Load Balanced Scalable Byzantine Agreement through Quorum Building, with Full Information

We address the problem of designing distributed algorithms for large scale networks that are robust to Byzantine faults. We consider a message passing, full information model: the adversary is malicious, controls a constant fraction of processors, and can view all messages in a round before sending out its own messages for that round. Furthermore, each bad processor may send an unlimited number of messages. The only constraint on the adversary is that it must choose its corrupt processors at the start, without knowledge of the processors’ private random bits.

A good quorum is a set of O(logn) processors, which contains a majority of good processors. In this paper, we give a synchronous algorithm which uses polylogarithmic time and Õ(vn) bits of communication per processor to bring all processors to agreement on a collection of n good quorums, solving Byzantine agreement as well. The collection is balanced in that no processor is in more than O(logn) quorums. This yields the first solution to Byzantine agreement which is both scalable and load-balanced in the full information model.

The technique which involves going from situation where slightly more than 1/2 fraction of processors are good and and agree on a short string with a constant fraction of random bits to a situation where all good processors agree on n good quorums can be done in a fully asynchronous model as well, providing an approach for extending the Byzantine agreement result to this model.

Local materials for building houses: Laterite valorization in Africa

This paper presents the preliminary results of geological and geomechanical studies on the laterite stone exploited at Dano quarry in Burkina Faso. The field work described the geological structure of quarry sites and their environment to determine the rocks alteration and the links between the bedrock and lateritic material. Physic-mechanical properties have been studied for assessing the potentiality of this material for lightweight housing, to be completed with thermal and environmental considerations. Some social and economic evaluations are in progress in order to foster its utilization under local conditions. © (2014) Trans Tech Publications, Switzerland.

Hygrothermal Features of Laterite Dimension Stones for Sub-Saharan Residential Building Construction

The building sector is widely recognized as having a major impact on sustainable development. Both in developed and developing countries, sustainability in buildings approaches are growing. Laterite dimension stone (LDS) is a building material that was traditionally used in sub-Saharan Africa, but its technical features still need to be assessed. This article presents some results of a study focused on the characterization of LDS exploited in Burkina Faso for building purposes. The measured average thermal conductivity is 0.51  W/mK, which increases with water content and evolves with the specific gravity and with porosity. Rock mineral phases (quartz, goethite, hematite, magnetite) are cemented by kaolinite. The porosity of the material is high (30%), with macropores visible on the surface and found in the rock inner structure as well. Results from the hygrothermal monitoring of a pilot building are also presented.

Comfort Care Rounds: A Staff Capacity-Building Initiative in Long-Term Care Homes

This article reports a pilot evaluation of Comfort Care Rounds (CCRs)-a strategy for addressing long-term care home staff's palliative and end-of-life care educational and support needs. Using a qualitative descriptive design, semistructured individual and focus group interviews were conducted to understand staff members' perspectives and feedback on the implementation and application of CCRs. Study participants identified that effective advertising, interest, and assigning staff to attend CCRs facilitated their participation. The key barriers to their attendance included difficulty in balancing heavy workloads and scheduling logistics. Interprofessional team member representation was sought but was not consistent. Study participants recognized the benefits of attending; however, they provided feedback on how the scheduling, content, and focus could be improved. Overall, study participants found CCRs to be beneficial to their palliative and end-of-life care knowledge, practice, and confidence. However, they identified barriers and recommendations, which warrant ongoing evaluation.

Co-Creating Knowledge Online: Approaches for Community Artists

Forming peer alliances to share and build knowledge is an important aspect of community arts practice, and these co-creation processes are increasingly being mediated by the internet. This paper offers guidance for practitioners who are interested in better utilising the internet to connect, share, and make new knowledge. It argues that new approaches are required to foster the organising activities that underpin online co-creation, building from the premise that people have become increasingly networked as individuals rather than in groups (Rainie and Wellman 2012: 6), and that these new ways of connecting enable new modes of peer-to-peer production and exchange. This position advocates that practitioners move beyond situating the internet as a platform for dissemination and a tool for co-creating media, to embrace its knowledge collaboration potential.

