Morphological Methods Research Articles

Morphology, morphogenesis, and molecular phylogeny of Holostichides (Holostichides) parachardezi nov. Spec. (Ciliophora, Hypotrichia, Urostylida), a new soil ciliate from China

A new urostylid ciliate, Holostichides (Holostichides) parachardezi, collected from a Chinese tropical city, was studied using morphological and molecular methods. Diagnostic features of the new species include: size 140–180 × 30–60 μm in vivo; 25–43 macronuclear nodules; colourless cortical granules; three to six frontoterminal cirri; a midventral complex composed of seven to eleven cirral pairs and one midventral row of five to eleven cirri; four bipolar dorsal kineties and six to nine caudal cirri in four groups; and a terrestrial habitat. Its ontogenesis follows the typical Holostichides mode in that (1) the proximal portion of the parental adoral zone of membranelles is partly renewed and the opisthe’s oral primordium originates very close to the midventral complex; (2) the last anlage n generates the frontoterminal cirral row, and the midventral complex is formed from anlage IV to n − 1; and (3) both marginal rows and dorsal kinety anlagen develop within the parental rows. The present SSU rDNA phylogenies corroborated the monophyly of the genus Holostichides.

Charge carrier dynamics of chemical vapor deposited carbon-doped titanium dioxide photoanodes

This study explores the synthesis of carbon-doped titanium dioxide TiO2(C) photoanodes through a single-step, low-pressure chemical vapor deposition (LCPVD) method, investigating the influence of carbon doping and oxygen vacancies on photoelectrochemical performance. The research employs morphological, structural, and photoelectrochemical characterization methods, including intensity-modulated photocurrent spectroscopy (IMPS) and distribution of relaxation times (DRT) analysis. We correlate the simultaneous presence of surface carbon and oxygen defects to improved charge separation and collection for TiO2(C) photoanodes. This work provides a comprehensive and detailed explanation of the photoelectrochemical performance of TiO2 electrodes, showing the potential behind combined IMPS-DRT analysis for photoelectrode characterization.

Species identification and pollination biology of an economically important true halophyte, Salicornia brachiata Roxb.

Members of the genus Salicornia have gained a global attraction due to their ability to thrive under high saline conditions and as potential candidates in saline agriculture. However, it has been a taxonomically challenging genus for decades since the members show plastic responses to extreme environmental conditions and due to incongruences between morphological and molecular identification methods. While only a handful of commercially grown Salicornia species are fully described, most of the species including S. brachiata, a native species in the Indian sub-continent, Myanmar, and Sri Lanka are poorly described. With the potentials in adapting S. brachiata in saline agriculture, the aim of this study was to establish a morphology and DNA barcode-based species delineation system and to study pollination biology for future crop improvement projects. Tentatively identified S. brachiata plant samples were collected from two populations in Sri Lanka and completely described. GenBank lacked authenticated barcode data for S. brachiata except for one chloroplast genome to which the matK sequence obtained in the present study matched with 100% identity. For the first time, well defined sequences of three barcode regions, ITS, ETS and matK, of S. brachiata were made available for accurate species identification. Reproductive dynamics in different parts of the inflorescence was studied. A facultative xenogamous mating system was recorded for the first time in the genus and while the lower florets in the cladode showed a preference towards outcrossing, the upper florets displayed adaptations for selfing. Data could be effectively utilized in future Salicornia breeding programs.

Isolation and identification of endophytic fungi from Alhagi sparsifolia Shap. and their antibacterial activity

