Planetary Protection Issues in the Human Exploration of Mars

This workshop report, long delayed, is the first 21st century contribution to what will likely be a series of reports examining the effects of human exploration on the overall scientific study of Mars. The considerations of human-associated microbial contamination were last studied in a 1990 workshop ("Planetary Protection Issues and Future Mars Missions," NASA CP-10086, 1991), but the timing of that workshop allowed neither a careful examination of the full range of issues, nor an appreciation for the Mars that has been revealed by the Mars Global Surveyor and Mars Pathfinder missions. Future workshops will also have the advantage of Mars Odyssey, the Mars Exploration Rover missions, and ESA's Mars Express, but the Pingree Park workshop reported here had both the NCR's (1992) concern that "Missions carrying humans to Mars will contaminate the planet" and over a decade of careful study of human exploration objectives to guide them and to reconcile. A daunting challenge, and one that is not going to be simple (as the working title of this meeting, "When Ecologies Collide?" might suggest), it is clear that the planetary protection issues will have to be addressed to enable human explorers to safely and competently extend out knowledge about Mars, and its potential as a home for life whether martian or human

Reflections on ten years of using economics games and experiments in teaching

In this paper, the author reflects on his 10 years’ experience of using games and experiments and in the process develops a type of practitioner’s guide. The existing quantitative and qualitative evidence on the impact of using games on student learning is reviewed. On balance, a positive effect, on measures of attainment, is found in the literature. Given these findings, it is surprising that there is also evidence in the UK and US that they are not widely used. Some factors are discussed that might deter tutors from employing them. Unsurprisingly, one of these is the additional cost, which might make the use of online games seem more attractive, given the way results can be automatically recorded. However, some relatively low-cost paper-based games were found to have significant advantages. In particular, they appear to facilitate social interaction which has a positive impact on student motivation and learning. One popular and effective paper-based game is discussed in some detail. A number of recommendations are provided on how to implement the game in order to maximise the learning benefits it can provide. Some ideas on how to maximise the learning benefits from using games more generally are also considered

OpenCache:Distributed SDN/NFV based in-network caching as a service

In-network content caching allows content to be located towards the edge of the network, closer to users. This approach addresses the challenge of exponentially increasing video traffic. We consider OpenCache: an open-source, highly configurable, efficient and transparent in-network caching that leverages Software Defined Networking (SDN) to benefit last mile environments. However, due to its reliance on a centralised OpenCache controller and SDN controller, it suffers from three issues: scalability, reliability and high availability. In this work, we build on and extend the capabilities of OpenCache as a caching solution by leveraging Network Functions Virtualisation (NFV) and using a distributed SDN controller. We discuss the architectural design and technology decisions for the caching platform distribution including the functional components and highlight the role of virtualising, orchestrating and managing the key processes of caching content and control functions. Our target is to design an open-source, distributed in-network caching platform that is highly available, reliable and with automated elasticity to enable serving the increasing VoD traffic quickly and efficiently

Evaluation of CMAF in live streaming scenarios

HTTP Adaptive Streaming (HAS) technologies such as MPEG DASH are now used extensively to deliver television services to large numbers of viewers. In HAS, the client requests segments of content using HTTP, with an ABR algorithm selecting the quality at which to request each segment to trade-off video quality with the avoidance of stalling. This introduces significant end to end latency compared to traditional broadcast, due to the the client requiring a large enough buffer for the ABR algorithm to react to changes in network conditions in a timely manner. The recently standardised Common Media Application Format (CMAF) has helped address the issue of latency by defining segments as composed of independently transferable chunks. In this paper, we describe a simulation model we have developed to evaluate the performance of four popular ABR algorithms using DASH and CMAF in various low latency live streaming scenarios. Realistic network conditions are used for the evaluation, which are based on throughput data taken from the CDN logs of a commercial live TV service. We quantify the performance of the ABR algorithms using a selection of QoE metrics, and show that CMAF can significantly improve ABR performance in low delay scenarios

The changing of the guard: groupwork with people who have intellectual disabilities

This paper considers the impact of service systems on group activities. It describes an inter-professional groupwork project facilitated by a social worker and a community nurse. The project provided an emancipatory experience for a group of adults who had intellectual disabilities. The group was charged with the task of reviewing and updating the recruitment and interview processes used by a 'Learning Disability Partnership Board', when employing new support workers. The paper begins with a brief history of intellectual disability and provides a context to the underpinning philosophical belief that people should be encouraged and supported to inhabit valued social roles no matter what disability they may have. It then identifies the ways in which the sponsoring health, education and social care services impacted on the creation and development of a groupwork project. It might have been expected that the nature of the intellectual disability would have been the major influence on group process. However the paper reveals that organisational constraints had a significant impact on group functioning. Issues including, staffing budgets and transport contracts impacted on group process and function. The results of the project show how, with adequate support, people with intellectual disability can make important decisions that have long-reaching impacts on the services

Llama - Low Latency Adaptive Media Algorithm

In the recent years, HTTP Adaptive Bit Rate (ABR) streaming including Dynamic Adaptive Streaming over HTTP (DASH) has become the most popular technology for video streaming over the Internet. The client device requests segments of content using HTTP, with an ABR algorithm selecting the quality at which to request each segment to trade-off video quality with the avoidance of stalling. This introduces high latency compared to traditional broadcast methods, mostly in the client buffer which needs to hold enough data to absorb any changes in network conditions. Clients employ an ABR algorithm which monitors network conditions and adjusts the quality at which segments are requested to maximise the user's Quality of Experience. The size of the client buffer depends on the ABR algorithm's capability to respond to changes in network conditions in a timely manner, hence, low latency live streaming requires an ABR algorithm that can perform well with a small client buffer. In this paper, we present Llama - a new ABR algorithm specifically designed to operate in such scenarios. Our new ABR algorithm employs the novel idea of using two independent throughput measurements made over different timescales. We have evaluated Llama by comparing it against four popular ABR algorithms in terms of multiple QoE metrics, across multiple client settings, and in various network scenarios based on CDN logs of a commercial live TV service. Llama outperforms other ABR algorithms, improving the P.1203 Mean Opinion Score (MOS) as well as reducing rebuffering by 33% when using DASH, and 68% with CMAF in the lowest latency scenario

Black girls navigate the physical and emotional landscape of the neighbourhood: Normalized violence and strategic agency

This article considers how young Black women living in gang-affected neighbourhoods in an urban area in England, UK navigate their safety in public and private spaces, and how these spaces overlap and intersect. Drawing on a project with 18 participants aged 14–19, the research seeks to understand how the participants inhabit, navigate and strategize for their safety through their narratives of life and survival in an unsafe neighbourhood. Findings indicate that they experience sexual harassment in public spaces and gang-associated sexual and physical violence as common, accepted aspects of their everyday realities, from as young as 12. The narratives suggest that participants navigate complex friendship groups to protect each other and their families through tight codes of trust, secrecy, privacy and conflict-management strategies. This article seeks to bring attention to how young women utilize their agency to illuminate the coping strategies they draw on to navigate their physical environments. The article concludes with a discussion of the implications for interventions

Intelligent diagnostic feedback for online multiple-choice questions

When students attempt multiple-choice questions (MCQs) they generate invaluable information which can form the basis for understanding their learning behaviours. In this research, the information is collected and automatically analysed to provide customized, diagnostic feedback to support students’ learning. This is achieved within a web-based system, incorporating the snap-drift neural network based analysis of students’ responses to MCQs. This paper presents the results of a large trial of the method and the system which demonstrates the effectiveness of the feedback in guiding students towards a better understanding of particular concepts