Search Results (267)

Obligate symbionts often exhibit some degree of co-speciation with their hosts. One prominent example is the symbiosis between termites and their wood-feeding hindgut protists. This symbiosis is mutually obligate, vertically inherited by anal feeding, and it predates the emergence of termites from their cockroach ancestors. Termites and their symbiotic protists might therefore be expected to have congruent phylogenies, but symbiont loss, transfer, and independent diversification can impact the coevolutionary history to varying degrees. Here, we have characterized the symbiotic protist communities of eight Neoisoptera species from three families in order to gauge the phylogenetic congruence between each lineage of protists and their hosts. Using microscopy and 18S rRNA gene sequencing of individually isolated protist cells, we identified protists belonging to the Parabasalia genera Pseudotrichonympha, Holomastigotoides, Cononympha, and Cthulhu. Pseudotrichonympha were present in all of the investigated termites, with a strong pattern of codiversification with hosts, consistent with previous studies. The phylogeny of Holomastigotoides indicates several instances of diversification that occurred independently of the hosts’ diversification, along with lineage-specific symbiont loss. Cononympha occurs only in Heterotermitidae and Psammotermes. Surprisingly, the small flagellate Cthulhu is widespread and exhibits cophylogeny with its hosts. This study demonstrates that different symbiont lineages can show different coevolutionary patterns, even within the same host. Full article

Pine wilt disease (PWD), a destructive pine forest disease caused by pine wood nematode (PWN), Bursaphelenchus xylophilus, has led to huge economic losses and ecological environment damage. Thaumatin-like proteins (TLPs) are the products of a complex gene family involved in host defense and a wide range of developmental processes in fungi, plants, and animals. In this study, a tlp gene of B. xylophilus (Bxtlp) (GenBank: OQ863020.1) was amplified via PCR and cloned into the expression vector pET-15b to construct the recombinant vector PET-15b-Bxtlp, which was then transformed into Escherichia coli BL-21(DE3). The recombinant protein was successfully purified using Ni-NTA affinity chromatography. The effect of the Bxtlp gene on the vitality and pathogenicity of PWNs was elucidated through RNA interference (RNAi) and overexpression. Bxtlp dsRNA significantly reduced the feeding, motility, spawning, and reproduction abilities of PWN; shortened its lifespan; and increased the female–male ratio. In contrast, the recombinant BxTLP markedly enhanced the reproductive ability of PWN. In addition, Bxtlp dsRNA increased reactive oxygen species (ROS) content in nematodes, while the recombinant BxTLP was confirmed to have antioxidant capacity in vitro. Furthermore, the bioassays on Pinus thunbergii saplings demonstrated that Bxtlp could significantly influence PWN pathogenicity. Overall, we speculate that Bxtlp affects the pathogenicity of PWNs mainly via regulating ROS levels, the motility, and hatching of PWN. Full article

Background: Pinus massoniana is a significant lipid-producing tree species in China and a susceptible host for both the pine wood nematode and its insect vector, Monochamus alternatus. The basic helix–loop–helix (bHLH) family of transcription factors play a crucial role in responding to both biotic and abiotic stresses. However, the role of bHLH in terpene-induced defense in P. massoniana remains poorly studied. Results: Transcriptome sequencing using DNA Nanoball Sequencing (DNBSEQ) and PacBio Sequel platforms was performed, revealing differences in gene expression in P. massoniana branch under the simulated feeding treatment of methyl jasmonate (MeJA) spraying. Fifteen bHLH genes were cloned and analyzed, among which eight highly upregulated PmbHLH genes showed similar temporal expression after MeJA treatment and M. alternatus adult feeding. Five highly upregulated bHLH genes with nuclear localization were highly expressed in P. massoniana after M. alternatus feeding and interacted with the promoter of the terpene synthase gene Pm TPS (−)-α-pinene, confirming their involvement in the defense response of P. massoniana against the M. alternatus adult feeding. Conclusions: Our results unveil the temporal changes and the regulation of the induced defense system in P. massoniana mediated by both MeJA signaling and M. alternatus feeding treatment. The potential application for transgenic experiments and the breeding of resistant species in the future were discussed. Full article

