The ecological impact of different mechanisms of chronic sub-lethal toxicity on feeding and respiratory physiology

Sub-lethal toxicity tests, such as the scope-for-growth test, reveal simple relationships between measures of contaminant concentration and effect on respiratory and feeding physiology. Simple models are presented to investigate the potential impact of different mechanisms of chronic sub-lethal toxicity on these physiological processes. Since environmental quality is variable, even in unimpacted environments, toxicants may have differentially greater impacts in poor compared to higher quality environments. The models illustrate the implications of different degrees and mechanisms of toxicity in response to variability in the quality of the feeding environment, and variability in standard metabolic rate. The models suggest that the relationships between measured degrees of toxic stress, and the maintenance ration required to maintain zero scope-for-growth, may be highly nonlinear. In addition it may be possible to define critical levels of sub-lethal toxic effect above which no environment is of sufficient quality to permit prolonged survival

Modelling sediment supply and transport in the River Lugg: strategies for controlling sediment loads

The River Lugg has particular problems with high sediment loads that have resulted in detrimental impacts on ecology and fisheries. A new dynamic, process-based model of hydrology and sediments (INCA- SED) has been developed and applied to the River Lugg system using an extensive data set from 1995–2008. The model simulates sediment sources and sinks throughout the catchment and gives a good representation of the sediment response at 22 reaches along the River Lugg. A key question considered in using the model is the management of sediment sources so that concentrations and bed loads can be reduced in the river system. Altogether, five sediment management scenarios were selected for testing on the River Lugg, including land use change, contour tillage, hedging and buffer strips. Running the model with parameters altered to simulate these five scenarios produced some interesting results. All scenarios achieved some reduction in sediment levels, with the 40% land use change achieving the best result with a 19% reduction. The other scenarios also achieved significant reductions of between 7% and 9%. Buffer strips produce the best result at close to 9%. The results suggest that if hedge introduction, contour tillage and buffer strips were all applied, sediment reductions would total 24%, considerably improving the current sediment situation. We present a novel cost-effectiveness analysis of our results where we use percentage of land removed from production as our cost function. Given the minimal loss of land associated with contour tillage, hedges and buffer strips, we suggest that these management practices are the most cost-effective combination to reduce sediment loads

"It's all interconnected… like a spider web": a qualitative study of the meanings of food and healthy eating in an Indigenous community.

Canadian Indigenous populations are disproportionately affected by rising rates of diet-related chronic disease and have been experiencing rapid lifestyle changes affecting diet. In recognition of these issues, this study aimed to obtain greater understanding of attitudes and meanings around healthy eating in a semi-remote community in Eeyou Istchee. A qualitative study design used semi-structured interviews and observational field notes to explore local accounts of food and health. Two distinct versions of "healthy eating" were identified: one relating to traditional food and preparation methods; the other reflecting medicalised accounts of illness and diagnosed conditions. The latter links with "southern" modes of accessing and preparing food, demonstrating local capacity to adapt to the rapid changes in body, lifestyle and environment being experienced. New connections, associating non-native ways with traditional practices, are being formed where traditional ways of living on the land have been severed. These local accounts show how people are continually negotiating different constructs of "healthy eating." These findings expand current understandings of the context of food and healthy eating in Eeyou Istchee, emphasising present-day and historical experiences of the land. Future research and diet-related health interventions must continue to acknowledge and incorporate local understandings of health to help address the broader socio-political factors that shape Indigenous lifestyles, environments and health

Wâhkôhtowin: the governance of good community-academic research relationships to improve the health and well-being of children in Alexander First Nation

Community-based participatory research (CBPR) is a promising decolonizing approach to health and social sciences research with First Nation Peoples. In CBPR, the use of a community advisory committee can act as an anchoring site for trusting reciprocal relationships, collaborative decision-making, and co-learning and co-creation. Through a qualitative case study, this article illustrates the collective experiences of a well-established, multidisciplinary, and intersectoral committee that reviews, monitors, and guides multiple research projects in a First Nation community in Canada. Participants of the Alexander Research Committee (ARC) share examples of the value of fostering a high level of commitment to building both positive working relationships and learning spaces that ultimately result in research and policy impacts for their community

