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1.
Int J Mol Sci ; 24(2)2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36675226

RESUMO

Euplatypus parallelus is one of the dominant rubber bark beetle species in Hainan's rubber-planting area. Semiochemicals, including the volatiles found in rubber trees and aggregation pheromones, play an important role in the search for suitable host plants. To examine the possible functional role of highly expressed odorant-binding protein 2 of Euplatypus parallelus (EparOBP2) in the semiochemical recognition process, we cloned and analyzed the cDNA sequence of EparOBP2. The results showed that EparOBP2 contains an open reading frame (ORF) of 393 bp that encodes 130 amino acids, including a 21-amino-acid residue signal peptide at the N-terminus. The matured EparOBP2 protein consists of seven α-helices, creating an open binding pocket and three disulfide bridges. The results of the fluorescence binding assay showed that EparOBP2 had high binding ability with α-pinene and myrcene. The docking results confirmed that the interactions of α-pinene and myrcene with EparOBP2 were primarily achieved through hydrophobic interactions. This study provides evidence that EparOBP2 may be involved in the chemoreception of semiochemicals and that it can successfully contribute to the integrated management of E. parallelus.


Assuntos
Receptores Odorantes , Gorgulhos , Animais , Feromônios/metabolismo , Borracha , Gorgulhos/metabolismo , Receptores Odorantes/metabolismo , Proteínas de Insetos/metabolismo , Ligação Proteica
2.
Sci Rep ; 13(1): 1344, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36693897

RESUMO

Marine microplastics are one of the global environmental issues. The present study examined whether rubber tips of artificial sports fields could be marine microplastics. We observed the migration of rubber tips from the artificial turf field to the surrounding ditch connected to sewer pipes and then examined the ingestion of rubber tips using the goldfish Carassius auratus. The rubber tips found in sediments in the ditch suggest that the rubber tips could be sent to the river and released into the ocean. The goldfish ingested rubber tips with or without fish feed, and rubber tips were found in the intestine. However, the fish discharged the rubber tips within 48 h after ingestion. These results indicate that ingestion of the rubber tips was not accidental but an active behavior. Therefore, artificial turf sports fields could be a source of marine microplastics and may cause hazardous effects on wild fishes through ingestion.


Assuntos
Borracha , Poluentes Químicos da Água , Animais , Plásticos , Carpa Dourada , Exposição Ambiental/análise , Microplásticos , Ingestão de Alimentos , Poluentes Químicos da Água/análise
3.
BMC Genomics ; 24(1): 13, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36627555

RESUMO

BACKGROUND: Taraxacum kok-saghyz Rodin (TKS) is a promising commercial alternative natural rubber (NR) yielding plant. Cultivating TKS with a high NR content is an important breeding target, and developing molecular markers related to NR content can effectively accelerate the breeding process of TKS. RESULTS: To construct a high-density SNP genetic map and uncover genomic regions related to the NR content in TKS, an F1 mapping population of TKS was constructed by crossing two parents (l66 and X51) with significant differences in NR contents. The NR content of the F1 plants ranged from 0.30 to 15.14% and was distributed normally with a coefficient of variation of 47.61%, indicating quantitative trait inheritance. Then, employing whole-genome resequencing (WGR), a TKS genetic linkage map of 12,680 bin markers comprising 322,439 SNPs was generated. Based on the genetic map and NR content of the F1 population, six quantitative trait loci (QTLs) for NR content with LOD > 4.0 were identified on LG01/Chr01 and LG06/Chr06. Of them, the 2.17 Mb genomic region between qHRC-C6-1 and qHRC-C6-2 on ChrA06, with 65.62% PVE in total, was the major QTL region. In addition, the six QTLs have significant additive genetic effects on NR content and could be used to develop markers for marker-assisted selection (MAS) in TKS with a high NR content. CONCLUSION: This work constructed the first high-density TKS genetic map and identified the QTLs and genomic regions controlling the NR content, which provides useful information for fine mapping, map-based cloning, and MAS in TKS.


