Artificial Conditions Research Articles

Methylosinus trichosporium OB3b drives composition-independent application of biogas in poly(3-hydroxybutyrate) synthesis

Biological conversion of biogas into poly(3-hydroxybutyrate) (PHB) via Type II methanotrophs holds great promise. However, a prerequisite for widespread biogas utilization is a comprehensive understanding of the effects of biogas composition on methanotrophic PHB synthesis. Herein, we explore the effects of biogas composition on the microbial growth and PHB accumulation of Methylosinus trichosporium OB3b under five different artificial biogas conditions with varying the ratio of methane (CH4) to carbon dioxide (CO2), the two main components of raw biogas. Stoichiometric and kinetic analyses revealed that increased CO2 concentrations correlated with higher maximum specific growth rates (0.021–0.029 h−1) and maximum CH4 utilization rates (0.029–0.042 mg CH4/mg TSS-h). Besides, no significant correlation was found between the CH4-to-CO2 ratio and other growth parameters. Consistent PHB contents (20.2–25.3 wt%) were achieved, irrespective of the CH4-to-CO2 ratio. Furthermore, the ability of M. trichosporium OB3b to grow and synthesize PHB (13.2 wt%) was confirmed using pilot-scale biogas. Our findings highlight the potential of biogas as a feedstock for producing valuable biodegradable polymers, thus contributing to waste-derived fuel (WDF) innovation and environmental sustainability.

Identification of a Promising Novel Genetic Source for Rice Root-Knot Nematode Resistance through Markers Associated with Trait-Specific Quantitative Trait Loci.

Direct-seeded rice (DSR) is gaining popularity among farmers due to its environmentally safe and resource-efficient production system. However, managing the rice root-knot nematode (RRKN), Meloidogyne graminicola, remains a major challenge in DSR cultivation. Developing genetic resistance is a pragmatic and effective approach compared to using hazardous pesticides. Pusa Basmati 1121 (PB1121) is the most popular Basmati rice variety, but it is highly susceptible to RRKN. In contrast, Phule Radha (PR) has shown highly resistant reaction to RRKN, as reported in our earlier study. We generated an F2:3 population from the cross of PB1121/PR and evaluated it for RRKN resistance-related traits under artificial inoculation conditions. The distribution pattern of traits in the F2:3 population indicated that resistance may be governed by a few major-effect genes and many minor-effect genes. The molecular markers reported to be associated with QTLs governing RRKN resistance traits were used to test in the current population. Although the simple linear regression identified significant associations between the markers and RRKN resistance-associated traits, these associations were spurious as the LOD score was below the threshold limit. This indicates that PR possesses novel genomic regions for resistance to RRKN as it does not possess any of the earlier reported QTLs.

Direct aging treatment of TiN modified Al–Mn–Sc alloy processed by laser powder bed fusion: On the microstructure evolution and mechanical property enhancement

In this study, the TiN nanoparticles modified Al–Mn-Sc composite and Al–Mn-Sc alloy have been fabricated by the laser powder bed fusion (LPBF). The microstructure, mechanical properties and strengthening mechanisms of these materials were discussed in details for both the as-built and artificial aged conditions. The results showed that the aged Al–Mn-Sc/TiN composite exhibits homogeneous nucleation with equiaxed grains ranging from 0.81 μm to 1.30 μm. After direct aging treatment of 300 °C, there are a volume fraction of secondary L12-Al3(Ti, Sc, Zr) nanoparticles precipitated in the composite sample, contributing to an ultra-high fracture strength of 701 ± 16 MPa. The increment in strength brought by TiN mainly comes from fine grains and high volume fraction of L12-Al3(Ti, Sc, Zr) nanoprecipitates. The fracture behaviors suggest that the uniform distribution of reinforced particles and less amount of micro pores can improve the strength and ductility of LPBF particle reinforced aluminum matrix composites.

Transcriptome analysis of the common moss Bryum pseudotriquetrum grown under Antarctic field condition.

