Quantum Zeno suppression of three-body losses in Bose-Einstein condensates

We study the possibility of suppressing three-body losses in atomic Bose-Einstein condensates via the quantum Zeno effect, which means the delay of quantum evolution by frequent measurements. It turns out that this requires very fast measurements with the rate being determined by the spatial structure of the three-body form factor, i.e., the point interaction approximation $\delta^3(\mathbf{r}-\mathbf{r'})$ is not adequate. Since the molecular binding energy $E_b$ provides a natural limit for the measurement rate, this suppression mechanism can only work if the form factor possesses certain special properties.Comment: 4 pages, 2 figure

Theory on the mechanism of DNA renaturation: Stochastic nucleation and zipping

Renaturation of complementary single strands of DNA is one of the important processes that requires better understanding in the view of molecular biology and biological physics. Here we develop a stochastic dynamical model on the DNA renaturation. According to our model there are at least three steps in the renaturation process viz. incorrect-contact formation, correct-contact formation and nucleation, and zipping. Most of the earlier two-state models combined nucleation with incorrect-contact formation step. In our model we suggest that it is considerably meaningful when we combine the nucleation with the zipping since nucleation is the initial step of zipping and the nucleated and zipping molecules are indistinguishable. Incorrect-contact formation step is a pure three-dimensional diffusion controlled collision process. Whereas nucleation involves several rounds of one-dimensional slithering dynamics of one single strand of DNA on the other complementary strand in the process of searching for the correct-contact and then initiate nucleation. Upon nucleation, the stochastic zipping follows to generate a fully renatured double stranded DNA. It seems that the square-root dependency of the overall renaturation rate constant on the length of reacting single strands originates mainly from the geometric constraints in the diffusion controlled incorrect-contact formation step. Further the inverse scaling of the renaturation rate on the viscosity of the reaction medium also originates from the incorrect-contact formation step. On the other hand the inverse scaling of the renaturation rate with the sequence complexity originates from the stochastic zipping which involves several rounds of crossing over the free-energy barrier at microscopic levels.Comment: 17 pages, 2 figure

Raising consumer demand for longer lasting products: challenges and opportunities

This briefing outlines the benefits of increasing consumer demand for longer lasting products and details the challenges to and opportunities for them to contribute to environmentally-sound, sustainable economic development

Practical hope for a warming world: a reflective essay

This essay takes a reflective approach to the question of whether or not Scotland would be able to meet the climate change targets it has set itself and how they would feel if the world was unable to avert dangerous climate change. The importance of maintaining 'practical hope' in the face of current environmental circumstances stregnthens the arguement for the Scottish Government's ability to meet its targets and the consideration of Scotland's role in the global goals in tackling climate change

Extensive heterogeneity in somatic mutation and selection in the human bladder

The extent of somatic mutation and clonal selection in the human bladder remains unknown. We sequenced 2097 bladder microbiopsies from 20 individuals using targeted (n = 1914 microbiopsies), whole-exome (n = 655), and whole-genome (n = 88) sequencing. We found widespread positive selection in 17 genes. Chromatin remodeling genes were frequently mutated, whereas mutations were absent in several major bladder cancer genes. There was extensive interindividual variation in selection, with different driver genes dominating the clonal landscape across individuals. Mutational signatures were heterogeneous across clones and individuals, which suggests differential exposure to mutagens in the urine. Evidence of APOBEC mutagenesis was found in 22% of the microbiopsies. Sequencing multiple microbiopsies from five patients with bladder cancer enabled comparisons with cancer-free individuals and across histological features. This study reveals a rich landscape of mutational processes and selection in normal urothelium with large heterogeneity across clones and individuals

Community repair: enabling repair as part of the movement towards a circular economy

Executive summary： Repair in the context of the circular economy. The growth in sales of household electrical and electronic equipment in recent years, combined with faster product obsolescence, has resulted in waste electrical and electronic equipment becoming the fastest growing waste stream globally (Baldé, Wang, Kuehr, & Huisman, 2015). Many products develop simple faults which are challenging for the amateur to repair; this quite often results in replacement products being purchased and equipment with small faults being disposed of, or hoarded (Green Alliance, 2015; WRAP, 2011a). It is within this context that innovative approaches to repair are emerging in the UK, with communitybased organisations focused on enabling consumers to attempt to repair a variety of products including clothing and electrical equipment. Access to information, spare parts and tools is being made available by companies like iFixit, providing consumers with the resources they need to attempt their own repairs. Some consumers, however, lack the skills, knowledge or confidence to attempt repairs, even when the resources are available. This report focuses on the work of the London-based Restart Project, who organise community-based events to assist these consumers. Volunteers acting as "Repair Coaches" at Restart Project repair events offer support and guidance to participants, enabling them to attempt to repair items that they may not have had the knowledge, skills or confidence to undertake previously. This report presents the findings from a survey with 99 participants undertaken at Restart Project events in late 2016. Key points to emerge are: - Many people (45%) cannot name a commercial repairer that they trust. The lack of knowledge of existing repair ventures and lack of trust in commercial repairers is a key issue to address. - Very few respondents were "extremely" confident in undertaking repairs at home (8%), many more were "somewhat" or "moderately" confident (33%) and 47% were only "slightly" or "not at all" confident. - Many of the respondents reported that they have previously attempted some kind of repairs at home (56%). However, they report varying levels of success with previous repairs and cite knowledge, skills and confidence as major barriers to further attempts at repair. It is these very barriers that The Restart Project addresses. - Respondents report that they are avid seekers of reuse options for their products when they no longer require them, with 82% reporting they looked for people to reuse items they no longer had a use for. - Small electrical and electronic items were not recycled by as many of the respondents as other types of household items. The Restart Project appears to have a role to play as 'environmental educator' in inspiring additional recycling within the community. Throughout the research, participants said they particularly valued the social aspect of the repair events. Feedback shows that there are high satisfaction levels with the events, even when repairs to the objects participants have brought along have been unsuccessful. Working in a social environment, meeting others with shared interests and learning or passing on repair skills in this way appears to offer considerable potential to empower communities to attempt repairs and thereby extend the lifetime of products. The repair network is complex and fragmented. Availability, location and consumer confidence in local repair networks, together with knowledge and skills are key issues that have emerged from this study. Informal community-based enterprises such as The Restart Project appear ideally placed to develop local responses to the gap in trust of existing networks revealed by this research, and that they have an important role to play in contributing to the circular economy