Assuntos
Locos de Características Quantitativas , Taraxacum , Borracha , Taraxacum/genética , Polimorfismo de Nucleotídeo Único , Melhoramento Vegetal , Fenótipo , Ligação Genética
4.
Environ Monit Assess ; 195(2): 348, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36719637

RESUMO

The present study focuses on the spread of rubber monoculture in the state of Tripura during past three decades (1990-2021) in the northeast region of India which is known for its rich biodiversity, shifting cultivation, and extensive forest dynamics. Earth observation (EO) data of seven time periods from Landsat missions (1990, 1995, 2000, 2004, and 2009) and Sentinel-2 (2016 and 2021) were the main source for mapping and were supplemented with MODIS-EVI temporal spectral profiles, GEDI-derived vegetation heights (2019), and Google Earth high-resolution historical images for additional cues to support discrimination, mapping, and accuracy assessment. The methodology for rubber used its unique phenology from spectral-temporal profile and multi-year comparison of patches and their dynamics for age-class mapping. The results indicate that in the state of Tripura (geographic area 1.08 Mha), the area under rubber increased from 0.3% in 1990 to 8.9% of the geographic area in 2021. The overall classification accuracy for the maps created for the years 1990, 1995, 2000, 2004, 2009, 2016, and 2021 was 84.2%, 83.9%, 84.8%, 88.0%, 86.0%, 86.7%, and 89.5%, respectively. New areas under rubber originated from various land cover classes including open forests, shifting cultivation lands, and scrub. Recent expansion has resulted in 84.3% of rubber plantations under the 10-year age class. Implications of this transformation of the natural landscape, biodiversity and biomass, and carbon pool assessment are discussed.


Assuntos
Monitoramento Ambiental , Borracha , Monitoramento Ambiental/métodos , Florestas , Biodiversidade , Índia
5.
Microbiol Res ; 268: 127290, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36571920

RESUMO

Colletotrichum siamense, a member of Colletotrichum gloeosporioides complex species, is the primary pathogen causing rubber anthracnose, which leads to significant economic loss in natural rubber production. Velvet family proteins are fungal-specific proteins and play an essential role in regulating development and secondary metabolism. In this study, we characterized two velvet proteins CsVosA and CsVelB in C. siamense as the orthologs of VosA and VelB in Aspergillus nidulans. CsVosA is located in the nucleus, and CsVelB displays a localization in both the nucleus and the cytoplasm. Deleting CsvosA or CsvelB results in a slow growth rate, and the CsvelB-knockout mutants also exhibit low mycelial density. CsVosA and CsVelB are involved in regulating chitin metabolism and distribution, leading to the variation in the cell wall integrity of C. siamense. Furthermore, disruption of CsvosA or CsvelB can decrease conidial production and viability, and the ΔCsvosA and ΔCsvelB mutants also lose the ability to produce fruiting bodies. Pathogenicity assays show that deleting CsvosA or CsvelB can lower the virulence, and the two velvet genes are essential for the full virulence of C. siamense. Based on the results of the yeast two-hybrid analysis and bimolecular fluorescence complementation assays, CsVosA can interact with CsVelB and form the complex CsVosA-CsVelB in the conidia of C. siamense, which may play essential roles in maintaining the cell wall integrity and conidial viability. In addition, CsVelB is also involved in regulating melanin production of C. siamense. In conclusion, CsVosA and CsVelB regulate vegetative growth, cell wall integrity, asexual/sexual sporulation, conidial viability and virulence in C. siamense.


Assuntos
Colletotrichum , Borracha , Virulência , Esporos Fúngicos , Borracha/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo
6.
Environ Res ; 216(Pt 3): 114775, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36370812

RESUMO

The current study emphasizes the activated carbon fabrication from rubber fig leaves, the establishment of its composite with iron oxide nanoparticles (RFAC@Fe2O3), and its relevance in the adsorptive elimination of tetracycline. The physical and functional properties of RFAC@Fe2O3 nanocomposite were uncovered by multiple approaches. Elemental analysis portrayed the existence of carbon, oxygen, and iron, while FESEM analysis revealed that Fe2O3 nanoparticle agglomerates were entrenched in the activated carbon matrix rendering it a rough abrasive texture. FT-IR analysis reported the presence of functional groups attributing to CC, -OH, crystalline iron oxide, and Fe-O stretching vibrations, and XRD corroborated graphitic crystalline structure, oxygenated functional groups attached to carbon accompanied by crystalline plane corresponding to Fe2O3 nanoparticles. XPS spectra depicted signature peaks for C, O, and Fe, while VSM studies designated its superparamagnetic nature. The high surface area (662.73 m2/g), pore size (3.12 nm), and mesoporous nature of RFAC@Fe2O3 make it apt for the adsorption of pollutants from contaminated samples. The adsorption of tetracycline (50 ppm) by RFAC@Fe2O3 was maximum at pH 4.0. As the nanocomposite dosage and stirring speed increased to 2.0 g/L and 150 rpm, maximum adsorption was observed due to more active binding sites and improved mixing. Freundlich isotherm along with pseudo-second-order model well described adsorption process divulging that tetracycline was adsorbed onto RFAC@Fe2O3 composite in multi-layers by chemisorption. Thermodynamic analysis signified negative values for ΔG°, while positive values for ΔH° and ΔS were obtained, indicating spontaneous feasible endothermic adsorption.