In order to explore the endophytic resources of Alhagi sparsifolia Shap. and identified novel antibacterial substances. Thirty endophytic fungal strains were isolated from the stems and roots of A. sparsifolia Shap. Morphological and molecular biology methods were used to identify ten strains of fungi, including four strains of Aspergillus niger, three strains of Alternaria alternata, two strains of Aspergillus flavus, and one strain of Fusarium incarnatum. All these strains were isolated from A. sparsifolia Shap. for the first time, and of these Aspergillus was the dominant genus. Antibacterial activity of the ten strains against Escherichia coli, Staphylococcus aureus, Candida albicans, and Pseudomonas aeruginosa were evaluated using the disc diffusion method. The results demonstrated that the metabolites from all the strains had inhibitory effects on at least one indicator bacterium. Notably, the endophytic fungi AFJ3 and AFG6 demonstrated strong broad-spectrum antibacterial activity, particularly against E. coli, with inhibition zones measuring 32.0 ± 0.3 and 31.3 ± 0.3 mm, respectively. The three endophytic fungi (AFG1, AFG2, and AFG3) isolated from the roots demonstrated significant antibacterial activity against P. aeruginosa forming an inhibition zone of diameter 31.3 ± 0.1, 25.6 ± 0.2, and 25.6 ± 0.2 mm, respectively. However, the strains of endophytic fungi demonstrated no significant inhibitory effects on C. albicans. Ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry/mass spectrometry (UPLC-QTOF-MS/MS) analysis depicted that the ethyl acetate phase of AFJ3 and AFG6 fermentation broth predominantly contained organic acids, phenolic acids, flavonoids, and fatty acids. These secondary metabolites often exhibited good antibacterial activity. This study broadens our understanding of endophytic fungi in A. sparsifolia Shap. The antibacterial activity of some strains of endophytic fungi was significant, making it worthy of further research on their active material.

An improved morphological filtering and feature enhancement method for rolling bearing fault diagnosis

Abstract The defects-induced periodic pulse is one of the important indices for the characterization of bearing failure. To solve the problem that the weak impact features caused by the early fault of the rolling bearing are easily to be interfered with by noise and strong background signal and are difficult to extract, an improved morphological filtering method combined with the Teager energy operator (TEO) is proposed to extract weak shock features. Firstly, according to the correlation between the periodic pulse induced by defects and the Morlet wavelet, the Morlet wavelet is used as the model to construct the structural elements. Then, capturing the Pearson correlation coefficient of the structural elements and the original signal and the signal is filtered by the variable scale morphological filter after threshold screening. Finally, the TEO is used as the post-enhancement link to suppress the noise in the signal after morphological processing and further highlight the fault characteristics. Simulation signals, experimental signals, and field signals verify the effectiveness and robustness of the proposed method.

The diversity of fungal associates of Dendrobium ovatum (L.) Kraenzl., an endemic orchid of the Western Ghats of India

Dendrobium ovatum is a tropical epiphytic orchid endemic to the Western Ghats of India and has been listed as a threatened species in recent research due to its declining populations and changes in flowering and fruit set patterns. This study aims to investigate the mycoflora associated with the roots, stems and leaves of D. ovatum. Both surface‐associated and endophytic fungal associates were isolated and identified using morphological and molecular methods. The study resulted in the isolation of 139 cultures, which were divided into 24 morphotypes, 99% of which belonged to Ascomycota. The most dominant members, Trichoderma harzianum and Colletotrichum gloeosporioides, were consistently observed across all the study sites. Tissue‐specific fungal diversity analysis revealed that each organ was dominated by a distinct fungal group, forming characteristic communities specific to each tissue. The roots of D. ovatum exhibited the highest species richness and diversity, compared to the stem and leaves. This research also represents the first documentation of fungal associates of the threatened orchid D. ovatum.

Profiling the biocontrol agents, nitrogen-fixing bacteria, and indole acetic acid-producing bacteria in anthill soil

Due to the adverse ecological impacts of prolonged and excessive use of agrochemicals, many researchers have called for the adoption of eco-friendly materials in farming. Consequently, the aim of this study is to profile the biocontrol agents, nitrogen-fixing, and indole-acetic-acid-producing bacteria present in anthill soil. Anthill soils and adjacent soils were collected, and their physicochemical properties were analysed using standard analytical methods. Viable bacteria were isolated and screened for plant growth-promoting (PGP) activity using standard biochemical, morphological, and bacteriological methods. The PGP capacity of the isolates was evaluated using standard protocol for nitrogen fixation and indole-acetic-acid production, while antagonistic effect against plant pathogens was evaluated using the disk diffusion assay. Results revealed that Pseudomonas aeruginosa, Klebsiella pneumoniae, and Bacillus sp. isolated from the anthill soil demonstrated PGP characteristics including IAA production and nitrogen fixation. Bacillus sp. exhibited zones of clearance with values of 20.00 ± 1.50 mm, 20.00 ± 1.75 mm, 17.00 ± 1.33 mm, and 17.00 ± 1.33 mm against Aspergillus niger, Trichoderma sp., Penicillium sp., and Fusarium sp., respectively. This study demonstrated that anthill soils contain beneficial microbes with the potential to stimulate plant growth and suppress soil-borne plant pathogens.

