Biophysical Perspective Research Articles

Biophysical economic interpretation of the Great Depression: A critical period of an energy transition

AbstractThe objective of this paper is to explain the cause and proceedings of the 1930s Great Depression from a biophysical economic perspective. The Depression was a painful episode in the socio‐technological transition from a coal/railroad regime to one based on hydrocarbons, motor vehicles, and electricity. The beginning—the Great Crash of October 1929—corresponded with drastic cuts in oil prices and announcement of oil supply certainty, following discovery of huge oilfields in the US Southwest. The Depression principally centered on a change from railroads to motor‐vehicle‐based transportation, but was long and drawn‐out due to the hegemonic power that the railroads held over the US economy. The late 1920s saw increased use of hydrocarbon‐based technologies, but the emerging technologies were still reliant on the old technological system. Methods of biophysical economics, mapping energy flows to capital formation, show the critical role of railroads in the Depression. In 1929, railroads accounted for 24% of the non‐residential capital stock; they delivered between 70% and 76% of energy needs; and 69% of energy required for capital formation. Thus a hypothesis emerges that dwindling investment in the railroads was a major constraint on the economy. In biophysical terms, the US economy's main energy delivery system—coal carried by railcars—was hamstrung. Energy flow Sankey diagrams for 1929 and 1939 show the gradual change in energy systems that occurred over the Depression.

Prioritizing urban nature-based solutions to support scaling-out strategies: A case study in Las Palmas de Gran Canaria

Nature-based solutions (NbS) can synergistically improve human well-being and biodiversity in urban areas by enhancing ecosystem functions and services. Scaling out NbS, understood as the widespread application of NbS in multiple contexts, is an important policy ambition to increase the number of people and regions benefiting from NbS. However, designing scaling-out strategies requires considering critical aspects of the nexus between NbS and ecosystem services (ES) supply to yield large-scale benefits effectively. The aim of the study is twofold: (i) to simulate the stepwise implementation of multiple NbS and (ii) to quantify their cumulative impacts on ES supply and beneficiaries. The NbS implementation was guided by a method that prioritizes different NbS types in multiple sites, by combining spatial information on ES demand and land suitability with a qualitative description of ES supply by NbS type. The cumulative impacts were computed stepwise using GIS modeling. The study was conducted in Las Palmas de Gran Canaria (Spain), focusing on five types of NbS (urban forests, urban parks, community gardens, infiltration ponds), and five ES (runoff mitigation, stormwater treatment, soil erosion control, recreation, and food supply). Overall, 179 NbS were simulated in 130 sites distributed in the city. The findings showed an improvement in all services, albeit significant increments occurred only for certain services. We observed a non-linear relationship between NbS and impacts, including constant, positive, and negative trends. We discussed several factors that were determinants of impacts, providing insights on how to design scaling-out strategies from the biophysical perspective. Moreover, we reflected on the role of multifunctionality, social preferences, and economic feasibility as prioritization criteria for NbS. Finally, we addressed the implementation of NbS scaling-out strategies from a broader perspective, deepening governance, economic and planning challenges, and potential actions for the case study.

Unraveling Membrane-Disruptive Properties of Sodium Lauroyl Lactylate and Its Hydrolytic Products: A QCM-D and EIS Study.

