Time-Energy Tradeoffs for Evacuation by Two Robots in the Wireless Model

Two robots stand at the origin of the infinite line and are tasked with searching collaboratively for an exit at an unknown location on the line. They can travel at maximum speed $b$ and can change speed or direction at any time. The two robots can communicate with each other at any distance and at any time. The task is completed when the last robot arrives at the exit and evacuates. We study time-energy tradeoffs for the above evacuation problem. The evacuation time is the time it takes the last robot to reach the exit. The energy it takes for a robot to travel a distance $x$ at speed $s$ is measured as $xs^2$. The total and makespan evacuation energies are respectively the sum and maximum of the energy consumption of the two robots while executing the evacuation algorithm. Assuming that the maximum speed is $b$, and the evacuation time is at most $cd$, where $d$ is the distance of the exit from the origin, we study the problem of minimizing the total energy consumption of the robots. We prove that the problem is solvable only for $bc \geq 3$. For the case $bc=3$, we give an optimal algorithm, and give upper bounds on the energy for the case $bc>3$. We also consider the problem of minimizing the evacuation time when the available energy is bounded by $\Delta$. Surprisingly, when $\Delta$ is a constant, independent of the distance $d$ of the exit from the origin, we prove that evacuation is possible in time $O(d^{3/2}\log d)$, and this is optimal up to a logarithmic factor. When $\Delta$ is linear in $d$, we give upper bounds on the evacuation time.Comment: This is the full version of the paper with the same title which will appear in the proceedings of the 26th International Colloquium on Structural Information and Communication Complexity (SIROCCO'19) L'Aquila, Italy during July 1-4, 201

Malawi District Energy Officer Blueprint : Recommendations Paper

This recommendations paper outlines the proposed role of District Energy Officers (DEOs) in Malawi as a conduit for the Government of Malawi to facilitate the decentralisation of a sustainable energy policy to district level. If developed sensitively and effectively and resourced appropriately, the implementation of DEOs in Malawi could help to strengthen levels of community ownership and empowerment; achieved through energy initiatives, improved communication and networking around energy issues at district level, electricity access development at district level and enhanced electricity literacy through roles in sensitisation and dissemination of knowledge of decentralised energy technologies and processes This paper confirms the Government of Malawi’s proposal that the introduction of an effective DEO programme will assist the Government in decentralisation of its national renewable energy strategy while aligning renewable electricity development with key national energy use targets ; 20% of national energy generation from renewable energy sources and a reduction of 22% in biomass usage by 2025. A decentralised DEO role, working within a centralised management and financial structure is supported by this recommendations paper as an effective methodology for energy decentralisation in Malawi. The support structure and accountability structure outlined in this recommendations paper can be used by the Government of Malawi to empower rural communities in Malawi in taking ownership of their energy sources and their energy use, primarily through design and support of community based development. DEOs act to improve community livelihoods through an increase in local earning potential and co-constructively act to improve national energy security and poverty alleviation across all districts of Malawi

Experiences of electric pressure cookers in East Africa

This paper seeks to highlight the emerging opportunity for manufacturers to enter the largely untapped market for efficient electric cooking appliances such as the Electric Pressure Cooker (EPC) in East and Southern Africa. The paper is an output of the UK Aid1 programme Modern Energy Cooking Services, a 5 year programme of work (2018 – 2023) led by Loughborough University. In East Africa, electricity networks are growing stronger and broader, opening up electric cooking to an almost entirely untapped market particularly in urban areas that are still dominated by charcoal. In each country, approximately 10 million people pay for polluting cooking fuels, yet they have a grid connection that is not used for cooking. Historically this has been due to the pricing and unreliability of the grids. As Grids get stronger and appliances more efficient the affordability and convenience of electric cooking is becoming more realistic. In Southern Africa, electric cooking has been and is more popular, however inefficient appliances are placing a heavy strain on national utilities, many of whom are now looking to manage demand more sustainably. Again, the advent of energy efficient appliances changes the dynamic for the household. Cooking is deeply cultural and any new energy efficient cooking devices must be compatible with local foods and cooking practices. This paper presents insights from cooking diaries, focus groups and ‘kitchen laboratory’ experiments carried out in Kenya, Tanzania and Zambia. The results show that EPCs are not only acceptable, but highly desirable. Over 90% of the menu can be cooked in an EPC and certain foods require just one fifth of the energy of a hotplate. In real homes, participants with EPCs, rice cookers and hotplates chose the efficient appliances for approximately half their menu and for these dishes, they used roughly half the energy of the hotplate. Without training and with limited experience of the new devices, the trial participants in Kenya who cooked solely on electricity had a median daily consumption of 1.4kWh/household/day, and the cooking of 50% of the menu on an EPC utilised 0.47kWh/household/day of that total. Given that EPCs could have cooked 90% of the desired menu, with appropriate training and broader experience, the median could have been reduced to less than 1kwh/day/household. This research feeds into a new UK Aid programme, Modern Energy Cooking Services and concludes with recommended design modifications that could enable users to do more cooking with EPCs and open up sizeable new market segments including strengthening weak-grid and off-grid

Two birds, one stone—reframing cooking energy policies in Africa and Asia

For the past 40 years, the dominant ‘policy’ on cooking energy in the Global South has been to improve the combustion efficiency of biomass fuels. This was said to alleviate the burdens of biomass cooking for three billion people by mitigating emissions, reducing deforestation, alleviating expenditure and collection times on fuels and increasing health outcomes. By 2015, international agencies were openly saying it was a failing policy. The dispersal of improved cookstoves was not keeping up with population growth, increasing urbanisation was leading to denser emissions and evidence suggested health effects of improved stoves were not as expected. A call was made for a new strategy, something other than ‘business as usual’. Conventional wisdom suggests that access to electricity is poor in Sub-Saharan Africa (SSA), that it is too expensive and that weak grids prevent even connected households from cooking. Could a new strategy be built around access to electricity (and gas)? Could bringing modern energy for cooking to the forefront kill two birds with one stone? In 2019, UK Aid announced a multi-million-pound programme on ‘Modern Energy Cooking Services’ (MECS), specifically designed to explore alternative approaches to address cooking energy concerns in the Global South. This paper outlines the rationale behind such a move, and how it will work with existing economies and policies to catalyse a global transition

eCook: what behavioural challenges await this potentially transformative concept?