The integration of acoustic emission (AE) signals into adaptive control systems for CNC wood milling represents a promising advancement in intelligent manufacturing. This study investigated the feasibility of using AE signals for the real-time monitoring and control of CNC milling processes, focusing on medium-density fiberboard (MDF) as the workpiece material. AE signals were captured using dual-channel sensors during side milling on a five-axis CNC machine, and their characteristics were analyzed across varying spindle speeds and feed rates. The results showed that AE signals were sensitive to changes in machining parameters, with higher spindle speeds and feed rates producing increased signal amplitudes and distinct frequency peaks, indicating enhanced cutting efficiency. The statistical analysis confirmed a significant relationship between AE signal magnitude and cutting conditions. However, limitations related to material variability, sensor configuration, and the narrow range of process parameters restrict the broader applicability of the findings. Despite these constraints, the results support the use of AE signals for adaptive control in wood milling, offering potential benefits such as improved machining efficiency, extended tool life, and predictive maintenance capabilities. Future research should address signal variability, tool wear, and sensor integration to enhance the reliability of AE-based control systems in industrial applications. Full article

Peptaibols are linear fungal peptides featuring α,α-dialkylated amino acids (e.g., α-aminoisobutyric acid (Aib), isovaline (Iva)) and characteristic C-terminal alcohol groups. Despite their promising antibacterial and antiplasmodial activities, detailed biosynthetic studies remain limited. A genome-guided study of the fungus Trichodema sp. SK1-7, isolated from decaying wood, revealed the production of previously described trichorozin IV (1), along with novel SF4-type peptaibol 2 (trichorozin V). The structures of these compounds were elucidated through MS analysis, NMR study and advanced Marfey’s method. The genome of Trichoderma sp. SK1-7 harbors two PKS-NRPS hybrid gene clusters containing 14 and 18 adenylation domains. Analysis of the modular architecture suggested that trichorozins are synthesized by a 14-module protein via a module skipping mechanism. Genome mining revealed several types of short peptaibol synthase architectures (10–14 adenylation domains) across various Trichoderma species, accompanied by similar long peptaibol synthases. Furthermore, putative Aib/Iva biosynthesis machinery in Trichoderma was identified, showing specific architectures potentially involved in regulating peptaibol biosynthesis. Feeding experiments demonstrated that peptaibol production depends on the ratio of Iva/Aib. The isolated compounds exhibited moderate antibacterial and cytotoxic activities along with a synergistic effect when combined with membrane-targeting antibiotics. Our findings suggest that genome-guided approaches hold promise for further development of peptabiotics with a wide range of applications, including antibiotic adjuvants. Full article

The aim of this study was to determine the influence of initial chain tension, feed force, and wood hardness on the variability of the cutter’s deflection angle during petrol chainsaw operation. Cutting wood with a chainsaw is a complex process that has not been fully elucidated to date. During operation, the position of cutters with respect to the workpiece may vary. The situation is additionally complicated by the fact that chainsaws are powered by one-cylinder gasoline engines characterized by highly variable instantaneous rotational speeds. The experiments involved two types of wood (pine and oak), two initial tension values (tight vs. slack chain), and two feed forces (20 N and 80 N). The cutting process was recorded with a high-speed camera at 12,000 fps to determine cutter deflection angles, instantaneous speeds, and accelerations for all the aforementioned cases. It was found that at the lower feed force the cutter deflection differed depending on the initial chain tension, and a greater cutter deflection angle was observed in pine wood processing. It was also found that speed and acceleration in the Y axis were much lower than in the X axis. Additionally, the rear part of the cutter revealed greater speed variation in the X axis. Full article

Red wood ants (RWA), belonging to the Formica rufa species group, play a crucial and fascinating role in Central Europe’s forest ecosystems. They have a high variety of effects, which they exert around their nests. Their generalist feeding on prey in the canopies of trees lowers the frequency of defoliator outbreaks, as well as increases local biodiversity. Nearly half of their diverse diet is insects, including species considered harmful by foresters. They also have a mutualistic relation with honeydew-producing aphids and planthoppers, which connection has unclear effects on the forests. The habit of RWAs building nests could also positively influence soil composition, due to its structure and high amount of organic matter, which could potentially benefit tree growth. RWAs are also known to enhance the species richness of forests by supporting various myrmecophilous species associated with them. In this study, we review the role of RWAs in forest protection, drawing on the literature focusing on Hungary and Central Europe. Full article

