61,627 research outputs found
Recent developments at the ANTARES AMS centre.
A. M. Smith, D. Fink, M. A. C. Hotchkis, G. E. Jacobsen, E. M. Lawson, C. Tuniz, E. Sacchi, D. Louvat, G. M. Zuppi and R. Bonett
Cisgenesis: an important sub-invention for traditional plant breeding companies
Modern plant breeding is highly dependent on new technologies to master future problems. More traits have to be combined, frequently originating from wild species. Traditional breeding is connected with linkage drag problems. The crop plant itself and its crossable species represent the traditional breeders gene pool. GM-breeding is a new way of improving existing varieties. Transgenes originate from non-crossable species and are representing a new gene pool. For release of GM-plants into the environment and onto the market in Europe Directive 2001/18/EC has been developed, primarily based on GM-technology and not on gene source. In society, opposition against GM crops is complicating the implementation of GM crops. In this paper, it is shown that not only transgenes, representing a new gene pool but also cisgenes and intragenes are available, representing the breeders gene pool. Cisgenes are natural genes and intragenes are composed of functional parts of natural genes from the crop plant itself or from crossable species. Cisgenesis is the combined use of only cisgenes with marker-free transformation, mimicking linkage drag free introgression breeding in one step. Therefore, cisgenesis is a new sub-invention in the traditional breeding field and indicates the need for reconsideration of GM Directives. Inventions are frequently containing not only hardware elements, but also software and orgware elements. For cisgenesis it is foreseen that the technical (hardware) and bioinformatic (software) elements will develop smoothly, but that implementation in society is highly dependent on acceptance and regulations (orgware). It could be made in a step by step approach by specific crop-gene derogations from the Directive, followed by adding cisgenesis to annex 1b of Directive 2001/18/EC for exemption. At present GM crops can only be introduced by large companies. An open innovation approach for cisgenesis by public private partnership including traditional SMEs has been discussed. Cisgenesis has been exemplified for resistance breeding of potato to Phytophthtora infestans
D-1638: 71 East 400 South, Logan, Utah, Flora A. Jacobsen/Rulon W. Everton/Harold M. and Bernice E. Currell residence. Lot 1-8 Block 2 Plat D
D-1638: 71 East 400 South, Logan, Utah, Flora A. Jacobsen/Rulon W. Everton/Harold M. and Bernice E. Currell residence. Lot 1-8 Block 2 Plat
A Facile Approach toward 8-O-4'-Neolignans: Synthesis of Threo-7',8'-Dihydromachilin D through Jacobsen Epoxidation
Neolignans are natural phenylpropanoid dimers with C-O-C linkages. Currently, neolignans remain as important synthetic targets due to their reported biological potential against parasites and fungal infections. Thereof, a new approach for the synthesis of the 8-O-4'-neolignan 7',8'-dihydromachilin D based on Jacobsen epoxidation as key step is described here. This stereoselective synthesis proceeded in only 4 steps in 3.9% overall yield. Jacobsen epoxidation was firstly optimized regarding to yield and enantioselectivity employing trans-stilbene as model substrate
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A Facile Approach toward 8-O-4\u27-Neolignans: Synthesis of Threo-7\u27,8\u27-Dihydromachilin D through Jacobsen Epoxidation
Neolignans are natural phenylpropanoid dimers with C-O-C linkages. Currently, neolignans remain as important synthetic targets due to their reported biological potential against parasites and fungal infections. Thereof, a new approach for the synthesis of the 8-O-4\u27-neolignan 7\u27,8\u27-dihydromachilin D based on Jacobsen epoxidation as key step is described here. This stereoselective synthesis proceeded in only 4 steps in 3.9% overall yield. Jacobsen epoxidation was firstly optimized regarding to yield and enantioselectivity employing trans-stilbene as model substrate
Dispelling the Myths Behind First-author Citation Counts
We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Reconstruction of a yeast cell from X-ray diffraction data
Details are provided of the algorithm used for the reconstruction of yeast cell images in the recent demonstration of diffraction microscopy by Shapiro, Thibault, Beetz, Elser, Howells, Jacobsen, Kirz, Lima, Miao, Nieman & Sayre [Proc. Natl Acad. Sci. USA (2005), 102, 15343-15346]. Two refinements of the iterative constraint-based scheme are developed to address the current experimental realities of this imaging technique, which include missing central data and noise. A constrained power operator is defined whose eigenmodes allow the identification of a small number of degrees of freedom in the reconstruction that are negligibly constrained as a result of the missing data. To achieve reproducibility in the algorithm's output, a special intervention is required for these modes. Weak incompatibility of the constraints caused by noise in both direct and Fourier space leads to residual phase fluctuations. This problem is addressed by supplementing the algorithm with an averaging method. The effect of averaging may be interpreted in terms of an effective modulation transfer function, as used in optics, to quantify the resolution. The reconstruction details are prefaced with simulations of wave propagation through a model yeast cell. These show that the yeast cell is a strong-phase-contrast object for the conditions in the experiment
Search for the rare decay D+ -> D(0)e(+)nu(e)
Kolcu, Onur Buğra (Arel Author)Using a data set with an integrated luminosity of 2.93 fb(-1) collected at root s = 3.773 GeV with the BESIII detector operating at the BEPCII storage rings, we search for the rare decay D+ -> D(0)e(+)nu(e). No signal events are observed. We set the upper limit on the branching fraction for D+ -> D(0)e(+)nu(e) to be 1.0 x 10(-4) at the 90% confidence level
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