Soil osmotic potential and its effect on vapor flow from a pervaporative irrigation membrane

Pervaporative irrigation is a membrane technology that can be used for desalination and subsurface irrigation simultaneously. To irrigate, the tube-shaped polymer membrane is buried in soil and filled with water. Due to the membrane transport process, water enters the soil in vapor phase, drawn across the membrane when the relative humidity in the air-filled pores is low. Soils are typically humid environments, however, the presence of hygroscopic compounds such as fertilisers decreases the humidity. For example, at 20oC the humidity in air in equilibrium above a saturated ammonium nitrate solution is 63%. Here, experiments showed that the presence of fertilisers in sand increased the water flux across the membrane by an order of magnitude. An expression for vapor sorption into sand containing different hygroscopic compounds was developed and combined with a model of vapor and liquid flow in soil. The success of the model in simulating experimental results suggests that the proposed mechanism, adsorption of moisture from the vapor phase by hygroscopic compounds, explains the observed increase in the flux from the irrigation system

Resilience and food security: rethinking an ecological concept

1. Focusing on food production, in this paper we define resilience in the food security context as maintaining production of sufficient and nutritious food in the face of chronic and acute environmental perturbations. In agri-food systems, resilience is manifest over multiple spatial scales: field, farm, regional and global. Metrics comprise production and nutritional diversity as well as socio-economic stability of food supply. 2. Approaches to enhancing resilience show a progression from more ecologically-based methods at small scales to more socially-based interventions at larger scales. At the field scale, approaches include the use of mixtures of crop varieties, livestock breeds and of forage species, polycultures, and boosting ecosystem functions. Stress-tolerant crops, or with greater plasticity, provide technological solutions. 3. At the farm scale, resilience may be conferred by diversifying crops and livestock and by farmers implementing adaptive approaches in response to perturbations. Biodiverse landscapes may enhance resilience, but the evidence is weak. At regional to global scales, resilient food systems will be achieved by coordination and implementation of resilience approaches among farms, advice to farmers and targeted research. 4. Synthesis. Threats to food production are predicted to increase under climate change and land degradation. Holistic responses are needed that integrate across spatial scales. Ecological knowledge is critical, but should be implemented alongside agronomic solutions and socio-economic transformations

Assessing the impact of climate change on sweet potato in Uganda

Sweet potato is a mainstay of household food security and a major source of vitamin A across sub-Saharan Africa, and particularly in Uganda. Understanding how climate change is likely to impact on sweet potato would be useful for policymakers in Uganda making decisions to improve food security and increase resilience to climate shocks. However, sweet potato is an under-researched crop and the impacts of climate change have not been systematically analysed. The Sweet Potato Catalyst Project aims to assess the impacts of climate change on sweet potato in Uganda and develop ways for local stakeholders to access and assess this information to strengthen governance. This policy briefing note provides an overview of the research, the approach being taken and anticipated outcomes that will feed into the UNFCCC Koronovia Joint Work on Agriculture

Diabetes and lipid screening among patients in primary care: A cohort study

<p>Abstract</p> <p>Background</p> <p>Obesity is associated with increased cardiovascular diseases and diabetes mellitus. Guidelines call for intensified glucose and lipid screening among overweight and obese patients. Data on compliance with these guidelines are scarce. The purpose of this study was to assess rates of diabetes and lipid screening in primary care according to demographic variables and weight status.</p> <p>Methods</p> <p>Over a 3-year follow-up period, we assessed screening rates for blood glucose, triglycerides, and HDL- and LDL-cholesterol among 5025 patients in primary care. From proportional hazards models we estimated screening rates among low, moderate, high, and very-high risk patients and compared them with recommendations of the American Diabetes Association (ADA), National Cholesterol Education Program (ATP III) and U.S. Preventive Services Task Force (USPSTF).</p> <p>Results</p> <p>Mean (SD) age was 47.4 (15.6); 69% were female, 21% were non-white, and 30% of males and 25% of females were obese (BMI ≥ 30 kg/m²). For both diabetes and lipid screening, the adjusted hazard was 260–330% higher among ≥65 than <35 year-olds, 50–90% higher in persons with BMI ≥ 35 than <25 kg/m², 10–30% lower for females than males, and not lower among racial/ethnic minorities. Screening rates were at least 80% among very-high risk persons, which we defined as 55–64 years old, BMI ≥ 35 kg/m², non-white, with baseline hypertension. In contrast, high-risk persons who were younger (35–44 years old) and less obese (BMI 30–<35 kg/m²) were screened less often (43% for LDL-cholesterol among females to 83% for diabetes among males) even though ADA, ATP III and USPSTF recommend diabetes and lipid screening among them.</p> <p>Conclusion</p> <p>Patients with higher BMI or age were more likely to be screened for cardiometabolic risk factors. Women were screened at lower rates than men. Even in a highly structured medical group practice, some obese patients were under-screened for diabetes and dyslipidemia.</p

