scholarly journals A Combined Global and Local Approach to Elucidate Spatial Organization of the Mycobacterial ParB-parSPartition Assembly

Biochemistry ◽  
2011 ◽  
Vol 50 (11) ◽  
pp. 1799-1807 ◽  
Author(s):  
Barnali N. Chaudhuri ◽  
Sayan Gupta ◽  
Volker S. Urban ◽  
Mark R. Chance ◽  
Rhijuta D’Mello ◽  
...  
Author(s):  
A. Amparan ◽  
S. Marcaida ◽  
Ion Zaballa

The structure of a rational matrix is given by its Smith-McMillan invariants. Some properties of the Smith-McMillan invariants of rational matrices with elements in different principal ideal domains are presented: In the ring of polynomials in one indeterminate (global structure), in the local ring at an irreducible polynomial (local structure), and in the ring of proper rational functions (infinite structure). Furthermore, the change of the finite (global and local) and infinite structures is studied when performing a Mobius transformation on a rational matrix. The results are applied to define an equivalence relation in the set of polynomial matrices, with no restriction on size, for which a complete system of invariants are the finite and infinite elementary divisors.


Author(s):  
Craig P. Lusk ◽  
Larry L. Howell

Change-point mechanisms are shown to be significant in the design of surface micromachined MEMS. The design space of change-point mechanisms is derived for an arbitrary single loop change-point mechanism using a global and local approach. A function on the design space, the mechanism’s length, is constructed for fourbars. An inversion operator, a mapping from the design space to the design space, is also constructed for fourbars. The method for constructing the function and the operator is shown to be capable of extension to single loop change-point mechanisms with five or more links. The results give insight into design possibilities and limitations of change-point mechanisms.


2016 ◽  
Vol 812 ◽  
pp. 222-250 ◽  
Author(s):  
Dominik Krug ◽  
Daniel Chung ◽  
Jimmy Philip ◽  
Ivan Marusic

To date, the understanding of the role buoyancy plays in the entrainment process in unstable configurations such as turbulent plumes remains incomplete. Towards addressing this question, we set up a flow in which a plume evolves in time instead of space. We demonstrate that the temporal problem is equivalent to a spatial plume in a strong coflow and address in detail how the temporal plume can be realized via direct numerical simulation. Using numerical data of plume simulations up to $Re_{\unicode[STIX]{x1D706}}\approx 100$, we show that the entrainment coefficient can be determined consistently using a global entrainment analysis in an integral framework as well as via a local approach. The latter is based on a study of the local propagation of the turbulent/non-turbulent interface relative to the fluid. Locally, this process is dominated by small-scale diffusion which is amplified by interface convolutions such that the total entrained flux is independent of viscosity. Further, we identify a direct buoyancy contribution to entrainment by baroclinic torque, which accounts for 8 %–12 % of the entrained flux locally, comparable to the 15 % buoyancy contribution at the integral level. It appears that the baroclinic torque is a mechanism that might explain higher values of the entrainment coefficient in spatial plumes compared with jets.


2017 ◽  
Vol 24 (04) ◽  
pp. 1740010 ◽  
Author(s):  
J. Onam González ◽  
Luis A. Correa ◽  
Giorgio Nocerino ◽  
José P. Palao ◽  
Daniel Alonso ◽  
...  

When deriving a master equation for a multipartite weakly-interacting open quantum systems, dissipation is often addressed locally on each component, i.e. ignoring the coherent couplings, which are later added ‘by hand’. Although simple, the resulting local master equation (LME) is known to be thermodynamically inconsistent. Otherwise, one may always obtain a consistent global master equation (GME) by working on the energy basis of the full interacting Hamiltonian. Here, we consider a two-node ‘quantum wire’ connected to two heat baths. The stationary solution of the LME and GME are obtained and benchmarked against the exact result. Importantly, in our model, the validity of the GME is constrained by the underlying secular approximation. Whenever this breaks down (for resonant weakly-coupled nodes), we observe that the LME, in spite of being thermodynamically flawed: (a) predicts the correct steady state, (b) yields with the exact asymptotic heat currents, and (c) reliably reflects the correlations between the nodes. In contrast, the GME fails at all three tasks. Nonetheless, as the inter-node coupling grows, the LME breaks down whilst the GME becomes correct. Hence, the global and local approach may be viewed as complementary tools, best suited to different parameter regimes.


2021 ◽  
Author(s):  
Omar Khalaf ◽  
◽  
Alhan Ibrahim ◽  
Nor Ja`Afar ◽  
◽  
...  

This paper deals with the historical overview of the castles and forts and what are the rules and foundations on which they arose. Castles constitute tourist attractions at the global and local levels as well as studying the variables and elements of spatial organization, in addition to the concepts of urban development strategies for historical regions. Salah al-Din Citadel was elected in Cairo because of the historical and urban depth it carries today. By studying how it originated and what changes occurred on it after the explorations and excavations that are taking place (design and development strategies) and then the practical study and analysis of the results of the practical study (General conclusions). The aim of the study is to analyze the urban fabric of Salah al-Din Citadel and define indicators for the characteristics of spatial organization using the Geographic Information Systems Program (GIS) and (Space Syntax) analysis, as they have an impact on the development of city centers and their importance in shaping the urban body of the city in an attempt to reach the strategies for urban development and possible urbanization of historic city centers (especially the cities of the castles). From the review of studies that dealt with the study of the organizational characteristics of urban spaces, the research problem crystallized (The lack of a clear perception of studying the characteristics of the spatial organization of castles and their impact on the development of urban development strategies) and the research hypothesis was formulated with (The study of the characteristics of the spatial organization of castles affects the integration of the castle with its urban surroundings and its historical characteristics ). The research was based on the development of the elements of a theoretical framework on the characteristics of spatial organization and then applied in practice to the castle of Salah al-Din as a model.


Author(s):  
Erasmo Carrera ◽  
Ibrahim Kaleel ◽  
Manish Nagaraj ◽  
Marco Petrolo

A global-local approach has been developed for the elasto-plastic analysis of thin-walled metal structures, which interfaces between commercial finite element software and advanced structural theories based on the Carrera Unified Formulation (CUF). The structure is modeled in CUF using the Component-Wise approach where Lagrange polynomials enhance the cross-section kinematics of the beam element. The von Mises constitutive model with isotropic work hardening is used to describe the material nonlinearity. Two types of the global-local approach have been discussed: (1) elastoplasticity is considered in both global and local analyses, and (2) a linear global analysis is followed by a nonlinear local analysis. It is shown that the second version maintains the accuracy of the solution for cases where the plastic zone is localized within the structure. The described approach results in a significant reduction in the computational size of the problem, compared to standard 3D finite element analysis.


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