Delayed inhibition of an anticipatory action during motion extrapolation

Background: Continuous visual information is important for movement initiation in a variety of motor tasks. However, even in the absence of visual information people are able to initiate their responses by using motion extrapolation processes. Initiation of actions based on these cognitive processes, however, can demand more attentional resources than that required in situations in which visual information is uninterrupted. In the experiment reported we sought to determine whether the absence of visual information would affect the latency to inhibit an anticipatory action. Methods: The participants performed an anticipatory timing task where they were instructed to move in synchrony with the arrival of a moving object at a determined contact point. On 50% of the trials, a stop sign appeared on the screen and it served as a signal for the participants to halt their movements. They performed the anticipatory task under two different viewing conditions: Full-View (uninterrupted) and Occluded-View (occlusion of the last 500 ms prior to the arrival at the contact point). Results: The results indicated that the absence of visual information prolonged the latency to suppress the anticipatory movement. Conclusion: We suggest that the absence of visual information requires additional cortical processing that creates competing demand for neural resources. Reduced neural resources potentially causes increased reaction time to the inhibitory input or increased time estimation variability, which in combination would account for prolonged latency

Influence of damaging and wilting red clover on lipid metabolism during ensiling and in vitro rumen incubation

This paper describes the relationship between protein-bound phenols in red clover, induced by different degrees of damaging before wilting and varying wilting duration, and in silo lipid metabolism. The ultimate effect of these changes on rumen biohydrogenation is the second focus of this paper For this experiment, red clover, damaged to different degrees (not damaged (ND), crushing or frozen/thawing (FT)) before wilting (4 or 24 h) was ensiled. Different degrees of damaging and wilting duration lead to differences in polyphenol oxidase (PPO) activity, measured as increase in protein-bound phenols. Treatment effects on fatty acid (FA) content and composition, lipid fractions (free FAs, membrane lipids (ML) and neutral fraction) and lipolysis were further studied in the silage. In FT, red clover lipolysis was markedly lower in the first days after ensiling, but this largely disappeared after 60 days of ensiling, regardless of wilting duration. This suggests an inhibition of plant lipases in FT silages. After 60 days of ensiling no differences in lipid fractions could be found between any of the treatments and differences in lipolysis were caused by reduced FA proportions in ML of wilted FT red clover Fresh, wilted (24 h) after damaging (ND or FT) and ensiled (4 or 60 days; wilted 24 h; ND or FT) red clover were also incubated in rumen fluid to study the biohydrogenation of C18:3n-3 and C18:2n-6 in vitro. Silages (both 60 days and to a lower degree 4 days) showed a lower biohydrogenation compared with fresh and wilted forages, regardless of damaging. This suggests that lipids in ensiled red clover were more protected, but this protection was not enhanced by a higher amount of protein-bound phenols in wilted FT compared with ND red clover The reduction of rumen microbial biohydrogenation with duration of red clover ensiling seems in contrast to what is expected, namely a higher biohydrogenation when a higher amount of FFA is present. This merits further investigation in relation to strategies to activate PPO toward the embedding of lipids in phenol protein complexes

Quark Recombination and Heavy Quark Diffusion in Hot Nuclear Matter

We discuss resonance recombination for quarks and show that it is compatible with quark and hadron distributions in local thermal equilibrium. We then calculate realistic heavy quark phase space distributions in heavy ion collisions using Langevin simulations with non-perturbative T-matrix interactions in hydrodynamic backgrounds. We hadronize the heavy quarks on the critical hypersurface given by hydrodynamics after constructing a criterion for the relative recombination and fragmentation contributions. We discuss the influence of recombination and flow on the resulting heavy meson and single electron R_AA and elliptic flow. We will also comment on the effect of diffusion of open heavy flavor mesons in the hadronic phase.Comment: Contribution to Quark Matter 2011, submitted to J.Phys.G; 4 pages, 5 figure

Development of Sequence Tagged Microsatellite Site (STMS) markers in Azalea

A genomic library was constructed from DNA of two azalea genotypes: a Belgian pot azalea R. simsii hybrid Mevr. Van Belle and a Chinese R. simsii from Daoxian. An enrichment of microsatellite containing sequences was performed as in Van de Wiel et al. (1999). Fragments were sequenced and primers were designed that allow the amplification of the microsatellite repeat. About 220 microsatellite containing clones were selected from the enrichment procedure. Mainly dinucleotide repeats and some trinucleotide repeats were found. The selected primers were tested in a small set of reference varieties to check their value (specificity and polymorphic rate) and to set up the PCR-conditions. Five primer pairs have been tested, two of them gave a specific and polymorphic pattern. They were further screened by radioactive PCR on a selection of 5 plants from the azalea breeders gene pool which included the two genotypes used library construction. These 2 STMS markers uniquely identified the 5 plants