Mosses are distributed all over the world including Antarctica. Although Antarctic mosses show active growth in a short summer season under harsh environments such as low temperature, drought and high levels of UV radiation, survival mechanisms for such multiple environmental stresses of Antarctic mosses have not yet been clarified. In the present study, transcriptome analyses were performed using one of the common mosses Bryum pseudotriquetrum grown under an Antarctic field and artificial cultivation conditions. Totally 88205 contigs were generated by de novo assembly, among which 1377 and 435 genes were significantly up and downregulated, respectively, under Antarctic field conditions compared with artificial cultivation conditions at 15°C. Among the upregulated genes, a number of lipid metabolism-related and oil body formation-related genes were identified. Expression levels of these genes were increased by artificial environmental stress treatments such as low temperature, salt and osmic stress treatments. Consistent with these results, B. pseudotriquetrum grown under Antarctic field conditions contained large amounts of fatty acids, especially α-linolenic acid, linolenic acid and arachidonic acid. In addition, proportion of unsaturated fatty acids, which enhance membrane fluidity, to the total fatty acids was also higher in B. pseudotriquetrum grown under Antarctic field conditions. Since lipid accumulation and unsaturation of fatty acids are generally important factors for the acquisition of various environmental stress tolerance in plants, these intracellular physiological and metabolic changes may be responsible for the survival of B. pseudotriquetrum under Antarctic harsh environments.

Energy-conserving SAV-Hermite–Galerkin spectral scheme with time adaptive method for coupled nonlinear Klein–Gordon system in multi-dimensional unbounded domains

In this article, we construct an efficient numerical scheme to solve the coupled nonlinear Klein–Gordon system in a multi-dimensional unbounded domain Rd(d=1,2,3). We first use the SAV method to equivalently deform the original system, then we treat the nonlinear part of the system explicitly in temporal discretization. Thanks to the SAV method, we ensure the unconditional energy conservation of the discrete system, as a cost, we only need to solve two completely linearized decoupled systems. To avoid the errors caused by domain truncation and the construction of artificial boundary conditions, we apply the Hermite–Galerkin spectral method with scaling factor for spatial discretization. In order to save computational costs, we utilize two time adaptive strategies to adjust the time step size, through which we can improve computational efficiency without sacrificing accuracy. Finally, we presented numerical experiments to demonstrate the accuracy, efficiency, and energy conservation properties of our algorithm, and applied it to simulate the interactions of two-dimensional and three-dimensional vector solitons.

Peniophora salaccae sp. nov. (Russulales, Basidiomycota), a snake fruit (Salacca zalacca) pathogen from southern Thailand

The genus Peniophora is known to be distributed from boreal to tropical regions worldwide. During surveys of plant diseases in southern Thailand in 2022 and 2023, two specimens of rotten snake fruits (Salacca zalacca) were collected. The new species, P. salaccae, is described based on collections with morphological and molecular data. This species is characterized by orange-gray to brownish-orange basidiomes, simple-septate generative hyphae, brown lamprocystidia, subclavate to subcylindrical gloeocystidia, and subtriangular basidiospores. It can be distinguished from P. trigonosperma by its larger basidiospores and shorter lamprocystidia. Molecular phylogenetic analyses of the internal transcribed spacers (ITS) and the large subunit (nrLSU) of the nuclear ribosomal DNA (rDNA) confirmed the position of the new species within the genus Peniophora. The full description, color photographs, illustrations, and the phylogenetic tree showing the position of P. salaccae are provided. Additionally, pathogenicity tests showed that P. salaccae could infect snake fruits, which developed the same symptoms under artificial inoculation conditions as those observed in the field.

Evaluation of Sheath Blight Resistance in Diverse Rice Varieties Under Artificial Inoculation and Field Conditions