Aspergillus aureoterreus, A. pseudonomiae, A. siamensis, and A. flocculosus-ochraceopetaliformis as Four New Pathogens of Eye Infection in DNA Barcoding Markers

Background: The use of a morphological method to determine Aspergillus species in routine laboratory investigation has always been challenged with low sensitivity and low specificity. Time-consuming specimen preparation and insufficient expertise are the crucial reasons. DNA barcoding markers have been introduced for identification as another gold standard method. Objective: To investigate DNA barcoding markers in identifying Aspergillus strains isolated from patients with eye infection. Methods: This study extracted 12 DNA samples of 12 Aspergillus strains. DNA barcoding genes, i.e., ITS, betatubulin (BT2), calmodulin (CAL), and actin (ACT) genes, were amplified and sequenced by polymerase chain reaction and Sanger's sequencing methods. All gene sequences were compared to those of the type or reference species collected from public databases. The species were identified with phylogenetic analyses in free applications from public websites. Results: ITS, BT2 and CAL, and ACT identified 5, 6, and 3 species and 3, 2, and 1 species complex of Aspergillus, respectively. DNA barcoding with multi-locus sequence typing revealed four new pathogens of human eye infection, including A. aureoterreus, A. pseudonomiae, A. siamensis, and A. flocculosus-ochraceopetaliformis. Conclusion: The DNA barcoding markers identified Aspergillus species with better specificity than the conventional method. The markers and techniques need to be used as tools for routine Aspergillus identification.

Maritime infrared image enhancement based on morphological pseudotransmittance modulation and radiation source enhancement

To address the problems of low contrast and fuzzy details in maritime infrared images, this paper constructs a pseudotransmittance model based on the principles of infrared radiation imaging, and proposes an enhancement algorithm of morphology single-scale pseudotransmittance modulation and radiation source enhancement. First, the original image is adaptively segmented to generate the radiation source region and the radiation source suppressed background. Then, the pseudotransmittance is calculated by estimating the radiation of the background through morphological methods. Finally, the pseudotransmittance is used to modulate the original image for background enhancement and the radiation source detail is enhanced as well. On this basis, an algorithm for maritime infrared image enhancement with morphological multiscale pseudotransmittance modulation and radiation source hierarchical fusion is developed to overcome the problem of edge overenhancement and neighbourhood enhancement. Experiments show that our methods perform well in detail and contrast enhancement and outperform other methods in both qualitative and quantitative evaluations.

DNA-based marine benthic assessment methods can perform as morphological ones, but an intercalibration is needed

There is an increasing need for legislation worldwide to monitor and assess the ecological status of marine ecosystems, due to increasing pressures from human activities. The costs and time of traditional analyses are high, while methods based on molecular analysis could reduce these costs and shorten evaluation times significantly. Some biotic indices used to assess the status need reference conditions to be applied. Hence, our objective here is to develop reference conditions for a molecular-based benthic index (M−gAMBI), which can be compared with a morphological one (M−AMBI). Using 6 years of data from estuaries and coasts, we have been able to set reference conditions for five water types, including richness, diversity and AMBI. However, one problem is the absence of the whole human pressure gradient in all water types, making difficult to validate the reference conditions. Based on the results of this research, the M−gAMBI index could be considered suitable for ecological status assessment since it meets most of the criteria for considering a genomics-based index suitable. However, it is considered necessary to advance in (i) improving the detection of errors in genomic methods and similarity with morphological methods, and (ii) an intercalibration exercise, allowing adjusting quality class boundaries and determining the ecological status in an equivalent manner using both methods.

A DNA barcode reference library for the Tipulidae (Insecta, Diptera) of Germany.

