Molecular basis of salt tolerance in Physcomitrella Patens model plant: potassium homeostasis and physiological roles of chx transporters

El suelo salino impone un estrés abiótico importante que causa graves problemas en la agricultura ya que la mayoría de los cultivos se ven afectados por la salinidad debido a efectos osmóticos y tóxicos. Por ello, la contaminación y la escasez de agua dulce, la salinización progresiva de tierras y el aumento exponencial de la población humana representan un grave problema que amenaza la seguridad alimentaria mundial para las generaciones futuras. Por lo tanto, aumentar la tolerancia a la salinidad de los cultivos es un objetivo estratégico e ineludible para garantizar el suministro de alimentos en el futuro. Mantener una óptima homeostasis de K+ en plantas que sufren estrés salino es un objetivo importante en el proceso de obtención de plantas tolerantes a la salinidad. Aunque el modelo de la homeostasis de K+ en las plantas está razonablemente bien descrito en términos de entrada de K+, muy poco se sabe acerca de los genes implicados en la salida de K+ o de su liberación desde la vacuola. En este trabajo se pretende aclarar algunos de los mecanismos implicados en la homeostasis de K+ en plantas. Para ello se eligió la briofita Physcomitrella patens, una planta no vascular de estructura simple y de fase haploide dominante que, entre muchas otras cualidades, hacen que sea un modelo ideal. Lo más importante es que no sólo P. patens es muy tolerante a altas concentraciones de Na+, sino que también su posición filogenética en la evolución de las plantas abre la posibilidad de estudiar los cambios claves que, durante el curso de la evolución, se produjeron en las diversas familias de los transportadores de K+. Se han propuesto varios transportadores de cationes como candidatos que podrían tener un papel en la salida de K+ o su liberación desde la vacuola, especialmente miembros de la familia CPA2 que contienen las familias de transportadores KEA y CHX. En este estudio se intenta aumentar nuestra comprensión de las funciones de los transportadores de CHX en las células de las plantas usando P. patens, como ya se ha dicho. En esta especie, se han identificado cuatro genes CHX, PpCHX1-4. Dos de estos genes, PpCHX1 y PpCHX2, se expresan aproximadamente al mismo nivel que el gen PpACT5, y los otros dos genes muestran una expresión muy baja. La expresión de PpCHX1 y PpCHX2 en mutantes de Escherichia coli defectivos en el transporte de K+ restauraron el crecimiento de esta cepa en medios con bajo contenido de K+, lo que viii sugiere que la entrada de K+ es energizada por un mecanismo de simporte con H+. Por otra parte, estos transportadores suprimieron el defecto asociado a la mutación kha1 en Saccharomyces cerevisiae, lo que sugiere que podrían mediar un antiporte en K+/H+. La proteína PpCHX1-GFP expresada transitoriamente en protoplastos de P. patens co-localizó con un marcador de Golgi. En experimentos similares, la proteína PpCHX2-GFP localizó aparentemente en la membrana plasmática y tonoplasto. Se construyeron las líneas mutantes simples de P. patens ΔPpchx1 y ΔPpchx2, y también el mutante doble ΔPpchx2 ΔPphak1. Los mutantes simples crecieron normalmente en todas las condiciones ensayadas y mostraron flujos de entrada normales de K+ y Rb+; la mutación ΔPpchx2 no aumentó el defecto de las plantas ΔPphak1. En experimentos a largo plazo, las plantas ΔPpchx2 mostraron una retención de Rb+ ligeramente superior que las plantas silvestres, lo que sugiere que PpCHX2 promueve la transferencia de Rb+ desde la vacuola al citosol o desde el citosol al medio externo, actuando en paralelo con otros transportadores. Sugerimos que transportadores de K+ de varias familias están involucrados en la homeostasis de pH de orgánulos ya sea mediante antiporte K+/H+ o simporte K+-H+.ix ABSTRACT Soil salinity is a major abiotic stress causing serious problems in agriculture as most crops are affected by it. Moreover, the contamination and shortage of freshwater, progressive land salinization and exponential increase of human population aggravates the problem implying that world food security may not be ensured for the next generations. Thus, a strategic and an unavoidable goal would be increasing salinity tolerance of plant crops to secure future food supply. Maintaining an optimum K+ homeostasis in plants under salinity stress is an important trait to pursue in the process of engineering salt tolerant plants. Although the model of K+ homeostasis in plants is reasonably well described in terms of K+ influx, very little is known about the genes implicated in K+ efflux or release from the vacuole. In this work, we aim to clarify some of the mechanisms involved in K+ homeostasis in plants. For this purpose, we chose the bryophyte plant Physcomitrella patens, a nonvascular plant of simple structure and dominant haploid phase that, among many other characteristics, makes it an ideal model. Most importantly, not only P. patens is very tolerant to high concentrations of Na+, but also its phylogenetic position in land plant evolution opens the possibility to study the key changes that occurred in K+ transporter families during the course of evolution. Several cation transporter candidates have been proposed to have a role in K+ efflux or release from the vacuole especially members of the CPA2 family which contains the KEA and CHX transporter families. We intended in this study to increase our understanding of the functions of CHX transporters in plant cells using P. patens, in which four CHX genes have been identified, PpCHX1-4. Two of these genes, PpCHX1 and PpCHX2, are expressed at approximately the same level as the PpACT5 gene, but the other two genes show an extremely low expression. PpCHX1 and PpCHX2 restored growth of Escherichia coli mutants on low K+-containing media, suggesting they mediated K+ uptake that may be energized by symport with H+. In contrast, these genes suppressed the defect associated to the kha1 mutation in Saccharomyces cerevisiae, which suggest that they might mediate K+/H+ antiport. PpCHX1-GFP protein transiently expressed in P. patens protoplasts co-localized with a Golgi marker. In similar experiments, the PpCHX2-GFP protein appeared to localize to tonoplast and plasma x membrane. We constructed the ΔPpchx1 and ΔPpchx2 single mutant lines, and the ΔPpchx2 ΔPphak1 double mutant. Single mutant plants grew normally under all the conditions tested and exhibited normal K+ and Rb+ influxes; the ΔPpchx2 mutation did not increase the defect of ΔPphak1 plants. In long-term experiments, ΔPpchx2 plants showed a slightly higher Rb+ retention than wild type plants, which suggests that PpCHX2 mediates the transfer of Rb+ from either the vacuole to the cytosol or from the cytosol to the external medium in parallel with other transporters. We suggest that K+ transporters of several families are involved in the pH homeostasis of organelles by mediating either K+/H+ antiport or K+-H+ symport.

