breeding objectives. Involvement of farmers in the process of setting up breeding objectives is also considered. In the optimal selection index, the relative importance of a trait is scaled by its economic value, derived as marginal profit related to a change in expression of defined size. Normative approaches to derive economic values use partial derivatives of a profit equation with respect to the traits involved or model the bio-economic system with various techniques. The theory is well developed and includes consideration of non-linear profit functions and traits with an intermediate optimum. It is frequently applied in animal breeding. In dairy cattle breeding, a major change of focus from traits related to output (i.e., milk yield) to traits related to cost of input (health, fertility, feed efficiency) has taken place recently. Plant breeders find the concept of deriving relative economic weights of traits difficult to apply and often replace the optimal index by restricted or desired gains indices. A change of paradigms similar to that in cattle breeding seems advisable. Participatory approaches to evaluate the relative importance of traits are more frequently applied in plant breeding than in animal breeding. We review two studies, dealing with methods of acquiring information about selection criteria of farmers planting maize in the Ethiopian highlands and of pastoralists keeping cattle in Uganda, in detail

    Does Stacking Restrain the Photodynamics of Individual Nucleobases?

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    Nonadiabatic photodynamical simulations of 4-aminopyrimidine (4-APy) used as a model for adenine were performed by embedding it between two stacking methyl-guanine (mGua) molecules to determine the effect of spatial restrictions on the ultrafast photodeactivation mechanism of this nucleobase. A hybrid multiconfigurational ab initio/molecular mechanical approach in combination with surface hopping was used. During the dynamics the formation of a significant fraction of intrastrand hydrogen bonding from 4-APy to mGua above and below is observed. These findings show that this type of hydrogen bond may play an important role for the photodynamics within one DNA strand and that it should be of interest even in irregular segments of double stranded nucleic acids structures. The relaxation mechanism of internal conversion to the ground state is dominated by ring puckering, and an overall elongation of the lifetime of the embedded system by approximately 20% as compared to the isolated 4-APy is computed

    Food safety of cereals: a chain wide approach to reduce Fusarium mycotoxins

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    Fusarium head blight (FHB) in wheat and barley and Fusarium ear rot in maize is caused by several Fusarium species. The disease reduces the quality of the seed since several of these fungi produce mycotoxins. From a food safety point of view, consumption of mycotoxin-infected cereals is dangerous as it threatens the health of men and animals. This project looked at a chain-wide approach to reduce Fusarium Mycotoxins
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