Membrane-disrupting lactylates are an important class of surfactant molecules that are esterified adducts of fatty acid and lactic acid and possess industrially attractive properties, such as high antimicrobial potency and hydrophilicity. Compared with antimicrobial lipids such as free fatty acids and monoglycerides, the membrane-disruptive properties of lactylates have been scarcely investigated from a biophysical perspective, and addressing this gap is important to build a molecular-level understanding of how lactylates work. Herein, using the quartz crystal microbalance-dissipation (QCM-D) and electrochemical impedance spectroscopy (EIS) techniques, we investigated the real-time, membrane-disruptive interactions between sodium lauroyl lactylate (SLL)-a promising lactylate with a 12-carbon-long, saturated hydrocarbon chain-and supported lipid bilayer (SLB) and tethered bilayer lipid membrane (tBLM) platforms. For comparison, hydrolytic products of SLL that may be generated in biological environments, i.e., lauric acid (LA) and lactic acid (LacA), were also tested individually and as a mixture, along with a structurally related surfactant (sodium dodecyl sulfate, SDS). While SLL, LA, and SDS all had equivalent chain properties and critical micelle concentration (CMC) values, our findings reveal that SLL exhibits distinct membrane-disruptive properties that lie in between the rapid, complete solubilizing activity of SDS and the more modest disruptive properties of LA. Interestingly, the hydrolytic products of SLL, i.e., the LA + LacA mixture, induced a greater degree of transient, reversible membrane morphological changes but ultimately less permanent membrane disruption than SLL. These molecular-level insights support that careful tuning of antimicrobial lipid headgroup properties can modulate the spectrum of membrane-disruptive interactions, offering a pathway to design surfactants with tailored biodegradation profiles and reinforcing that SLL has attractive biophysical merits as a membrane-disrupting antimicrobial drug candidate.

Evaluating temporal-spatial variations of wetland ecosystem service value in China during 1990–2020 from the donor side based on cosmic exergy

China has pledged to strictly maintain wetland ecosystem services at the COP 14 of the Ramsar Convention on Wetlands that was recently held in Wuhan, highlighting the necessity of measuring wetland ecosystem service value (ESV) in China. Yet existing studies mainly focus on ecosystem service valuation of wetlands from the consumer side, while a donor-side evaluation of the temporal-spatial characteristics of the wetland ESV of China is lacking. This study introduces the thermodynamic concept of cosmic exergy into the evaluation of wetland ESV, which provides an objective evaluation index for the unified measurement and analysis of the ecological value and degradation of resources in the process of material, energy, and information transformation of the ecosystem. By constructing a cosmic-exergy-based accounting framework for wetland ecosystem valuation, this study comprehensively investigated the temporal-spatial variations of China's wetland ESV during 1990–2020 from the donor side. Results showed that from 1990 to 2020, the total wetland ESV in China first decreased and then increased notably, with an overall growth rate of 22%. Meanwhile, the ecological quality of wetlands, as indicated by cosmic exergy intensity, showed an upward trend in the middle and lower reaches of the Yangtze River Basin, but a downward trend in western China. Regions in the Yangtze River Basin, the Qinghai-Tibet Plateau, and Northeast China were demonstrated as the major contributors to the total wetland ESV. In addition, this study identified the vital role of marsh wetlands in ecosystem service supply, contributing nearly 30% to the total ESV, and microclimate regulation was the most prominent service type, accounting for up to 74%. The outcome of this study can offer a new biophysical perspective for the donor-side valuation of wetland ecosystem services and may provide a benchmark reference for policymakers to formulate supporting measures for wetland production and restoration.

Developmental Pattern Formation: Spanish Contributions from a Biophysical Perspective

During the last few decades, developmental pattern formation has evolved from being a descriptive discipline to a quantitative one. That process has been possible due to the implementation of multidisciplinary approaches where biophysicists and mathematicians have played a key role. In this review, we highlight relevant Spanish contributions and stress their biophysical approaches, as well as provide some historical context. Finally, this work also aimed at bridging the concepts from biology to physics/math (and back) and at shedding light on some directions for future research.

Development of Hybrid DSPC:DOPC:P(OEGMA950-DIPAEMA) Nanostructures: The Random Architecture of Polymeric Guest as a Key Design Parameter.

