exclusive processes
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2022 ◽  
pp. 135-152
Author(s):  
Hugo Ferrinho Lopes ◽  
Alona Bondarenko

This chapter puts the European and Euro-Atlantic integration of the Balkans into the spotlight and further analyzes the reactions from Russia. This integrative process is a relevant intention, especially after the revolutionary changes of the 1990s and the collapse of the communist bloc. Literature is scarce, lacks an integrated approach, and barely addresses the topic from a comparative perspective. This research seeks to fill this gap through an empirical, systematic, and comparative analysis of the integration and disintegration processes across the region. The argument is that the integration is asymmetric, both between the two international organizations and between the two sub-regions, and that Russian investment decreases as integration goes forward. Findings highlight the complex interactions and interdependencies of the three mutually exclusive processes: the integration into the EU and NATO, the internal fragmentation of the region, and a transformation in the relationship with Russia when chasing the enlargement into these structures.


2022 ◽  
Vol 258 ◽  
pp. 02007
Author(s):  
Edward Shuryak

Exclusive processes are traditionally described by perturbative hard blocks and “distribution amplitudes" (DAs), matrix elements of operators of various chiral structure and twist. One paper (with I.Zahed) calculate instanton contribution to hard blocks, which is found comparable to perturbative one in few-GeV2 Q2 region of interest. Another paper aims at comprehensive wave functions of mesons, baryons and pentaquarks. The last ones are also included as 5-quark component of the baryons. The calculation, using ’t Hooft operator, gives x-dependence and magnitude of the antiquark PDF. It explains long standing issue of strong flavor asymmetry of antiquark sea. The third paper (also with I.Zahed) is semi-review on the instanton-sphaleron processes in QCD and electroweak theories, with emphasis on their possible experimental observation via double diffractive events at LHC and RHIC. Insert your english abstract here.


2021 ◽  
Vol 106 (6) ◽  
pp. 42-51
Author(s):  
Roman Bugrov ◽  

The purpose of the article is to analyze possible strategies for the development of the EU, as a key institutional driver of integration that plays a visible role both at the regional and global levels. In recent decades the EU pursued a policy of dynamic expansion, which nowadays meets with resistance from both the “external environment” and within the EU. In this regard, there is a need to determine the limits of the development of regional integration, this is especially important in the context of modern global crisis. This issue is considered from the point of view of balancing between widening and deepening of integration processes. Enlargement (considered more as an expansion) and deepening may put the EU before a choice of priorities; however, they are not mutually exclusive processes. The main challenge is the choice of a strategy that is subordinated to the political will and interests of decision-makers. In order to analytically address the issue, the concept of regionalism and its modern version of “open” regionalism is used as a theoretical approach. It is outlined the extra-regional (global) nature of the EU development strategy. The author concludes that the current anti-crisis strategy of the EU is the construction of a global trading system with elements of regulatory mechanisms that ensures the sustainable competitiveness of the EU, even at the expense of internal centralization.


2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Martin Beneke ◽  
Philipp Böer ◽  
Jan-Niklas Toelstede ◽  
K. Keri Vos

Abstract We discuss the generalization of the leading-twist light-cone distribution amplitude for light mesons including QED effects. This generalization was introduced to describe virtual collinear photon exchanges at the strong-interaction scale ΛQCD in the factorization of QED effects in non-leptonic B-meson decays. In this paper we study the renormalization group evolution of this non-perturbative function. For charged mesons, in particular, this exhibits qualitative differences with respect to the well-known scale evolution in QCD only, especially regarding the endpoint-behaviour. We analytically solve the evolution equation to first order in the electromagnetic coupling αem, which resums large logarithms in QCD on top of a fixed-order expansion in αem. We further provide numerical estimates for QED corrections to Gegenbauer coefficients as well as inverse moments relevant to (QED-generalized) factorization theorems for hard exclusive processes.


