Columbia

Strategic networks such as Collaborative Networked Organisations (CNOs) and Virtual Customer Communities (VCCs) show a high potential as drivers of value co-creation and collaborative innovation in today's Networking Era. Both look at the network structures as a source of jointly value creation and open innovation through access to new skills, knowledge, markets and technologies by sharing risk and integrating complementary competencies. This collaborative endeavour has proven to be able to enhance the ...

Collaborative Engineering Environments (CEE) have become really important in Virtual Organizations (VO) because they enable the coordination and collaboration among engineering groups, supported by tools and methodologies that enable intellectual capital sharing and engineering activities in real time, among organizations regardless of their locations. A platform that integrates and facilitates the operation in Virtual Organizations focused in manufactured product development, is an important tool that supports a rapid respond to customers, and improve the communication among its members. This paper present a way to improve business process in a VO based on the development and use of a CEE. The methodology presented in this paper was implemented in a real manufacturing VO, improving the product transfer process: the coordinators of each business opportunity easily manage VO information, and VO partners were totally involved during the process.

Enterprise interoperability enables the access to relevant information within an enterprise. Traditionally, enterprise integration implementations are managed as merely technological solutions, but integration requirements outcome from business process needs, such as just-in-time information and integration with strategic partners. Without a business process driven methodology that comprises both technical and behavioural views, enterprise integration projects are prone to failure. This paper proposes a business process driven modelling ...

Abstract—This paper introduces a mobile learning environment based on micro-learning. The micro-learning model presented is an extension to the ontological model defined at the University: Tecnológico de Monterrey, Campus Ciudad de México, Méxicofor mobile learning resources classification and management. The micro-learning model proposed is based on a Web-didactics model. This mobile learning model based on micro-learning provides students “self-learning” capabilities by allowing them to create their own ...

Abstract. The creation of industrial networks represents a value-added strategy to foster the individual competencies of Small & Medium Enterprises (SME). These networks require the support of e-services to enable the coordination and cooperation among different companies to integrate their capabilities in the configuration of virtual organizations. This paper present the integration of five e-services in an open technological platform named e-HUB. The technical design of its software architecture, the results of its implementation in ...

The knowledge about a product and its value adding services is becoming as important as the physical product itself. This paper aims to address some knowledge management challenges to support the so-called “dynamic” product-service business ecosystems operating based on the creation, operation/evolution and dissolution of goal-oriented collaborative networks, such as Virtual Manufacturing and Service Enterprises, and their breeding environments.

Supporting integrated Sustainable Mass-Customized (S-MC) product developments requires true computer integrated manufacturing environments and sustainable supporting tools (lifecycle assessments) in order to integrate diverse product development methods and tools, and manage different and sometimes contradictory engineering, customization and sustainability constraints and/or requirements at product, process/manufacturing system and supply chain entity levels to design, engineer, manufacture, deliver and recycle S-MC ...

Concurrent Engineering/Enterprising success relies on the ability of multidisciplinary teams and manufacturing enterprise networks to be able to communicate their requirements to each other effectively, and coordinate their simultaneous activities and their dependencies during the product development process. Concurrent strategies demand a huge amount of cooperation between individuals and/or organisations during the product development process, and collaboration technologies play a key role as the enablers of ...

According to the United Nations Environment Programme, the construction industry is a key sector to achieve sustainable development, as it can provide important benefits in the complete construction lifecycle considering its three axes: social, economic and environmental. At the same time, negative impacts can be drastically reduced if new collaborative business models and strategies are defined integrating both end-users and different actors in the construction value-chain. Therefore, this paper introduces a general ...

Nowadays more manufacturing enterprises are requiring the adoption of a structured process to improve their practices in a product development project. Using an enterprise multilevel framework, this paper introduces an Integrated Product, manufacturing Process and Manufacturing system Development (IPPMD) reference map and methodology to create a particular product development model and setting-up based-on it a successful concurrent product development process that is independent of the enterprise industrial sector and focuses on specific issues such as: market opportunities, technological constraints, stakeholders' interrelations and declared goals related to the enterprise strategies. Furthermore, a study case is presented following the IPPMD methodology, which is supported by a reference map as part of the enterprise multilevel framework, and starts with a project scope definition and moves forward to the establishment of a particular product development model for a specific project, in this case: the development of a Universal Numerical Control (UNC) machine