This paper discusses cutting beech wood (Fagus sylvatica L.) using a CO₂ laser and optimising its feed speed and laser power concerning the roughness of the cut surface and the kerf width. The roughness, defined by the parameters Ra, Rz, Rv, and Rp, and the kerf width changed with varying technological parameters of the CO₂ laser—feed speed and laser power. The lowest roughness was achieved at 50% laser power and a 15 mm·s⁻¹ feed speed, while the highest roughness was reached at 50% and 30 mm·s⁻¹. The lowest kerf width was achieved at 50% laser power and a feed speed of 15 mm·s⁻¹ on both the upper and lower sides and vice versa. The result of the experiment was the creation of second-degree polynomial regression models, from which the optimal values of the technological parameters of the CO₂ laser for cutting wood were determined for surface roughness and kerf width. The achieved accuracy of the models was 98.01% for the kerf width on the upper side, 95.95% for the kerf width on the lower side, 82.71% for the Ra parameter and 85.44% for the Rz parameter. Full article

A carbon-negative heating system can be realized by pyrolyzing wood pellets, burning the product gas, and storing the produced biochar. Oxidative pyrolysis simplifies the reactor design by replacing an external heat supply with internal oxidation driven by a sub-stoichiometric “primary” air supply. Previous studies have only examined the influence of primary air supply on biochar yield and heating power in a continuous pyrolysis reactor within a limited fuel–air spectrum. In this work, an oxidative pyrolysis reactor, with a nominal heating power of 15 kW, was investigated with the aim to vary the useful heat output and biochar yield over a wide range and still produce biochar of the highest quality in accordance with the EBC (European Biochar Certificate) guidelines. This study demonstrated that within an air flux range of 0.03–0.14 kg/(m²s), there is a linear relationship between air flux and both wood flux and useful heat, resulting in a power output range of 4–30 kW. The useful heat output could be varied by a factor of three in less than 15 min, verifying concept feasibility as a central heating system to meet the variable heating demands of both single and multi-household applications. The biochar yield was observed to range from 12% to 24% of the incoming wood mass flow, meeting the EBC Feed Plus quality standards at all conditions. Depending on the operating point, up to 40% of the biomass’s heating value is stored in the biochar. Full article

Building materials, including polyvinyl chloride (PVC), play a key role in construction engineering, influencing the durability, esthetics, and functionality of structures. PVC stands out for its lightness, thermal insulation, and corrosion resistance. This makes it competitive with wood, aluminum, or steel, particularly in the manufacture of window joinery. One of the key technological processes in the processing of PVC profiles is welding, the quality of which depends on the precise control of parameters such as the temperature, time, and pressure regulating the speed of the welding heads. In modern welding machines, the use of servo drives guarantees the adequate precision and repeatability of the process, which allows better adjustment to technological requirements than in older machines. This study aimed to determine the effect of the heating head feed rate for selected milling depths on the quality and strength of window frame welds. A criterion in the assessment of the strength of the window frames was the result of failure load tests on the welds. In addition, the tests took into account the quality of the welds. The tests showed that the welding head feed rate of 0.25 mm/s generated the highest-quality welds, taking into account the continuity and symmetry of the weld and its highest failure load. When milling the composite to a depth of 1 mm, the average value of the failure load was 3637 N. Meanwhile, for speeds of 0.19 mm/s and 0.31 mm/s, it was 3157 N and 3033 N, respectively. For the 0.5 mm milling variant and without milling the composite, the average load values were significantly smaller. Full article

As a kind of high-oxygen organic liquid produced during biomass pyrolysis, wood vinegar possesses significant industrial value due to its rich composition of acetic acid, phenols, and other bioactive compounds. In this study, we explore the application of advanced machine learning models in optimizing the dual-column distillation process for wood vinegar production, such as Random Forest algorithms. Through the integration of Aspen Plus simulation and deep learning, an adaptive control strategy is proposed to enhance the separation efficiency of key components under varying feed conditions. The experimental results demonstrate that the Random Forest model exhibits superior predictive accuracy to traditional decision tree methods, and an R² of 0.9728 can be achieved for phenol concentration prediction. This AI-driven system can provide real-time process optimization, enhancing energy efficiency, stabilizing component yields, and contributing to the advancement of sustainable practices within the biomass chemical industry. These findings are anticipated to offer valuable insights into the integration of green chemistry principles with intelligent control systems to facilitate the achievement of Industry 4.0 objectives in bio-based production. Full article

In this study, a modified 3D printer hotend equipped with a load cell, attached to the feeding system, was used to evaluate the effects of filament material composition and printing parameters on the extrusion force required. Four different materials (commercial PLA, pure PLA, wood-PLA with different ratios of wood particles, and wood-PLA with different ratios of thermally modified wood particles) were used for 3D printing, and the feeding resistance was measured. The filament feeder was connected to the extruder hotend via a load cell, which measured the forces required to push the filament through the extruder and the nozzle. Three printing nozzle temperatures of 200, 210, and 220 °C were used. The results show that the printing temperature and the material influence the required extrusion forces, which varied between 1 and 8 N, but the variation was high. With proper optimization and integration into the printer firmware, this setup could also be used to detect nozzle clogging during printing, modify printing parameters during the process, and prevent the uneven extrusion of composite filaments. Full article

