How to reduce the carbon footprint of the agricultural sector? Factors influencing farmers' decision to participate in carbon sequestration programs.

Mitigating climate change by sequestering carbon in agricultural soils through humus formation is a crucial component of sustainable agriculture. Humus programs that are designed to incentivize farmers to build more humus are still recent innovations, so current knowledge about farmers' motivation to participate is limited. This study examines the adoption of non-governmental humus programs to promote carbon sequestration by analyzing farmers' willingness to participate in humus programs and influential factors. We specifically investigate behavioral factors underlying farmers' adoption of humus programs using the Theory of Planned Behavior. To this end, we collected data using an online survey with 190 German farmers and applied partial least squares structural equation modeling. The results show that (i) perceived economic benefits, (ii) the actions of fellow farmers, and (iii) farmers' sense of responsibility with regard to climate change have a statistically significant influence on farmers' intention to participate in a humus program. In contrast, the perceived ecological benefits, political pressure, the possibility of establishing humus-building measures, and prior knowledge of humus programs have no statistically significant influence. Our findings suggest that farmers' decision to participate in humus programs is strongly influenced by the financial benefits, but the actions and thoughts of other farmers, as well as their own moral claims regarding climate change, also play a crucial role. We found that farmers lack knowledge about the registration and general functioning of humus programs, which can currently be one of the biggest barriers to participation in such initiatives.

RGD-coated polymeric microbubbles promote ultrasound-mediated drug delivery in an inflamed endothelium-pericyte co-culture model of the blood-brain barrier.

Drug delivery to central nervous pathologies is compromised by the blood-brain barrier (BBB). A clinically explored strategy to promote drug delivery across the BBB is sonopermeation, which relies on the combined use of ultrasound (US) and microbubbles (MB) to induce temporally and spatially controlled opening of the BBB. We developed an advanced in vitro BBB model to study the impact of sonopermeation on the delivery of the prototypic polymeric drug carrier pHPMA as a larger molecule and the small molecule antiviral drug ribavirin. This was done under standard and under inflammatory conditions, employing both untargeted and RGD peptide-coated MB. The BBB model is based on human cerebral capillary endothelial cells and human placental pericytes, which are co-cultivated in transwell inserts and which present with proper transendothelial electrical resistance (TEER). Sonopermeation induced a significant decrease in TEER values and facilitated the trans-BBB delivery of fluorescently labeled pHPMA (Atto488-pHPMA). To study drug delivery under inflamed endothelial conditions, which are typical for e.g. tumors, neurodegenerative diseases and CNS infections, tumor necrosis factor (TNF) was employed to induce inflammation in the BBB model. RGD-coated MB bound to and permeabilized the inflamed endothelium-pericyte co-culture model, and potently improved Atto488-pHPMA and ribavirin delivery. Taken together, our work combines in vitro BBB bioengineering with MB-mediated drug delivery enhancement, thereby providing a framework for future studies on optimization of US-mediated drug delivery to the brain.

Farmers' Willingness to Participate in a Carbon Sequestration Program - A Discrete Choice Experiment.

Farmers can counteract global warming by drawing carbon dioxide from the air into agricultural soils by building up humus. Humus programs were developed to motivate farmers for even more humus formation (= carbon sequestration) through an additional financial incentive. These programs are still at an early stage of development, which is why the number of participating farmers and research work is still low. This study is the first to analyze the willingness of German farmers to participate in hypothetical humus programs. The results of a discrete choice experiment show that a (higher) threshold for the payout of the premium, regional (rather than field-specific) reference values, and the risk of repayment clearly discourage farmers from participating. Program providers must more than double the premium (set at around 240 € per hectare and 0.1% humus increase) to maintain farmers' willingness to participate despite a payout threshold. Regional reference values and an additional premium/repayment system would lead to an increase in the premium of around 20 € per hectare in order to keep the willingness to participate at the same level. The motivation to build up humus, the desire to maximize subsidies, and a higher livestock density have a positive influence on farmers' decision to participate. Farm size and risk attitude have an impact on farmers' preferences for program design. The study is relevant for policymakers and non-governmental organizations concerned with carbon management, as our findings highlight pathways for efficient, targeted designs of humus programs and carbon sequestration policies.

[Motion analysis in lower limb exoprosthetics-possibilities and limitations]. / Die Bewegungsanalyse in der Exoprothetik der unteren Extremität ­ Möglichkeiten und Grenzen.

