Laboratory Experiments Research Articles

Do-Nothing Prebiotic Chemistry: Chemical Kinetics as a Window into Prebiotic Plausibility.

ConspectusOrigin of Life research is a fast growing field of study with each year bringing new breakthroughs. Recent discoveries include novel syntheses of life's building blocks, mechanisms of activation and interaction between molecules, and newly identified environments that provide promising conditions for these syntheses and mechanisms. Even with these new findings, firmly grounded in rigorous laboratory experiments, researchers often find themselves uncertain about how to apply them. How can a bridge be built between the laboratory and the geochemical environment? A critical question to ask when seeking to apply new results in origins is: how can this chemistry occur without direct intervention from a chemist? We believe the first step toward answering this question lies in the determination of rate constants and the construction of chemical networks to describe prebiotic chemistry in geochemical environments.So far, our group has measured several rate constants relevant to different prebiotic reaction networks, starting with the synthetic pathways of the cyanosulfidic network. The reactions we explore often involve ultraviolet light-driven photochemistry, facilitated by our StarLab setup that accurately simulates the spectrum of the young Sun and other stars. Our latest work investigates environments with active photochemistry in the absence of cyanide. In this study, we measure the effective rate constant for the production of formate from the reduction of carbon species using sulfite within the context of early Martian waters. The underlying goal of the work done in our group is to predict the likelihood that certain geological conditions will result in a specific set of chemical products. These predictions can be combined with those we have made for the necessary astrophysical conditions in certain origins of life scenarios on extrasolar planets.In the near future we expect that a sufficient number of rate constants will be measured, by our group and others, to allow for aspects of prebiotic chemistry to be predicted using chemical kinetics models. Once these models have been benchmarked against experimental data, our next step will be applying them to natural environments that better mimic the conditions thought to have been present at the onset of life. Following this, we can test these models by comparing their predictions to additional experiments. After refinement, these models will be able to provide guidance on the optimal conditions for conducting laboratory experiments, while helping to minimize and characterize any interference from a chemist.This approach can provide valuable insights into what is possible within geochemical environments, where all chemistry is by necessity do-nothing chemistry.

Exploring tumor microenvironment interactions and apoptosis pathways in NSCLC through spatial transcriptomics and machine learning.

The most common type of lung cancer is non-small cell lung cancer (NSCLC), accounting for 85% of all cases. Programmed cell death (PCD), an important regulatory mechanism for cell survival and homeostasis, has become increasingly prominent in cancer research in recent years. As such, exploring the role of PCD in NSCLC may help uncover new mechanisms for therapeutic targets. We utilized the GEO database and TCGA NSCLC gene data to screen for co-expressed genes. To delve deeper, single-cell sequencing combined with spatial transcriptomics was employed to study the intrinsic mechanisms of programmed cell death in cells and their interaction with the tumor microenvironment. Furthermore, Mendelian randomization was applied to screen for causally related genes. Prognostic models were constructed using various machine learning algorithms, and multi-cohort multi-omics analyses were conducted to screen for genes. In vitro experiments were then carried out to reveal the biological functions of the genes and their relationship with apoptosis. Cells with high programmed cell death activity primarily activate pathways related to apoptosis, cell migration, and hypoxia, while also exhibiting strong interactions with smooth muscle cells in the tumor microenvironment. Based on a set of programmed cell death genes, the prognostic model NSCLCPCD demonstrates strong predictive capabilities. Moreover, laboratory experiments confirm that SLC7A5 promotes the proliferation of NSCLC cells, and the knockout of SLC7A5 significantly increases tumor cell apoptosis. Our data indicate that programmed cell death is predominantly associated with pathways related to apoptosis, tumor metastasis, and hypoxia. Additionally, it suggests that SLC7A5 is a significant risk indicator for the prognosis of non-small cell lung cancer (NSCLC) and may serve as an effective target for enhancing apoptosis in NSCLC tumor cells.