Tipulidae, commonly known as true crane flies, represent one of the most species-rich dipteran families, boasting approximately 4,500 known species globally. Their larvae serve as vital decomposers across diverse ecosystems, prompting their frequent and close observation in biomonitoring programs. However, traditional morphological identification methods are laborious and time-consuming, underscoring the need for a comprehensive DNA barcode reference library to speed up species determination. In this study, we present the outcomes of the German Barcode of Life initiative focused on Tipulidae. Our DNA barcode library comprises 824 high-quality cytochrome c oxidase I (COI) barcodes encompassing 76 crane fly species, counting for ca. 54% of the German tipulid fauna. Our results significantly increased the number of European tipulid species available in the Barcode of Life Data System (BOLD) by 14%. Additionally, the number of barcodes from European tipulid specimens more than doubled, with an increase of 118%, bolstering the DNA resource for future identification inquiries. Employing diverse species delimitation algorithms - including the multi-rate Poisson tree processes model (mPTP), Barcode Index Number assignments (BIN), Assemble Species by Automatic Partitioning (ASAP), and the TaxCI R-script - we successfully match 76-86% of the morphologically identified species. Further validation through neighbor-joining tree topology analysis and comparison with 712 additional European tipulid barcodes yield a remarkable 89% success rate for the species identification of German tipulids based on COI barcodes. This comprehensive DNA barcode dataset not only enhances species identification accuracy but also serves as a pivotal resource for ecological and biomonitoring studies, fostering a deeper understanding of crane fly diversity and distribution across terrestrial landscapes.

Integrated characterization and in vitro biocontrol of Fusarium sp. using Trichoderma asperellum

Pepper is a crop of great economic importance in Mexico. However, it is affected by multiple diseases. The aim of this research was to identify through morphological and molecular methods the causal agent of both foliar and root wilting in jalapeño pepper plants (Capsicum annuum L.), and the ability of Trichoderma asperellum to control these diseases in vitro. The causal agent of the disease was isolated from soil and foliar samples of jalapeño pepper fields in Delicias, Chihuahua, Mexico. The fungus was cultured on solid PDA medium to study its morphology. The CTAB method was used to extract DNA from Fusarium sp. The ITS1 and ITS4 primer pair was used to amplify a 850 bp DNA fragment by PCR. The sequence was deposited in Genbank (acc. no. OR801070) and used for phylogenetic analysis using Bayesian inference. The analysis revealed five clades and the isolate was placed in clade 4, which showed high genetic similarity with F. oxysporum (99.28% identity). Based on these molecular, morphological and phylogenetic data, the isolate was identified as Fusarium oxysporum Schltdl. The biocontrol potential of T. asperellum (accession No. MN95047) against F. oxysporum was tested in vitro and it showed 40% to 87.5% inhibition of the pathogen. These findings are important for managing this pathogen and reducing the use of chemical fungicides.

Effect of CeO2 morphology and Ru impregnation method on CH4 selectivity reduction in polyethylene waste conversion to liquid fuels and lubricants

Hydrogenolysis of polyolefins offers a sustainable pathway by giving plastic waste a second life as valuable resources, transforming it into fuels and lubricants. Supported Ru catalysts have shown potential for depolymerizing polyolefins under mild conditions; however, depolymerization via terminal C-C bond cleavage can lead to the excessive formation of CH4. This study investigated the effects of CeO2 morphology and Ru impregnation method on the suppression of CH4 formation and increasing liquid and wax proportions (C5-C41) in the production of liquid fuels and lubricants through polyethylene hydrogenolysis. Controlling the morphology of CeO2 and impregnating Ru via electrostatic adsorption can enhance the formation of oxygen vacancies and strengthen the interaction between Ru and CeO2. The presence of defects in CeO2 also correlated with smaller particle size of Ru and a higher hydrogen reservoir site, which effectively suppress CH4 formation.

Development and age estimation of the intrapuparial period of Phormia regina (Diptera: Calliphoridae) for postmortem interval estimation.

Phormia regina (Meigen, 1826; Diptera: Calliphoridae) is a Holarctic species that rapidly colonizes carcasses and has been used as an indicator for determining the minimum postmortem interval. However, studies using morphological methods to estimate the intrapuparial age of P. regina are lacking. In this study, morphological changes within the puparium were observed under a stereomicroscope at 7 constant temperatures ranging from 16 °C to 34 °C. The intrapuparial period was categorized into 12 substages. Morphological indicators, including compound eyes, mouthparts, antennae, thorax, legs, wings, and abdomen, were recorded in detail. The observed morphological changes were divided into 6-10 substages, and the duration of each substage was also recorded in detail. The results of this study provide primary data for using the intrapuparial morphology of P. regina when pupae are collected at a crime scene and estimating the minimum postmortem interval.