Rice (Oryza sativa L.) a vital food crop for nearly half of the global population, facing significant threats from various biotic and abiotic stresses. Among biotic stresses, diseases pose the most common challenge. Sheath blight, caused by soil-borne fungal pathogen Rhizoctonia Solani Kühn (R. solani), is a major concern, leading to substantial damage to rice and cereal crops worldwide. This study evaluated sheath blight resistance across diverse rice varieties, including short grain, long grain, aromatic, hybrid, and wild types, under both artificial inoculation and field conditions. Ten host plant species were assessed for resistance to sheath blight caused by Rhizoctonia Solani, using physiological screening one-week post-inoculation. The highly virulent R. solani isolate (AG-1 IA anastomosis group) was cultured on PDA media, covering the entire plate 3 to 5 days. Screening of cultivated rice varieties, was conducted using field conditions and humidified chamber methods, with results confirmed through molecular characterization. Among the ten cultivated rice varieties, Arize 6444 and Dhanya 748 exhibited the lowest disease index, classifying them as moderately resistant. In contrast, Kalanamak and Pusa Basmati were highly susceptible, displaying high disease indices. Among wild rice accessions, Oryza rufipogon showed a disease index of five or less. Visual ratings indicated the highest susceptibility in Kalanamak, followed by Pusa Basmati and Swarna sub-1, while the lowest visual ratings were observed in wild rice accessions Oryza australiensis and Oryza rufipogon across all tested hosts. The findings underscore the importance of identifying resistant rice varieties to manage sheath blight effectively. The moderately resistant cultivars and wild rice accessions identified in this study offer valuable genetic resources for breeding programs aimed at enhancing sheath blight resistance in rice.

Prediction of reproductive performance in wintering females of Siberian sturgeon (Acipenser baerii, Brandt) based on in vitro ovulation rate of isolated follicles

Early prediction of the reproductive success of sturgeon females is important both for artificial breeding conditions in sturgeon farms and for monitoring wild fish populations approaching spawning. This study demonstrated that ovarian follicles removed from wintering Acipenser baerii females can undergo in vitro ovulation when exposed to 17α,20β-dihydroxy-4-pregnen-3-one. The research was conducted from 2015 to 2021 and involved the examination of 110 wintering Siberian sturgeon females (A. baerii), with an average weight of 8–11 kg and an age range of 8–10 years. Selection of females for spawning was based on the polarization index (PI) at the time when the river temperature dropped to +8 °C. The selected females were overwintered in concrete flow-through tanks with water from the Volga River for approximately two months. At the end of this period, oocyte samples were collected for in vitro incubation. An increase in water temperature to 15 °C, which precedes spawning, was achieved by mixing with warm effluent from a regional power station. The reproductive success of females was evaluated based on fertilization and embryonic survival rates. High reproductive success was characterized by females with fertilization rates above 70% and hatching rates above 60%. We identified a positive correlation between the percentage of in vitro ovulated follicles and the in vivo fertilization and embryo survival rates, with correlation coefficients of Rsp = 0.60 and Rsp = 0.48, respectively. Statistical analysis showed that females whose in vitro ovulation rate of follicles exceeded 30% displayed high reproductive performance compared to those with an in vitro ovulation rate below 30%. The predictive accuracy of this criterion was determined by calculating the ratio of ranks between females with high and low reproductive performance, averaging 80.9% for fertilization and 77% for embryonic survival. Therefore, we propose a new criterion to select females of A. baerii for spawning based on the in vitro oocyte ovulation rate obtained from wintering individuals.

Biological Characteristics, Artificial Domestication Conditions Optimization, and Bioactive Components of Beauveria caledonica.

In this study, one strain of Beauveria caledonica was isolated from wild fruiting bodies collected from Guizhou Province, China, and its species identification, biological characteristics, domestication, and cultivation methods were studied along with polysaccharide and adenosine content analysis. The mycelia were identified by ITS sequencing, and the fruiting bodies of B. caledonica were domestically cultivated for the first time using wheat and rice as basic cultivation media. The carbon sources, nitrogen sources, cultivation temperatures, and pH for mycelial growth were optimized through single-factor experiments and response surface methodology (RSM) experiments. The polysaccharide content was detected by the phenol-sulfuric acid method, and the adenosine content was measured by high-performance liquid chromatography (HPLC). The results confirmed that the identified mycelia were B. caledonica. The optimum medium for solid culture was 25.8 g/L glycerol, 10.9 g/L yeast extract, 1 g/L MgSO4·7H2O, 1 g/L KH2PO4, 10 mg/L vitamin B1, and 20 g/L agar; the optimum pH was 6.5, and the optimum culture temperature was 25 °C. The optimal liquid culture medium was 26.2 g/L glycerol, 11.1 g/L yeast extract, 1 g/L MgSO4·7H2O, 1 g/L KH2PO4, and 10 mg/L vitamin B1; the mycelia grew well at pH 6.6 and 25 °C. The average biological efficiencies of fruiting bodies on wheat and rice as culture media were 1.880% and 2.115%, respectively; the polysaccharide contents of fruiting bodies on the two media were 6.635% and 9.264%, respectively, while the adenosine contents were 0.145% and 0.150%, respectively. This study provides a valuable reference for further artificial cultivation and utilization of B. caledonica by investigating its biological characteristics, cultivation conditions for artificial domestication, and polysaccharide and adenosine contents in cultivated fruiting bodies.