Hybrid nanoparticles have gained a lot of attention due to their advantageous properties and versatility in pharmaceutical applications. In this perspective, the formation of novel systems and the exploration of their characteristics not only from a physicochemical but also from a biophysical perspective could promote the development of new nanoplatforms with well-defined features. In the current work, lipid/copolymer bilayers were formed in different lipid to copolymer ratios and examined via differential scanning calorimetry as a preformulation study to decipher the interactions between the biomaterials, followed by nanostructure preparation by the thin-film hydration method. Physicochemical and toxicological evaluations were conducted utilizing light scattering techniques, fluorescence spectroscopy, and MTS assay. 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine (DSPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) in different weight ratios were the chosen lipids, while a linear random copolymer with pH- and thermoresponsive properties comprised of oligo (ethylene glycol) methyl ether methacrylate (OEGMA) and 2-(diisopropylamino) ethyl methacrylate (DIPAEMA) in different ratios was used. According to our results, non-toxic hybrid nanosystems with stimuli-responsive properties were successfully formulated, and the main parameters influencing their overall performance were the hydrophilic/hydrophobic balance, lipid to polymer ratio, and more importantly the random copolymer topology. Hopefully, this investigation can promote a better understanding of the factors affecting the behavior of hybrid systems.

Inner-hair-cell induced hearing loss: A biophysical modeling perspective.

In recent years, experimental studies have demonstrated that malfunction of the inner-hair cells and their synapse to the auditory nerve is a significant hearing loss (HL) contributor. This study presents a detailed biophysical model of the inner-hair cells embedded in an end-to-end computational model of the auditory pathway with an acoustic signal as an input and prediction of human audiometric thresholds as an output. The contribution of the outer hair cells is included in the mechanical model of the cochlea. Different types of HL were simulated by changing mechanical and biochemical parameters of the inner and outer hair cells. The predicted thresholds yielded common audiograms of hearing impairment. Outer hair cell damage could only introduce threshold shifts at mid-high frequencies up to 40 dB. Inner hair cell damage affects low and high frequencies differently. All types of inner hair cell deficits yielded a maximum of 40 dB HL at low frequencies. Only a significant reduction in the number of cilia of the inner-hair cells yielded HL of up to 120 dB HL at high frequencies. Sloping audiograms can be explained by a combination of gradual change in the number of cilia of inner and outer hair cells along the cochlear partition from apex to base.

Exploring a multi-disciplinary model of supportive cancer care for monoclonal antibody treatment-related dermatological symptoms.

The present study examined the perspectives of healthcare providers (HCPs) in designing a multi-disciplinary model of supportive cancer care for the relief of dermatology-related symptoms caused by monoclonal antibody therapies. The study employed a mixed research methodology, with qualitative research embedded within a pragmatic prospective study of a registry protocol study. Patients undergoing oncology therapy with MoAB, anti-HER2, and anti-PD-L1 monoclonal antibodies were identified among a cohort of patients referred to an integrative oncology (IO) consultation for symptom relief and improved quality of life (QoL). Case studies with significant dermatology-related concerns were selected and presented to a panel of 6 HCPs trained in medical oncology, oncology nursing, family medicine, supportive cancer care, and IO. HCP narratives were qualitatively analyzed and assessed using ATLAS.Ti software for systematic coding. Of the 924 patients referred to the IO consultation, 208 were treated with monoclonal antibodies, from which 50 were selected for further evaluation. Of these, 7 cases were presented to the HCP team who were asked to identify treatment gaps requiring a multi-disciplinary approach. Qualitative analysis identified 3 major themes: a biophysical perspective; a psycho-social-spiritual perspective; and the implementation of integrated care. There is a need for a multi-disciplinary approach when treating patients suffering from monoclonal antibody treatment-related skin toxicities. HCP-reported themes highlight the need to identify patients for whom such an approach is warranted; conditions in which a psycho-social-spiritual perspective should be considered, in addition to a bio-physical approach; and considerations of who should be designated as the patient's primary case manager.

