To allow the online selection of events, the readout of the P̅ANDA detector will reconstruct particles online. Several algorithms to perform this task in one of the subsystems, the electromagnetic ...calorimeter, are being developed. The algorithms are discussed, and a simple test case shows that they appear to behave similarly in terms of the ability to reconstruct events, and the time it takes to do this. However, some peculiarities, like the fact that the algorithms show the best performance in what is expected to be the worst-case scenario, still require additional investigation.
Near-edge X-ray absorption mass spectrometry of a gas-phase peptide González-Magaña, O; Reitsma, G; Tiemens, M ...
The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory,
11/2012, Letnik:
116, Številka:
44
Journal Article
Recenzirano
We have studied the dissociation of the gas-phase protonated peptide leucine enkephalin YGGFL+H(+) upon X-ray absorption in the region of the C K-edge. The yield of photodissociation products was ...recorded as a function of photon energy. The total photoabsorption yield is qualitatively similar to near-edge X-ray absorption fine structure (NEXAFS) spectra recorded from condensed phase peptides and proteins. Fragment specificity reveals distinct quantitative differences between spectra obtained for different masses. Fragmentation channels can be assigned to specific electronic transitions some of which are site specific. For instance, C 1s → π(★) excitations in the leucine enkephalin aromatic side chains lead to relatively little fragmentation, whereas such excitations along the peptide backbone induce strong fragmentation.
One of the physics goals of the future ANDA experiment at FAIR is to research newly discovered exotic states. Because the detector response created by these particles is very similar to the ...background channels, a new type of data readout had to be developed, called "triggerless" readout. In this concept, each detector subsystem preprocesses the signal, so that in a later stage, high-level phyiscs constraints can be applied to select events of interest. A dedicated clock source using a protocol called SODANET over optical fibers ensures proper synchronisation between the components. For this new type of readout, a new way of simulating the detector response also needed to be developed, taking into account the effects of pile-up caused by the 20 MHz interaction rate.
One of the physics goals of the future P A N D A experiment at FAIR is to research newly discovered exotic states. Because the detector response created by these particles is very similar to the ...background channels, a new type of data readout had to be developed, called "triggerless" readout. In this concept, each detector subsystem preprocesses the signal, so that in a later stage, high-level phyiscs constraints can be applied to select events of interest. A dedicated clock source using a protocol called SODANET over optical fibers ensures proper synchronisation between the components. For this new type of readout, a new way of simulating the detector response also needed to be developed, taking into account the effects of pile-up caused by the 20 MHz interaction rate.
The natural approach taken by organic agriculture obviates the use of synthetic agrochemicals and emphasizes farming in accordance with agroecological principles. Also implicit in this approach is an ...appreciation for the integrity of living farm organisms, with the integrity being evaluated from a biocentric perspective. The ethical value assigned to integrity of organisms has challenged us to develop criteria for evaluating both integrity and breeding techniques. For cultivated plants, integrity refers to their inherent nature, their wholeness, completeness, species-specific characteristics, and their being in balance with their (organically farmed) environment. We evaluate integrity using criteria derived from four different perspectives: integrity of life, plant-specific integrity, genotypic integrity, and phenotypic integrity. These criteria were used to assess whether existing breeding and propagation techniques violate the integrity of crop plants. In vitro techniques and techniques that engineer at the DNA level appeared to be incompatible with the integrity of crops, with the exception of use of DNA markers. On the other hand, breeding techniques that work at the level of breeding, evaluation, and selection for whole plant performance, and which do not break reproductive barriers between species, may conform to the principles of organic farming. In the selection process, the so-called breeder's eye can be developed to become a more consciously applied instrument for perceiving and assessing aspects of the wholeness or phenotypic integrity of a plant. Thus, the challenge given by the organic community to breeders implies the further development of scientific approaches, evaluation, and choice of breeding techniques, and the systematic development of the respectful and artful eye of the individual breeder.
In organic agriculture the use of genetically modified organisms (GMOs) is banned. Recently, two novel breeding techniques have been developed, i.e., cisgenesis and reverse breeding, both of which ...are based on gene technology but should raise less moral concerns from the public. Whether the products of these breeding processes are classified as GMOs depends on the interpretation of the relevant EU regulations. In cisgenic plants, the genes introduced through genetic modification are from a crossable donor plant so that the source of the genes is considered to be of the same nature. In reverse breeding, the recombinant genes, essential to the breeding process, are no longer present in the product resulting from the entire breeding process, and thus the product as such is not transgenic. Should varieties obtained through cisgenesis or reverse breeding be allowed in organic agriculture? The answer to this question depends on whether the product or the process of breeding is taken into account. Assessment based on the product implies a choice of an ethical approach that only considers the extrinsic consequences of human action by making a risk-benefit analysis. It neglects so-called intrinsic, ethical arguments related to the applied technology (the process itself. The organic movement uses the intrinsic argument of 'unnaturalness' against genetic engineering. We therefore conclude that products of cisgenesis and reverse breeding should be subject to the current GMO-regulations in organic agriculture and should thus be banned from organic agriculture.
Organic growers need information on variety performance under their growing conditions. A 4-year onion variety research project was carried out to investigate whether setting up a variety testing ...system combining conventional and organic variety trials is feasible and efficient rather than organizing separate variety trials under the two management systems. During 4 years commercial onion cultivars were tested at a certified organic and a non-organic location. Both systems were managed without chemical pest, disease and sprouting control, but differed in fertility management (organic manure in autumn versus synthetic fertilizer), soil cultivation and weed management (mechanical weeding versus application of herbicide). Management system significantly affected plant density, thickness of neck, and proportion of small and large bulbs. Variety × management system interactions were significant for bulb uniformity, earliness, proportion of large bulbs, dormancy and relative storage success but did not change the ranking of the varieties. We conclude that organic growers can profit from a more conscious variety choice when conventionally fertilised trials would refrain from using pesticides, fungicides, herbicides and sprout inhibitors. However, this would require an adaptation of the management protocol in such a way that trials might no longer represent conditions of conventional farmers. Furthermore, assessments of leaf erectness, disease resistance to downy mildew and leaf blight should be included in the protocols for organic use. We advocate better communication between breeders and growers on specific variety characteristics contributing to improving yield stability under low-input, organic growing conditions.
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