Assuntos
Ficus , Hevea , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Borracha , Árvores , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise , Cinética , Tetraciclina/química , Água , Termodinâmica , Antibacterianos/análise , Folhas de Planta , Fenômenos Magnéticos , Concentração de Íons de Hidrogênio
7.
Plant Physiol Biochem ; 194: 440-448, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36493591

RESUMO

Taraxacum kok-saghyz Rodin (Tk) is a promising alternative rubber-producing grass. However, low biomass and rubber-producing capability limit its commercial application. As a carbon source transporter in plants, sugar will eventually be exported transporters (SWEETs) have been reported to play pivotal roles in diverse physiological events in the context of carbon assimilate transport and utilization. Theoretically, SWEETs would participate in Tk growth, development and response to environmental cues with relation to the accumulation of rubber and biomass, both of which rely on the input of carbon assimilates. Here, we identified 22 TkSWEETs through homology searching of the Tk genomes and bioinformatics analyses. RNA-seq and qRT-PCR analysis revealed these TkSWEETs to have overlapping yet distinct tissue expression patterns. Two TkSWEET isofroms, TkSWEET1 and TkSWEET12 expressed substantially in the latex, the cytoplasm of rubber-producing laticifers as well as the rubber source. As revealed by the transient expression analysis using Tk mesophyll protoplasts, both TkSWEET1 and TkSWEET12 were located in the plasma membrane. Heterologous expressions of the two TkSWEETs in a yeast mutant revealed that only TkSWEET1 exhibited apparent sugar transport activities, with a preference for monosaccharides. Interestingly, TkSWEET12, the latex-predominant TkSWEET isoform, seemed to have evolved from a tandem duplication event that results in a cluster of six TkSWEET genes with the TkSWEET12 therein, suggesting its specialized roles in the laticifers.


Assuntos
Látex , Taraxacum , Borracha/metabolismo , Taraxacum/genética , Taraxacum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Membrana Transportadoras/genética , Saccharomyces cerevisiae/metabolismo , Isoformas de Proteínas/metabolismo , Açúcares/metabolismo , Regulação da Expressão Gênica de Plantas
8.
ACS Appl Mater Interfaces ; 15(1): 973-983, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36567465

RESUMO

An environmentally friendly triboelectric nanogenerator (TENG) is fabricated from a natural rubber (NR)-Ag nanocomposite for harvesting mechanical energy from human motions. Ag nanoparticles (AgNPs) synthesized with two different capping agents are added to NR polymer for improving dielectric constant that contributes to the enhancement of TENG performance. Dielectric constant is modulated via interfacial polarization between AgNPs and NR matrix. The effects of AgNP concentration, particle size and dispersion in NR composite, and type of capping agents on dielectric properties and electrical output of the NR composite TENG are elucidated. It is found that, apart from AgNPs content in the NR-Ag nanocomposite, cations of CTAB capping agent play important roles not only on the dispersion of AgNPs in NR matrix but also on intensifying tribopositive charges in the NR composite. In addition, the application of the NR-Ag TENG as a shoe insole is also demonstrated to convert human footsteps into electricity to power small electronic devices. Furthermore, with the presence of Ag nanoparticles, the fabricated shoe insole also exhibits antibacterial property against Staphylococcus aureus that causes foot odor.


Assuntos
Antígenos de Grupos Sanguíneos , Nanopartículas Metálicas , Nanocompostos , Humanos , Borracha , Prata , Eletricidade
9.
Chemosphere ; 313: 137523, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36509193