2021 ◽  
Vol 7 (7) ◽  
pp. 509
Author(s):  
Nikita Mehta ◽  
Ravindra Patil ◽  
Abhishek Baghela

The conidia of a hemibiotrophic fungus, Colletotrichum gloeosporioides, can conventionally form a germ tube (GT) and develop into a fungal colony. Under certain conditions, they tend to get connected through a conidial anastomosis tube (CAT) to share the nutrients. CAT fusion is believed to be responsible for the generation of genetic variations in few asexual fungi, which appears problematic for effective fungal disease management. The physiological and molecular requirements underlying the GT formation versus CAT fusion remained underexplored. In the present study, we have deciphered the physiological prerequisites for GT formation versus CAT fusion in C. gloeosporioides. GT formation occurred at a high frequency in the presence of nutrients, while CAT fusion was found to be higher in the absence of nutrients. Younger conidia were found to form GT efficiently, while older conidia preferentially formed CAT. Whole transcriptome analysis of GT and CAT revealed highly differential gene expression profiles, wherein 11,050 and 9786 genes were differentially expressed during GT formation and CAT fusion, respectively. A total of 1567 effector candidates were identified; out of them, 102 and 100 were uniquely expressed during GT formation and CAT fusion, respectively. Genes coding for cell wall degrading enzymes, germination, hyphal growth, host-fungus interaction, and virulence were highly upregulated during GT formation. Meanwhile, genes involved in stress response, cell wall remodeling, membrane transport, cytoskeleton, cell cycle, and cell rescue were highly upregulated during CAT fusion. To conclude, the GT formation and CAT fusion were found to be mutually exclusive processes, requiring differential physiological conditions and sets of DEGs in C. gloeosporioides. This study will help in understanding the basic CAT biology in emerging fungal model species of the genus Colletotrichum.


Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 3034
Author(s):  
Christian Bailly ◽  
Xavier Thuru ◽  
Bruno Quesnel

Upon T-cell receptor stimulation, the Programmed cell Death-1 receptor (PD-1) expressed on T-cells can interact with its ligand PD-L1 expressed at the surface of cancer cells or antigen-presenting cells. Monoclonal antibodies targeting PD-1 or PD-L1 are routinely used for the treatment of cancers, but their clinical efficacy varies largely across the variety of tumor types. A part of the variability is linked to the existence of several forms of PD-L1, either expressed on the plasma membrane (mPD-L1), at the surface of secreted cellular exosomes (exoPD-L1), in cell nuclei (nPD-L1), or as a circulating, soluble protein (sPD-L1). Here, we have reviewed the different origins and roles of sPD-L1 in humans to highlight the biochemical and functional heterogeneity of the soluble protein. sPD-L1 isoforms can be generated essentially by two non-exclusive processes: (i) proteolysis of m/exoPD-L1 by metalloproteases, such as metalloproteinases (MMP) and A disintegrin and metalloproteases (ADAM), which are capable of shedding membrane PD-L1 to release an active soluble form, and (ii) the alternative splicing of PD-L1 pre-mRNA, leading in some cases to the release of sPD-L1 protein isoforms lacking the transmembrane domain. The expression and secretion of sPD-L1 have been observed in a large variety of pathologies, well beyond cancer, notably in different pulmonary diseases, chronic inflammatory and autoimmune disorders, and viral diseases. The expression and role of sPD-L1 during pregnancy are also evoked. The structural heterogeneity of sPD-L1 proteins, and associated functional/cellular plurality, should be kept in mind when considering sPD-L1 as a biomarker or as a drug target. The membrane, exosomal and soluble forms of PD-L1 are all integral parts of the highly dynamic PD-1/PD-L1 signaling pathway, essential for immune-tolerance or immune-escape.


2021 ◽  
Vol 8 ◽  
Author(s):  
Wilfried J. J. Meijer ◽  
D. Roeland Boer ◽  
Saúl Ares ◽  
Carlos Alfonso ◽  
Fernando Rojo ◽  
...  

