T cell signaling: biochemical and structural characterization of Itk, CypA and HS1.

T cell signaling pathway involves complicated intermolecular and intramolecular interactions. Interleukin-2 tyrosine kinase (Itk), cyclophilin A (CypA) and hematopoietic lineage cell-specific protein (HS1) are three key mediators in this pathway. This thesis explores the negative regulation of Itk activity by CypA and the autoinhibitory regulation mechanism by the HS1 protein through biochemical and structural methods

Matching the B-meson quasidistribution amplitude in the RI/MOM scheme

Within the framework of large momentum effective theory (LaMET), the light-cone distribution amplitude of $B$-meson in heavy-quark effective theory (HQET) can be extracted from lattice calculations of quasidistribution amplitude through hard-collinear factorization formula. This quasiquantity can be renormalized in a regularization-independent momentum subtraction scheme (RI/MOM). In this work, we derive the matching coefficient which connects the renormalized quasiditribution amplitude in the RI/MOM scheme and standard LCDA in the $\overline{\textrm{MS}}$ scheme at one-loop accuracy. Our numerical analysis approves of the feasibility of RI/MOM scheme for renormalizing $B$-meson quasidistribution amplitude. These results will be crucial for exploring the partonic structure of heavy-quark hadrons.Comment: 19 pages, 4 figure

BROKEN MIRRORS "THE SHAPELESS IMAGE"

[EN] What is has no name. What has a name is not. The question of the reflection of reality is on the base of our own cultures. The construction of the language, the patrimony of the artistic reflection of the above mentioned reality, shape our hereditary baggage. Consequently, it determines the way in which we approach its comprehension from every culture. A big differentiation appears in the two cultures in which I establish these small reflections: our western culture and that from the other side of the mirror, the Chinese. This differentiation is in the essence of the two cultures, for example in the denomination of things, that is, their own languages. It is not by chance that our western languages have been defined in an oral way and, on the contrary, the Chinese language is structured in a written way, "pictographic" in origin. This will be our Ariadna's thread in this small labyrinth of mirrors that I propose here.[ES] Lo que es, no tiene nombre. Lo que tiene nombre, no es. La cuestión del reflejo de la realidad está en la base de nuestras propias culturas. La construcción del lenguaje, el patrimonio del reflejo artístico de la misma, conforman nuestro bagaje hereditario. En consecuencia, determina la manera en que, desde cada cultura, nos acercamos a su comprensión. En las dos culturas en las que establezco estas pequeñas reflexiones: la nuestra Occidental y, la del otro lado del espejo, la China, se da, en origen, una diferenciación tan grande en la esencia de las mismas como es la denominación de las cosas, o sea, su propio lenguaje. No es casual que nuestros idiomas occidentales se hayan definido de manera oral y, por contra, el lenguaje chino se halla estructurado de manera escrita, "pictográfica" en origen. Este será nuestro hilo de Ariadna en este pequeño laberinto de espejos que, aquí, propongo.Celaya, P. (2012). ESPEJOS ROTOS "LA IMAGEN SIN FORMA". EGA. Revista de Expresión Gráfica Arquitectónica. 17(19):170-179. doi:10.4995/ega.2012.1368SWORD1701791719FENG Xiao Min, L'union de l'encre et du pinceau. Ed. Flammarion, París, 2003.GUO Ruo Xu, Tu hua jian wen zhi. Ed. Ren Min Shu Chubansque. Beijin, 1983.YU Anlan, Hua lun cong kan . Ed. Ren Min Shu Chubansque. Beijin, 1960

Seismic Performance Investigation of Cold-Formed Steel Framed Shear Walls with Steel Sheathing

Cold-formed steel (CFS) framed shear walls with steel sheet sheathing can achieve higher shear resistance compared to conventional CFS framed shear walls. Experimental and numerical investigation of seismic behavior was present on two CFS shear walls sheathed with steel sheet for the base layer combined with gypsum wallboards for the face layer on both sides. Monotonic shear and cyclic loading tests were conducted on wall specimens. The failure mechanism, bearing capacity, stiffness and ductility of specimens were obtained. On the basis of rational simplification of CFS framed shear walls, the finite element software ABAQUS was used to simulate the monotonic behavior of CFS shear walls and the structural analysis software OpenSees was used in developing and calibrating 2D models of reversed cyclic shear wall test. A comparison between the numerical simulations and the test results showed a good agreement between the results of the numerical studies and the test results. The conclusions of this study can be applied to the seismic design of CFS framed shear walls

Inverse Moment of the \u3cstrong\u3e\u3cem\u3eB\u3c/em\u3e\u3c/strong\u3e Meson Quasidistribution Amplitude

We perform a study on the structure of the inverse moment (IM) of quasidistributions, by taking B-meson quasidistribution amplitude (quasi-DA) as an example. Based on a one-loop calculation, we derive the renormalization group equation and velocity evolution equation for the first IM of quasi-DA. We find that, in the large velocity limit, the first IM of B-meson quasi-DA can be factorized into IM as well as logarithmic moments of light-cone distribution amplitude (LCDA), accompanied by short distance coefficients. Our results can be useful either in understanding the patterns of perturbative matching in large momentum effective theory or evaluating inverse moment of B-meson LCDA on the lattice

Miniaturized guided wave structures and applications

This thesis examines the properties of novel transmission lines and waveguides as well as their practical applications. The research begins with a discussion of metamaterial transmission lines. Two new composite right/left-handed designs formed in shielded striplines are presented and shown to have great left-handed bands. In the waveguides research, we demonstrate the multilayer, narrowband and half-mode folded waveguide with the benefit of guide miniaturization. Due to the almost half metallic surface reduction of half-mode waveguide, a novel planar half-mode substrate integrated waveguide is presented and its properties are analyzed. It has the great integration with planar components and stops the radiation of conventional open waveguides. One application based on this medium is a novel switchable substrate waveguide that can be switched between two types of mode via the biasing of pin diodes. Another application is a tunable phase shifter that has a maximum phase shift of 50 degrees with acceptable insertion loss. A theoretical method for the analysis of planar half-mode waveguides using transverse resonance technique is introduced in this thesis. This method is used to locate the cut-off frequency of the waveguide and analyse the equivalent circuit loaded with discrete components. This novel technique has the advantage of simplicity and compares well with results of electromagnetic simulation and measurement

A Remote Substrate Docking Mechanism for the Tec Family Tyrosine Kinases

During T cell signaling, Itk selectively phosphorylates a tyrosine within its own SH3 domain and a tyrosine within PLCγ1. We find that the remote SH2 domain in each of these substrates is required to achieve efficient tyrosine phosphorylation by Itk and extend this observation to two other Tec family kinases, Btk and Tec. Additionally, we detect a stable interaction between the substrate SH2 domains and the kinase domain of Itk and find that addition of specific, exogenous SH2 domains to the in vitro kinase assay competes directly with substrate phosphorylation. On the basis of these results, we show that the kinetic parameters of a generic peptide substrate of Itk are significantly improved via fusion of the peptide substrate to the SH2 domain of PLCγ1. This work is the first characterization of a substrate docking mechanism for the Tec kinases and provides evidence of a novel, phosphotyrosine-independent regulatory role for the ubiquitous SH2 domain