This paper aims to identify and understand the challenges that may confront the scaling up of a proposed battery electric cooking concept (Batchelor 2013), eCook, which offers the potential for emission free cooking, with time/money savings and broader environmental benefits from reduced fuelwood/charcoal consumption. By drawing on the literature on the transition to electric cooking in South Africa and more broadly, literature from across the Global South analysing the uptake of ICS (improved cookstoves), LPG (liquid petroleum gas) and solar home systems, this study identifies the factors (e.g. successful delivery models and marketing strategies) that have enabled these innovations to reach scale. This knowledge is then related to the eCook concept, by identifying the potential users of this promising technology and outlining potential marketing strategies, as well as a user-focused iterative design process, that will enable social enterprises to reach them. Uptake is predicted to be most rapid in hot climates where fuelwood/charcoal is purchased and low energy diets and low power cooking devices are the standard. Mobile enabled fee-for-service (utility) business models, the establishment of a service network, awareness raising campaigns on the benefits of clean cooking, female-focussed training programs and bundling eCook systems with locally appropriate appliances to enable productive activities are seen as key to reaching scale

Dystroglycan versatility in cell adhesion: a tale of multiple motifs

Dystroglycan is a ubiquitously expressed heterodimeric adhesion receptor. The extracellular a-subunit makes connections with a number of laminin G domain ligands including laminins, agrin and perlecan in the extracellular matrix and the transmembrane b-subunit makes connections to the actin filament network via cytoskeletal linkers including dystrophin, utrophin, ezrin and plectin, depending on context. Originally discovered as part of the dystrophin glycoprotein complex of skeletal muscle, dystroglycan is an important adhesion molecule and signalling scaffold in a multitude of cell types and tissues and is involved in several diseases. Dystroglycan has emerged as a multifunctional adhesion platform with many interacting partners associating with its short unstructured cytoplasmic domain. Two particular hotspots are the cytoplasmic juxtamembrane region and at the very carboxy terminus of dystroglycan. Regions which between them have several overlapping functions: in the juxtamembrane region; a nuclear localisation signal, ezrin/radixin/moesin protein, rapsyn and ERK MAP Kinase binding function, and at the C terminus a regulatory tyrosine governing WW, SH2 and SH3 domain interactions. We will discuss the binding partners for these motifs and how their interactions and regulation can modulate the involvement of dystroglycan in a range of different adhesion structures and functions depending on context. Thus dystroglycan presents as a multifunctional scaffold involved in adhesion and adhesion-mediated signalling with its functions under exquisite spatiotemporal regulation

Governing decentralised energy provision: approaches to energy transitions in Kenya [poster]

Governing decentralised energy provision: approaches to energy transitions in Kenya [poster

Decentralization : the key to accelerating access to distributed energy services in sub-Saharan Africa?

The decentralization of governance is increasingly considered crucial for delivering development and is being widely adopted in sub-Saharan countries. At the same time, distributed (decentralized) energy systems are increasingly recognized for their role in achieving universal access to energy and are being promoted in sub-Saharan countries. However, little attention has been paid by governments and energy practitioners to the dynamic interrelationships between national and local government and the role of governance decentralization in transitioning to distributed energy systems. This paper traces the complex relationships between accelerated delivery of distributed energy and decentralized local governance systems. The argument is grounded in an exploration of two different approaches to decentralized energy systems governance in Kenya and Malawi. For Kenya, analysis focuses on the energy sector since the adoption of the new decentralized constitution in 2010. In Malawi, it focuses on the involvement of the authors in piloting Local Authority Energy Officers in districts under the decentralization of Malawian energy policy. Our analysis shows that accelerating the speed and scale of implementation for distributed energy systems and enhancing their sustainability and socio-economic impacts is directly linked to the quality of local and national governance structures and their interrelationships. The paper extends existing work in energy and evidence literacy for policy actors by developing an analytical framework, to enable more effective local governance within energy access initiatives in the Global South

Microglial activation and chronic neurodegeneration

Microglia, the resident innate immune cells in the brain, have long been implicated in the pathology of neurode-generative diseases. Accumulating evidence points to activated microglia as a chronic source of multiple neurotoxic factors, including tumor necrosis factor-α, nitric oxide, interleukin-1β, and reactive oxygen species (ROS), driving progressive neuron damage. Microglia can become chronically activated by either a single stimulus (e.g., lipopolysaccharide or neuron damage) or multiple stimuli exposures to result in cumulative neuronal loss with time. Although the mechanisms driving these phenomena are just beginning to be understood, reactive microgliosis (the microglial response to neuron damage) and ROS have been implicated as key mechanisms of chronic and neurotoxic microglial activation, particularly in the case of Parkinson’s disease. We review the mechanisms of neurotoxicity associated with chronic microglial activation and discuss the role of neuronal death and microglial ROS driving the chronic and toxic microglial phenotype