Background: Development of more effective interventions for nonspecific chronic low back pain (LBP), requires a robust theoretical framework regarding mechanisms underlying the persistence of LBP. Altered movement patterns, possibly driven by pain-related cognitions, are assumed to drive pain persistence, but cogent evidence is missing. Aim: To assess variability and stability of lumbar movement patterns, during repetitive seated reaching, in people with and without LBP, and to investigate whether these movement characteristics are associated with painrelated cognitions. Methods: 60 participants were recruited, matched by age and sex (30 back-healthy and 30 with LBP). Mean age was 32.1 years (SD13.4). Mean Oswestry Disability Index-score in LBP-group was 15.7 (SD12.7). Pain-related cognitions were assessed by the ‘Pain Catastrophizing Scale’ (PCS), ‘Pain Anxiety Symptoms Scale’ (PASS) and the task-specific ‘Expected Back Strain’ scale(EBS). Participants performed a seated repetitive reaching movement (45 times), at self-selected speed. Lumbar movement patterns were assessed by an optical motion capture system recording positions of cluster markers, located on the spinous processes of S1 and T8. Movement patterns were characterized by the spatial variability (meanSD) of the lumbar Euler angles: flexion-extension, lateralbending, axial-rotation, temporal variability (CyclSD) and local dynamic stability (LDE). Differences in movement patterns, between people with and without LBP and with high and low levels of pain-related cognitions, were assessed with factorial MANOVA. Results: We found no main effect of LBP on variability and stability, but there was a significant interaction effect of group and EBS. In the LBP-group, participants with high levels of EBS, showed increased MeanSDlateral-bending (p = 0.004, η2 = 0.14), indicating a large effect. MeanSDaxial-rotation approached significance (p = 0.06). Significance: In people with LBP, spatial variability was predicted by the task-specific EBS, but not by the general measures of pain-related cognitions. These results suggest that a high level of EBS is a driver of increased spatial variability, in participants with LBP.
Literature highlights the need for research on changes in lumbar movement patterns, as potential mechanisms underlying the persistence of low-back pain. Variability and local dynamic stability are frequently used to characterize movement patterns. In view of a lack of information on reliability of these measures, we determined their within- and between-session reliability in repeated seated reaching. Thirty-six participants (21 healthy, 15 LBP) executed three trials of repeated seated reaching on two days. An optical motion capture system recorded positions of cluster markers, located on the spinous processes of S1 and T8. Movement patterns were characterized by the spatial variability (meanSD) of the lumbar Euler angles: flexion–extension, lateral bending, axial rotation, temporal variability (CyclSD) and local dynamic stability (LDE). Reliability was evaluated using intraclass correlation coefficients (ICC), coefficients of variation (CV) and Bland-Altman plots. Sufficient reliability was defined as an ICC ≥ 0.5 and a CV < 20%. To determine the effect of number of repetitions on reliability, analyses were performed for the first 10, 20, 30, and 40 repetitions of each time series. MeanSD, CyclSD, and the LDE had moderate within-session reliability; meanSD: ICC = 0.60–0.73 (CV = 14–17%); CyclSD: ICC = 0.68 (CV = 17%); LDE: ICC = 0.62 (CV = 5%). Between-session reliability was somewhat lower; meanSD: ICC = 0.44–0.73 (CV = 17–19%); CyclSD: ICC = 0.45–0.56 (CV = 19–22%); LDE: ICC = 0.25–0.54 (CV = 5–6%). MeanSD, CyclSD and the LDE are sufficiently reliable to assess lumbar movement patterns in single-session experiments, and at best sufficiently reliable in multi-session experiments. Within-session, a plateau in reliability appears to be reached at 40 repetitions for meanSD (flexion–extension), meanSD (axial-rotation) and CyclSD.
MULTIFILE
Nature-based strategies, such as wave attenuation by tidal marshes, are increasingly proposed as a complement to mitigate the risks of failure of engineered flood defense structures such as levees. However, recent analysis of historic coastal storms revealed smaller dike breach dimensions if there were natural, high tidal marshes in front of the dikes. Since tidal marshes naturally only experience weak flow velocities (~0-0.3 ms-1 during normal spring tides), we lack direct observations on the stability of tidal marsh sediments and vegetation under extreme flow velocities (order of several ms-1) as may occur when a dike behind a marsh breaches. As a first approximation, the stability of a tidal marsh sediment bed and winter-state vegetation under high flow velocities were tested in a flume. Marsh monoliths were excavated from Phragmites australis marshes in front of a dike along the Scheldt estuary (Dutch-Belgian border area) and installed in a 10 m long flume test section. Both sediment bed and vegetation responses were quantified over 6 experimental runs under high flow velocities up to 1.75 ms-1 and water depth up to 0.35 m for 2 hours. These tests showed that even after a cumulative 12 hours exposure to high flow velocities, erosion was limited to as little as a few millimeters. Manual removal of the aboveground vegetation did not enhance the erosion either. Present findings may be related to the strongly consolidated, clay- and silt-rich sediment and P. australis root system in this experiment. During the flow exposure, the P. australis stems were strongly bent by the water flow, but the majority of all shoots recovered rapidly when the flow had stopped. Although present results may not be blindly extrapolated to all other marsh types, they do provide a strong first indication that marshes can remain stable under high flow conditions, and confirm the potential of well-developed tidal marshes as a valuable extra natural barrier reducing flood discharges towards the hinterland, following a dike breach. These outcomes promote the consideration to implement tidal marshes as part of the overall flood defense and to rethink dike strengthening in the future.
