Single Top production at LHC

The Production of single top quarks at LHC provides an ideal framework to investigate the properties of electroweak interaction, in particular of the {\it tWb} coupling. Moreover, single top is a powerful mean to identify physics beyond the standard model. All three different production mechanisms of single top are expected to be observed at LHC. Recent studies from ATLAS and CMS are presented.Comment: 5 pages, Presented at the XLIrst Rencontres de Moriond - QCD and High Energy Hadronic Interaction

Study of anomalous top quark FCNC interactions via tWtW-channel of single top

The potential of the LHC for investigation of anomalous top quark interactions with gluon ($tug,tcg$) through the production of $tW$-channel of single top quark is studied. In the Standard Model, the single top quarks in the $tW$-channel mode are charge symmetric meaning that $\sigma(pp\to t+W^{-}) = \sigma(pp\to \bar{t}+W^{+})$. However, the presence of anomalous FCNC couplings leads to charge asymmetry. In this paper a method is proposed in which this charge asymmetry may be used to constrain anomalous FCNC couplings. The strength of resulting constraints is estimated for the LHC for the center of mass energies of 7 and 14 TeV.Comment: 13 pages, 4 figures, new references adde

Semi-Leptonic Decay of a Polarized Top Quark in the Noncommutative Standard Model

In this paper we study the noncommutative effects to the lepton spectrum from the decay of a polarized top quark. It is shown that the lowest contribution comes from the quadratic terms of the noncommutative parameter. The deviations from the standard model are significant for small values of the noncommutative characteristic scale. However, the charged lepton spin correlation coefficient has a remarkable deviation from the standard model from very low values of the noncommutative characteristic scale to 1 TeV.Comment: 8 pages, 4 figure

Systematic discovery of structural elements governing stability of mammalian messenger RNAs.

Decoding post-transcriptional regulatory programs in RNA is a critical step towards the larger goal of developing predictive dynamical models of cellular behaviour. Despite recent efforts, the vast landscape of RNA regulatory elements remains largely uncharacterized. A long-standing obstacle is the contribution of local RNA secondary structure to the definition of interaction partners in a variety of regulatory contexts, including--but not limited to--transcript stability, alternative splicing and localization. There are many documented instances where the presence of a structural regulatory element dictates alternative splicing patterns (for example, human cardiac troponin T) or affects other aspects of RNA biology. Thus, a full characterization of post-transcriptional regulatory programs requires capturing information provided by both local secondary structures and the underlying sequence. Here we present a computational framework based on context-free grammars and mutual information that systematically explores the immense space of small structural elements and reveals motifs that are significantly informative of genome-wide measurements of RNA behaviour. By applying this framework to genome-wide human mRNA stability data, we reveal eight highly significant elements with substantial structural information, for the strongest of which we show a major role in global mRNA regulation. Through biochemistry, mass spectrometry and in vivo binding studies, we identified human HNRPA2B1 (heterogeneous nuclear ribonucleoprotein A2/B1, also known as HNRNPA2B1) as the key regulator that binds this element and stabilizes a large number of its target genes. We created a global post-transcriptional regulatory map based on the identity of the discovered linear and structural cis-regulatory elements, their regulatory interactions and their target pathways. This approach could also be used to reveal the structural elements that modulate other aspects of RNA behaviour

Open Government Data Ecosystems: A Closed-Loop Perspective

Open data initiatives have opened new alternatives in creating benefits for the public through secondary use governmental data. From some perspectives, benefits will come from the development of innovative applications using the data, and from the new business models enabled by these applications. From other perspectives, open data applications offer an opportunity for increased citizen participation, improved transparency and accountability. Although the number of published governmental datasets has increased in many countries, producing the expected benefits – and even measuring them – has proven difficult. Creating the expected benefits depends on the development of an ‘ecosystem’ of government actors and private stakeholders that enables multiple forms of interactions and value creation. We propose that modeling and simulation of this open data ecosystem can expand our understanding of its enablers and barriers, leading to improvements in policy making and ultimate outcome of open data initiatives