Drawing on a design experiment I developed to promote online knowledge co-creation, this paper suggests three development phases – developing connections, developing ideas, and developing agility – to ground six methods. They are: switching and routing, engaging in small trades of ideas with networked individuals; organising, co-ordinating networked individuals and their data; beta-release, offering ‘beta’ artifacts as knowledge trades; beta-testing, trialing and modifying other peoples ‘beta’ ideas; adapting, responding to technological disruption; and, reconfiguring, embracing opportunities offered by technological disruption. These approaches position knowledge co-creation as another capability of the community artist, along with co-creating art and media.

Public management, Peace-building and Creating Change: Shifting the Lens of Analysis from the Macro to the Micro

Considerable time, research money and expertise has been spent exploring the complex reality of ethno nationalist conflict and the role that public management plays in supporting the transition from violent conflict to stability, order and prosperity (Esman 1999; Guelke and Milton-Edwards 2000; Brinkerhoff 2005; Brinkerhoff, Wetterberg et al. 2012; Rao 2014). However, there seems to be a gap in relation to the practical challenges of managing change within, through and beyond such conflict. This paper aims to begin the process of putting a framework around the real experience of public management in conflict and transition by shifting the lens of analysis from macros concerns about sequencing interventions (Rao 2014) and legitimate requirements of security, stability and service delivery (Brinkerhoff, Wetterberg et al. 2012) to a micro analysis of the attitudes, behaviours, challenges and compromises held and faced by those public servants on the front line of conflict management and conflict transformation processes. Using senior managers as the unit of analysis and Northern Ireland as an embryonic case study, this paper discusses the links between ethno nationalist societal conflict, public sector reform and manager behaviour. In doing so, it highlights some initial data from an early pilot study into the experiences of individuals in significant public service roles at various stages of the NI conflict / peace process and draws some tentative conclusions about the viability of a wider study.

Seismic Assessment of a Steel Braced Plan Mass Symmetric/Asymmetric Building Structure

This paper presents a seismic response investigation into a code designed concentrically braced frame structure that is subjected to but not designed for in-plan mass eccentricity. The structure has an accidental uneven distribution of mass in plan resulting in an increased torsional component of vibration. The level of inelasticity that key structural elements in plan mass asymmetric structures are subjected to is important when analysing their ability to sustain uneven seismic demands. In-plan mass asymmetry of moment resisting frame and shear wall type structures have received significant investigation, however, the plan asymmetric response of braced frame type structures is less well understood. A three-dimensional non-linear time history analysis (NLTHA) model is created to capture the torsional response of the plan mass asymmetric structure to quantify the additional ductility demand, interstorey drifts and floor rotations. Results show that the plan mass asymmetric structure performs well in terms of ductility demand, but poorly in terms of interstorey drifts and floor rotations when compared to the plan mass symmetric structure. New linear relationships are developed between the normalised ductility demand and normalised slenderness of the bracing on the sides of the plan mass symmetric/asymmetric structures that the mass is distributed towards and away from.

Alkali Activated Fuel Ash and Slag Mixes:Optimization Study from Mortars to Concrete Building Blocks

Alkali activated binders, based on ash and slag, also known as geopolymers, can play a key role in reducing the carbon footprint of the construction sector by replacing ordinary Portland cement in some concretes. Since 1970s, research effort has been ongoing in many research institutions. In this study, pulverized fuel ash (PFA) from a UK power plant, ground granulated blast furnace slag (GGBS) and combinations of the two have been investigated as geopolymer binders for concrete applications. Activators used were sodium hydroxide and sodium silicate solutions. Mortars with sand/binder ratio of 2.75 with several PFA and GGBS combinations have been mixed and tested. The optimization of alkali dosage (defined as the Na2O/binder mass ratio) and modulus (defined as the Na2O/SiO2 mass ratio) resulted in strengths in excess of 70 MPa for tested mortars. Setting time and workability have been considered for the identification of the best combination of PFA/GGBS and alkali activator dosage for different precast concrete products. Geopolymer concrete building blocks have been replicated in laboratory and a real scale factory trial has been successfully carried out. Ongoing microstructural characterization is aiming to identify reaction products arising from PFA/GGBS combinations.