Quarkonia and Heavy-Quark Relaxation Times in the Quark-Gluon Plasma

A thermodynamic T-matrix approach for elastic 2-body interactions is employed to calculate spectral functions of open and hidden heavy-quark systems in the Quark-Gluon Plasma. This enables the evaluation of quarkonium bound-state properties and heavy-quark diffusion on a common basis and thus to obtain mutual constraints. The two-body interaction kernel is approximated within a potential picture for spacelike momentum transfers. An effective field-theoretical model combining color-Coulomb and confining terms is implemented with relativistic corrections and for different color channels. Four pertinent model parameters, characterizing the coupling strengths and screening, are adjusted to reproduce the color-average heavy-quark free energy as computed in thermal lattice QCD. The approach is tested against vacuum spectroscopy in the open (D, B) and hidden (Psi and Upsilon) flavor sectors, as well as in the high-energy limit of elastic perturbative QCD scattering. Theoretical uncertainties in the static reduction scheme of the 4-dimensional Bethe-Salpeter equation are elucidated. The quarkonium spectral functions are used to calculate Euclidean correlators which are discussed in light of lattice QCD results, while heavy-quark relaxation rates and diffusion coefficients are extracted utilizing a Fokker-Planck equation.Comment: 33 pages, 28 figure

Analyses of Genetic Change in Grass-Clover Based Systems Over Time

Since the use of nitrogen fertilisers is reduced, swards based on grass-clover mixtures regain importance in grassland production. Management of these swards is more complicated than the management of pure grass swards. The population structure will develop in response to abiotic and biotic stresses. In this study we will test the genetic change in the clover components of grass-clover mixtures

Uncovering the Mechanism of Aggregation of Human Transthyretin.

The tetrameric thyroxine transport protein transthyretin (TTR) forms amyloid fibrils upon dissociation and monomer unfolding. The aggregation of transthyretin has been reported as the cause of the life-threatening transthyretin amyloidosis. The standard treatment of familial cases of TTR amyloidosis has been liver transplantation. Although aggregation-preventing strategies involving ligands are known, understanding the mechanism of TTR aggregation can lead to additional inhibition approaches. Several models of TTR amyloid fibrils have been proposed, but the segments that drive aggregation of the protein have remained unknown. Here we identify β-strands F and H as necessary for TTR aggregation. Based on the crystal structures of these segments, we designed two non-natural peptide inhibitors that block aggregation. This work provides the first characterization of peptide inhibitors for TTR aggregation, establishing a novel therapeutic strategy

Identification of quantitative trait loci controlling root and shoot traits associated with drought tolerance in a lentil (Lens culinaris Medik.) recombinant inbred line population

Drought is one of the major abiotic stresses limiting lentil productivity in rainfed production systems. Specific rooting patterns can be associated with drought avoidance mechanisms that can be used in lentil breeding programs. In all, 252 co-dominant and dominant markers were used for Quantitative Trait Loci (QTL) analysis on 132 lentil recombinant inbred lines based on greenhouse experiments for root and shoot traits during two seasons under progressive drought-stressed conditions. Eighteen QTLs controlling a total of 14 root and shoot traits were identified. A QTL-hotspot genomic region related to a number of root and shoot characteristics associated with drought tolerance such as dry root biomass, root surface area, lateral root number, dry shoot biomass and shoot length was identified. Interestingly, a QTL (QRSratioIX-2.30) related to root-shoot ratio, an important trait for drought avoidance, explaining the highest phenotypic variance of 27.6 and 28.9% for the two consecutive seasons, respectively, was detected. This QTL was closed to the co-dominant SNP marker TP6337 and also flanked by the two SNP TP518 and TP1280. An important QTL (QLRNIII-98.64) related to lateral root number was found close to TP3371 and flanked by TP5093 and TP6072 SNP markers. Also, a QTL (QSRLIV-61.63) associated with specific root length was identified close to TP1873 and flanked by F7XEM6b SRAP marker and TP1035 SNP marker. These two QTLs were detected in both seasons. Our results could be used for marker-assisted selection in lentil breeding programs targeting root and shoot characteristics conferring drought avoidance as an efficient alternative to slow and labor-intensive conventional breeding methods