Carbon dioxide removal–What’s worth doing? A biophysical and public need perspective

Carbon dioxide removal (CDR) has become a focal point for legislators and policymakers who are pursuing strategies for climate change mitigation. This paper employs a policy framework of collective biophysical need to examine two broad categories of CDR methods being subsidized and advanced by the United States and other countries: mechanical capture and biological sequestration. Using published data on these methods, we perform a biophysical input-outcome analysis, focusing on the U.S., and compare methods on the basis of three criteria: effectiveness at net carbon removal, efficiency at a climate-relevant scale, and beneficial and adverse co-impacts. Our findings indicate that biological methods have a superior return on resource inputs in comparison to mechanical methods. Biological methods are both more effective and more resource efficient in achieving a climate-relevant scale of CO2 removal. Additionally, the co-impacts of biological methods are largely positive, while those of mechanical methods are negative. Biological methods are also far less expensive. Despite their disadvantages and a track record of failure to date, mechanical CDR methods continue to receive large subsidies from the US government while biological sequestration methods do not. To achieve more optimal CDR outcomes, policymakers should evaluate CDR methods’ effectiveness, efficiency, and biophysical co-impacts. We present tools for this purpose.

Optimizing single-molecule experimental approaches for the study of complex protein assemblies on DNA.

Over the past few decades, together with biochemical approaches single-molecule biophysics has made substantial contributions to our understanding of molecular machines. This has led to our understanding of their mechanochemical cycles, their different types of behavior (e.g. depending on substrate or cellular conditions), their interplay with other proteins, etc. etc. An ongoing challenge is to probe more complex molecular machines from a biophysical perspective and how to do so while maintaining an acceptable degree of experimental efficiency.

Static and Dynamic: Evolving Biomaterial Mechanical Properties to Control Cellular Mechanotransduction.

The extracellular matrix (ECM) is a highly dynamic system that constantly offers physical, biological, and chemical signals to embraced cells. Increasing evidence suggests that mechanical signals derived from the dynamic cellular microenvironment are essential controllers of cell behaviors. Conventional cell culture biomaterials, with static mechanical properties such as chemistry, topography, and stiffness, have offered a fundamental understanding of various vital biochemical and biophysical processes, such as cell adhesion, spreading, migration, growth, and differentiation. At present, novel biomaterials that can spatiotemporally impart biophysical cues to manipulate cell fate are emerging. The dynamic properties and adaptive traits of new materials endow them with the ability to adapt to cell requirements and enhance cell functions. In this review, an introductory overview of the key players essential to mechanobiology is provided. A biophysical perspective on the state-of-the-art manipulation techniques and novel materials in designing static and dynamic ECM-mimicking biomaterials is taken. In particular, different static and dynamic mechanical cues in regulating cellular mechanosensing and functions are compared. This review to benefit the development of engineering biomechanical systems regulating cell functions is expected.

Resource exergy analysis of the Chinese society in 2017.

China has made huge efforts to increase the efficiency of its resources and change its resource-intensive economic trajectory. A question which should be raised is whether the impacts of such shifts can be measured. Exergy analysis provides a unified method of ecological diagnosis of resource allocation and metabolism in social systems from a biophysical perspective. This paper explores the resource utilization pattern within Chinese society by employing an exergy-based accounting method. Nationally total resource consumption amounted to 153.7 EJ in 2017, and non-biological resources reached 137.1 EJ. China's resource self-sufficiency rate was revealed as 79.1%. After China experienced a transition period with a medium-high economic growth rate, the total net resource input into Chinese society marked an increase of around 1% from 2012 to 2017. The per capita resource consumption dropped from 112.0 GJ in 2012 to 110.6 GJ in 2017. The proportion of resource exergy consumption in the tertiary sector was upregulated from 10.0% in 2012 to 17.6% in 2017. To be specific, the exergy conversion efficiency of the domestic sector rose from 1.3% in 2012 to 20.6% in 2017. The results confirm that the resource exergy utilization structures and the conversion efficiencies of the main social sectors in China's economic transition period were significantly optimized towards a more sustainable future. A reasonable analysis of the resource exergy utilization pattern provides a solid reference for assessing the comprehensive effect of the changed development speed, industrial structure, and driving force of a developing society.