Larval habitat diversity, physicochemical characterization and their effect on the density of larval malaria vectors in the city of Accra, Ghana.

Malaria is more prevalent in rural areas due to fewer mosquito breeding habitats in urban settings. However, urban factors such as irrigated farming, open sewers, and discarded containers create mosquito breeding sites. This study investigates the diversity and distribution of larval habitats and the impact of physicochemical characteristics on the presence and density of Anopheles gambiae s.l. larvae in Accra, Ghana. Larval surveys and collections were conducted at fifteen locations in Accra, divided into five categories: Irrigated Urban Farming (IUF), Lower Socioeconomic Status (LS), Middle Socioeconomic Status (MS), High Socioeconomic Status (HS), and Peri-urban (PU) areas. Physicochemical parameters were measured, and species identification was performed using morphological and molecular methods. A total of 727 breeding habitats were identified, with 65.34% (475/727) positive for Anopheles larvae. Drainage ditches were the most common habitat type (48.21%, 229/475). The highest abundance of An. gambiae s.l. was found in IUF sites (6,244/22,919), especially during the rainy season (77.01%, 17,650/22,919; R2 = 3.46, P = 0.000). Polluted habitats, including household effluents, had higher ammonium levels (3.4 mg/L NH -N) compared to unpolluted ones (1.3 mg/L NH -N). Other distinguishing parameters included dissolved oxygen (34% vs 52.9%), conductivity (5106 μS/cm vs 2049 μS/cm), and total dissolved solids (3181 mg/L vs 1255 mg/L). The predominant malaria vector was An. coluzzii(54.4%, 368/677). Additionally, the invasive An. stephensi, previously unreported in Ghana, was detected. Malaria vectors breed in diverse and often polluted urban habitats, with high larval densities in urban agricultural areas. The detection of the invasive An. Stephensi highlights the need for continuous monitoring and vector control strategies in urban settings.

Parasitoid complex associated with the flea weevil Orchestes alni L. (Coleoptera: Curculionidae) in Bulgaria and a review of host–parasitoid interactions of genus Orchestes Illiger

ABSTRACT Leaves of field elm, Ulmus minor, with mines of Orchestes alni, were collected at four sites in Sofia city during 2018, 2019 and 2023, and kept under laboratory conditions to observe and count emerging parasitoid adults. Results revealed that the parasitoid complex included 22 hymenopteran species belonging to five families: Braconidae (two species), Ichneumonidae (one species) (Ichneumonoidea), Eulophidae (14 species), Eupelmidae (three species) and Pteromalidae (two species) (Chalcidoidea). The most abundant species was Pnigalio agraules (27%), followed by Minotetrastichus platanellus (18%) (Eulophidae) and Trichomalus inscitus (Pteromalidae) (14%). Nine host–parasitoid associations are reported as new. Tetrastichus miser is reported from Bulgaria for the first time. These findings are discussed in relation to the known host–parasitoid associations of the genus Orchestes. The identification of the host species, O. alni, was supported by both morphological and molecular methods.

Mitigating the Threat of Invasive Mosquito Species Expansion: A Comprehensive Entomological Surveillance Study on Kastellorizo, a Remote Greek Island.

The expansion of the tiger mosquito, a vector that can transmit diseases such as dengue, chikungunya, and Zika virus, poses a growing threat to global health. This study focuses on the entomological surveillance of Kastellorizo, a remote Greek island affected by its expansion. This research employs a multifaceted approach, combining KAP survey (knowledge, attitude, practices), mosquito collection using adult traps and human landing catches, and morphological and molecular identification methods. Results from questionnaires reveal community awareness and preparedness gaps, emphasizing the need for targeted education. Mosquito collections confirm the presence of the Aedes albopictus, Aedes cretinus, and Culex pipiens mosquitoes, highlighting the importance of surveillance. This study underscores the significance of community engagement in entomological efforts and proposes a citizen science initiative for sustained monitoring. Overall, this research provides essential insights for developing effective mosquito control programs in remote island settings, thereby emphasizing the importance of adopting a One Health approach to mitigate the spread of vector-borne diseases.