Good practices for the industrial cultivation of the cyanobacterium Arthrospira platensis under a greenhouse in a temperate zone (northern Italy)

Arthrospira, Spirulina, and Limnospira are cyanobacteria widely known as food supplements or additives and cultivated worldwide under the commercial name of spirulina. Many studies have been focused on the improvement of operational conditions for optimizing cell growth and harvesting. At present, greater attention is paid to obtaining a good-quality, possibly food-grade, product that can be added to different food formulations and to reducing the environmental impact by saving water and avoiding or minimizing the release of mineral salts in the environment. A few studies have addressed these aspects although, in most cases, through laboratory experiments or pilot plants. This study focused on the effects of medium recycling, monitored at each harvesting step, and nutrient replenishment on Arthrospira platensis growth, biomass, biochemical composition, and extracellular polysaccharide (EPS) production, in a production plant located in a temperate zone (northeastern Italy). Four out of the seven largest ponds (11,000 L each) of the plant were followed for a three-month semi-continuous cultivation, which included the period with the highest biomass productivity. Recycling the culture medium after biomass harvest effectively allowed the best nutritional status of the cells. Biomass productivity increased from June to August 2023 (mean values: 0.029 and 0.038 g L-1 d-1 at 25–26 °C and 27–29 °C, respectively). Protein, polysaccharides, and C-phycocyanin contents were 62, 22, and 12%, respectively, while EPS was < 7 mg L-1. The biochemical composition did not vary during the cultivation period, differently from previous studies performed with small culture volumes and for a short time.

Marine heatwaves in the Subarctic and the effect of acute temperature change on the key grazer Strongylocentrotus droebachiensis (Echinoidea, Echinodermata)

Abstract Subarctic fjord systems are facing a continuous temperature increase as well as more frequent and more intense marine heatwaves (MHWs). MHWs are periods of exceptionally high temperatures above the long-term average. In the Porsangerfjord (Northern Norway), the average water temperature ranges from 2.5°C in March to 10°C in August. MHWs frequently exceed the summer maximum by up to 6°C with so far unknown ecological effects. The green sea urchin, Strongylocentrotus droebachiensis, is a key grazer on habitat-forming kelp in Subarctic fjord systems. At high abundances, sea urchins transform productive kelp beds through pronounced grazing into depleted sea urchin barrens. In a laboratory experiment, we investigated the influence of acute temperature change on the grazing activity and the metabolic performance of the green sea urchin. Grazing rates increased continuously from 2 to 10°C but decreased again at 14°C. At 22°C, rapid decay of sea urchins were associated with changes of the metabolic energy state from aerobiosis to anaerobiosis. We propose two scenarios: Moderate warming might lead to the proliferation of the sea urchin population and increased grazing pressure on kelp forests, while extreme warming, as predicted by the end of the century, as well as the occurrence of extreme MHWs, may severely impair the sea urchin population and, in turn, might favour the proliferation of adaptable kelp species.

Numerical Modeling of Engineering-Scale Jointed Coal Mass and Confining Pressure Effect

In coal masses, joints serve as crucial components influencing mechanical responses and failure mechanisms. The joint distribution complicates the acquisition of physical parameters for engineering-scale coal masses, and traditional laboratory or in situ tests often suffer from inaccuracies and high costs. Therefore, examination of the dynamic properties of engineering-scale coal mass is generally performed by numerical simulations. This paper proposes a model construction approach using two-dimension Particle Flow Code (PFC2D) software to study the mechanical properties of engineering-scale jointed coal mass, addressing the limitations of conventional models by integrating scale effects, accuracy, and computational efficiency. Firstly, the distribution characteristics and mechanical parameters of the joints in the coal mass were obtained based on field statistics and laboratory experiments. The parameters of the laboratory-scale model were calibrated by the numerical matching method. The discrete element model for the engineering-scale coal mass was constructed by the step-by-step matching method. The confining pressure effect on the coal mass under a biaxial loading condition was studied, while the strength change, fissure evolution, and failure mechanism under different confining pressures and fissure degrees were investigated. Based on the simulation results, a quantitative relationship was established between the mechanical parameters, fissure degree, and confining pressure under compression conditions. Ultimately, the failure zone ahead of the working face and the distribution of the abutment pressure were assessed using the mechanics parameters of coal masses with diverse joint distributions.

Standardization of Seed to Solution Ratio and Hydropriming Duration for Seed Priming of Fenugreek (Trigonella foenum-graecum L.)

A laboratory experiment was carried out to standardize the seed to solution ratio and hydropriming duration for seed priming in fenugreek at Department of Seed Science & Technology, College of Agriculture, UAS, Raichur during Rabi 2023-24. The experiment was laid out in Two Factorial Completely Randomized Design. The first factor consisted of seed to solution ratios viz., 1:1, 1:1.5, 1:2, 1:2.5 and 1:3. The second factor was hydropriming durations viz., 8, 12, 16, 20 and 24 hours. The results revealed that seed priming in 1:2.5 seed to solution for 12 hours has recorded higher seed quality parameters viz., seed germination (97.25 %), seedling length (21.50 cm), seedling dry weight (11.24 mg), seedling vigour index-I and II (2091 & 1093). While, seed priming in 1:1 seed to solution for 8 hours has recorded lower seed quality parameters (89.50 %, 15.99 cm, 8.30 mg, 1431 and 743, respectively). Based on the results, it can be concluded that for priming in fenugreek 1:2.5 seed to solution ratio for 12 hours duration suitable to get good quality seedlings.