LINK
The textile and clothing sector belongs to the world’s biggest economic activities. Producing textiles is highly energy-, water- and chemical-intensive and consequently the textile industry has a strong impact on environment and is regarded as the second greatest polluter of clean water. The European textile industry has taken significant steps taken in developing sustainable manufacturing processes and materials for example in water treatment and the development of biobased and recycled fibres. However, the large amount of harmful and toxic chemicals necessary, especially the synthetic colourants, i.e. the pigments and dyes used to colour the textile fibres and fabrics remains a serious concern. The limited range of alternative natural colourants that is available often fail the desired intensity and light stability and also are not provided at the affordable cost . The industrial partners and the branch organisations Modint and Contactgroep Textiel are actively searching for sustainable alternatives and have approached Avans to assist in the development of the colourants which led to the project Beauti-Fully Biobased Fibres project proposal. The objective of the Beauti-Fully Biobased Fibres project is to develop sustainable, renewable colourants with improved light fastness and colour intensity for colouration of (biobased) man-made textile fibres Avans University of Applied Science, Zuyd University of Applied Sciences, Wageningen University & Research, Maastricht University and representatives from the textile industry will actively collaborate in the project. Specific approaches have been identified which build on knowledge developed by the knowledge partners in earlier projects. These will now be used for designing sustainable, renewable colourants with the improved quality aspects of light fastness and intensity as required in the textile industry. The selected approaches include refining natural extracts, encapsulation and novel chemical modification of nano-particle surfaces with chromophores.
Buildings are responsible for approximately 40% of energy consumption and 36% of carbon dioxide (CO2) emissions in the EU, and the largest energy consumer in Europe (https://ec.europa.eu/energy). Recent research shows that more than 2/3 of all CO2 is emitted during the building process whereas less than 1/3 is emitted during use. Cement is the source of about 8% of the world's CO2 emissions and innovation to create a distributive change in building practices is urgently needed, according to Chatham House report (Lehne et al 2018). Therefore new sustainable materials must be developed to replace concrete and fossil based building materials. Lightweight biobased biocomposites are good candidates for claddings and many other non-bearing building structures. Biocarbon, also commonly known as Biochar, is a high-carbon, fine-grained solid that is produced through pyrolysis processes and currently mainly used for energy. Recently biocarbon has also gained attention for its potential value with in industrial applications such as composites (Giorcellia et al, 2018; Piri et.al, 2018). Addition of biocarbon in the biocomposites is likely to increase the UV-resistance and fire resistance of the materials and decrease hydrophilic nature of composites. Using biocarbon in polymer composites is also interesting because of its relatively low specific weight that will result to lighter composite materials. In this Building Light project the SMEs Torrgas and NPSP will collaborate with and Avans/CoE BBE in a feasibility study on the use of biocarbon in a NPSP biocomposite. The physicochemical properties and moisture absorption of the composites with biocarbon filler will be compared to the biocomposite obtained with the currently used calcium carbonate filler. These novel biocarbon-biocomposites are anticipated to have higher stability and lighter weight, hence resulting to a new, exciting building materials that will create new business opportunities for both of the SME partners.
Aiming for a more sustainable future, biobased materials with improved performance are required. For biobased vinyl polymers, enhancing performance can be achieved by nanostructuring the material, i.e. through the use of well-defined (multi-)block, gradient, graft, comb, etc., copolymer made by controlled radical polymerization (CRP). Dispoltec has developed a new generation of alkoxyamines, which suppress termination and display enhanced end group stability compared to state-of-art CRP. Hence, these alkoxyamines are particularly suited to provide access to such biobased nanostructured materials. In order to produce alkoxyamines in a more environmentally benign and efficient manner, a photo-chemical step is beneficial for the final stage in their synthesis. Photo-flow chemistry as a process intensification technology is proposed, as flow chemistry inherently leads to more efficient reactions. In particular, photo-flow offers the benefit of significantly enhancing reactant concentrations and reducing batch times due to highly improved illumination. The aim of this project is to demonstrate at lab scale the feasibility of producing the new generation of alkoxy-amines via a photo-flow process under industrially relevant conditions regarding concentration, duration and efficiency. To this end, Zuyd University of Applied Sciences (Zuyd), CHemelot Innovation and Learning Labs (CHILL) and Dispoltec BV want to enter into a collaboration by combining the expertise of Dispoltec on alkoxyamines for CRP with those of Zuyd and CHILL on microreactor technology and flow chemistry. Improved access to these alkoxyamines is industrially relevant for initiator manufacturers, as well as producers of biobased vinyl polymers and end-users aiming to enhance performance through nanostructuring biobased materials. In addition, access in this manner is a clear demonstration for the high industrial potential of photo-flow chemistry as sustainable manufacturing tool. Further to that, students and professionals working together at CHILL will be trained in this emerging, industrially relevant and sustainable processing tool.