Chondrocyte De-Differentiation: Biophysical Cues to Nuclear Alterations.

Autologous chondrocyte implantation (ACI) is a cell therapy to repair cartilage defects. In ACI a biopsy is taken from a non-load bearing area of the knee and expanded in-vitro. The expansion process provides the benefit of generating a large number of cells required for implantation; however, during the expansion these cells de-differentiate and lose their chondrocyte phenotype. In this review we focus on examining the de-differentiation phenotype from a mechanobiology and biophysical perspective, highlighting some of the nuclear mechanics and chromatin changes in chondrocytes seen during the expansion process and how this relates to the gene expression profile. We propose that manipulating chondrocyte nuclear architecture and chromatin organization will highlight mechanisms that will help to preserve the chondrocyte phenotype.

Evaluation of organ weights and ventricular thicknesses in electrocution related deaths based on autopsy reports: A biophysical approach.

To evaluate autopsy reports of the deaths due to electrocution in terms of body mass index, body surface area, and organ weights with a biophysical perspective. The retrospective study was conducted in Malatya, Turkiye, and comprised autopsy reports of electrocution cases that were obtained from the local branch of the Council of Forensic Medicine related to the period from 2012 to 2019. Organ weights and ventricular thicknesses were compared in terms of body mass index and body surface area. Electrical marks were also evaluated in detail. Data was analysed using SPSS 18. Of the 45 cases, 36(%) were male and 9(%) were female. The overall mean age was 39±13 years (range: 20-71 years). There were no significant differences in organ weights and ventricular thicknesses in different body mass index groups (p>0.05). The weights of head and heart were significantly different in relation to body surface area (p<0.05), but no significant difference were found for other organs and ventricular thickness (p>0.05). Comparing the organ weights in electrocution autopsies to normal organ weights may help decide the cause of death. During autopsy, electrical marks should be evaluated by considering the characteristics of the electrical current.

Solution behavior of native and denatured beta lactoglobulin in presence of pyridinium based ionic liquids: A biophysical perspective of folding and refolding pattern of the protein

Herein, the effect of pyridinium based ionic liquids – butyl pyridinium bromide (BPB) and octyl pyridinium bromide (OPB) on the native and denatured state of β-lactoglobulin (BLG) was studied using multi-spectroscopic techniques like steady state fluorescence spectroscopy, time resolved fluorescence, time resolved fluorescence anisotropy, circular dichroism (CD) and dynamic light scattering (DLS). Circular dichroism revealed the increase in the negative ellipticity of the native protein in presence of both the ionic liquids which confirms the increase in the secondary structural content of the protein. Time resolved fluorescence and time resolved fluorescence anisotropy revealed the presence of slow and fast decaying fluorophore populations. There was a decrease in the hydrodynamic diameter of the protein when treated with both the ionic liquids. The protein was denatured utilizing chemical denaturant Guanidinium hydrochloride (GdmCl). The denatured protein was treated with ionic liquids – BPB and OPB. The ionic liquids seem to induce a refolding effect in the denatured protein. The detailed study revealed that BPB was more capable of refolding the unfolded BLG than OPB. The results of all the techniques utilized here corroborate with each other.

Biophysical Characterization of LTX-315 Anticancer Peptide Interactions with Model Membrane Platforms: Effect of Membrane Surface Charge.