Effect of oil and diesel fuel pollution on enzymatic activity of meadow chernozem-like soil

In the laboratory experiment, the effect of oil pollution on the short-term dynamics of the activity of urease, phosphatase, catalase, peroxidase and polyphenol oxidase of the chernozem soil of the south of the Far East was studied. It was found that when soil was contaminated with oil and petroleum products, urease activity decreased by 20–44% at the end of incubation, peroxidase activity increased by 39–49% in the middle and end of incubation, polyphenol oxidase activity increased 1.6–2.0 times in the middle of incubation. The activity of phosphatase and catalase was stable at different levels of contamination throughout the experiment. Examining the effect of the incubation period, it was found that the maximum activity of urease was on the 10th day, phosphatase – on the 20th, peroxidase – on the 20th and 30th, polyphenol oxidase – on the 30th day of the experiment. Catalase activity was stable throughout all incubation periods. It was shown that in the case of contamination of chernozem-like soil with oil and diesel fuel in doses up to 5000 mg/kg, inhibition of enzymatic activity did not occur in the early stages.

A State-of-the-Art Review of Hydraulic Fracturing in Geothermal Systems

As a renewable and green energy source, geothermal energy holds tremendous developmental value. Hydraulic fracturing plays a significant role in enhancing geothermal energy extraction by improving reservoir permeability and creating pathways for fluid flow. Previous reviews have primarily focused on specific aspects of hydraulic fracturing, such as fracturing processes, cyclic hydraulic fracturing, and sustainability metrics, without comprehensively addressing the gaps in experimental and modeling approaches under real geothermal conditions. This work aims to bridge these gaps by summarizing the current studies on hydraulic fracturing methods, examining critical factors such as loading scheme, injection fluid, and rate, identifying limitations, and proposing potential solutions. Key findings reveal that rock temperature, sample size, and confining pressure significantly influence fracture propagation. However, laboratory experiments often fail to replicate field-scale conditions, particularly for temperatures exceeding 200 °C and for large rock samples. Numerical and theoretical models, although insightful, require further validation through experimental data. To address these limitations, this study suggests potential approaches suitable for hydraulic fracturing under real-world conditions, such as ultra-high-temperature, high-stress environments, and large-scale experiments, which are critical for advancing geothermal systems. This work can serve as a foundation for enhancing the efficiency and sustainability of geothermal energy extraction through hydraulic fracturing.

Increasing Authenticity of the Laboratory through the MICRO Project: Analysis of Analytical Chemistry Laboratory Experiments for Their Level of Inquiry

Increasing Authenticity of the Laboratory through the MICRO Project: Analysis of Analytical Chemistry Laboratory Experiments for Their Level of Inquiry

LAUKSAIMNIECĪBAS BERAMKRAVU MATERIĀLU TRANSPORTĒŠANAS GLIEMEŽTRANSPORTIERA JAUDAS PARAMETRU PĒTĪJUMI

The article presents the results of theoretical and experimental laboratory investigations of an improved screw conveyor for bulk agricultural materials that has been created, which, instead of a solid spiral winding, fixed to the drive shaft, uses a spiral winding, formed by separate curvilinear planes (blades), which are also separately fixed to the shaft, yet as a whole form a single spiral. An analytical dependence was obtained for determination of the magnitude of the torque on the drive shaft of this transport working element. The numerical values, obtained as a result of the laboratory experiments, made it possible, when conducting a regression analysis, to derive a new analytical expression in the form of a regression equation. The analysis of the regression equation shows that these factors, which have a significant impact upon the increase in the torque, are the factors: x1 (D) – the diameter of the fixed casing in which the screw is installed and x2 (ψ) – the filling factor of the conveyor with the transported bulk material. Increasing the value of the factor x3(n), i.e., the rotation speed of the vane working body leads to a decrease in the torque value.