The scientific community has placed increasing importance on sustainability, leading to the exploration of alternative bedding materials to the widely used aspen wood chips. Bedding plays a critical role in ensuring the wellbeing of animals and the validity of experimental outcomes. Compared to the frequently evaluated biological materials, such as corncobs or spelts, synthetic materials such as plastic granules have been less investigated. We characterized two thermostable plastic materials as an alternative bedding material in C57BL/6J and BALB/c mice. We examined the impact of those bedding alternatives on physiological parameters, behavior, health status, and cage climate in static and digitally ventilated cages as well as the possibility of a reuse cycle after reprocessing. The mouse lines showed different locomotor activity, feeding, and nestbuilding behavior on plastic granules. While ammonia levels were constantly higher in static cages than in ventilated cages, blood parameters were unaltered, and health status was maintained during the reuse procedure. We show the use of plastic granulate as bedding material for mice that has the potential for processing and recycling. Further, we show that the material is accepted differently by the lines in the preference choice test without affecting their health or hygiene status. Full article

This study integrates the Backpropagation (BP) Neural Network with several optimization algorithms, namely Hippopotamus Optimization (HO), Parrot Optimization (PO), Osprey Optimization Algorithm (OOA), and Goose Optimization (GO), to develop four predictive models for the adhesive strength of heat-treated wood: HO-BP, PO-BP, OOA-BP, and GO-BP. These models were used to predict the adhesive strength of the wood that was heat-treated under multiple variables such as treatment temperature, time, feed rate, cutting speed, and abrasive particle size. The efficacy of the BP neural network models was assessed utilizing the coefficient of determination (R²), error rate, and CEC test dataset. The outcomes demonstrate that, relative to the other algorithms, the Hippopotamus Optimization (HO) method shows better search efficacy and convergence velocity. Furthermore, XGBoost was used to statistically evaluate and rank input variables, revealing that cutting speed (m/s) and treatment time (hours) had the most significant impact on model predictions. Taken together, these four predictive models demonstrated effective applicability in assessing adhesive strength under various processing conditions in practical experiments. The MAE, RMSE, MAPE, and R² values of the HO-BP model reached 0.0822, 0.1024, 1.1317, and 0.9358, respectively, demonstrating superior predictive accuracy compared to other models. These findings support industrial process optimization for enhanced wood utilization. Full article

Populus alba var. pyramidalis (PaP) is a very important and main planted tree species in northwestern China. However, it has been threatened by Asian longhorned beetle Anoplophora glabripennis (ALB) infestation. A feasible way to protect PaP is by improving its own insect resistance ability. In order to achieve this goal, we first checked whether ALB could induce the defense system of PaP by comparing the ALB-attracted volatiles of PaP before and after ALB infestation through the collection and identification of volatiles by gas chromatography–mass spectrometry (GC-MS). We found that attractant volatiles (Z)-3-hexenol (Z3H) and (Z)-3-hexen-1-yl acetate (Z3HA) decreased by 72.99% and 74.53% after ALB infestation, respectively. Then, the contents of the plant hormones salicylic acid (SA), jasmonic acid (JA), methyl salicylate (MeSA), and methyl jasmonate (MeJA) and the defense substances hydrogen peroxide (H₂O₂), peroxidase (POD), and total superoxide dismutase (T-SOD) in the phloem of PaP were determined before and after ALB infestation by high-performance liquid chromatography–mass spectrometry (HPLC-MS) and a manufacturer’s kit, respectively. The results showed that the quantities of SA decreased, but JA and MeJA increased by 2.1 times and 3.02 times, respectively, and the increase in H₂O₂ and POD was also significant. Therefore, we hypothesized that MeJA might be closely related to the induced ALB resistance of PaP. Further exogenous spraying of MeJA on PaP showed that the feeding and oviposition of ALB adults were significantly decreased on PaP, confirming that MeJA could improve PaP’s resistance against ALB. The concentration effect showed that 10⁻⁴ mol/L of MeJA treatment induced the strongest results. Our results clearly demonstrated the response of a poplar species to a wood borer infestation and provide an alternative method to protect PaP in the future. Full article