BACKGROUND: Gait analysis is of high relevance in prosthetics as it is an essential part of the fitting process. The documentation of movement by means of videos and instrumented methods is becoming increasingly important in prosthetics as benefits of a complex prosthesis can best be shown by structured observation. PROCEDURE: A movement analysis should always be preceded by an anamnesis and clinical examination in order to detect functional limitations of the examined person and thus to establish correlations to gait deviations. Additionally, the orthopaedic aid should be evaluated as well. In addition to walking on level ground, walking on everyday obstacles such as stairs and ramps is also of interest when observing people using prosthetic limbs. Functional tests can be used to determine the functional status more comprehensively. An instrumental-3D gait analysis is indicated for specific questions, especially regarding kinetic parameters.

Varus Knee Limits Pain Relief Effects of Laterally Wedged Insoles and Ankle-Foot Orthoses in Medial Knee Osteoarthritis.

OBJECTIVE: To investigate the impact of varus malalignment of the knee on pain reduction achieved by an ankle-foot orthosis and a laterally wedged insole in patients with medial knee osteoarthritis. DESIGN: Secondary analysis of a randomized, clinically prospective cross-over study. PATIENTS: Twenty-eight participants with medial knee osteoarthritis. METHODS: All participants wore a 5-mm laterally wedged insole and an ankle-foot orthosis for a period of 6 weeks each in a randomized order. Pain was reported on a numerical rating scale and was correlated with limb alignment, as defined by the mechanical axis deviation in full-leg standing radiographs. RESULTS: Insole and orthosis use reduced pain compared with baseline (median knee pain change: insole -0.5 (-5 to +6), orthosis -1.5 (-7 to +5). A higher mechanical axis deviation (greater varus) correlated significantly with smaller pain reduction for both aids (insole p = 0.003, orthosis p < 0.001). A cut-off to predict pain response was found at a mechanical axis deviation of 14-15 mm for both aids, i.e. > 3° knee varus. CONCLUSION: There is a correlation between varus malalignment and pain reduction. There seems to be a mechanical axis deviation cut-off that predicts the response to treatment with the aids with good sensitivity.

Hindfoot Flexibility Influences the Biomechanical Effects of Laterally Wedged Insoles and Ankle-Foot Orthoses in Medial Knee Osteoarthritis.

OBJECTIVE: To investigate the relationship of frontal plane ankle mobility with the effects of an ankle-foot orthosis (AFO) and a laterally wedged insole (LWI) on knee adduction moment (KAM) in the treatment of medial knee osteoarthritis. DESIGN: Randomized, nonblinded crossover trial. SETTING: Outpatient clinic of university hospital. PARTICIPANTS: Referred sample of 20 patients (N=20) with medial knee osteoarthritis stage 1-3 (Kellgren and Lawrence), aged 56.4±6.5 years; 58 patients were assessed, 21 were included, and 1 was a dropout. There were 14 healthy reference participants without knee osteoarthritis (convenience sample) who were matched by age. INTERVENTIONS: Patients received AFO and LWI for 6 weeks each with gait analysis after each 6-week intervention. Patients underwent additional barefoot gait analysis, walking on even ground and on a cross slope of 5° lateral elevation and standing on inclinations of 0°, 5°, 10°, and 20°. MAIN OUTCOME MEASURES: Spearman correlation between the immediate change in first peak of KAM with each aid and the change in hindfoot varus on the cross slope relative to level ground. RESULTS: The KAM reduction with AFO correlated significantly with hindfoot varus reaction to the cross slope during walking: the greater the hindfoot valgization on the cross slope, the greater the KAM reduction with AFO (Spearman ρ=0.53, P=.02). The KAM reduction with LWI correlated moderately negatively with the change in hindfoot varus: the greater the hindfoot valgization on the cross slope, the smaller the KAM reduction with LWI (r=-0.31 P=.18). CONCLUSIONS: LWI may be suitable for patients with limited to normal frontal plane ankle mobility. Patients with greater frontal plane ankle mobility benefit most from frontal plane ankle bridging with AFO. Studies with larger samples are necessary.

A comparison between laterally wedged insoles and ankle-foot orthoses for the treatment of medial osteoarthritis of the knee: A randomized cross-over trial.

