Dijet correlations at RHIC, leading-order ktk_t-factorization approach versus next-to-leading order collinear approach

We compare results of $k_t$-factorization approach and next-to-leading order collinear-factorization approach for dijet correlations in proton-proton collisions at RHIC energies. We discuss correlations in azimuthal angle as well as correlations in two-dimensional space of transverse momenta of two jets. Some $k_t$-factorization subprocesses are included for the first time in the literature. Different unintegrated gluon/parton distributions are used in the $k_t$-factorization approach. The results depend on UGDF/UPDF used. For collinear NLO case the situation depends significantly on whether we consider correlations of any two jets or correlations of leading jets only. In the first case the $2 \to 2$ contributions associated with soft radiations summed up in the $k_t$-factorization approach dominate at $\phi \sim \pi$ and at equal moduli of jet transverse momenta. The collinear NLO $2 \to 3$ contributions dominate over $k_t$-factorization cross section at small relative azimuthal angles as well as for asymmetric transverse momentum configurations. In the second case the NLO contributions vanish at small relative azimuthal angles and/or large jet transverse-momentum disbalance due to simple kinematical constraints. There are no such limitations for the $k_t$-factorization approach. All this makes the two approaches rather complementary. The role of several cuts is discussed and quantified.Comment: 26 pages, 17 figure

GLS-1, a Novel P Granule Component, Modulates a Network of Conserved RNA Regulators to Influence Germ Cell Fate Decisions

Post-transcriptional regulatory mechanisms are widely used to influence cell fate decisions in germ cells, early embryos, and neurons. Many conserved cytoplasmic RNA regulatory proteins associate with each other and assemble on target mRNAs, forming ribonucleoprotein (RNP) complexes, to control the mRNAs translational output. How these RNA regulatory networks are orchestrated during development to regulate cell fate decisions remains elusive. We addressed this problem by focusing on Caenorhabditis elegans germline development, an exemplar of post-transcriptional control mechanisms. Here, we report the discovery of GLS-1, a new factor required for many aspects of germline development, including the oocyte cell fate in hermaphrodites and germline survival. We find that GLS-1 is a cytoplasmic protein that localizes in germ cells dynamically to germplasm (P) granules. Furthermore, its functions depend on its ability to form a protein complex with the RNA-binding Bicaudal-C ortholog GLD-3, a translational activator and P granule component important for similar germ cell fate decisions. Based on genetic epistasis experiments and in vitro competition experiments, we suggest that GLS-1 releases FBF/Pumilio from GLD-3 repression. This facilitates the sperm-to-oocyte switch, as liberated FBF represses the translation of mRNAs encoding spermatogenesis-promoting factors. Our proposed molecular mechanism is based on the GLS-1 protein acting as a molecular mimic of FBF/Pumilio. Furthermore, we suggest that a maternal GLS-1/GLD-3 complex in early embryos promotes the expression of mRNAs encoding germline survival factors. Our work identifies GLS-1 as a fundamental regulator of germline development. GLS-1 directs germ cell fate decisions by modulating the availability and activity of a single translational network component, GLD-3. Hence, the elucidation of the mechanisms underlying GLS-1 functions provides a new example of how conserved machinery can be developmentally manipulated to influence cell fate decisions and tissue development

Registration and quantitative analysis of serum proteins of unstable structure

Niektóre liotropowe układy ciekłokrystaliczne tworzące taśmowe układy micelarne mają zdolność tworzenia kompleksów z białkami pod warunkiem możliwości penetracji do wnętrza bryły białkowej. Możliwość taką stwarzają białka o niestabilnej strukturze w tym głównie białka patologiczne a także część białek należących do białek ostrej fazy. Modyfikacja ładunku białka w wyniku kompleksowania może być ujawniona w rozdziale elektroforetycznym. Dwukierunkowy rozdział elektroforetyczny z dodatkiem liganda supramolekularnego w drugim prostopadłym kierunku rozdziału pozwala na ujawnienie i izolację kompleksów z ciekłokrystalicznym ligandem. Otwiera to istotne możliwości diagnostyczne. Oczekiwane jest opracowanie numerycznej techniki ilościowej oceny proporcji ujawnionych frakcji białkowych. Wiązanie ligandów ciekłokrystalicznych okazuje się też aktualne w przypadku kompleksowania ich przez złogi amyloidowe. Czerwień Kongo jest w tym przypadku markerem specyficznym.Some lyotropic liquide crystals of ribbon-like micellar structure form complexes with proteins of unstable structure due to possible penetration to their interior. Misfolded proteins and some acute phase serum proteins belong to that group. The altered charge of proteins engaged in complexation which becomes modified by the charge of bound ligand affects electrophoretic migration and allows differentiation of ubnormal proteins from among serum proteins. Two-dimensional agarose electrophoresis of serum proteins undergone complexation with supramolecular ligand after perpendicular reorganization of migration fulfils the requirement. The exposure of misfolded proteins and their quantitative analysis has a significant diagnostic meaning. Elaboration of numerical analysis is expected. Ligands in form of liquide crystals have been found to be bound to amyloids. Congo red appeared to be the specific marker for recognition of amyloid fibrils. This type of ligand seems to be the new category of ligands complexes in form of multimolecular system