Renormalizacija tenzorske svojstvene energije u rezonantnoj kiralnoj teoriji

We study the problems related to the renormalization of propagators in resonance chiral theory, concentrating on the case of vector resonances in the antisymmetric tensor formalism. The general form of the propagators for antisymmetric tensor fields contains not only the resonance states but also the states that are ghosts or tachyons which decouple in the free-field limit. However, when the interaction terms are taking into account they are dynamically generated through the renormalization procedure.Proučavamo probleme oko renormalizacije propagatora u rezonantnoj kiralnoj teoriji, usredotočivši se na vektorske rezonancije u formalizmu antisimetričnih tenzora. Opći oblik propagatora antisimetričnih tenzorskih polja sadrži pored rezonantnih stanja i duhove i tahione koji se odvajaju u granici slobodnog polja. Međutim, ako se članovi međudjelovanja uzmu u obzir, oni se stvaraju dinamički renormalizacijskim postupkom

Renormalization and additional degrees of freedom within the chiral effective theory for spin-1 resonances

We study in detail various aspects of the renormalization of the spin-1 resonance propagator in the effective field theory framework. First, we briefly review the formalisms for the description of spin-1 resonances in the path integral formulation with the stress on the issue of propagating degrees of freedom. Then we calculate the one-loop 1-- meson self-energy within the Resonance chiral theory in the chiral limit using different methods for the description of spin-one particles, namely the Proca field, antisymmetric tensor field and the first order formalisms. We discuss in detail technical aspects of the renormalization procedure which are inherent to the power-counting non-renormalizable theory and give a formal prescription for the organization of both the counterterms and one-particle irreducible graphs. We also construct the corresponding propagators and investigate their properties. We show that the additional poles corresponding to the additional one-particle states are generated by loop corrections, some of which are negative norm ghosts or tachyons. We count the number of such additional poles and briefly discuss their physical meaning.Comment: 65 pages, 12 figure

Renormalization of the antisymmetric tensor field propagator and dynamical generation of the 1+−1^{+-} mesons in Resonance Chiral Theory

We discuss the renormalization of the $1^{--}$ vector meson propagator within Resonance chiral theory at one loop. Using the particular form of the interaction Lagrangian we show that additional poles of the renormalized propagator corresponding to $1^{+-}$ degrees of freedom can be generated. We give a concrete example of such an effect.Comment: 4 pages, 1 figure, to appear in Proceedings of the conference QCD 08, Montpellier, 7-12 July 200

Liquid droplet formation by HP1α suggests a role for phase separation in heterochromatin.

Gene silencing by heterochromatin is proposed to occur in part as a result of the ability of heterochromatin protein 1 (HP1) proteins to spread across large regions of the genome, compact the underlying chromatin and recruit diverse ligands. Here we identify a new property of the human HP1α protein: the ability to form phase-separated droplets. While unmodified HP1α is soluble, either phosphorylation of its N-terminal extension or DNA binding promotes the formation of phase-separated droplets. Phosphorylation-driven phase separation can be promoted or reversed by specific HP1α ligands. Known components of heterochromatin such as nucleosomes and DNA preferentially partition into the HP1α droplets, but molecules such as the transcription factor TFIIB show no preference. Using a single-molecule DNA curtain assay, we find that both unmodified and phosphorylated HP1α induce rapid compaction of DNA strands into puncta, although with different characteristics. We show by direct protein delivery into mammalian cells that an HP1α mutant incapable of phase separation in vitro forms smaller and fewer nuclear puncta than phosphorylated HP1α. These findings suggest that heterochromatin-mediated gene silencing may occur in part through sequestration of compacted chromatin in phase-separated HP1 droplets, which are dissolved or formed by specific ligands on the basis of nuclear context

Antenatally diagnosed ADPKD

[Extract] Advances in antenatal ultrasonographyhave substantially improved the counseling of pregnantwomen.1�4With this advancement comes a diagnosticdilemma in the approach to antenatal diagnoses of cystickidney disease. The differential diagnosis of enlargedcystic echogenic kidneys includes autosomal dominantpolycystic kidney disease (ADPKD), autosomal recessivepolycystic kidney disease, renal cysts and diabetessyndrome, and other syndromic disorders

All-Multiplicity Non-Planar MHV Amplitudes in sYM at Two Loops

We give a closed-form, prescriptive representation of all-multiplicity two-loop MHV amplitude integrands in fully-color-dressed (non-planar) maximally supersymmetric Yang-Mills theory.Comment: Corrected a sign mistake for the pentabox numerators (table IV). Minor improvements and references added in v2. 4+3 pages, 22 figures, 4 tables, infinity of new amplitudes. Ancillary files contain a Mathematica implementation of our resul

Long-term variability of drought indices in the Czech Lands and effects of external forcings and large-scale climate variability modes

While a considerable number of records document the temporal variability of droughts for central Europe, the understanding of its underlying causes remains limited. In this contribution, time series of three drought indices (Standardized Precipitation Index – SPI; Standardized Precipitation Evapotranspiration Index – SPEI; Palmer Drought Severity Index – PDSI) are analyzed with regard to mid- to long-term drought variability in the Czech Lands and its potential links to external forcings and internal climate variability modes over the 1501–2006 period. Employing instrumental and proxy-based data characterizing the external climate forcings (solar and volcanic activity, greenhouse gases) in parallel with series representing the activity of selected climate variability modes (El Niño–Southern Oscillation – ENSO; Atlantic Multidecadal Oscillation – AMO; Pacific Decadal Oscillation – PDO; North Atlantic Oscillation – NAO), regression and wavelet analyses were deployed to identify and quantify the temporal variability patterns of drought indices and similarity between individual signals. Aside from a strong connection to the NAO, temperatures in the AMO and (particularly) PDO regions were disclosed as one of the possible drivers of inter-decadal variability in the Czech drought regime. Colder and wetter episodes were found to coincide with increased volcanic activity, especially in summer, while no clear signature of solar activity was found. In addition to identification of the links themselves, their temporal stability and structure of their shared periodicities were investigated. The oscillations at periods of approximately 60–100 years were found to be potentially relevant in establishing the teleconnections affecting the long-term variability of central European droughts.</p

Phenotypic Transition of the Collecting Duct Epithelium in Congenital Urinary Tract Obstruction

Epithelial-mesenchymal transition (EMT) has emerged in recent years as an important process in the development of organ fibrosis in many human diseases. Our previous experience in a nonhuman primate model of obstructive nephropathy suggested that EMT of collecting duct epithelium contributes to the development of interstitial fibrosis. In this study we demonstrate for the first time in humans that obstructed fetal collecting duct epithelium undergoes transition to mesenchymal phenotype, characterized by decreased expression of epithelial markers, de novo expression of mesenchymal markers with subsequent loss of cell-cell interaction, disruption of the basement membrane, and increased deposition of extracellular matrix into the expanded interstitium of the obstructed kidney. The results of this study therefore support the previous findings from animal studies and suggest that EMT of the collecting duct epithelium might contribute to the development of interstitial fibrosis in human fetal obstructive nephropathy