Multi-level socioecological drivers of agrarian change:Longitudinal evidence from mixed rice-livestock-aquaculture farming systems of Bangladesh

Coastal systems are facing natural and human-driven change coupled with a rising population. With increasing shifts in socioecological conditions during the past several decades, it is important to understand how socioecological drivers at different hierarchical levels: -micro, -meso, and -macro affect coastal farming systems, which play a crucial role in the livelihoods of coastal dwellers. Mixed rice-livestock-aquaculture farming in Southern Bangladesh exemplifies the rapid change occurring in many of the world's coastal farming systems in response to these drivers. We used panel data observations from the above study area and modeled trajectories of farm typologies, and the impact of multi-level socioecological drivers by a novel approach. Our approach integrates: (1) a well-articulated conceptual frame of change observed using (2) a temporal view of the potential drivers, change process and farm type outcomes, with the twenty years panel data of 502 households that is analyzed by means of (3) multivariate statistics in conjunction with panel data models that operationalize the conceptual frame. Our approach allows (a) estimating dynamic effects over time that typically cannot be estimated in a cross-sectional data set, (b) distinguishing between time-invariant fixed and time dependent random effects of multi-level socioecological drivers, and (c) controlling for omitted variables to a certain extent. Considering farming systems both within and outside of polder embankment systems intended to protect against oceanic water intrusion, we found a gradual shift from heterogeneous, rice-livestock farm types to more homogenous farms with less livestock and more off-farm activities. Micro-level factors including farm plot fragmentation, farmers' experience in cropping, machinery, salinity and soil fertility were influencing changes in farming systems. Meso-level factors including markets, road infrastructure, labor availability, access to extension and land tenure also affect the trajectory of farming systems change. Among macro-level drivers, increasing population density positively and significantly influenced cropping intensity among farms outside polder systems. Within polders, a positive but non-significant trend was observed for the influence of population density on cropping intensity. Our data also indicate negative and significant influence of cyclonic storms on cropping intensity over time in both areas. Our results underscore the importance of accounting for multiple levels of socioecological drivers of change when developing appropriate policy options for sustainable development in South Asia's coastal farming systems

Operationalizing the concept of robustness of nitrogen networks in mixed smallholder systems:A pilot study in the mid-hills and lowlands of Nepal

Nitrogen (N) is often the most limiting nutrient to productivity in smallholder mixed crop-livestock systems such as commonly found in the mid-hills and lowland (Terai) of Nepal. Identifying current bottlenecks constraining agroecosystem functioning in terms of N flows and associated improvement options in these systems is paramount. Here, we explore variations in robustness, a concept from ecological network analysis (ENA) which represents the balance of system’s degree of order between organization (order/constraint) and adaptive flexibility (freedom/resilience) of N flows. Robustness can provide a detailed assessment of N flows and assist in evaluation of measures to reduce nutrient losses. In this study, the FarmDESIGN model was employed to quantify nitrogen flows, generate ENA indicators of integration, diversity and robustness, and to explore the impact of crop intensification options on N networks across farm types in the mid-hills and lowland (Terai) of Nepal. Results revealed that the farms in the different agroecosystems recycled only a small portion of the total N inputs (<15%), and had therefore high rates of N losses (63–1135 kg N per ha per year) and high dependency on N imports in the form of fodder (feed self-reliance 11–43%). The farm N networks were organised (high productivity) but inflexible (poorly resilient) and consequently unbalanced (low robustness). Scenarios of improved management (improved seed, intercropping, use of fertilizers, better timing of activities) resulted in improved crop production, leading to reduced fodder imports and less N losses. Consequently, the N networks increased in flexibility which resulted in greater robustness of the N flow network in the farm systems. Increasing on-farm biomass production by improved farm management could be an important element on the way to sustainably intensify smallholder farms, especially when dependency on external resources can be reduced. We conclude that a detailed analysis of nutrient flows and their robustness is a suitable instrument for targeted improvement of nutrient use in smallholder crop-livestock systems