Nitrogen-fixing bacteria collectively called rhizobia are adapted to live in polyphenol-rich environments. The mechanisms that allow these bacteria to overcome toxic concentrations of plant polyphenols have not been clearly elucidated. We used a crude extract of polyphenols released from the seed coat of the black bean to simulate a polyphenol-rich environment and analyze the response of the bean-nodulating strain Rhizobium etli CFN42. Our results showed that the viability of the wild type as well as that of derivative strains cured of plasmids p42a, p42b, p42c, and p42d or lacking 200 kb of plasmid p42e was not affected in this environment. In contrast, survival of the mutant lacking plasmid p42f was severely diminished. Complementation analysis revealed that the katG gene located on this plasmid, encoding the only catalase present in this bacterium, restored full resistance to testa polyphenols. Our results indicate that oxidation of polyphenols due to interaction with bacterial cells results in the production of a high quantity of H 2 O 2 , whose removal by the katG-encoded catalase plays a key role for cell survival in a polyphenol-rich environment.

Background: A traditional concept in bacterial genetics states that housekeeping genes, those involved in basic metabolic functions needed for maintenance of the cell, are encoded in the chromosome, whereas genes required for dealing with challenging environmental conditions are located in plasmids. Exceptions to this rule have emerged from genomic sequence data of bacteria with multipartite genomes. The genome sequence of R. etli CFN42 predicts the presence of panC and panB genes clustered together on the 642 kb plasmid p42f and a second copy of panB on plasmid p42e. They encode putative pantothenate biosynthesis enzymes (pantoate-β-alanine ligase and 3-methyl-2oxobutanoate hydroxymethyltransferase, respectively). Due to their ubiquitous distribution and relevance in the central metabolism of the cell, these genes are considered part of the core genome; thus, their occurrence in a plasmid is noteworthy. In this study we investigate the contribution of these genes to pantothenate biosynthesis, examine whether their presence in plasmids is a prevalent characteristic of the Rhizobiales with multipartite genomes, and assess the possibility that the panCB genes may have reached plasmids by horizontal gene transfer.

Background: Bean-nodulating Rhizobium etli originated in Mesoamerica, while soybean-nodulating Sinorhizobium fredii evolved in East Asia. S. fredii strains, such as GR64, have been isolated from bean nodules in Spain, suggesting the occurrence of conjugative transfer events between introduced and native strains. In R. etli CFN42, transfer of the symbiotic plasmid (pRet42d) requires cointegration with the endogenous self-transmissible plasmid pRet42a. Aiming at further understanding the generation of diversity among bean nodulating strains, we analyzed the plasmids of S. fredii GR64: pSfr64a and pSfr64b (symbiotic plasmid). Results: The conjugative transfer of the plasmids of strain GR64 was analyzed. Plasmid pSfr64a was self-transmissible, and required for transfer of the symbiotic plasmid. We sequenced pSfr64a, finding 166 ORFs. pSfr64a showed three large segments of different evolutionary origins; the first one presented 38 ORFs that were highly similar to genes located on the chromosome of Sinorhizobium strain NGR234; the second one harbored 51 ORFs with highest similarity to genes from pRet42d, including the replication, but not the symbiosis genes. Accordingly, pSfr64a was incompatible with the R. etli CFN42 symbiotic plasmid, but did not contribute to symbiosis. The third segment contained 36 ORFs with highest similarity to genes localized on pRet42a, 20 of them involved in conjugative transfer. Plasmid pRet42a was unable to substitute pSfr64a for induction of pSym transfer, and its own transfer was significantly diminished in GR64 background. The symbiotic plasmid pSfr64b was found to differ from typical R. etli symbiotic plasmids.

New technological advances have enabled the creation of distributed collaborative industrial networks giving origin to new collaborative e-business models such as the Virtual Organisation (VO). These industrial networks require new Information and Communication Technologies Infrastructures (ICT-I) playing the intermediary role as the enablers of interoperation among their participant organisations. Furthermore, these networks require coordination and cooperation mechanism among its members which in turn can be supported through specific vertical applications deployed over a common platform. PyME CREATIVA was a project defined with the aim of playing the role of a service provider of an open technological platform named the e-HUB, providing a set of collaborative electronic solutions named the e-services, to support collaborative business processes among Small and Medium-sized Enterprises (SMEs). Till today, the e-HUB platform has proved to be a complete IT architecture able to satisfy SMEs technological requirements to get involved in collaborative business opportunities, nevertheless with the technology progress new opportunities appear to improve the way these e-services are delivered to the SMEs. This paper provides an insight into the benefits and implications of evolving the e-HUB architecture into new one based-on Software-as-a-Service (SaaS) premises.

