Genome-scale analyses of health-promoting bacteria: probiogenomics

The human body is colonized by an enormous population of bacteria (microbiota) that provides the host with coding capacity and metabolic activities. Among the human gut microbiota are health-promoting indigenous species (probiotic bacteria) that are commonly consumed as live dietary supplements. Recent genomics-based studies (probiogenomics) are starting to provide insights into how probiotic bacteria sense and adapt to the gastrointestinal tract environment. In this Review, we discuss the application of probiogenomics in the elucidation of the molecular basis of probiosis using the well-recognized model probiotic bacteria genera Bifidobacterium and Lactobacillus as examples.

Micropropagation of Begonia and a study of genome stability in Begonia rex

The development of procedures and media for the micropropagation of B. rex are described. Media for the production of plantlets from a number of other Begonia hybrids are also provided. Growth analysis data is given for plants produced in vivo from leaf cuttings and in vitro from mature leaf petioles and immature leaves derived from singly and multiply recycled axenic plantlets. No significant difference was found in phenotype or quantitative vegetative characters for any of the populations assessed. The results presented from studies on the development of broad spectrum media for the propagation of a number of B. rex cultivars using axenic leaf explants on factorial combinations of hormones illustrate the major influence played by the genotype on explant response in vitro and suggest media on which a range of B. rex cultivars may be propagated. Procedures for in vitro irradiation and colchicine treatments to destabilize the B. rex genome have also been described. Variants produced from these treatments indicate the utility of in vitro procedures for the expression of induced somatic variation. Colour variants produced from irradiation treatment have been cultured and prove stable. Polyploids produced as variants from irradiation treatment have been subcultured but prove unstable. Media for the induction and proliferation of callus are outlined. The influence of callus subculture and aging on the stability of the B. rex genome is assessed by chromosomal analysis of cells, in vitro and in regenerants. The B. rex genome is destabilized in callus culture but attenuation of variation occurs on regeneration. Diploid cell lines are maintained in callus subcultures and supplementation of regenerative media with high cytokinin concentrations, casein hydrolysate or adenine failed to produce variants. Callus aging however resulted in the production of polyploids. The presence and expression of pre-existing somatic variation in B. rex pith and root tissue is assessed and polyploids have been produced from pith tissues cultured in vitro. The stability of the B. rex genome and the application of tissue culture to micropropagation and breeding of B. rex are discussed.

Analysis of institutional arrangements and common pool resources governance: the case of Lake Tana sub-basin, Ethiopia

Although Common Pool Resources (CPRs) make up a significant share of total income for rural households in Ethiopia and elsewhere in developing world, limited access to these resources and environmental degradation threaten local livelihoods. As a result, the issues of management, governance of CPRs and how to prevent their over-exploitation are of great importance for development policy. This study examines the current state and dynamics of CPRs and overall resource governance system of the Lake Tana sub-basin. This research employed the modified form of Institutional Analysis and Development (IAD) framework. The framework integrates the concept of Socio-Ecological Systems (SES) and Interactive Governance (IG) perspectives where social actors, institutions, the politico-economic context, discourses and ecological features across governance and government levels were considered. It has been observed that overexploitation, degradation and encroachment of CPRs have increased dramatically and this threatens the sustainability of Lake Tana ecosystem. The stakeholder analysis result reveals that there are multiple stakeholders with diverse interest in and power over CPRs. The analysis of institutional arrangements reveals that the existing formal rules and regulations governing access to and control over CPRs could not be implemented and were not effective to legally bind and govern CPR user’s behavior at the operational level. The study also shows that a top-down and non-participatory policy formulation, law and decision making process overlooks the local contexts (local knowledge and informal institutions). The outcomes of examining the participation of local resource users, as an alternative to a centralized, command-and-control, and hierarchical approach to resource management and governance, have called for a fundamental shift in CPR use, management and governance to facilitate the participation of stakeholders in decision making. Therefore, establishing a multi-level stakeholder governance system as an institutional structure and process is necessary to sustain stakeholder participation in decision-making regarding CPR use, management and governance.

Integrating mobile and cloud resources management using the cloud personal assistant

The mobile cloud computing model promises to address the resource limitations of mobile devices, but effectively implementing this model is difficult. Previous work on mobile cloud computing has required the user to have a continuous, high-quality connection to the cloud infrastructure. This is undesirable and possibly infeasible, as the energy required on the mobile device to maintain a connection, and transfer sizeable amounts of data is large; the bandwidth tends to be quite variable, and low on cellular networks. The cloud deployment itself needs to efficiently allocate scalable resources to the user as well. In this paper, we formulate the best practices for efficiently managing the resources required for the mobile cloud model, namely energy, bandwidth and cloud computing resources. These practices can be realised with our mobile cloud middleware project, featuring the Cloud Personal Assistant (CPA). We compare this with the other approaches in the area, to highlight the importance of minimising the usage of these resources, and therefore ensure successful adoption of the model by end users. Based on results from experiments performed with mobile devices, we develop a no-overhead decision model for task and data offloading to the CPA of a user, which provides efficient management of mobile cloud resources.