OBJECTIVE: To compare biomechanical and clinical outcome of laterally wedged insoles (LWI) and an ankle-foot orthosis (AFO) in patients with medial knee osteoarthritis. DESIGN: Single-centre, block-randomized, cross-over controlled trial. SETTING: Outpatient clinic. SUBJECTS: About 39 patients with symptomatic medial knee osteoarthritis. INTERVENTIONS: Patients started with either LWI or AFO, determined randomly, and six weeks later changed to the alternative. MAIN MEASURES: Change in the 1st maximum of external knee adduction moment (eKAM) was assessed with gait analysis. Additional outcomes were other kinetic and kinematic changes and the patient-reported outcomes EQ-5D-5L, Oxford Knee Score (OKS), American Knee Society Clinical Rating System (AKSS), Hannover Functional Ability Questionnaire - Osteoarthritis and knee pain. RESULTS: Mean age (SD) of the study population was 58 (8) years, mean BMI 30 (5). Both aids significantly improved OKS (LWI P = 0.003, AFO P = 0.001), AKSS Knee Score (LWI P = 0.01, AFO P = 0.004) and EQ-5D-5L Index (LWI P = 0.001, AFO P = 0.002). AFO reduced the 1st maximum of eKAM by 18% (P < 0.001). The LWI reduced both maxima by 6% (P = 0.02, P = 0.03). Both AFO and LWI reduced the knee adduction angular impulse (KAAI) by 11% (P < 0.001) and 5% (P = 0.05) respectively. The eKAM (1st maximum) and KAAI reduction was significantly larger with AFO than with LWI (P = 0.001, P = 0.004). CONCLUSIONS: AFO reduces medial knee load more than LWI. Nevertheless, no clinical superiority of either of the two aids could be shown.

The influence of hip muscle strength on gait in individuals with a unilateral transfemoral amputation.

INTRODUCTION: A unilateral transfemoral amputation (TFA) has a major impact on function. A leg-length discrepancy is the primary structural change, accompanied by the loss of lower-limb muscle volume and function. Prostheses can help individuals with a TFA to regain function, but such individuals still do not reach the functional level of unimpaired peers and exhibit gait deviations. This study gives insight into the causality between residual limb strength and gait deviations in individuals with a TFA. METHODS: A convenient sample of 13 male individuals with a TFA (38.0 ± 12.6y; 179.7cm ± 6.5cm; 82.9kg ± 12.4kg) was recruited for this study. One participant with TFA was excluded, as he differed from the rest of the cohort, in residual limb length and the use of walking aids. A cohort of 18 unimpaired subjects served as a reference group (REF; nine females; 44y ± 13y; 174cm ± 9cm; 71kg ± 12kg). All participants underwent a conventional clinical gait analysis using a marker based 3D motion capture system and force platforms. Kinematics and kinetics were determined utilizing standard modelling methods. All subjects underwent a strength test, using a custom-made device to determine isometric moments of the hip joint in abduction, adduction, extension, and flexion. Peak values for maximum isometric moments for each movement direction and selected kinematic and kinetic values were derived from the results. Differences between subjects with TFA and unimpaired were compared using a Mann-Whitney U Test and associations between groups by Spearman's rank correlation. RESULTS: The participants with a TFA showed a significantly lower maximum isometric moment for hip abduction (0.85 vs. 1.41 Nm/kg p < .001), adduction (0.87 vs. 1.37 Nm/kg p = .001) and flexion (0.93 vs. 1.63 Nm/kg p = .010) compared to the reference group. Typically reported gait deviations in people with a TFA were identified, i.e. significant lower cadence and increased step width. We further identified altered coronal plane hip and trunk kinematics, with significantly higher ranges of motion during involved side stance-phase. Gait kinetics of individuals with a TFA showed significantly lower peak values during stance for hip abduction, adduction and extension moments in comparison to the reference group. We identified a moderate negative correlation between maximum isometric moment for hip abduction and trunk obliquity range of motion (ρ = -0.45) for participants with a TFA, which was not significant (p = 0.14). CONCLUSION: We showed that there are strength deficits in individuals with TFA and, that there are moderate correlations between gait deviations, i.e. lateral trunk lean during involved side stance and isometric hip abductor moment. The relation between maximum moments during gait and the corresponding maximum isometric moment may therefore be helpful to detect strength related compensation mechanisms. However, the moderate, non-significant correlation between lateral trunk lean and isometric hip abductor moment was the only one which corresponded directly to a gait deviation. Thus results must be interpreted with care. This study suggests that gait deviations in individuals with TFA are multifactorial and cannot be exclusively explained by their strength deficits. Future studies should explore the relationship between strength with kinematics and kinetics during gait in this population.

Benefits of an increased prosthetic ankle range of motion for individuals with a trans-tibial amputation walking with a new prosthetic foot.