A novel tube law analysis under anisotropic external load

Mathematical and physical modeling of flows in collapsible pipes often relates the flow area to the difference between the internal and the external pressures (i.e. the transmural pressure). The relation is used to model the conduits of the human body transporting biological fluids, is called tube law and usually considers the transmural pressure resulting from isotropic external pressure only. We provide a new empirical tube law considering anisotropic conditions of the external load; our formulation is based on the hypothesis, supported by clinical and experimental findings, that in physiological conditions both isotropic and anisotropic stresses are combined in the external load acting on vessels. The proposed mathematical model was validated through laboratory experiments reproducing the flow through a collapsible tube representing the physiological conditions of male urethra during micturition. The proposed tube law better agrees with the experimental observations, in comparison to classic formulations available in literature, thus showing that the proposed model better describes the physiological condition of flow in collapsible tubes subjected to anisotropic external load. The application of our model can be readily extended to several types of vessels.

Evaluating the Efficiency of Dust Stone as an Improvement Material for Cement Gravel Column

This research explores the feasibility of incorporating dust stone into cement gravel columns to enhance their mechanical properties and sustainability profile. A series of laboratory experiments including unconfined compressive strength (UCS) and permeability tests were carried out. 15 mixture designs were prepared to investigate the effect of stone dust (5-20% of cement and 0, 5, 10, 15, and 20% by weight of highest porous sample) on volume fractions of CG samples on engineering and physical properties of cemented gravel samples, at 7 and 28 days. The findings indicate that the ideal proportion of stone dust is 10%, which significantly enhances the compressibility of the CG mixture while preserving satisfactory permeability. The finding indicates that stone dust is a feasible and efficient additive for improving the performance of cement gravel columns in civil engineering applications. Moreover, stone dust provides sustainability advantages by minimizing waste production and contributing to a circular economy.

Experience Minimizes the Pull-to-Center Effect in Newsvendor Decisions

Problem definition: The asymmetric pull-to-center effect for newsvendors is a robust finding in operations, and understanding why newsvendors make suboptimal decisions is key for identifying ways to improve decision-making quality in this critical task. Although prior studies have indicated that experience does not substantially mitigate the pull-to-center effect, the experience levels achieved in those previous studies are limited in comparison with the experience level that a near-continuous time environment can provide. Methodology/results: We conduct a set of laboratory experiments using a near-continuous time environment to determine the effect that extensive experience has on newsvendor behavior and the extent to which resultant learning is transferable across conditions. Observed behavior clearly demonstrates that the pull-to-center effect is substantially reduced, if not eliminated, with sufficient experience and that this learning can have positive spillovers to more traditional settings. Further, the experiments suggest that it is the repeated feedback regarding a given inventory decision rather than the ability to explore many strategies that drives improved decision making. Managerial implications: Experience can mitigate the pull-to-center effect, and near-continuous time environments can be an effective training tool for gaining such experience. Funding: This work was supported by the Ministerstvo školstva, vedy, výskumu a športu Slovenskej republiky [Grants VEGA 1/0660/23 and VEGA 1/0721/24] and the Slovak Research and Development Agency [Grant APVV-19-0573]. Supplemental Material: The online appendix is available at https://doi.org/10.1287/msom.2021.0439 .

Nutrient limitation determines biological interactions between a mixotrophic Chrysophyte and toxin-producing Microcystis

Abstract Blooms of toxigenic cyanobacteria pose a mounting risk to aquatic ecosystems. Relative to abiotic drivers of cyanobacteria success, biotic processes have received less attention. Mixotrophic nanoflagellates that combine heterotrophic ingestion of particulate prey with photoautotrophy are among the eukaryotes that can resist cyanotoxins. We used laboratory experiments in culture to integrate top-down (herbivory) and bottom-up (nitrogen and phosphorus limitation) controls on the growth and production of microcystin-LR, including biodegradation products, of Microcystis by Ochromonas (mixotroph) and Spumella (heterotroph). A notable reduction in the growth rate of toxic Microcystis was evident in co-culture with either Ochromonas or Spumella under P-limitation. Under P-limitation, the co-culture of toxic Microcystis with Ochromonas also led to a reduction in concentration of microcystin-LR (MC-LR and an increase in biodegradation products. Grazing rates up to 31 and 50 cell−1 day−1 on toxic Microcystis were recorded for Ochromonas and Spumella, respectively. The highest grazing rates by Ochromonas were observed on toxic Microcystis under N-limitation. Hence, it is likely that Ochromonas is an herbivore of toxic Microcystis under N-limitation and a competitor for nutrients under P-limitation. Collectively, these results suggest a role of eukaryotic nanoflagellates in decreasing the biomass and toxicity associated with cyanobacteria blooms that vary with nutrient availability.

