94 research outputs found
Total Cross Sections
A unified approach to total cross-sections, based on the QCD contribution to
the rise with energy, is presented for the processes , , . For proton processes, a discussion of
the role played by soft gluon summation in taming the fast rise due to
mini-jets is presented. For photon-photon processes, a comparison with other
models indicates the need for precision measurements in both the low and high
energy region, likely only with measurements at future Linear Colliders.Comment: 15 pages, 9 figures, LaTeX, uses hsproc.sty and art10.sty. Talk given
by G. Pancheri at 'International Hadron Structure-2000', October 1-6,
Staralesn
On the variability and increasing trends of heat waves over India
Over India, heat waves occur during the summer months of April to June. A gridded daily temperature data set for the period, 1961–2013 has been analyzed to examine the variability and trends in heat waves over India. For identifying heat waves, the Excess Heat Factor (EHF) and 90th percentile of maximum temperatures were used. Over central and northwestern parts of the country, frequency, total duration and maximum duration of heat waves are increasing. Anomalous persistent high with anti-cyclonic flow, supplemented with clear skies and depleted soil moisture are primarily responsible for the occurrence of heat waves over India. Variability of heat waves over India is influenced by both the tropical Indian Ocean and central Pacific SST anomalies. The warming of the tropical Indian Ocean and more frequent El Nino events in future may further lead to more frequent and longer lasting heat waves over India
QCD predictions for total cross-sections and the Froissart Bound
This article does not have an abstract
The current status and future prospects for therapeutic targeting of KEAP1-NRF2 and β-TrCP-NRF2 interactions in cancer chemoresistance
Drug resistance is one of the biggest challenges in cancer treatment and limits the potential to cure patients. In many tumors, sustained activation of the protein NRF2 makes tumor cells resistant to chemo- and radiotherapy. Thus, blocking inappropriate NRF2 activity in cancers has been shown to reduce resistance in models of the disease. There is a growing scientific interest in NRF2 inhibitors. However, the compounds developed so far are not target-specific and are associated with a high degree of toxicity, hampering clinical applications. Compounds that can enhance the binding of NRF2 to its ubiquitination-facilitating regulator proteins, either KEAP1 or β-TrCP, have the potential to increase NRF2 degradation and may be of value as potential chemosensitising agents in cancer treatment. Approaches based on molecular glue-type mechanisms, in which ligands stabilise a ternary complex between a protein and its binding partner have shown to enhance β-catenin degradation by stabilising its interaction with β-TrCP. This strategy could be applied to rationally discover degradative β-TrCP-NRF2 and KEAP1-NRF2 protein-protein interaction enhancers. We are proposing a novel approach to selectively suppress NRF2 activity in tumors. It is based on recent methodology and has the potential to be a promising new addition to the arsenal of anticancer agents
Total and inelastic cross-sections at LHC at CM energy of 7 TeV and beyond
We discuss expectations for the total and inelastic cross-sections at LHC CM
energies {and } obtained in an eikonal minijet
model augmented by soft gluon -resummation, which we describe in some
detail. We present a band of predictions which encompass recent LHC data and
suggest that the inelastic cross-section described by two channel eikonal
models include only uncorrelated processes. We show that this interpretation of
the model is supported by the LHC data.Comment: 32 pages, 6 figures, Version to appear in Physical Review
Soft Gluon kt-Resummation and the Froissart bound
We study soft gluon kt-resummation and the relevance of zero momentum gluons
for the energy dependence of total hadronic cross-sections. We discuss a model
in which consistency of the energy dependence of the cross-section with the
limitation of the Froissart bound, is directly related to the behaviour of the
strong coupling constant in the infrared region. Our predictions for the
asymptotic behaviour are shown to be related to the ansatz that the infrared
behaviour of the QCD strong coupling constant follows an inverse power law.Comment: To be published in Physics Letters B. This version is 25% shorter
than the previous one, as requested by the restrictions on the number of
pages for this Journal. Some equations have been skipped, some text has been
summarized. The earliest version may be useful for a better understanding of
some of the materia
Total cross-section and rapidity gap survival probability at the LHC through an eikonal with soft gluon resummation
New results are presented for total
cross-sections, in the framework of our QCD based model (GGPS). This is an
improved eikonal mini-jet model, where soft gluon radiation tames the fast
energy rise normally present in mini-jet models. We discuss the variability in
our predictions and provide a handy parametrization of our results for the LHC.
We find that our model predictions span the range . While this matches nicely with the range of most other
models, it does not agree with recent ones which include a "hard" Pomeron, even
though our model does include hard scattering. We compute the survival
probability for Large Rapidity Gap (LRG) events at the LHC and at the Tevatron.
These events are relevant, for example, for Higgs signal in the fusion
process. We also explore whether measurements of the total cross-sections at
the LHC can help us sharpen the model parameters and hence estimates for these
survival probabilities, further.Comment: 15 pages, 3 figures, LaTe
Theoretical expectations for total cross-sections at the large hadron collider
In this note, we summarize and compare various model predictions for
total cross-section , giving an estimate of the range of
predictions for the total cross-section, expected at
the LHC. We concentrate on the results for \sigma_{\tot}^{pp} obtained in a
particular QCD based model of the energy dependence of the total cross-section,
including the effect of soft gluon radiation. We obtain the range of
predictions in this model by exploring the allowed range of model parameters.
We further give a handy parametrisation of these results which incidentally
spans the range of various other available predictions at the LHC as well.Comment: 12 pages, 6 figures, laTeX, requires ias.cls, ias.sty include
Combined docking and machine learning identify key molecular determinants of ligand pharmacological activity on β2 adrenoceptor
G protein-coupled receptors (GPCRs) are valuable therapeutic targets for many diseases. A central question of GPCR drug discovery is to understand what determines the agonism or antagonism of ligands that bind them. Ligands exert their action via the interactions in the ligand binding pocket. We hypothesized that there is a common set of receptor interactions made by ligands of diverse structures that mediate their action and that among a large dataset of different ligands, the functionally important interactions will be over-represented. We computationally docked ~2700 known β2AR ligands to multiple β2AR structures, generating ca 75 000 docking poses and predicted all atomic interactions between the receptor and the ligand. We used machine learning (ML) techniques to identify specific interactions that correlate with the agonist or antagonist activity of these ligands. We demonstrate with the application of ML methods that it is possible to identify the key interactions associated with agonism or antagonism of ligands. The most representative interactions for agonist ligands involve K972.68×67 , F194ECL2 , S2035.42×43 , S2045.43×44 , S2075.46×641 , H2966.58×58 , and K3057.32×31 . Meanwhile, the antagonist ligands made interactions with W2866.48×48 and Y3167.43×42 , both residues considered to be important in GPCR activation. The interpretation of ML analysis in human understandable form allowed us to construct an exquisitely detailed structure-activity relationship that identifies small changes to the ligands that invert their pharmacological activity and thus helps to guide the drug discovery process. This approach can be readily applied to any drug target
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