A continuous-discontinuous model for crack branching

This is the peer reviewed version of the following article: Tamayo, E. [et al.]. A continuous-discontinuous model for crack branching. "International journal for numerical methods in engineering", 5 Octubre 2019, vol. 120, núm. 1, p. 86-104, which has been published in final form at https://doi.org/10.1002/nme.6125. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.A new continuous-discontinuous model for fracture that accounts for crack branching in a natural manner is presented. It combines a gradient-enhanced damage model based on nonlocal displacements to describe diffuse cracks and the extended finite element method (X-FEM) for sharp cracks. Its most distinct feature is a global crack tracking strategy based on the geometrical notion of medial axis: the sharp crack propagates following the direction dictated by the medial axis of a damage isoline. This means that, if the damage field branches, the medial axis automatically detects this bifurcation, and a branching sharp crack is thus easily obtained. In contrast to other existing models, no special crack-tip criteria are required to trigger branching. Complex crack patterns may also be described with this approach, since the X-FEM enrichment of the displacement field can be recursively applied by adding one extra term at each branching event. The proposed approach is also equipped with a crack-fluid pressure, a relevant feature in applications such as hydraulic fracturing or leakage-related events. The capabilities of the model to handle propagation and branching of cracks are illustrated by means of different two-dimensional numerical examples.Peer ReviewedPostprint (author's final draft

High shear stress relates to intraplaque haemorrhage in asymptomatic carotid plaques

AbstractBackground and aimsCarotid artery plaques with vulnerable plaque components are related to a higher risk of cerebrovascular accidents. It is unknown which factors drive vulnerable plaque development. Shear stress, the frictional force of blood at the vessel wall, is known to influence plaque formation. We evaluated the association between shear stress and plaque components (intraplaque haemorrhage (IPH), lipid rich necrotic core (LRNC) and/or calcifications) in relatively small carotid artery plaques in asymptomatic persons.MethodsParticipants (n = 74) from the population-based Rotterdam Study, all with carotid atherosclerosis assessed on ultrasound, underwent carotid MRI. Multiple MRI sequences were used to evaluate the presence of IPH, LRNC and/or calcifications in plaques in the carotid arteries. Images were automatically segmented for lumen and outer wall to obtain a 3D reconstruction of the carotid bifurcation. These reconstructions were used to calculate minimum, mean and maximum shear stresses by applying computational fluid dynamics with subject-specific inflow conditions. Associations between shear stress measures and plaque composition were studied using generalized estimating equations analysis, adjusting for age, sex and carotid wall thickness.ResultsThe study group consisted of 93 atherosclerotic carotid arteries of 74 participants. In plaques with higher maximum shear stresses, IPH was more often present (OR per unit increase in maximum shear stress (log transformed) = 12.14; p = 0.001). Higher maximum shear stress was also significantly associated with the presence of calcifications (OR = 4.28; p = 0.015).ConclusionsHigher maximum shear stress is associated with intraplaque haemorrhage and calcifications

Guiding community discussions on human–water challenges by serious gaming in the upper Ewaso Ngiro River basin, Kenya

Water-related conflicts in river catchments occur due to both internal and external pressures that affect catchment water availability. Lack of common understanding of human–water perspectives by catchment stakeholders increases the complexity of human–water issues at the river catchment scale. Among a range of participatory approaches, the development and use of serious games gained prominence as a tool to stimulate discussion and reflection among stakeholders about sustainable resource use and collective action. This study designed and implemented the ENGAGE (Exploring New Gaming Approach to Guide and Enlighten) game that mimics the dynamics observed during the dry season in the upper Ewaso Ngiro catchment, northwest of Mount Kenya. The purpose of this study was to explore the potential role of serious gaming in subsequent steps of strengthening stakeholder engagement (agenda setting, shared understanding, commitment to collective action, and means of implementation) toward addressing complex human–water challenges at the catchment scale. We assessed the type of decisions made during gameplay, the communication dynamics, the active participation, and the implication of decisions made on water availability. The results of three game sessions show that the ENGAGE game raised awareness and provided a recognizable hydrologic background to conflicts while guiding community discussions toward implementable decisions. The results revealed increasing active participation, knowledge gain, and use of plural pronouns and decreasing individual interests and conflicts among game participants. This study presents important implications for creating a collective basis for water management and can inform human–water policies and modification of the process behind water allocation rules in a river catchment.</p