Abstract and Acoustic Targets in Phonetic Imitation

ABSTRACTPhonetic imitation (also called convergence or accommodation) occurs when talkers alter their pronunciation towards speech they hear. This can happen spontaneously with only a few minutes of exposure in a laboratory experiment even without instruction to imitate. While there is considerable evidence for spontaneous imitation, in many cases it is not clear exactly which aspects of the model talker are being imitated. It is possible to imitate the raw acoustics of the model's voice or more abstract targets like normalised acoustics of the model's voice, phonological patterns the model exhibits, or speech style. Although there is substantial literature demonstrating convergent speech behaviour, existing work typically does not distinguish between these different types of targets. This has theoretical implications for accounts of imitation and normalisation, methodological significance for analysis of imitation studies, and potential applied significance for how imitation is used in language teaching and clinical speech therapy. This paper will review these issues, discuss the statistical challenges associated with measuring convergence to competing targets, and make methodological recommendations for future studies.

Investigating STEM Secondary School Teachers’ CLIL Assessment Practices in EFL Contexts: the Repertory Grid Technique

Within the context of content and language integrated learning (CLIL), assessment assumes a pivotal role in fostering learning, given the dual emphasis on content and language acquisition. This dual focus engenders a heightened complexity in the assessment process within CLIL classrooms. Despite the escalating prevalence of CLIL classrooms, the aspect of CLIL assessment remains inadequately explored, constituting an unresolved issue in CLIL research and pedagogy. The enquiry into the assessment practices of CLIL teachers serves as a means to elucidate this research lacuna. This study aims to scrutinize the assessment practices employed by five Thai secondary school CLIL teachers, utilizing personal construct theory (PCT) as the foundational framework. Methodologically, data collection encompasses repertory grids and retrospective semi-structured interviews, with a pivotal application of focus grid analysis for data scrutiny and interpretation. The findings revealed that there was a strong preference for interactive and collaborative assessment methods that enhance both language skills and cognitive abilities. In particular, problem-solving tasks, lab experiments, and group discussions are effective in promoting higher-order thinking, while interactive projects and presentations boost language development. In contrast, traditional assessments such as multiple-choice questions are less effective. These findings highlight the need for professional development programmes and supportive educational policies to integrate dynamic, dual-focused assessments into CLIL curricula.

Technical note: A low-cost, automatic soil–plant–atmosphere enclosure system to investigate CO2 and evapotranspiration flux dynamics

Abstract. Investigating greenhouse gases (GHGs) and water flux dynamics within the soil–plant–atmosphere interphase is key for understanding ecosystem functioning, as they reflect the ecosystem's responses to environmental changes. Understanding these responses is essential for developing sustainable agricultural systems that can help to adapt to global challenges such as increased drought. Typically, an initial understanding of GHGs and water flux dynamics is gained through laboratory or greenhouse pot experiments, where gas exchange is often measured using commercially available manual closed-chamber (leaf) systems. However, these systems are rather expensive and often labor-intensive, thus limiting the number of different treatments and their repetitions that can be studied. Here, we present a fully automatic, low-cost (EUR <1000 per unit) multi-chamber system based on Arduino, termed “greenhouse coffins”. It is designed to continuously measure canopy CO2 and evapotranspiration (ET) fluxes. It can operate in two modes: an independent and a dependent measurement mode. The independent measurement mode utilizes low-cost NDIR (non-dispersive infrared) CO2 (K30 FR) and relative humidity (SHT31) sensors, thus making each greenhouse coffin a fully independent measurement device. The dependent measurement mode connects multiple greenhouse coffins via a low-cost multiplexer (EUR <250) to a single infrared gas analyzer (LI-850, LI-COR Inc., Lincoln, USA), allowing for measurements in series, achieving cost efficiency while also gaining more flexibility in terms of target GHG fluxes (potential extension to N2O, CH4 and stable isotopes). In both modes, CO2 and ET fluxes are determined through the respective concentration increase during closure time. We tested both modes and demonstrated that the presented system is able to deliver precise and accurate CO2 and ET flux measurements using low-cost sensors, with an emphasis on calibrating the sensors to improve measurement precision. By connecting multiple greenhouse coffins via our low-cost multiplexer to a single infrared gas analyzer in the dependent mode, we could additionally show that the system can efficiently measure CO2 and ET fluxes in a high temporal resolution across various treatments with both labor and cost efficiency. Therefore, the developed system is expected to be a valuable tool for conducting greenhouse experiments, enabling comprehensive testing of plant–soil dynamic responses to various treatments and conditions.

