Canola hybrids and hybrid canola development

Non-Peer Reviewe

Linear resolutions of powers and products

The goal of this paper is to present examples of families of homogeneous ideals in the polynomial ring over a field that satisfy the following condition: every product of ideals of the family has a linear free resolution. As we will see, this condition is strongly correlated to good primary decompositions of the products and good homological and arithmetical properties of the associated multi-Rees algebras. The following families will be discussed in detail: polymatroidal ideals, ideals generated by linear forms and Borel fixed ideals of maximal minors. The main tools are Gr\"obner bases and Sagbi deformation

Data Protection: International Trends and the Austrian Example

Ensuring personal privacy in today's computerized-information society seems to be a common goal among the member states of the OECD. In this paper an attempt is made to summarize the discussions at the political and law-making level, both nationally and internationally within the framework of the OECD member countries. From the concrete outcome of these discussions, i.e., the data protection acts adopted and yet in force, the Austrian situation has been chosen as example

Can We Study Titin Properties in Passive Myofibrils?

Titin is a giant molecular spring in skeletal and cardiac muscles. It has a variety of important passive, structural, sensing and force-regulatory functions, and thus has been investigated widely (Granzier & Labeit, 2007). Studying the mechanical properties of isolated titin has been difficult because of the enormous size and great instability of this protein. However, the passive properties in single myofibrils are almost exclusively explained by titin, and thus we asked the question if we can study titin properties in intact, passive myofibrils (Bartoo et al., 1997). Single myofibrils were isolated in a standard way (Leonard & Herzog, 2010) and three consecutive stretches of 1.0-3.5μm/sarcomere magnitude were performed at a nominal stretch speed of 0.1 sarcomere length/sarcomere/s. Sarcomere length were measured using a high resolution photo diode array and forces were measured using micro-electronically machined silicon nitrate levers. Single myofibrils frequently showed a distinct change in stiffness upon stretch at sarcomere length of approximately 3.6-3.8μm, they showed a decrease in loading energy with repeat stretch cycles and their efficiency decreased for all loading cycles with increasing stretch magnitude. These properties are in agreement with results observed in single titin preparations (Kellermayer et al., 1997). Therefore, we conclude that titin properties can be studied using single myofibrils. This has at least two significant advantages over tests with isolated titin proteins: (i) testing is technically much easier and (ii) titin is arranged in its intact structural arrangement. In the future, we would like to study titin properties in calcium activated myofibrils in which active (actin-myosin based cross-bridges forces) are eliminated either by chemical inhibition or by deletion of regulatory proteins on actin, as we have done before (Joumaa et al., 2008)

Spinning Dragging Strings

We use the AdS/CFT correspondence to compute the drag force experienced by a heavy quark moving through a maximally supersymmetric SU(N) super Yang-Mills plasma at nonzero temperature and R-charge chemical potential and at large 't Hooft coupling. We resolve a discrepancy in the literature between two earlier studies of such quarks. In addition, we consider small fluctuations of the spinning strings dual to these probe quarks and find no evidence of instabilities. We make some comments about suitable D7-brane boundary conditions for the dual strings.Comment: 25 pages, 4 figures; v2 refs added; v3 to appear in JHEP, clarifying comment

Mol. Cell. Proteomics

Chemical cross-linking in combination with mass spectrometric analysis offers the potential to obtain low-resolution structural information from proteins and protein complexes. Identification of peptides connected by a cross-link provides direct evidence for the physical interaction of amino acid side chains, information that can be used for computational modeling purposes. Despite impressive advances that were made in recent years, the number of experimentally observed cross-links still falls below the number of possible contacts of cross-linkable side chains within the span of the cross-linker. Here, we propose two complementary experimental strategies to expand cross-linking data sets. First, enrichment of cross-linked peptides by size exclusion chromatography selects cross-linked peptides based on their higher molecular mass, thereby depleting the majority of unmodified peptides present in proteolytic digests of cross-linked samples. Second, we demonstrate that the use of proteases in addition to trypsin, such as Asp-N, can additionally boost the number of observable cross-linking sites. The benefits of both SEC enrichment and multiprotease digests are demonstrated on a set of model proteins and the improved workflow is applied to the characterization of the 20S proteasome from rabbit and Schizosaccharomyces pombe

Anomalous dimensions and splitting functions beyond the next-to-next-to-leading order

We report on recent progress on the splitting functions for the evolution of parton distributions and related quantities, the (lightlike) cusp anomalous dimensions, in perturbative QCD. New results are presented for the four-loop (next-to-next-to-next-to-leading order, N^3LO) contributions to the flavour-singlet splitting functions and the gluon cusp anomalous dimension. We present first results, the moments N=2 and N=3, for the five-loop (N^4LO) non-singlet splitting functions.Comment: 10 pages, LaTeX (PoS style), 3 eps-figures. Contribution to the proceedings of `Loops & Legs 2018', St. Goar (Germany), April/May 201

Temperature- and Magnetic-Field-Dependent Optical Properties of Heavy Quasiparticles in YbIr2Si2

We report the temperature- and magnetic-field-dependent optical conductivity spectra of the heavy electron metal YbIr$_2$Si$_2$. Upon cooling below the Kondo temperature ($T_{\rm K}$), we observed a typical charge dynamics that is expected for a formation of a coherent heavy quasiparticle state. We obtained a good fitting of the Drude weight of the heavy quasiparticles by applying a modified Drude formula with a photon energy dependence of the quasiparticle scattering rate that shows a similar power-law behavior as the temperature dependence of the electrical resistivity. By applying a magnetic field of 6T below $T_{\rm K}$, we found a weakening of the effective dynamical mass enhancement by about 12% in agreement with the expected decrease of the $4f$-conduction electron hybridization on magnetic field.Comment: 5 pages, 4 figures. to be published in Journal of the Physical Society of Japan Vol. 79 (2010) No. 1