Extending product lifetimes through WEEE reuse and repair: opportunities and challenges in the UK

Discarded electrical and electronic equipment is a rapidly growing waste stream which has increased in part be-cause advances in technology have contributed to shorter product lifetimes [1],[2]. As such, waste electrical and electronic equipment (WEEE) has received increasing attention from policy makers. Previous research has re-vealed the large proportion of end-of-life consumer electronics disposed of through residual waste collections and destined for landfill disposal or incineration [3],[4]. This represents a missed opportunity for extending their lifetime by facilitating recovery for repair or reuse, which would be preferable in the context of their high levels of embodied carbon [5] and the valuable materials they contain. This paper outlines the current policy context following recently updated WEEE Regulations and explores the current routes for end-of-life electrical and electronic equipment in the UK and opportunities for product life ex-tension through reuse of discarded items. Following a literature review, a series of semi-structured interviews were undertaken with policy makers, producer responsibility organisations, third sector organisations, waste collection authorities and waste management companies. The paper reports the findings from this research, which aimed to determine whether the current collection sys-tem for end-of-life equipment in the UK adequately encourages increased repair and reuse in line with the UK Government’s waste reduction programme [6], or whether there is an excessive focus on recycling. An analysis of the findings is used to discuss whether the UK policy framework is adequate to embed legislative require-ments and improve current practices and whether the current system promotes awareness and understanding by householders sufficient to encourage behaviour change

Towards a circular economy: exploring routes to reuse for discarded electrical and electronic equipment

Waste reduction should be an integral strategy for meeting European Union commitments on the circular economy. The reuse of household goods, thereby increasing their life-spans, is thus not only part of the waste reduction agenda but necessary for progression towards a circular economy. Reuse does take place through many different routes and involves many actors. This complexity makes monitoring and increasing reuse particularly challenging. Previous research has concentrated on reuse through local government collections and there has been with limited enquiry into other routes. This paper characterises and analyses operations of two UK organisations that facilitate the resale of used electrical and electronic equipment in order to establish how levels of reuse may be increased. It discusses findings from semi-structured interviews with senior representatives from the organisations and makes recommendations for reuse networks that could manage waste streams more effectively. The paper illustrates how different business approaches can make a significant contribution to tackling waste and implementing the circular economy

Active surveillance of prostate cancer: a questionnaire survey of urologists, clinical oncologists and urology nurse specialists across three cancer networks in the United Kingdom

Abstract Background Active surveillance is considered a mainstream strategy in the management of patients with low-risk prostate cancer. A mission-critical step in implementing a robust active surveillance program and plan its resource and service requirements, is to gauge its current practice across the United Kingdom. Furthermore it is imperative to determine the existing practices in the context of the recommendations suggested by the recent National Institute for Health and Clinical Excellence guidance on active surveillance of prostate cancer. Methods An internet questionnaire was circulated to urologists, clinical oncologists and urology nurse specialists across three geographically distinct cancer networks. Twenty five questions across four domains were assessed. (i) hospital resources (staff and clinical areas) utilised for active surveillance (ii) enrolment criteria (iii) follow up (iv) criteria that trigger conversion to active treatment. Results We received 35 responses, 20 of which were from urologists. The survey data suggests that there is marked heterogeneity in enrolment criteria with patients having features of intermediate-risk prostate cancer often recruited into Active Surveillance programs. Only 60 % of our respondents use multiparametric MRI routinely to assess patient suitability for active surveillance. In addition, marked variation exists in how patients are followed up with regard to PSA testing intervals and timing of repeat biopsies. Only 40 % undertake a repeat biopsy at 12 months. Tumour upgrading on repeat biopsy, an increase in tumour volume or percentage of core biopsies involved would prompt a recommendation for treatment amongst most survey respondents. In addition allocation of resources and services for active surveillance is poor. Currently there are no dedicated active surveillance clinics, which are well-structured, -resourced and -supported for regular patient counselling and follow up. Conclusion This variability in enrolment criteria and follow up is also demonstrated in international and national series of active surveillance. Resources are not currently in place across the UK to support an active surveillance program and a national discussion and debate to plan resources is much required so that it can become a mainstream therapeutic strategy