Hierarchically structured nanospherical fibrous silica-supported bimetallic catalysts: An enhanced performance in methane decomposition

Hydrogen production by methane catalytic decomposition is a promising method that also allows the formation of valuable carbon nanomaterials which can be utilized in transportation fuels, chemical synthesis, and fuel cell technology. In this study, bimetallic 3d transition metal (Ni, Fe, Co) catalysts supported on spherical mesoporous nanofibrous silica (KCC1) were successfully synthesized using a hydrothermal method followed by sono co-impregnation. The catalysts were evaluated for their performance in the catalytic decomposition of methane. Comprehensive characterization of the catalysts was conducted utilizing XRD, FTIR, SEM, TEM, STEM, XPS, H2-TPR, and BET techniques. XRD and TEM analyses confirmed the formation of Ni–Fe, Ni–Co, and Co–Fe bimetallic alloys on the nanofibrous silica without compromising its dendrimeric hierarchical structure. STEM HAADF imaging revealed a uniform dispersion of bimetallic nanoparticles within the spherical fibrous framework. Catalytic tests demonstrated that all bimetallic catalysts showed high stability and activity for methane cracking at 700 °C over 180 min of time on stream (TOS). Among them, Fe-based catalysts Ni–Fe/KCC1 and Co–Fe/KCC1 achieved the highest hydrogen yields of 80% and 60%, respectively. Methane conversion was 1.56 and 2.23 times higher in Ni–Fe/KCC1 compared to Co–Fe/KCC1 and Ni–Co/KCC1, respectively. Post-reaction characterization of the spent catalysts was performed using XRD, Raman spectroscopy, SEM, TEM, and TGA. XRD and Raman spectroscopy were used to evaluate the degree of graphitization and crystallinity in the carbon nanotubes (CNTs) produced on the catalysts, enabling a correlation with the catalyst properties. TEM examination was used to investigate the structural morphology and growth methods of the CNTs, including tip or base growth and chain-like or parallel-wall types. TGA results revealed that all bimetallic catalysts exhibited no amorphous carbon during methane cracking reaction.

Morphological discrimination of fouling Ulva and Blidingia species on Pyropia rafts in Rudong, China: an in-field protocol for early monitoring of algae forming the Yellow Sea green tide

Abstract Fouling seaweeds on nori cultivation rafts in Subei radial sand ridges (Jiangsu, China) are believed to be the source of the Yellow Sea green tide (YSGT). Although major species are consistent across years, their biomass and proportions undergo significant annual changes, which was speculated to be related to the size of YSGT. Therefore, early detection and biomass assessment of the bloom-forming algae are crucial, increasing the need to develop a morphological identification method suitable for large sample sizes in the field. In this study, fouling seaweeds were collected from this area in spring 2017. Five major species, Ulva aragoënsis, Ulva compressa, Ulva linza, Ulva prolifera, and Blidingia sp. were molecularly identified, and confirmed as the predominant fouling seaweeds on nori rafts over the past decade. In this unique ecological niche, the morphological features of species changed significantly yet stably. Based on morphological observations, an identification key for these five species was established. Furthermore, a simplified version containing only two indices was developed for practical field use, with an average accuracy of 81 % (δ 2 = 0.003) in empirical accuracy assessments. This method can be used to monitor the community structure and succession of fouling seaweeds at the geographical source of YSGT.

Cu-Ni Bimetallic Nanowires with Various Structures Originating from Ni Reduction Kinetics.

Bimetallic nanowires play important roles in the fields of electronics and mechanics. However, their structure types and morphological control methods are limited, especially for systems with low lattice mismatch. Herein, for a Cu-Ni bimetallic system with lattice mismatch ratio less than 2.5%, a novel preparation approach of various Cu-Ni nanowires dominated by Ni(II) reduction kinetics is presented. With the increase of Ni(II) reduction rate, the core-shell Cu@Ni straight nanowires, the asymmetric Cu-Ni nanocurves, and asymmetric Cu-Ni nanocoils can be prepared, respectively. The formation of Cu-Ni nanowires with different structures can be divided into the growth of Cu nanowires and the deposition of Ni. The regulatory effects were revealed by establishing a kinetic model for Ni(II) reduction. For the novel Cu-Ni asymmetrically distributed nanocurves and nanocoils, the formation mechanism was proposed by considering the Cu nanowire bending due to the rearrangement of surface ligand and bending-induced symmetry breaking of Ni(II) reduction.