Artificial Boundary Conditions for Random Elliptic Systems with Correlated Coefficient Field

Artificial Boundary Conditions for Random Elliptic Systems with Correlated Coefficient Field

Induction of Three New Secondary Metabolites by the Co-Culture of Endophytic Fungi Phomopsis asparagi DHS-48 and Phomopsis sp. DHS-11 Isolated from the Chinese Mangrove Plant Rhizophora mangle.

Co-cultivation is a powerful emerging tool for awakening biosynthetic gene clusters (BGCs) that remain transcriptionally silent under artificial culture conditions. It has recently been used increasingly extensively to study natural interactions and discover new bioactive metabolites. As a part of our project aiming at the discovery of structurally novel and biologically active natural products from mangrove endophytic fungi, an established co-culture of a strain of Phomopsis asparagi DHS-48 with another Phomopsis genus fungus DHS-11, both endophytes in mangrove Rhizophora mangle, proved to be very efficient to induce the production of new metabolites as well as to increase the yields of respective target metabolites. A detailed chemical investigation of the minor metabolites produced by the co-culture of these two titled fungal strains led to the isolation of six alkaloids (1-6), two sterols (7, 8), and six polyketides (9-14). In addition, all the compounds except 8 and 10, as well as three new metabolites phomopyrazine (1), phomosterol C (7), and phomopyrone E (9), were not present in discrete fungal cultures and only detected in the co-cultures. The structures were elucidated on the basis of spectroscopic analysis, and the absolute configurations were assumed by electronic circular dichroism (ECD) calculations. Subsequently, the cytotoxic, immunosuppressive, and acetylcholinesterase inhibitory properties of all the isolated metabolites were determined in vitro. Compound 8 exhibited moderate inhibitory activity against ConA-induced T and LPS-induced B murine splenic lymphocytes, with IC50 values of 35.75 ± 1.09 and 47.65 ± 1.21 µM, respectively.

Comprehensive risk assessment of the inhalation of plasticizers from the use of face masks

Disposable masks, formed mainly from polymers, often incorporate various chemical additives to enhance their performance. These additives, which include plasticizers, may be released during mask usage, presenting a novel source of human exposure to these compounds. In this study, the presence of 16 organophosphate esters (OPEs), 11 phthalates, and four alternative plasticizers, in four various types of face masks, were studied, as well as their release during simulated mask use (artificial laboratory conditions). Total plasticizer concentrations exhibited minimal variation across different mask types, with mean values of 7.27 µg/face mask for surgical, 8.61 µg/face mask for reusable, 11.0 µg/face mask for KN-95, and 13.9 µg/face mask for FFP2 masks. To explore plasticizer release behavior, inhalation experiments were conducted under different conditions. The findings revealed a significant temperature-dependent enhancement in plasticizer release from masks, subsequently increasing human inhalation exposure. The inhalation experiments showed variation in the release percentages, ranging from 0.1 to 95 %, depending on the specific compound and mask type. Notably, OPEs exhibited a mean release percentage of 1.0 %, similar to phthalates, which showed a 1.2 % release. Although alternative plasticizers were less frequently released, they still presented a notable percentage of release of 4.1 %. Daily intake estimations via inhalation ranged from 0.01 to 9.04 ng/kg body weight (bw)/day for these additives. Using these estimations, carcinogenic and non-carcinogenic risks associated with this exposure to these compounds were evaluated. All calculated values for the specific compounds studied in this paper remained below the established threshold limits. However, they do represent an additional exposure pathway that, when considered alongside other more predominant routes such as indoor/outdoor inhalation, dermal absorption, and dietary intake, makes the total exposure worthy of consideration.