RESUMO

Tire wear particles are a notable source of tire microplastics (TMPs) in the environment. However, only a few reports have focused on the aquatic toxicity effects of composite TMPs and their additives and the mechanistic analysis at the microscopic level. Therefore, this paper study the toxic effects of tire microplastics and their additives on zebrafish based on theoretical chemical calculation method (Taguchi orthogonal experiment method, full factorial experimental design, molecular docking, and molecular dynamics computational technique). We designed five kinds of proportioning schemes of tire rubber polymers and additive components (64 groups in each). The compound toxicity effects of the tire rubber polymers and their additives on zebrafish were simulated and calculated. The simulation results indicated styrene butadiene rubber had the most significant toxic effect on zebrafish. Subsequently, taking the composition ratio scheme of styrene butadiene rubber with the lowest biotoxicity effect as an example, we analyzed the main effects, second-order interactions, and third-order interactions of styrene butadiene rubber polymer and its additive combination in terms of biotoxicity using the fixed effects model. The toxic effects (developmental toxicity, neurotoxicity, and reproductive toxicity) of styrene butadiene rubber on marine and freshwater organisms could be drastically alleviated by adjusting the ratio of rubber additives. The analysis of the interaction between amino acid residues and non-bonds during the docking process of styrene butadiene rubber and toxic receptors revealed the interaction mechanisms between the styrene butadiene rubber polymer and its additives and between the additive molecules. Hydrophobic interaction was found to be the key factor for the binding of styrene butadiene rubber additives to nonpolar amino acids in the receptor proteins. Our findings are expected to provide theoretical support for identifying and regulating the toxicity characteristics of rubber TMPs and to aid in proposing a strategy to alleviate the toxic effects on aquatic organisms.


Assuntos
Plásticos , Borracha , Animais , Microplásticos/química , Peixe-Zebra , Butadienos/toxicidade , Organismos Aquáticos , Simulação de Acoplamento Molecular , Estirenos , Polímeros , Água Doce
10.
Environ Pollut ; 319: 120951, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36581238

RESUMO

Bioplastics are promoted as safer alternatives to tackle the long-term persistence of conventional plastics. However, information on the potential release of additives and non-intentionally added substances (NIAS) in the surrounding environment is limited, and biological effects of the leachates have been little studied. Leachates produced from three bioplastics, i.e. compostable bags (CB), bio-polyethylene terephthalate bottles (bioPET) and polylactic acid cups (PLA), and a control polymeric material, i.e. rubber tire (TR), were examined. The chemical nature of bioplastic polyesters PET, PLA and poly (butylene adipate-co-terephthalate) (PBAT) in CB, was confirmed by analytical pyrolysis. Fragments were incubated in artificial sea water for 14 days at 20 °C in darkness and leachate contents examined by GC-MS and HPLC-MS/MS. Catalysts and stabilizers represented the majority of chemicals in TR, while NIAS (e.g. 1,6-dioxacyclododecane-7,12-dione) were the main components of CB. Bisphenol A occurred in all leachates at a concentration range 0.3-4.8 µg/L. Trace metals at concentrations higher than control water were found in all leachates, albeit more represented in leachates from CB and TR. A dose response to 11 dilutions of leachates (in the range 0.6-100%) was tested for biological effects on early embryo stages of Mytilus galloprovincialis. Embryotoxicity was observed in the whole range of tested concentrations, the magnitude of effect depending on the polymers. The highest concentrations caused reduction of egg fertilization (CB, bioPET, TR) and of larvae motility (CB, PLA, TR). TR leachates also provoked larvae mortality in the range 10-100%. Effects on adult mussel physiology were evaluated after a 7-day in vivo exposure to the different leachates at 0.6% concentration. Nine biomarkers concerning lysosomal functionality, neurotransmission, antioxidant and immune responses were assessed. All lysosomal parameters were affected, and serum lysozyme activity inhibited. Harmonized chemical and biological approaches are recommended to assess bioplastic safety and support production of sustainable bioplastics.


Assuntos
Mytilus , Espectrometria de Massas em Tandem , Animais , Larva , Plásticos/toxicidade , Poliésteres/toxicidade , Borracha , Polímeros/toxicidade , Mytilus/fisiologia
11.
Water Res ; 229: 119480, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36528929