The Effectiveness of Bajakah Wood Extract (Spatholobus Littoralis Hassk) From South Kalimantan against Candida Albicans ATCC 10231

Root canal treatment (RCT) is a procedure performed to remove inflamed or infected pulp tissue. Candida albicans is the most pathogenic type of fungus found in the oral cavity, accounting for 80%. Bajakah wood (Spatholobus littoralis Hassk) contains antifungal components such as phenols, flavonoids, tannins, and saponins. This research is to determine the antifungal effectiveness of Bajakah wood (Spatholobus littoralis Hassk) against Candida albicans. This research is an experimental laboratory study using the dilution method in the laboratory. A total of 20 samples of Candida albicans ATCC 10231 cultures in Sabouraud Dextrose Broth medium were tested. The treatment variations of Bajakah wood were concentrations of 50%, 75%, 100%, and 2.5% NaOCl (K+) with 5 repetitions. The results showed that the average number of fungal growths at 50% concentration was 387, at 75% concentration it was 449.4, while at 100% concentration it was 2.4, and in the positive control it was 1. Data analysis using the Kruskal-Wallistest showed significant differences (p<0.05) across all treatment groups. It can be concluded that Bajakah wood at 100% concentration has the highest antifungal content and is effective in inhibiting the growth of Candida albicans.

Trophic ecology of the clingfish Gobiesox marmoratus (Gobiesocidae): experimental evaluation of constraints to foraging behaviour

ABSTRACT The Chilean clingfish Gobiesox marmoratus Jenyns (Gobiesocidae) is a common carnivorous fish inhabiting the rocky intertidal pools along the Chilean coast. In spite of its wide-ranging distribution, basic knowledge about this species is scarce and as a consequence important aspects of its biology such as dietary composition, dietary selectivity and trophic behaviour have received little attention. The goals of this work were to assess quantitatively the dietary composition of this species, its trophic selectivity, assimilation rate of its prey and to experimentally analysed the role of the prey energy value, pre-digestive and post-digestive limitations in the dietary selection of this species. The diet of this species is mainly based on invertebrates, particularly amphipods, crabs and limpets as the most important food items. In laboratory, crabs and amphipods were the most preferred and consumed items over limpets and snails. Our results show that the amphipod is the prey item that provides to G. marmoratus with greater energy per unit of time of manipulation, which would explain its preference in the laboratory experiments and suggests that G. marmoratus feeds according to the net energy gain of their prey, supporting energy maximization, an underlying assumption of foraging theory.

Germinated finger millet supplemented with dry maize cob is a promising diet for the farming of edible grasshopper, Ruspolia differens

Abstract The edible grasshopper, Ruspolia differens (Orthoptera: Tettigoniidae) is food and a source of income for many people in East Africa. Recent laboratory experiments have succeeded in rearing them on germinated finger millet (GFM). However, long-term mass production on such a feed would be costly. Incorporating inexpensive and locally abundant agricultural byproducts into GFM could be another option to lower the production cost while maximising its profits. We experimentally evaluated the effect of blending GFM with 25%, 50%, or 75% by weights of three agricultural byproducts (soybean hull meal, local brew waste and dry maize cob) on the survival, developmental period, adult wet weight and reproductive performance of R. differens. A total of 390 R. differens were reared individually on each of the dietary treatments, including GFM as control, till death. Data was analysed using generalised linear models. Overall, the R. differens performed optimally on GFM supplemented with dry maize cob, and poorly on GFM supplemented with soybean hull meal. However, performance varied across supplementation levels with dry maize cob. GFM supplemented with 25% dry maize cob yielded the highest overall survival (86.2%) and highest 14-day-old male adult wet weight (0.54 g). While the shortest overall developmental period (86.8 days), highest fledgling adult wet weight (0.53 g), and highest 14-day-old female adult wet weight (0.82 g) were observed on GFM supplemented with 50% dry maize cob. Supplementing GFM with 75% dry maize cob resulted in the shortest pre-oviposition period (10.6 days) and the highest percentage hatchability (82.7%). Generally, supplementing GFM with dry maize cob greatly improves the performance of R. differens. Our findings recommend including dry maize cob on the list of low-cost substrates for the farming of this endangered valuable edible insect species.