Gait Asymmetry Post-Stroke: Determining Valid and Reliable Methods Using a Single Accelerometer Located on the Trunk

Asymmetry is a cardinal symptom of gait post-stroke that is targeted during rehabilitation. Technological developments have allowed accelerometers to be a feasible tool to provide digital gait variables. Many acceleration-derived variables are proposed to measure gait asymmetry. Despite a need for accurate calculation, no consensus exists for what is the most valid and reliable variable. Using an instrumented walkway (GaitRite) as the reference standard, this study compared the validity and reliability of multiple acceleration-derived asymmetry variables. Twenty-five post-stroke participants performed repeated walks over GaitRite whilst wearing a tri-axial accelerometer (Axivity AX3) on their lower back, on two occasions, one week apart. Harmonic ratio, autocorrelation, gait symmetry index, phase plots, acceleration, and jerk root mean square were calculated from the acceleration signals. Test–retest reliability was calculated, and concurrent validity was estimated by comparison with GaitRite. The strongest concurrent validity was obtained from step regularity from the vertical signal, which also recorded excellent test–retest reliability (Spearman’s rank correlation coefficients (rho) = 0.87 and Intraclass correlation coefficient (ICC21) = 0.98, respectively). Future research should test the responsiveness of this and other step asymmetry variables to quantify change during recovery and the effect of rehabilitative interventions for consideration as digital biomarkers to quantify gait asymmetry

Assessing the Extent to Which the UK’s National Risk Register Supports Local Risk Management

This paper examines how a national risk register supports the implementation of disaster risk management practices at a local level. We present a case study of the UK’s National Risk Register of Civil Emergencies and explore stakeholder understanding, views, perceptions, opinions, and application within the East of England. A semi-structured interview methodology was adopted for this paper with 14 key stakeholders from across the East of England interviewed. Thematic coding analysis was used to structure the results against a set of research questions. Interviewees were found to be largely unaware of the National Risk Register, and as such its usefulness as a risk management tool is limited. In particular, restricted local resources, limited understanding of risk, and a lack of actionable strategies were highlighted as barriers to action. Opportunities for capacity building at the local level, sharing best practice, and improved risk communication were all identified. The National Risk Register could be used to improve risk management at local levels but more engagement with it at a local level is required

Modelling impacts of seasonal wastewater treatment plant effluent permits and biosolid substitution for phosphorus management in catchments and river systems

The issues of diffuse and point source phosphorus (P) pollution in river systems are presented using a catchment model to assess nutrient behaviour, seasonal effluent standards and biosolid substitution. A process-based, dynamic water quality model (INCA-P) has been applied to four UK catchments, namely, the Rivers Tywi, Wensum, Lunan and Hampshire Avon, to simulate water fluxes, sediments, total phosphorus and soluble reactive phosphorus (SRP) concentrations. The model has been used to assess impacts of both agricultural runoff and point P sources from wastewater treatment plants (WWTPs) on water quality. With increasing costs for P fertilizer and P reduction at WWTPs, a strategy of recycling P from WWTPs as biosolids to substitute for fertilizers in vulnerable catchments has been investigated. Significant reductions in P concentrations are achieved if this substitution were implemented on a large scale. Reductions in SRP of between 6% and 41% can be achieved using this strategy. The effects of implementing new WWTP standards are shown to reduce SRP by 30%. Seasonal consent standards applied in only summer months could reduce SRP by 53% and achieve a substantial reduction in treatment costs year round