RESUMO

Polyethylene (PE) pipes are often the material of choice for water supply systems, thanks to their favorable properties, such as high strength-density ratio and corrosion resistance. However, previous studies have shown that organic compounds can migrate from PE pipes to the water. This study aimed to identify potential organic compounds migrating from high-density PE (HDPE) pipes used to distribute drinking water in Denmark, based on laboratory experiments and sampling in the distribution system using a two-tiered study design. In the first tier, migration of volatile and semi-volatile organic compounds (VOCs and semi-VOCs) from HDPE pipes were investigated over one, three, and nine days in laboratory experiments, performed according to modified standards for migration testing (EN 12,873-1). The analytical workflow consisted of solid-phase extraction (SPE) for 10,000 times enrichment and gas chromatography - mass spectrometry (GC-MS) analysis from the water phase after migration. A total of 133 compounds originating from the PE pipes were detected. Thirty-one compounds were detected by suspect screening (SS), while the remaining 102 compounds were detected by non-target screening (NTS) analysis. Among the detected compounds were also hindered amine stabilizers (HALS), flame retardant, and plasticizer tris(2-chloroethyl) phosphate. In the second tier, drinking water from a water distribution system in Copenhagen, Denmark, with a newly installed HDPE pipe was sampled and analyzed with GC-MS and liquid chromatography high-resolution mass spectrometry (LCHRMS). A total of 51 compounds were detected in the water, 12 of which were assigned to migration from HDPE. Surprisingly, HDPE antioxidants and their degradation products contributed only a relatively small percentage of the total measured compound intensities in the drinking water distribution system. Instead, a larger proportion of the compounds detected were assigned to rubber seals, used upstream in the water system from the abstraction site to delivery at the consumer tap. Seals are considered trifle in the larger picture of materials in contact with drinking water, however these results may cause a reconsideration of this position.


Assuntos
Água Potável , Compostos Orgânicos Voláteis , Poluentes Químicos da Água , Água Potável/química , Abastecimento de Água , Polietileno/análise , Borracha , Compostos Orgânicos Voláteis/análise , Poluentes Químicos da Água/análise
12.
Water Sci Technol ; 86(11): 2808-2819, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36515190

RESUMO

Rubber processing generates a large volume of wastewater containing rubber latex residues and chemicals. Remediation of the wastewater needs a cost-effective and environment-friendly treatment method. For this study, Moringa oleifera stem bark and Pseudomonas sp. bacteria were used for adsorption and microbial treatment of the effluent. The adsorbent surface was mostly amorphous with crystallinity index 37.9% and the BET surface area was 6.622 m2/g. FTIR analysis indicated involvement of O-H stretching, ketone α, ß-unsaturated, C-H stretching, carboxylic acid and derivatives O-C stretching functional groups in the adsorption process. The assessment of the above two agents was based on their reduction capabilities of the toxic parameters, such as total suspended and dissolved solids, total solids, biological and chemical oxygen demand, sulphate, ammonium, dissolved oxygen, phosphate, pH, electrical conductivity, turbidity, and oxidation reduction potential from the wastewater. A comparative study of the present work revealed that both the agents were effective in reduction of most of the above parameters below the safe discharge limits. However, the adsorption using Moringa oleifera stem bark was better compared to the biodegradation by Pseudomonas sp. bacteria. The main challenges that typically accompany biodegradation include microbe handling and a lower removal percentage than adsorption.


Assuntos
Moringa oleifera , Moringa oleifera/química , Borracha , Casca de Planta , Pseudomonas , Adsorção
13.
Sci Rep ; 12(1): 22633, 2022 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-36587183

RESUMO

This research aims to enhance the mechanical characteristics of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by using epoxidized natural rubber (ENR-25 and ENR-50) as a toughening agent and polybutadiene (PB) grafted with maleic anhydride (MA) (3 MA groups/chain) as a compatibilizer. The PHBV/ENR blends were mixed in 100/0, 90/10, 80/20, and 70/30 with PB-g-MA at 0, 5, and 10% (wt./wt.), using an internal mixer set to 175 °C with a rotor speed of 50 rpm. The findings indicated that at 70/30 PHBV/ENR composition, the impact strength of the blends with 25 and 50 epoxide contents were the greatest at 6.92 ± 0.35 J m-1 and 7.33 ± 1.19 J m-1, respectively, which are about two times greater than that of neat PHBV. Furthermore, the biodegradability of the PHBV/ENR blends was more substantial than that of neat PHBV, showing a mass reduction of approximately 40% and 45% for PHBV/ENR-25 and PHBV/ENR-50, respectively. In comparison, while the mass loss of PHBV was approximately 37% after three months of soil burial. The results indicate that ENR improves the toughness of the blends while simultaneously increasing PHBV degradation, which could pave the way for broadening PHBV for sustainability purposes.