Modelling logical expressions exercises

Exercises of application of the systematic procedure to derive linear inequalities for logic expressions (Ejercicios de aplicación del método sistemático de obtención de restricciones lineales para expresiones lógicas).

The New Financial Regulatory Paradigm: A transatlantic perspective. CEPS Policy Brief No. 287, 21 March 2013

This CEPS Policy Brief reviews key aspects of the new financial paradigm in a transatlantic perspective, focusing on the general approach in EU and US legislation in response to the financial crisis and the G-20 commitments and specifically as regards the extraterritorial implications. Following discussion of the institutional setting, conclusions are offered on what these changes mean in the context of the recently proposed Transatlantic Trade and Investment Partnership. In comparing the EU and the US efforts in re-engineering their regulatory regimes in response to the financial crisis, the paper finds, with the notable exception of the banking union, serious grounds for concern that the outcome may be an even more fragmented European financial market, access to which for third-country institutions is highly problematic.

The Protocol of Frankfurt: a new treaty for the eurozone. EPC Discussion Paper, 12 January 2016

At a time when the EU finds itself in a perfect storm of crises which it seems unable to overcome, a bold move is needed to reinvigorate the EU’s system of government and stave off the risk of disintegration. In order to address the inherent weakness of the EU’s monetary and economic governance, this pamphlet proposes a new treaty for the eurozone: the Protocol of Frankfurt. Written by Andrew Duff, former Member of the European Parliament and Visiting Fellow at the EPC, it is the first ever attempt to draft a treaty aimed at setting up a fiscal union. “The Protocol of Frankfurt provides the constitutional framework for a proper economic government and will, hopefully, also serve to accelerate the debate on the Five Presidents’ Report”. Realising that the time is not ripe for a major constitutional overhaul, the pamphlet instead puts forward a shorter treaty revision that concentrates on re-engineering the Maastricht arrangements for the economic and monetary union, taking on the form of a Protocol to be added on to the existing Treaties. Article 48(2) of the Treaty on European Union allows the government of any member state, the European Parliament or the Commission to table amendments to the Treaties. Our hope is that somebody, informed by this draft Protocol, does just that.