Concerning with the global competitive environment and the impact of collaborative engineering environments on Small and Medium-sized Enterprises (SMEs), it is now necessary the development of new models and tools that can keep helping the designers and engineers in the decision-making processes related to the product design lifecycle. The tolerance synthesis purpose is to provide a rational basis for assigning tolerances to dimensions, and it has become an important subject in the product design process. The aim of this research work is to present an approach to support a concurrent conceptual tolerance synthesis evaluation process in a mechanical design within a collaborative engineering environment context, e.g. Virtual Enterprise. The reference model proposed was developed and refined through a set of mechanical design study cases. The analysis and reflections of the study case presented in this manuscript are described in detail to show an example of how the different study cases were used to develop an understanding of how the reference model proposed can stimulated the conceptual synthesis evaluation of tolerances in the product design process.

Metagenomics holds the promise of greatly advancing the study of diversity in natural communities, but novel theoretical and methodological approaches must first be developed and adjusted for these data sets. We evaluated widely used macroecological metrics of taxonomic diversity on a simulated set of metagenomic samples, using phylogenetically meaningful protein-coding genes as ecological proxies. To our knowledge, this is the first approach of this kind to evaluate taxonomic diversity metrics derived from metagenomic data sets. We demonstrate that abundance matrices derived from protein-coding marker genes reproduce more faithfully the structure of the original community than those derived from SSU-rRNA gene. We also found that the most commonly used diversity metrics are biased estimators of community structure and differ significantly from their corresponding real parameters and that these biases are most likely caused by insufficient sampling and differences in community phylogenetic composition. Our results suggest that the ranking of samples using multidimensional metrics makes a good qualitative alternative for contrasting community structure and that these comparisons can be greatly improved with the incorporation of metrics for both community structure and phylogenetic diversity. These findings will help to achieve a standardized framework for community diversity comparisons derived from metagenomic data sets.

Gene conversion is defined as the non-reciprocal transfer of information between homologous sequences. Despite methodological problems to establish non-reciprocity, gene conversion has been demonstrated in a wide variety of bacteria. Besides examples of high-frequency reversion of mutations in repeated genes, gene conversion in bacterial genomes has been implicated in concerted evolution of multigene families. Gene conversion also has a prime importance in the generation of antigenic variation, an interesting mechanism whereby some bacterial pathogens are able to avoid the host immune system. In this review, we analyze examples of bacterial gene conversion (some of them spawned from the current genomic revolution), as well as the molecular models that explain gene conversion and its association with crossovers.

In different bacterial species, ccmIEFH genes have been suggested to code for subunits of a bacterial haem-lyase catalyzing the covalent attachment of haem to c-type apoproteins. In Rhizobium etli CE3 there are two copies of ccmIEFH: one in the chromosome and the other located in plasmid pf. However, the null phenotype of chromosomal ccmF mutant indicates that the gene locus of plasmid pf is not functional. Two ccmI chromosomal mutants, previously isolated, produced detectable levels of ctype cytochromes under certain culture conditions in contrast with the ccmF mutant, suggesting that ccmF could be transcribed independently. The transcriptional organization of ccmIEFH operon was established. Two promoters from the chromosomal locus were mapped by primer extension, one located upstream of ccmI and the second located upstream of ccmF. The regulation of the expression of both promoters was studied using appropriate lacZ gene fusions (ccmI-lacZ and ccmEF-lacZ). The ccmI-lacZ gene fusion was expressed in complex medium, during exponential growth, under microaerobic conditions and in a R. etli mutant that accumulates reducing power, conditions where a higher respiration rate could be limited by c-type cytochrome content. The ccmEF-lacZ fusion was also primarily expressed in complex medium and under microaerophilic conditions. The finding of two independent promoters in this gene locus could suggest that the step catalyzed by CcmFH could be a rate-limiting step for c-type cytochrome assembly under certain culture conditions.

The recombination genes involved in Holliday junction migration (ruvB, recG, radA) and heteroduplex editing (mutS) were studied in the α-proteobacterium Rhizobium etli. The genes were interrupted with a loxPSp interposon and R. etli mutants, either single or in combination, were constructed by marker exchange. Our results show that these systems play a differential role in sensitivity to DNA damaging agents and recombination in R. etli. RuvB appears to be the main system for tolerance toward agents instigating singleor double-strand breaks (such as UV light, methyl methanesulphonate and nalidixic acid) while the RecG and RadA systems play minor roles in tolerance to these agents. Using five different recombination assays, we have found that a ruvB null mutant showed a notable reduction in recombination proficiency, while a radA mutant was only weakly affected. A null mutation in recG had the opposite effect, enhancing recombination in most of our assays. This effect was more clearly seen in an assay that measured recombination between divergent sequences (i.e. homeologous), but is unaffected by inactivation of mutS. These data indicate that RecG in R. etli limits intra-and intergenomic plasticity.