Assuntos
Poliésteres , Borracha , Anidridos Maleicos
14.
Sci Rep ; 12(1): 21426, 2022 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-36504116

RESUMO

Nanofibrous mats provide substantial delamination hindering in composite laminates, especially if the polymer (as rubbers) can directly toughen the composite resin. Here, the well-known Nylon 66 nanofibers were impregnated with Nitrile Butadiene Rubber (NBR) for producing rubber/thermoplastic membranes for hampering the delamination of epoxy Carbon Fiber Reinforced Polymers (CFRPs). The starting polyamide mats were electrospun using two different solvent systems, and their effect on the mat's thermal and mechanical properties was investigated, as well as the laminate Mode I delamination resistance via Double Cantilever Beam (DCB) tests. Plain Nylon 66 mats electrospun from formic acid/chloroform perform better than the ones obtained from a solvent system containing trifluoroacetic acid, showing up to + 64% vs + 53% in interlaminar fracture toughness (GI), respectively. The effect of NBR coating benefits both nanofiber types, significantly raising the GI. The best results are obtained when interleaving medium-thickness and lightweight mats (20 µm, 9-10 g/m2) with 70-80 wt% of loaded rubber, achieving up to + 180% in GI. The work demonstrates the ability of NBR at improving the delamination hindering of common polyamide nonwovens, paving the way to the use of NBR-coated Nylon 66 nanofibers as effective interleaves for GI enhancement and overall composite safety improvement.


Assuntos
Fraturas Ósseas , Nanofibras , Humanos , Borracha , Nylons , Fibra de Carbono , Polímeros , Nitrilas , Solventes
15.
BMC Ecol Evol ; 22(1): 144, 2022 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-36517771

RESUMO

BACKGROUND: In the last decades, Southeast Asia has experienced massive conversion of rainforest into rubber and oil palm monoculture plantations. The effects of this land-use change on canopy arthropods are still largely unknown. Arboreal Collembola are among the most abundant canopy arthropods in tropical forests, potentially forming a major component of the canopy food web by contributing to the decomposition of arboreal litter and being an important prey for canopy arthropod predators. We investigated abundance, richness, and community composition of, as well as the influence of a series of environmental factors on, canopy Collembola communities in four land-use systems in Jambi Province, Sumatra, Indonesia: (1) lowland rainforest, (2) jungle rubber (rubber agroforest), and monoculture plantations of (3) rubber and (4) oil palm. RESULTS: Using canopy fogging in 32 research plots in both the dry and rainy seasons in 2013, we collected 77,104 specimens belonging to 68 (morpho) species. Generally, Collembola communities were dominated by few species including two species of the genus Salina (Paronellidae; 34% of total individuals) and two species of Lepidocyrtinae (Entomobryidae; 20%). The abundance of Collembola in lowland rainforest (53.4 ± 30.7 ind. m-2) was more than five times higher than in rubber plantations, and more than ten times higher than in oil palm plantations; abundances in jungle rubber were intermediate. Collembola species richness was highest in rainforest (18.06 ± 3.60 species) and jungle rubber (16.88 ± 2.33 species), more than twice that in rubber or oil palm. Collembola community composition was similar in rainforest and jungle rubber, but different from monoculture plantations which had similar Collembola community composition to each other. The environmental factors governing community composition differed between the land-use systems and varied between seasons. CONCLUSIONS: Overall, this is the first in-depth report on the structure of arboreal Collembola communities in lowland rainforest and agricultural replacement systems in Southeast Asia. The results highlight the potentially major consequences of land-use change for the functioning of arboreal arthropod food webs.


Assuntos
Artrópodes , Floresta Úmida , Humanos , Animais , Borracha , Árvores , Agricultura
16.
Sensors (Basel) ; 22(24)2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36560321

RESUMO

Biomedical receptors such as cutaneous receptors or intelligent cells with tactile, auditory, gustatory, and olfactory sensations function in the five senses of the human body. Investigations focusing on the configuration of such receptors are useful in the fields of robotics and sensors in the food industry, among others, which involve artificial organs or sensory machines. In the present study, we aimed to produce the receptors for four senses (excepting vision) by morphologically mimicking virtual human ones. The mimicked receptors were categorized into eight types of configured structure. Our proposed magnetic-responsive hybrid fluid (HF) in elastic and soft rubber and proposed electrolytic polymerization technique gave the solidified HF rubber electric characteristics of piezoelectricity and piezo-capacity, among others. On the basis of these electric characteristics, the mimicked receptors were configured in various types of electric circuits. Through experimental estimation of mechanical force, vibration, thermal, auditory, gustatory, and olfactory responses of each receptor, the optimum function of each was specified by comparison with the actual sensations of the receptors. The effect of hairs fabricated in the receptors was also clarified to viably reproduce the distinctive functions of these sensations.