Optimal artificial boundary conditions based on second-order correctors for three dimensional random elliptic media

We are interested in numerical algorithms for computing the electrical field generated by a charge distribution localized on scale l in an infinite heterogeneous medium, in a situation where the medium is only known in a box of diameter L ≫ l around the support of the charge. We propose a boundary condition that with overwhelming probability is (near) optimal with respect to scaling in terms of l and L, in the setting where the medium is a sample from a stationary ensemble with a finite range of dependence (set to be unity and with the assumption that l ≫ 1 ). The boundary condition is motivated by quantitative stochastic homogenization that allows for a multipole expansion. This work extends, the algorithm in which is optimal in two dimension, and thus we need to take quadrupoles, next to dipoles, into account. This in turn relies on stochastic estimates of second-order, next to first-order, correctors. These estimates are provided for finite range ensembles under consideration, based on an extension of the semi-group approach of Gloria and Otto.

Screening of Castor Germplasm and Efficacy Studies of Bioagents and Fungicides Against Botryotinia ricini (Godfrey) Whetzel

Castor is an important non-edible oilseed crop having exceptional oil characteristics for the chemical industry. The crop hosts several diseases, among them gray mold is the most destructive one hindering its productivity. This article presents a study assessing the resistance of different germplasm lines screened against Botrytis ricini under artificial conditions. It also examines the effect of various fungicides on B. ricini isolates, which were obtained from infected Ricinus communis (castor oil plant) using standard tissue isolation techniques. The fungus was isolated from infected Castor raceme by standard tissue isolation technique and its pathogenicity was established by proving Koch’s postulates. Out of 47 germplasm lines screened, TSIL-19 showed resistance response to gray mold under both detached spike and capsule method. Under in vitro assessment, Trichoderma viride (86.11 %) and Pseudomonas fluorescens (71.48 %) bio agents exhibited maximum mycelial growth inhibition of the pathogen. Among the seven combination fungicides evaluated, Fenamidone 10% + Mancozeb 50% WG recorded highest mycelial growth inhibition (100%) of B. ricini.

Quantum Simulation for Quantum Dynamics with Artificial Boundary Conditions

Quantum Simulation for Quantum Dynamics with Artificial Boundary Conditions

Feelings of safety for visitors recreating outdoors at night in different artificial lighting conditions

Artificial light can impact the actual and perceived safety of visitors recreating outdoors at night. Actual safety refers to how visitors identify aspects of their environment such as pathways and obstacles, while perceptions of safety refer to how safe they feel based on perceptions of the environment. Both influence the acceptability of different light conditions. The objective of this study is to better understand how light conditions influence visitors' perceptions of safety and their potential for pleasant experiences while recreating at night in a park-like setting. This paper explores study participants' self-reported feelings of safety across eight different light conditions using two different colors, 3000 K Correlated Color Temperature (warm white) and monochromatic amber, and 4 four different intensities (0.5, 1.0, 5.0, or 10.0 lux) during a nighttime recreation-focused experiment in a university's arboretum. Prior experience with nighttime outdoor recreation and community type (urban, suburban, rural) during adolescence were evaluated alongside light conditions as predictors of feelings of safety using ordered logistic regression. Participants of this study were 31.6% more likely to report higher feelings of safety in warm white light than amber light and 81.7% more likely to report higher feelings of safety at 5.0 lux than 0.5 lux. Further, individuals who felt safer in any lighting condition were 19.6 times more likely to feel greater potential for a pleasant experience while recreating than someone who did not report feeling safe or felt unsafe. Understanding the connection between light and perceived safety in park settings can help managers tailor lighting conditions to the needs of visitors while reducing ecological impacts - brighter and cooler temperature lighting have greater negative impacts on wildlife. Adjusting the distribution and intensity of light can increase the accessibility of nighttime recreation opportunities and the potential for comfortable and pleasant experiences for visitors.