Bacterial conjugation is the main horizontal gene transfer route responsible for the spread of antibiotic resistance, virulence and toxin genes. During conjugation, DNA is transferred from a donor to a recipient cell via a sophisticated channel connecting the two cells. Conjugation not only affects many different aspects of the plasmid and the host, ranging from the properties of the membrane and the cell surface of the donor, to other developmental processes such as competence, it probably also poses a burden on the donor cell due to the expression of the large number of genes involved in the conjugation process. Therefore, expression of the conjugation genes must be strictly controlled. Over the past decade, the regulation of the conjugation genes present on the conjugative Bacillus subtilis plasmid pLS20 has been studied using a variety of methods including genetic, biochemical, biophysical and structural approaches. This review focuses on the interplay between RcopLS20, RappLS20 and Phr*pLS20, the proteins that control the activity of the main conjugation promoter Pc located upstream of the conjugation operon. Proper expression of the conjugation genes requires the following two fundamental elements. First, conjugation is repressed by default and an intercellular quorum-signaling system is used to sense conditions favorable for conjugation. Second, different layers of regulation act together to repress the Pc promoter in a strict manner but allowing rapid activation. During conjugation, ssDNA is exported from the cell by a membrane-embedded DNA translocation machine. Another membrane-embedded DNA translocation machine imports ssDNA in competent cells. Evidences are reviewed indicating that conjugation and competence are probably mutually exclusive processes. Some of the questions that remain unanswered are discussed.


2021 ◽  
Vol 81 (3) ◽  
Author(s):  
V. P. Goncalves ◽  
D. E. Martins ◽  
M. S. Rangel

AbstractThe dilepton production at forward rapidities in diffractive and exclusive processes present in ultraperipheral PbPb collisions at the LHC is investigated. Predictions for the $$e^+ e^-$$ e + e - , $$\mu ^+ \mu ^-$$ μ + μ - and $$\tau ^+ \tau ^-$$ τ + τ - cross sections are presented taking into account of realistic cuts that can be implemented by the LHCb Collaboration in a future experimental analysis. Our results indicate that the background associated with the diffractive production can be strongly suppressed and the exclusive processes can be cleanly separated. For the $$\tau ^+ \tau ^-$$ τ + τ - production, the semi and purely leptonic decay channels are considered. Our results indicate that a future experimental analysis of the dilepton production at the LHCb is feasible and can be useful to search for BSM physics.


2021 ◽  
Author(s):  
Nikita Mehta ◽  
Ravindra Patil ◽  
Abhishek Baghela

AbstractThe conidia of a hemibiotrophic fungus Colletotrichum gloeosporioides can conventionally form germ tube (GT) and develop in to a fungal colony, while under certain conditions, they tend to get connected with each other through conidial anastomosis tube (CAT) so as to share the nutrients. CAT fusion is believed to be responsible for generation of genetic variations in few asexual fungi, which appears problematic for effective fungal disease management. The physiological and molecular mechanism underlying the GT versus CAT formation remained unexplored. In the present study, we have deciphered the decision switch responsible for GT formation versus CAT fusion in C. gloeosporioides. GT formation occurred at high frequency in the presence of nutrients, while CAT fusion was found to be higher in absence of nutrients. Younger conidia were found to form GT efficiently, whilst older conidia preferentially formed CAT. Whole transcriptome analysis of GT and CAT fusion revealed differential molecular requirements for these two processes. We identified 11050 and 9786 differentially expressed genes (DEGs) in GT and CAT, respectively. A total 1567 effector candidates were identified, of them 103 and 101 were uniquely secreted during GT and CAT formation respectively. Genes coding for cell wall degrading enzymes, germination, hyphal growth, host-fungus interaction and virulence were up-regulated during GT formation. Whilst, genes involved in stress response, cell wall remodelling, membrane transport, cytoskeleton, cell cycle, and cell rescue were highly up-regulated during CAT fusion. To conclude, the GT and CAT fusion were found to be mutually exclusive processes, requiring differential physiological conditions and sets of DEGs in C. gloeosporioides. This will help to understand the basic CAT biology in the genus Colletotrichum.


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