Assuntos
Borracha , Tato , Humanos , Tato/fisiologia , Pele , Olfato , Eletricidade
17.
PLoS One ; 17(12): e0277749, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36520800

RESUMO

Molecular biodiversity surveys have been increasingly applied in hyperdiverse tropical regions as an efficient tool for rapid species assessment of partially undiscovered fauna and flora. This is done by overcoming shortfalls in knowledge or availability of reproductive structures during the sampling period, which often represents a bottleneck for accurate specimens' identification. DNA sequencing technology is intensifying species discovery, and in combination with morphological identification, has been filling gaps in taxonomic knowledge and facilitating species inventories of tropical ecosystems. This study aimed to apply morphological taxonomy and DNA barcoding to assess the occurrence of Lamiaceae species in converted land-use systems (old-growth forest, jungle rubber, rubber, and oil palm) in Sumatra, Indonesia. In this species inventory, we detected 89 specimens of Lamiaceae from 18 species distributed in seven subfamilies from the Lamiaceae group. One third of the species identified in this study lacked sequences in the reference database for at least one of the markers used (matK, rbcL, and ITS). The three loci species-tree recovered a total of 12 out of the 18 species as monophyletic lineages and can be employed as a suitable approach for molecular species assignment in Lamiaceae. However, for taxa with a low level of interspecific genetic distance in the barcode regions used in this study, such as Vitex gamosepala Griff. and V. vestita Wall. ex Walp., or Callicarpa pentandra Roxb. and C. candidans (Burm.f.) Hochr., the use of traditional taxonomy remains indispensable. A change in species composition and decline in abundance is associated with an increase in land-use intensification at the family level (i.e., Lamiaceae), and this tendency might be constant across other plant families. For this reason, the maintenance of forest genetic resources needs to be considered for sustainable agricultural production, especially in hyperdiverse tropical regions. Additionally, with this change in species composition, accurate species identification throughout molecular assignments will become more important for conservation planning.


Assuntos
Ecossistema , Lamiaceae , Indonésia , Borracha , Lamiaceae/genética , Árvores/genética , Código de Barras de DNA Taxonômico
18.
West Afr J Med ; 39(12): 1294-1298, 2022 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-36583928

RESUMO

BACKGROUND: Chronic manifestations of bancrofti filariasis can be debilitating. There is paucity of description of this disease in the childhood population, yet early detection can prevent disability such as elephantiasis. OBJECTIVE: The objective of the study was to determine the prevalence and clinical features of this infection among children in a plantation estate in Cross River State, Nigeria. METHODS: It was a cross-sectional study in subjects aged 1 to 18 years, recruited from the nine camps of the settlement, using multistage sampling technique. The presence of Circulating Filarial Antigen (CFA) was tested for using Immunochromatographic Card Technique (ICT). Simple proportions, percentages, Chi square and Fisher's exact tests were used to analyse the data. RESULTS: A total of 342 subjects were recruited into the study. One hundred and sixty three (47.7%) were males. The mean age was 8.52± 4.41years. Majority of the subjects, 316(92.4%), were from families of low socioeconomic status. Twenty of the 342 children (5.8%) were positive for microfilaria antigenaemia. Increasing age (p=0.006) and duration of stay in the estate (p=0.005) were positively associated with antigenaemia. None (0%) of the 55 subjects who used insecticide treated nets was positive for CFA, while 20 (6.97%) of the 287 who did not, were positive (p=0.03). Only ten (3.95%) of the 253 subjects who used insecticide spray vs 10 (11.0%) of the 89 who did not use spray were positive for CFA (p=0.016). Itching was the only significant symptom identified. CONCLUSION: The prevalence of Wuchereria bancrofti in the subjects was 5.8%, with increasing prevalence with age. Itching was the only significant clinical feature. The use of insecticide treated nets and insecticide sprays significantly reduced the chances of being infected. There is a need for elimination programme to be extended to the childhood population and to sub-urban areas.