17 ways to say yes:Toward nuanced tone of voice in AAC and speech technology

People with complex communication needs who use speech-generating devices have very little expressive control over their tone of voice. Despite its importance in human interaction, the issue of tone of voice remains all but absent from AAC research and development however. In this paper, we describe three interdisciplinary projects, past, present and future: The critical design collection Six Speaking Chairs has provoked deeper discussion and inspired a social model of tone of voice; the speculative concept Speech Hedge illustrates challenges and opportunities in designing more expressive user interfaces; the pilot project Tonetable could enable participatory research and seed a research network around tone of voice. We speculate that more radical interactions might expand frontiers of AAC and disrupt speech technology as a whole

Scaling the nexus: towards integrated frameworks for analysing water, energy and food

The emergence of the water-energy-food (WEF) nexus concept following the 2011 Bonn Nexus Conference has resulted in a change to the way we perceive our natural resources. Global pressures such as climate change, and population growth have highlighted the fragility of our WEF systems, necessitating integrated solutions across multiple scales and levels. Whilst a number of frameworks and analytical tools have been developed since 2011, a comprehensive WEF nexus tool remains elusive, hindered in part by our limited data and understanding of the interdependencies and connections across the WEF systems. To achieve this, the community of academics, practitioners and policy-makers invested in WEF nexus research are addressing several critical areas that currently remain as barriers. Firstly, the plurality of scales (e.g., spatial, temporal, institutional, jurisdictional) necessitates a more comprehensive effort to assess interdependencies between water, energy and food, from household to institutional and national levels. Secondly, and closely related to scale, a lack of available data often hinders our ability to quantify physical stocks and flows of resources. In this paper, we elucidate many of the challenges that have arisen across nexus research, including the impact of multiple scales in operation across the nexus, and concomitantly, what impact these scales have on data accessibility. We review some of the critical frameworks and tools that are applied by nexus researchers and discuss some of the steps required to develop from nexus thinking to an operationalizable concept, with a consistent focus on scale and data availability

Storylines for decision-making: climate and food security in Namibia

Storylines are plausible descriptions of past or future events and can be used to characterise uncertainty through discrete possible futures. They thereby bridge the gap between global-scale future projections and local-scale impacts, providing decision-makers with useful information about potential impacts in multivariate systems despite large swathes of missing data. Here we demonstrate the storyline approach using the case of household food security in the Caprivi region of Namibia, an example of a complex system with multiple interacting drivers. We develop a network characterising influences on household food security, highlighting drivers that are affected by the local weather (with climate understood to constitute the collection of possible weather states). The network is used to understand the storyline leading to household impacts in 2013-14, a consumption year affected by flooding, and the effects of a range of interventions across wealth groups. Counterfactual storylines are also developed to characterise potential impacts under different local and national conditions. Through this we demonstrate how a storyline approach can embed local contextual information to provide decision-makers with comprehensible and assessable information about possible futures and interventions. We also highlight the importance of identifying common drivers, in this case the local weather, in producing plausible impact storylines

Commemorating the First World War in Britain: A Cultural Legacy of Media Remembrance

One of the often-overlooked legacies of the First World War is how the conflict established the media’s role in remembrance. In the years that have followed, media’s circulation of iconic images of national and local commemoration have enabled individuals to engage with public remembrance. This article takes a historical approach to First World War remembrance in Britain, looking at how the practices and meaning of remembrance became established, although they were never fixed but instead constantly shifting, reinvented and contested. They are also gendered, in remembrance, as in war, women, are often seen as to be playing supportive roles; yet within media texts, women have always found spaces to exert influence over who is remembered and how, as memories jostle for prominence

A broken silence? Mass Observation, Armistice Day and ‘everyday life’ in Britain 1937–1941

Between 1937 and 1941 the social survey organization Mass Observation collected material on the ways that the British people experienced and thought about the commemorative practices that marked the anniversary of the Armistice of 1918. What they found was that while people were largely united in their observation of the rituals of remembrance, their thoughts and feelings about these practices were diverse. For some, the acts of commemoration were a fitting way to pay tribute to both the dead and the bereaved. For others, these acts were hypocritical in a nation preparing for war. This article draws on the Mass Observation material to trace some of the diverse ways that remembrance was embodied in everyday life, practised, experienced and understood by the British people as the nation moved once again from peace to war, arguing that studies of the practices of remembrance alone tell us little about how they have been understood by participants