LTX-315 is a clinical-stage, anticancer peptide therapeutic that disrupts cancer cell membranes. Existing mechanistic knowledge about LTX-315 has been obtained from cell-based biological assays, and there is an outstanding need to directly characterize the corresponding membrane-peptide interactions from a biophysical perspective. Herein, we investigated the membrane-disruptive properties of the LTX-315 peptide using three cell-membrane-mimicking membrane platforms on solid supports, namely the supported lipid bilayer, intact vesicle adlayer, and tethered lipid bilayer, in combination with quartz crystal microbalance-dissipation (QCM-D) and electrochemical impedance spectroscopy (EIS) measurements. The results showed that the cationic LTX-315 peptide selectively disrupted negatively charged phospholipid membranes to a greater extent than zwitterionic or positively charged phospholipid membranes, whereby electrostatic interactions were the main factor to influence peptide attachment and membrane curvature was a secondary factor. Of note, the EIS measurements showed that the LTX-315 peptide extensively and irreversibly permeabilized negatively charged, tethered lipid bilayers that contained high phosphatidylserine lipid levels representative of the outer leaflet of cancer cell membranes, while circular dichroism (CD) spectroscopy experiments indicated that the LTX-315 peptide was structureless and the corresponding membrane-disruptive interactions did not involve peptide conformational changes. Dynamic light scattering (DLS) measurements further verified that the LTX-315 peptide selectively caused irreversible disruption of negatively charged lipid vesicles. Together, our findings demonstrate that the LTX-315 peptide preferentially disrupts negatively charged phospholipid membranes in an irreversible manner, which reinforces its potential as an emerging cancer immunotherapy and offers a biophysical framework to guide future peptide engineering efforts.

Engineering physical microenvironments to study innate immune cell biophysics.

Innate immunity forms the core of the human body's defense system against infection, injury, and foreign objects. It aims to maintain homeostasis by promoting inflammation and then initiating tissue repair, but it can also lead to disease when dysregulated. Although innate immune cells respond to their physical microenvironment and carry out intrinsically mechanical actions such as migration and phagocytosis, we still do not have a complete biophysical description of innate immunity. Here, we review how engineering tools can be used to study innate immune cell biophysics. We first provide an overview of innate immunity from a biophysical perspective, review the biophysical factors that affect the innate immune system, and then explore innate immune cell biophysics in the context of migration, phagocytosis, and phenotype polarization. Throughout the review, we highlight how physical microenvironments can be designed to probe the innate immune system, discuss how biophysical insight gained from these studies can be used to generate a more comprehensive description of innate immunity, and briefly comment on how this insight could be used to develop mechanical immune biomarkers and immunomodulatory therapies.

Impact of Saline-Alkali Land Greening on the Local Surface Temperature—A Multiscale Assessment Based on Remote Sensing

In recent years, the conversion of saline-alkali land to rice fields has become the most dominant land use change feature in western Jilin, leading to significant surface greening. Saline–alkali land and paddy fields have distinct surface biophysical properties; however, there is a lack of systematic assessment of the moderating effect of planting rice on saline–alkali land on regional climate by changing surface properties. In this paper, multiscale data on the surface temperature of saline–alkali land and paddy fields were obtained using 1 km MODIS product, 30 m Landsat 8 satellite imagery and centimeter-scale UAV imagery in Da’an City, western Jilin as the study area, and the various characteristics of the surface temperature of saline-alkali land and paddy fields in different months of the year and at different times of the day were analyzed. Furthermore, the effect of rice cultivation in saline–alkali land on the local surface temperature was assessed using a space-for-time approach. The results based on satellite observations including both MODIS and Landsat showed that the surface temperature of saline–alkali land was significantly higher than that of paddy fields during the crop growing season, especially in July and August. The high temporal resolution MODIS LST data also indicated the paddy fields cool the daytime surface temperature, while warming the nighttime surface temperature, which was in contrast for saline–alkali land during the growing season. High-resolution UAV observations in July confirmed that the cooling effect of paddy fields was most significant at the middle of day. From the biophysical perspective, the reclamation of saline–alkali land into paddy fields leads to an increase in leaf area index, followed by a significant increase in evapotranspiration. Meanwhile, rice cultivation in saline–alkali land reduces surface albedo and increases surface net radiation. The trade-off relationship between the two determines the seasonal difference in the surface temperature response of saline–alkali land for rice cultivation. At the same time, the daily cycle of crop evapotranspiration and the thermal insulation effect of paddy fields at night are the main reasons for the intraday difference in surface temperature between saline–alkali land and paddy field. Based on the multiscale assessment of the impact of rice cultivation in saline-alkali land on surface temperature, this study provides a scientific basis for predicting future regional climate change and comprehensively understanding the ecological and environmental benefits of saline–alkali land development.