Identification of the endangered species Haplotropis brunneriana (Insecta: Orthoptera) from South Korea using exuviae

Most Pamphagidae species are at risk of being endangered due to their flightlessness, low mobility, and small habitat range. For the same reason, Haplotropis brunneriana (Orthoptera: Pamphagidae) has been designated an endangered species in South Korea. Endangered species with small populations are difficult to observe and investigate because any damage or disturbance to them are prohibited. To address these problems, we first performed non-invasive genomic DNA (gDNA) extraction using exuviae to identify H. brunneriana. Second, we tested the limit of detection of gDNA in the exuviae and how long it could persist when exposed to artificial environmental conditions. Using exuviae, we identified cytochrome b as a species-specific marker of H. brunneriana that could distinguish them from other grasshoppers with sufficient specificity. In the limit of detection test, gDNA could persist and be amplified from exuviae for up to 40 days. Our results demonstrated that fewer than 10 days is recommended for amplifying gDNA from exuviae to obtain reproducible results. In conclusion, this non-invasive identification method using exuviae can be used as an alternative to species identification when it is difficult to find H. brunneriana in the habitat and has the advantage of allowing genetic research to be conducted without harming the endangered species.

Far-red light effects on plant photosynthesis: from short-term enhancements to long-term effects of artificial solar light

Abstract Background and Aims Long-term exposure over several days to Far-Red (FR) increases leaf expansion, while short-term exposure (minutes) may enhance the PSII operating efficiency (ϕPSII). The interaction between these responses at different time scales, and their impact on photosynthesis at whole-plant level is not well understood. Our study aimed to assess the effects of FR in an irradiance mimicking the spectrum of sunlight (referred to as artificial solar irradiance) both in the long and short-term, on whole-plant CO2 assimilation rates and in leaves at different positions in the plant. Methods Tomato (Solanum lycopersicum) plants were grown under artificial solar irradiance conditions with either a severely reduced or normal fraction of FR (SUN(FR-) vs. SUN). To elucidate the interplay between the growth light treatment and the short-term reduction of FR, we investigated this interaction at both the whole-plant and leaf level. At whole-plant level, CO2 assimilation rates were assessed under artificial solar irradiance with a normal and a reduced fraction of FR. At the leaf level, the effects of removal and presence of FR (0FR and 60FR) during transition from high to low light on CO2 assimilation rates and chlorophyll fluorescence were evaluated in upper and lower leaves. Key Results SUN(FR-) plants had lower leaf area, shorter stems, and darker leaves than SUN plants. While reducing FR during growth did not affect whole-plant photosynthesis under high light intensity, it had a negative impact at low light intensity. Short-term FR removal reduced both plant and leaf CO2 assimilation rates, but only at low light intensity and irrespective of the growth light treatment and leaf position. Interestingly, the kinetics of ϕPSII from high to low light were accelerated by 60FR, with a larger effect in lower leaves of SUN than in SUN(FR-) plants. Conclusions Growing plants with a reduced amount of FR light lowers whole-plant CO2 assimilation rates at low light intensity through reduced leaf area, despite maintaining similar leaf-level CO2 assimilation to leaves grown with a normal amount of FR. The short-term removal of FR brings about significant but marginal reductions in photosynthetic efficiency at the leaf level, regardless of the long-term growth light treatment.

Numerical investigation of discharge evolution and breakdown characteristics of ArF excimer lasers

The corona bar induced pre–ionization is a crucial preliminary process in the operation of ArF excimer lasers, directly impacting the uniformity and stability of output laser. The ultraviolet corona pre–ionization, as the mainstream method, is tightly coupled with the main discharge process, which complicates analysis. Here, we establish a numerical model of a single pulse discharge incorporating an external circuit to analyze the pre–ionization process and its influence on the breakdown characteristics. (1) By adopting detailed input parameters of photoionization model, we observe uniform and dispersed plasma propagation from the corona bar to the main gap. (2) An artificial boundary condition is proposed to investigate the phenomenological effect of high–energy electrons emission, emphasizing the influence of surface discharge along the cathode. (3) The propagation and breakdown characteristics of the two pre–ionization setup methods, photoionization and background electron density, are compared numerically. This study enhances the understanding of the pre–ionization process in ArF excimer lasers and provides theoretical insights for their optimization and design.

Screening of Cowpea Germplasm against Cowpea Aphid (Aphis craccivora Koch, 1854) under Artificial Conditions

Screening of Cowpea Germplasm against Cowpea Aphid (Aphis craccivora Koch, 1854) under Artificial Conditions