A Large Outbreak of Legionnaires’ Disease at a Flower Show, the Netherlands, 1999

In 1999, an outbreak of Legionnaires’ disease affected many visitors to a flower show in the Netherlands. To identify the source of the outbreak, we performed an environmental investigation, as well as a case-control study among visitors and a serologic cohort study among exhibitors to measure exposure to possible sources. Of 77,061 visitors, 188 became ill (133 confirmed and 55 probable cases), for an attack rate of 0.23% for visitors and 0.61% for exhibitors. Two whirlpool spas in halls 3 and 4 of the exhibition and a sprinkler in hall 8 were culture positive for Legionella pneumophila. One of three genotypes found in both whirlpool spas was identical to the isolates from 28 of 29 culture-positive patients. Persons who paused at the whirlpool spa in hall 3 were at increased risk for becoming ill. This study illustrates that whirlpool spas may be an important health hazard if disinfection fails

A mixed-methods study to define Textbook Outcome for the treatment of patients with uncomplicated symptomatic gallstone disease with hospital variation analyses in Dutch trial data

Background: International consensus on the ideal outcome for treatment of uncomplicated symptomatic gallstone disease is absent. This mixed-method study defined a Textbook Outcome (TO) for this large group of patients. Methods: First, expert meetings were organised with stakeholders to design the survey and identify possible outcomes. To reach consensus, results from expert meetings were converted in a survey for clinicians and for patients. During the final expert meeting, clinicians and patients discussed survey outcomes and a definitive TO was formulated. Subsequently, TO-rate and hospital variation were analysed in Dutch hospital data from patients with uncomplicated gallstone disease. Results: First expert meetings returned 32 outcomes. Outcomes were distributed in a survey among 830 clinicians from 81 countries and 645 Dutch patients. Consensus-based TO was defined as no more biliary colic, no biliary and surgical complications, and the absence or reduction of abdominal pain. Analysis of individual patient data showed that TO was achieved in 64.2% (1002/1561). Adjusted-TO rates showed modest variation between hospitals (56.6-74.9%). Conclusion: TO for treatment of uncomplicated gallstone disease was defined as no more biliary colic, no biliary and surgical complications, and absence or reduction of abdominal pain.TO may optimise consistent outcome reporting in care and guidelines for treating uncomplicated gallstone disease

Keeping an eye on noisy movements: On different approaches to perceptual-motor skill research and training

Contemporary theorising on the complementary nature of perception and action in expert performance has led to the emergence of different emphases in studying movement coordination and gaze behaviour. On the one hand, coordination research has examined the role that variability plays in movement control, evidencing that variability facilitates individualised adaptations during both learning and performance. On the other hand, and at odds with this principle, the majority of gaze behaviour studies have tended to average data over participants and trials, proposing the importance of universal 'optimal' gaze patterns in a given task, for all performers, irrespective of stage of learning. In this article, new lines of inquiry are considered with the aim of reconciling these two distinct approaches. The role that inter- and intra-individual variability may play in gaze behaviours is considered, before suggesting directions for future research

Tremor in multiple sclerosis

Tremor is estimated to occur in about 25 to 60 percent of patients with multiple sclerosis (MS). This symptom, which can be severely disabling and embarrassing for patients, is difficult to manage. Isoniazid in high doses, carbamazepine, propranolol and gluthetimide have been reported to provide some relief, but published evidence of effectiveness is very limited. Most trials were of small size and of short duration. Cannabinoids appear ineffective. Tremor reduction can be obtained with stereotactic thalamotomy or thalamic stimulation. However, the studies were small and information on long-term functional outcome is scarce. Physiotherapy, tremor reducing orthoses, and limb cooling can achieve some functional improvement. Tremor in MS remains a significant challenge and unmet need, requiring further basic and clinical research