The use of ICT by logistics service providers and implications for training needs:a cross-country perspective

Changes in the international economic scenario in recent years have made it necessary for both industrial and service firms to reformulate their strategies, with a strong focus on the resources required for successful implementation. In this scenario, information and communication technologies (ICT) has a potentially vital role to play both as a key resource for re-engineering business processes within a framework of direct connection between suppliers and customers, and as a source of cost optimisation. There have also been innovations in the logistics and freight transport industry in relation to ICT diffusion. The implementation of such systems by third party logistics providers (3PL) allows the real-time exchange of information between supply chain partners, thereby improving planning capability and customer service. Unlike other industries, the logistics and freight transport industry is lagging somewhat behind other sectors in ICT diffusion. This situation is to be attributed to a series of both industry-specific and other factors, such as: (a) traditional resistance to change on the part of transport and logistics service providers; (b) the small size of firms that places considerable constraints upon investment in ICT; (c) the relative shortage of user-friendly applications; (d) the diffusion of internal standards on the part of the main providers in the industry whose aim is to protect company information, preventing its dissemination among customers and suppliers; (e) the insufficient degree of professional skills for using such technologies on the part of staff in such firms. The latter point is of critical importance insofar as the adoption of ICT is making it increasingly necessary both to develop new technical skills to use different hardware and new software tools, and to be able to plan processes of communication so as to allow the optimal use of ICT. The aim of this paper is to assess the impact of ICT on transport and logistics industry and to highlight how the use of such new technologies is affecting providers' training needs. The first part will provide a conceptual framework of the impact of ICT on the transport and logistics industry. In the second part the state of ICT dissemination in the Italian and Irish third party logistics industry will be outlined. In the third part, the impact of ICT on the training needs of transport and logistics service providers - based on case studies in both countries - are discussed. The implications of the foregoing for the development of appropriate training policies are considered. For the covering abstract see ITRD E126595.

Editorial

Editorial of the special issue "Special LRN conference edition: re-engineering logistics and supply chain management to regain competitiveness"

Rethinking change:downsizing businesses, changing behaviours and still managing to come out on top

As an indicator of global change and shifting balances of power, every September in Dalian, China, the World Economic Forum meets. The subject in 2011 – Mastering Quality Growth. On the agenda is pursuing new frontiers of growth linked to embracing disruptive innovation. With growth coming from emerging markets, and European and North American economies treading water, many firms in the West are facing the reality of having to not just downsize but actually close manufacturing operations and re-open them elsewhere, where costs are lower, to remain competitive. There are thousands of books on “change management”. Yet very few of these devote much time to downsizing preferring to talk about re-engineering or restructuring. What lessons are available from the past to achieve a positive outcome from what will inevitably be something of a human, as well as an economic, tragedy. The authors reached three fundamental conclusions from their experience and research in facility closure management within Vauxhall, UK: put your people first, make sure you keep running the business and manage your legacy. They devlop the ideas into a new business model linked to the emotions of change.

Modeling of a Heat-Induced Buckling of Plates Using the Mesh-free Method

In the process of engineering design of structural shapes, the flat plate analysis results can be generalized to predict behaviors of complete structural shapes. In this case, the purpose of this project is to analyze a thin flat plate under conductive heat transfer and to simulate the temperature distribution, thermal stresses, total displacements, and buckling deformations. The current approach in these cases has been using the Finite Element Method (FEM), whose basis is the construction of a conforming mesh. In contrast, this project uses the mesh-free Scan Solve Method. This method eliminates the meshing limitation using a non-conforming mesh. I implemented this modeling process developing numerical algorithms and software tools to model thermally induced buckling. In addition, convergence analysis was achieved, and the results were compared with FEM. In conclusion, the results demonstrate that the method gives similar solutions to FEM in quality, but it is computationally less time consuming.

PORBS: A parallel observation-based slicer

Abstract—This paper presents PORBS, a parallelised observation-based slicing tool. The tool itself is written in Java making it platform independent and leverages the build chain of the system being sliced to avoid the need to replicate complex compiler analysis. The target audience of PORBS is software engineers and researchers working with and on tools and techniques for software comprehension, debugging, re-engineering, and maintenance.

Preparation of Ni-P electroless and its corrosion resistance against sea water

Electroless coating is much appropriate process at engineering surface. Since the discovery of electroless nickel-phosphorus coating in 3996, due to technical and economic advantages as well as desirable characteristics such as resistance to corrosion, abrasion and a high hardness has found wide application at engineering industries. Properties of electroless nickel-phosphorus coating depend on the characteristics of the used bath and heat treatment. In this study, optimal conditions and concentration of sodium citrate, sodium acetate and lactic acid in the bath of electroless nickel-phosphorus coating to the steel ck67 surface was determined. Structure, chemical composition and phases occurring in the coating were investigated using Scanning Electron Microscope (SEM) and X-ray diffraction analysis (XRD). The corrosion behavior of coatings in solution 3.5٪ NaCl was studied using electrochemical. The results showed that corrosion resistance of the coating with composition sodium citrate, sodium acetate and lactic acid decreased respectively.