Dendrons with spermine surface groups as potential building blocks for nonviral vectors in gene therapy

This paper investigates a series of dendrons based on the Newkome dendritic scaffold that displays a naturally occurring polyamine (spermine) on their surface. These dendrons have previously been shown to interact with DNA in a generation dependent manner with the more highly branched dendrons exhibiting a strong multivalency effect for the spermine surface groups. In this paper, we investigate the ability of these dendrons to transfect DNA into cells (human breast carcinoma cells, MDA-MB-231, and murine myoblast cells, C2C12) as determined by the luciferase assay. Although the dendrons are unable to transfect DNA in their own right, they are capable of delivering DNA in vitro when administered with chloroquine, which assists with escape from endocytic vesicles. The cytotoxicity of the dendrons was determined using the XTT assay, and it was shown that the dendrons were nontoxic either alone or in the presence of DNA. However, when administered with DNA and chloroquine, the most highly branched dendron did exhibit some cytotoxicity. This paper elucidates the relationship between in vitro transfection efficiency and toxicity. While transfection efficiencies are modest, the low toxicity of the dendrons, both in their own right, and in the presence of DNA, provides encouragement that this type of building block, which has a relatively high affinity for DNA, will provide a useful starting point for the further synthetic development of more effective gene transfection agents.

Self-assembly using dendritic building blocks - towards controllable nanomaterials

Dendritic molecules have well defined, three-dimensional branched architectures, and constitute a unique nanoscale toolkit. This review focuses on examples in which individual dendritic molecules are assembled into more complex arrays via non-covalent interactions. In particular, it illustrates how the structural information programmed into the dendritic architecture controls the assembly process, and as a consequence, the properties of the supramolecular structures which are generated. Furthermore, the review emphasises how the use of non-covalent (supramolecular) interactions, provides the assembly process with reversibility, and hence a high degree of control. The review also illustrates how self-assembly offers an ideal approach for amplifying the branching of small, synthetically accessible, relatively inexpensive dendritic systems (e.g. dendrons), into highly branched complex nanoscale assemblies.

The review begins by considering the assembly of dendritic molecules to generate discrete, well-defined supramolecular assemblies. The variety of possible assembled structures is illustrated, and the ability of an assembled structure to encapsulate a templating unit is described. The ability of both organic and inorganic building blocks to direct the assembly process is discussed. The review then describes larger discrete assemblies of dendritic molecules, which do not exist as a single well-defined species, but instead exist as statistical distributions. For example, assembly around nanoparticles, the assembly of amphiphilic dendrons and the assembly of dendritic systems in the presence of DNA will all be discussed. Finally, the review examines dendritic molecules, which assemble or order themselves into extended arrays. Such systems extend beyond the nanoscale into the microscale or even the macroscale domain, exhibiting a wide range of different architectures. The ability of these assemblies to act as gel-phase or liquid crystalline materials will be considered.

Taken as a whole, this review emphasises the control and tunability that underpins the assembly of nanomaterials using dendritic building blocks, and furthermore highlights the potential future applications of these assemblies at the interfaces between chemistry, biology and materials science. 

Building capacity in palliative care for personal support workers in long-term care through experiential learning

Background

Providing palliative care in long-term care (LTC) homes is an area of growing importance. As a result, attention is being given to exploring effective palliative care learning strategies for personal support workers (PSWs) who provide the most hands-on care to LTC residents.

The purpose of this intervention was to explore hospice visits as an experiential learning strategy to increase the capacity of PSWs in palliative care, specifically related to their new learning, and how they anticipated this experience changed their practices in LTC.

This study utilised a qualitative descriptive design.

Eleven PSWs from four Ontario LTC homes were sent to their local hospice to shadow staff for one to two days. After the visit, PSWs completed a questionnaire with open-ended questions based on critical reflection. Data were analysed using thematic content analysis.

PSWs commented on the extent of resident-focused care at the hospice and how palliative care interventions were tailored to meet the needs of residents. PSWs were surprised with the lack of routine at the hospice but felt that hospice staff prioritised their time effectively in order to meet family and client care needs. Some PSWs were pleased to see how well integrated the PSW role is on the community hospice team without any hierarchical relationships. Finally, PSWs felt that other LTC staff would benefit from palliative care education and becoming more comfortable with talking about death and dying with other staff, residents and family members.

This study highlighted the benefits of PSWs attending a hospice as an experiential learning strategy. Future work is needed to evaluate this strategy using more rigorous designs as a way to build capacity within PSWs to provide optimal palliative care for LTC residents and their family members.

PSWs need to be recognised as important members within the interdisciplinary team. PSWs who shadow staff at hospices view this experience as a positive strategy to meet their learning needs related to palliative care.