BACKGROUND: Individuals with trans-tibial amputation show a greater peak prosthetic ankle power (push- off) when using energy storing and returning (ESAR) prosthetic feet as compared to solid-ankle cushion-heel feet. ESAR feet further contribute to the users' body support and thus limit prosthetic ankle motion. To improve ankle motion, articulating prosthetic feet have been introduced. However, articulating feet may diminish push-off. RESEARCH QUESTION: Does a novel prosthetic foot, with a serial layout of carbon fibre leaf springs, connected by a multi-centre joint construction, have advantages in kinematics and kinetics over a conventional ESAR prosthetic foot?> METHODS: Eleven individuals with unilateral trans-tibial amputation were fitted with the novel foot (NF) and a conventional ESAR Foot (CF) and underwent 3D gait analysis. As an additional power estimate of the prosthetic ankle, a unified, deformable, segment model approach was applied. Eleven matched individuals without impairments served as a reference. RESULTS: The NF shows an effective prosthetic ankle range of motion that is closer to a physiologic ankle range of motion, at 31.6° as compared to 15.2° with CF (CF vs. NF p = 0.003/NF vs. Reference p = 0.171) without reducing the maximum prosthetic ankle joint moment. Furthermore, the NF showed a great increase in prosthetic ankle power (NF 2.89 W/kg vs. CF 1.48 W/kg CF vs. NF p = <0.001) and a reduction of 19% in the peak knee varus moment and 13% in vertical ground reaction forces on the sound side for NF in comparison to CF. SIGNIFICANCE: The NF shows that serial carbon fibre leaf springs, connected by a multi-centre joint construction gives a larger ankle joint range of motion and higher ankle power than a conventional carbon fibre structure alone. Consequently load is taken off the contralateral limb, as measured by the decrease in vertical ground reaction forces and peak knee varus moment.

Knee-ankle-foot orthosis with powered knee for support in the elderly.

A prototype of a powered knee orthotic device was developed to determine whether fractional external torque and power support to the knee relieves the biomechanical loads and reduces the muscular demand for a subject performing sit-to-stand movements. With this demonstrator, consisting of the subsystems actuation, kinematics, sensors, and control, all relevant sensor data can be acquired and full control is maintained over actuator parameters. A series-elastic actuator based on a direct current motor provides up to 30 Nm torque to the knee via a hinge joint with an additional sliding degree of freedom. For reasons of feasibility under everyday conditions, user intention is monitored by employing a noninvasive, nonsticking muscle activity sensor to replace electromyographic sensors, which require skin preparation. Furthermore, foot plates with force sensors have been developed and included to derive ground reaction forces. The actual knee torque needed to provide the desired support is based on an inverse dynamics model using ground reaction forces signals and leg kinematics. A control algorithm including disturbance feed forward has been implemented. A demonstration experiment with two subjects showed that 23 % of moment support in fact leads to a similar reduction in activation of the main knee extensor muscle.

Functional effects of a prosthetic torsion adapter in trans-tibial amputees during unplanned spin and step turns.

BACKGROUND: Shear stress at the stump in trans-tibial amputees induced by turning movements may be reduced with the use of torsion adapters in the prosthesis. OBJECTIVE: Monitoring the motion and kinetic effects of a regular torsion adapter in comparison to a rigid placebo in unplanned spin and step turns. STUDY DESIGN: Single-blinded placebo-controlled cohort study. METHODS: In total, 10 trans-tibial amputees underwent three-dimensional gait analysis in level walking and unplanned spin and step turns with a torsion adapter and with a rigid placebo. RESULTS: Kinetic effects varied among participants. No statistically significant reduction of peak internal and peak external transverse plane moments was found for the torsion adapter in any walking condition. However, transverse plane rotation of the adapter was monitored in all participants. CONCLUSION: Motion between the socket and the residual limb may be reduced during turns due to transverse plane motion of the torsion adapter and shear stress on the residual limb may be reduced. However, there may be good and bad responders to torsion adapters due to differences in coupling between the residual limb and the socket. CLINICAL RELEVANCE: Strong coupling between stump and socket will help the user controlling his prosthesis. Shear stress at the stump may increase in stump-socket interface stiffness and may be the reason for residual limb problems. Torsion adapters therefore may be beneficial for comfort and stump condition in individual cases.

Integrating strength tests of amputees within the protocol of conventional clinical gait analysis: a novel approach.

Clinical experience tells us that the lower-limb amputees are one of the patient groups who clearly suffer from a strength deficit in their involved side. However, there is no obvious evidence for the relation between the residual limb strength and walking ability in this population. Correlating the results of the conventional clinical gait analysis (CGA) with strength tests could help to find out how deficits in strength impact the amputees' gait. In this contribution, a new device for measuring the isometric muscle strength of the hip and the knee was tested for feasibility. Three groups were tested: one group of 11 healthy subjects (29±5 years) to test the repeatability of the device, two unilateral amputees (one transfemoral for 56 years, one transtibial for 65 years), and a reference group of 17 healthy subjects (55±10 years). The new method presents an adequate technique to integrate strength testing within a standard protocol of the CGA. Results showed to be repeatable within sessions [i.e., within-day, intraclass correlation coefficient (ICC)>0.972] and between repeated measurements (i.e., day-to-day, ICC>0.765). The tested amputees showed clear deficits in maximum isometric joint moments in their most distal joint. The first results suggest evidence for a relation between the maximum isometric joint moments and gait deviations in amputees.