Fault detection with Conditional Gaussian Network

International audience

Code pattern analysis of object-oriented programming languages

Code patterns, including programming patterns and design patterns, are good references for programming language feature improvement and software re-engineering. However, to our knowledge, no existing research has attempted to detect code patterns based on code clone detection technology. In this study, we build upon the previous work and propose to detect and analyze code patterns from a collection of open source projects using NiPAT technology. Because design patterns are most closely associated with object-oriented languages, we choose Java and Python projects to conduct our study. The tool we use for detecting patterns is NiPAT, a pattern detecting tool originally developed for the TXL programming language based on the NiCad clone detector. We extend NiPAT for the Java and Python programming languages. Then, we try to identify all the patterns from the pattern report and classify them into several different categories. In the end of the study, we analyze all the patterns and compare the differences between Java and Python patterns.

New Rigorous Decomposition Methods for Mixed-integer Linear and Nonlinear Programming

Process systems design, operation and synthesis problems under uncertainty can readily be formulated as two-stage stochastic mixed-integer linear and nonlinear (nonconvex) programming (MILP and MINLP) problems. These problems, with a scenario based formulation, lead to large-scale MILPs/MINLPs that are well structured. The first part of the thesis proposes a new finitely convergent cross decomposition method (CD), where Benders decomposition (BD) and Dantzig-Wolfe decomposition (DWD) are combined in a unified framework to improve the solution of scenario based two-stage stochastic MILPs. This method alternates between DWD iterations and BD iterations, where DWD restricted master problems and BD primal problems yield a sequence of upper bounds, and BD relaxed master problems yield a sequence of lower bounds. A variant of CD, which includes multiple columns per iteration of DW restricted master problem and multiple cuts per iteration of BD relaxed master problem, called multicolumn-multicut CD is then developed to improve solution time. Finally, an extended cross decomposition method (ECD) for solving two-stage stochastic programs with risk constraints is proposed. In this approach, a CD approach at the first level and DWD at a second level is used to solve the original problem to optimality. ECD has a computational advantage over a bilevel decomposition strategy or solving the monolith problem using an MILP solver. The second part of the thesis develops a joint decomposition approach combining Lagrangian decomposition (LD) and generalized Benders decomposition (GBD), to efficiently solve stochastic mixed-integer nonlinear nonconvex programming problems to global optimality, without the need for explicit branch and bound search. In this approach, LD subproblems and GBD subproblems are systematically solved in a single framework. The relaxed master problem obtained from the reformulation of the original problem, is solved only when necessary. A convexification of the relaxed master problem and a domain reduction procedure are integrated into the decomposition framework to improve solution efficiency. Using case studies taken from renewable resource and fossil-fuel based application in process systems engineering, it can be seen that these novel decomposition approaches have significant benefit over classical decomposition methods and state-of-the-art MILP/MINLP global optimization solvers.

ENFOQUES Y ESTILOS GERENCIALES MODERNOS ADAPTADOS A AMBIENTES INTERNACIONALES

Este artículo intenta destacar la importancia de los enfoques y estilos gerenciales en un contexto de competencia internacional. Aborda los lineamientos centrales de enfoques gerenciales tales como el empowerment, la reingeniería, la calidad total y el benchmarking.Además, se reconoce que los ambientes internacionales han ido moldeando las gerencias de tal forma que hoy día se necesitan gerentes multiculturales que puedan motivar a personas de diferentes culturas así como ser aceptados por estas. Esos gerentes deben ser capaces de traspasar las barreras culturales y guiar a las empresas hacia la consecución de sus metas.Abstract:This article intends to focus on the importance of the approach and managerial styles in an international competitive context. It states the central guidelines of the managerial approaches such as the empowerment, the re-engineering, the total quality and benchmarking.This document also states that the international or foreign environments have been modeling management. Therefore, nowadays it is necessary to count on multicultural manages who are able to motivate other people from different cultures, as well as to be accepted from these cultural groups. These managers must be able to cross cultural boundaries and guide the companies to reach their goals.