Hunger among Inuit children in Canada

Background and objectives. Inuit populations may be at increased risk for experiencing poor nutrition or hunger due to limited access and availability to food. The prevalence and correlates of parental perceptions of hunger among a nationally representative sample of Inuit children in Canada have not yet been reported. Design. Data are from the 2006 Aboriginal Children's Survey (ACS). Sociodemographic information, dietary behaviours and hunger status were parent-reported via a household interview for Inuit children aged 2–5 years (n=1,234). Prevalence of hunger was calculated among Inuit children by sociodemographic factors and by dietary behaviours. In addition, a multivariate logistic regression model was conducted to determine factors associated with parental perception of ever experiencing hunger. Results. The prevalence of Inuit children in Canada aged 2–5 years ever experiencing hunger was 24.4%. Children who were reported to have experienced hunger consumed milk and milk products (p<0.001); fish, eggs and meat (p<0.05); fruits (p<0.001); and vegetables (p<0.001) significantly less often than never-hungry children. Fast food and processed foods, soft drinks and juice, and salty snacks, sweets and desserts were consumed as often as never-hungry children (all p>0.05). The majority (81%) of Inuit parents/guardians of ever-hungry children sought help from family or friends. Factors associated with an increased likelihood of experiencing hunger include sociodemographic characteristics (such as income and household size), living in an Inuit region and living in a community with cultural activities. Conclusion. About 1 in 4 Inuit children were reported by their parents to have experienced hunger, and hunger was associated with region, sociodemographic and community factors. Future research could further examine the impact of ever experiencing hunger on the health status of Inuit children and their families in Canada

Structure of the Mg-Chelatase Cofactor GUN4 Reveals a Novel Hand-Shaped Fold for Porphyrin Binding

In plants, the accumulation of the chlorophyll precursor Mg-protoporphyrin IX (Mg-Proto) in the plastid regulates the expression of a number of nuclear genes with functions related to photosynthesis. Analysis of the plastid-to-nucleus signaling activity of Mg-Proto in Arabidopsis thaliana led to the discovery of GUN4, a novel porphyrin-binding protein that also dramatically enhances the activity of Mg-chelatase, the enzyme that synthesizes Mg-Proto. GUN4 may also play a role in both photoprotection and the cellular shuttling of tetrapyrroles. Here we report a 1.78-Å resolution crystal structure of Synechocystis GUN4, in which the porphyrin-binding domain adopts a unique three dimensional fold with a “cupped hand” shape. Biophysical and biochemical analyses revealed the specific site of interaction between GUN4 and Mg-Proto and the energetic determinants for the GUN4 • Mg-Proto interaction. Our data support a novel protective function for GUN4 in tetrapyrrole trafficking. The combined structural and energetic analyses presented herein form the physical-chemical basis for understanding GUN4 biological activity, including its role in the stimulation of Mg-chelatase activity, as well as in Mg-Proto retrograde signaling

Energy absorption evaluation and design at the ballistic level in composites

The research presented in this thesis is directed towards the evaluation and understanding of a range of composite materials impacted at a ballistic level under both normal and oblique orientations, and the development of a novel recycled composite material with enhanced ballistic performance. It compares the ballistic performance of normal and oblique impacts of metallic and composite materials, describes the development, production and testing of a novel recycled composite material, and the performance of a Kolsky experiment on this novel material. For the Certification Authorities within the Aerospace Industry, the effects of angled impacts onto composites have not been addressed to the same extent as normal impacts, primarily because perpendicular impacts are largely considered to be the worst case scenarios. However, this research highlights certain aspects within the behaviour of composite materials in which that assumption may be too simplistic. Composites offer many advantages in ballistic protection but they are still relatively expensive and once damaged the ‘used’ material is usually discarded in secure landfill or burnt, and new pristine protective panels are required in their place. The development of a new recycled composite material could potentially therefore reduce costs, for example, if employed in partly replacing current battle-damaged polymeric armour panels used in the protection of air/land/sea vehicles, equipment and buildings. Further insight has been gained through the implementation of a Kolsky bar impact test based on a Hopkinson bar methodology, which has been modified to encompass a Taylor impact type concept. In this test, a polymeric specimen is fired against an instrumented steel bar, which measures the strain generated during the impact event, and the process of material deformation and disintegration is captured on video for subsequent analysis. Tests have been carried out on Aluminium, pristine cylindrical and cuboid Dyneema® specimens and also recycled cylindrical Dyneema® specimens.Open Acces