CONTEXTE: Les manifestations chroniques de la filariose de bancrofti peuvent être débilitantes. Il existe peu de descriptions de cette maladie dans la population infantile, mais une détection précoce peut prévenir des handicaps tels que l'éléphantiasis. OBJECTIF: L'objectif de l'étude était de déterminer la prévalence et caractéristiques cliniques de cette infection chez les enfants d'une plantation dans l'État de Cross River, au Nigéria. METHODES: Il s'agissait d'une étude transversale chez des sujets âgés de 1 à 18 ans, recrutés dans les neuf camps de la colonie, en utilisant la technique d'échantillonnage à plusieurs degrés. La présence d'antigène filarien circulant (CFA) a été testée à l'aide de la technique de carte immunochromatographique (ICT). Des proportions simples, des pourcentages, le Chi carré et des tests exacts de Fisher ont été utilisés pour analyser les données. RESULTATS: Un total de 342 sujets ont été recrutés dans l'étude. Cent soixante trois (47,7 %) étaient des hommes. L'âge moyen était de 8,52 ± 4,41 ans. La majorité des sujets, 316 (92,4 %), provenaient de familles de faible statut socio-économique. Vingt des 342 enfants (5,8 %) étaient positifs pour l'antigénémie des microfilaires. L'augmentation de l'âge (p = 0,006) et de la durée de séjour dans le domaine (p = 0,005) était positivement associée à l'antigénémie. Aucun (0%) des 55 sujets qui ont utilisé des moustiquaires imprégnées d'insecticide n'était positif pour le CFA, tandis que 20 (6,97%) des 287 qui n'en avaient pas étaient positifs (p=0,03). Seuls dix (3,95 %) des 253 sujets qui ont utilisé un insecticide contre 10 (11,0 %) des 89 qui n'ont pas utilisé de spray étaient positifs pour le CFA (p = 0,016). Les démangeaisons étaient le seul symptôme significatif identifié. CONCLUSION: La prévalence de Wuchereria bancrofti chez les sujets était de 5,8 %, avec une prévalence croissante avec l'âge. Les démangeaisons étaient la seule caractéristique clinique significative. L'utilisation de moustiquaires imprégnées d'insecticide et de pulvérisations d'insecticide a considérablement réduit les risques d'infection. Il est nécessaire d'étendre le programme d'élimination à la population infantile et aux zones suburbaines. Mots clés: Filariose de Bancrofti, Enfants, Zone d'Endémie.


Assuntos
Filariose Linfática , Inseticidas , Masculino , Animais , Humanos , Criança , Pré-Escolar , Adolescente , Feminino , Wuchereria bancrofti , Filariose Linfática/tratamento farmacológico , Filariose Linfática/epidemiologia , Filariose Linfática/prevenção & controle , Borracha/uso terapêutico , Inseticidas/uso terapêutico , Nigéria/epidemiologia , Estudos Transversais , Antígenos de Helmintos/uso terapêutico , Prevalência
19.
Artigo em Inglês | MEDLINE | ID: mdl-36360951

RESUMO

Accurate monitoring of forest carbon flux and its long-term response to meteorological factors is important. To accomplish this task, the model parameters need to be optimized with respect to in situ observations. In the present study, the extended Fourier amplitude sensitivity test (eFAST) method was used to optimize the sensitive ecophysiological parameters of the Biome BioGeochemical Cycles model. The model simulation was integrated from 2010 to 2020. The results showed that using the eFAST method quantitatively improved the model output. For instance, the R2 increased from 0.53 to 0.72. Moreover, the root-mean-square error was reduced from 1.62 to 1.14 gC·m-2·d-1. In addition, it was reported that the carbon flux outputs of the model were highly sensitive to various parameters, such as the canopy average specific leaf area and canopy light extinction coefficient. Moreover, long-term meteorological factor analysis showed that rainfall dominated the trend of gross primary production (GPP) of the study area, while extreme temperatures restricted the GPP. In conclusion, the eFAST method can be used in future studies. Furthermore, eFAST could be applied to other biomes in response to different climatic conditions.


Assuntos
Ecossistema , Borracha , Florestas , China , Ciclo do Carbono , Carbono/análise
20.
Int J Occup Saf Ergon ; 28(4): 2668-2675, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36337028

RESUMO

This work aimed to study the end of service life of soles of protective footwear resistant to selected mechanical factors and mineral oil. Three sole variants were examined; made from poly(ethylene-co-vinyl acetate) (EVA), poly(vinyl chloride) (PVC) and polyurethane (PU), currently widely used in all-rubber protective footwear. The preliminary study focused on the abrasion resistance and bending strength of the three sole materials after different times of exposure to mineral oil. Changes in density and hardness of the examined materials were evaluated following exposure to cyclical factors. Statistical analysis was performed to identify significant differences between the three types of polymers in terms of abrasion resistance, density and hardness following exposure to mineral oil for three different periods. Surface morphology of the sole materials was examined by means of scanning electron microscopy. The presented studies elucidate the effects of mineral oil on the basic mechanical parameters of all-rubber footwear soles.


Assuntos
Óleo Mineral , Sapatos , Humanos , Borracha , Poliuretanos , Dureza
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