The generation of diverse traveling pulses and its solution scheme in an excitable slow-fast dynamics.

In this article, we report on the generation and propagation of traveling pulses in a homogeneous network of diffusively coupled, excitable, slow-fast dynamical neurons. The spatially extended system is modeled using the nearest neighbor coupling theory, in which the diffusion part measures the spatial distribution of coupling topology. We derive analytically the conditions for traveling wave profiles that allow the construction of the shape of traveling nerve impulses. The analytical and numerical results are used to explore the nature of propagating pulses. The symmetric or asymmetric nature of traveling pulses is characterized, and the wave velocity is derived as a function of system parameters. Moreover, we present our results for an extended excitable medium by considering a slow-fast biophysical model with a homogeneous, diffusive coupling that can exhibit various traveling pulses. The appearance of series of pulses is an interesting phenomenon from biophysical and dynamical perspective. Varying the perturbation and coupling parameters, we observe the propagation of activities with various amplitude modulations and transition phases of different wave profiles that affect the speed of pulses in certain parameter regimes. We observe different types of traveling pulses, such as envelope solitons and multi-bump solutions, and show how system parameters and coupling play a major role in the formation of different traveling pulses. Finally, we obtain the conditions for stable and unstable plane waves.

A participatory assessment of nitrified urine fertilizer use in Swayimane, South Africa: Crop production potential, farmer attitudes and smallholder challenges

Long-term nutrient mining of soil hampers agricultural production across Africa. However, emerging sanitation technologies afford a hygienically safe and ecologically sustainable solution to this development challenge by providing fertilizers derived from human excreta that could facilitate a socio-technical transition toward a more sustainable food system. To evaluate one such technology, nitrified urine fertilizer (NUF), we conducted participatory action research to assess the potential, from both a biophysical and social perspective, of NUF to serve as a soil fertilizer to support smallholder agricultural production in Swayimane, South Africa. To achieve this objective, we formed a stakeholder group comprised of a cooperative of smallholder farmers, a local NGO (Zimele), and researchers from ETH Zurich and the University of Kwazulu-Natal. Over the course of two growing seasons (2016 and 2017) this stakeholder group assessed the potential of NUF to support smallholder vegetable production (i.e., cabbage). First, we adopted a randomized complete block design incorporating five treatments in season 1 (unfertilized control, nitrified urine, nitrified urine+bone meal, urea, and urea+diammonium phosphate (DAP) and six treatments (unfertilized control, urea, urea+DAP, DAP, nitrified urine, and nitrified urine+DAP) in season 2 to assess cabbage yield and leaf nutrient concentration (sodium, phosphorus, potassium, carbon, nitrogen). Although we observed large variability in yields, the urine-based treatments were as effective as any of the chemical fertilizers. Second, beyond the biophysical analysis, we elicited the challenges and opportunities of the smallholder farmers in our stakeholder group, as well as their attitudes toward the use of NUF as a fertilizer. Through this qualitative work, farmers indicated that their attitudes about the use of NUF as a fertilizer improved and that they would be willing to incorporate this product into their production practices if it was available at scale. Thus, we demonstrate the potential of participatory action research to co-produce knowledge and awareness around an innovative technology. In so doing, we provide evidence that this approach can support a change toward nutrient recycling-based agriculture.