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1.
Am J Bot ; 111(6): e16355, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38831659

RESUMO

PREMISE: Theories of plant-herbivore interactions hold that seedlings are more vulnerable to herbivory in warmer and more stable climates at lower elevations. Hypotheses of plant apparency, resource concentration, and resource availability have been proposed to explain variability in leaf herbivory. However, seasonal differences in the effects of these hypotheses on leaf herbivory on seedlings remain unclear. METHODS: We evaluated the three herbivory hypotheses by comparing the percentage and frequency of leaf herbivory in understory broadleaf seedlings in a subtropical forest in May (spring) and October (autumn) along an elevational gradient (290-1370 m a.s.l.). In total, we measured 2890 leaves across 696 seedlings belonging to 95 species and used beta regressions to test the effects of plant apparency (e.g., leaf area, seedling height), resource concentration (e.g., plant species diversity), and resource availability (e.g., canopy openness, soil available N and P) on leaf herbivory. RESULTS: Seedlings exhibited unimodal patterns of leaf herbivory along elevation, with drivers of leaf herbivory varying by the month. Variation in the frequency of leaf herbivory was best explained by the resource concentration hypothesis (e.g., plant species diversity) in both months, and herbivory was lower on seedlings in sites with higher plant diversity. Plant apparency hypothesis (e.g., leaf area, seedling height) was weakly supported only in spring, and the evidence for resource availability hypothesis (e.g., canopy openness, soil nutrients) was mixed. CONCLUSIONS: This study supports the resource concentration hypothesis and reveals the importance of seasonal difference on understanding leaf herbivory patterns and the drivers of plant diversity in subtropical forests.


Assuntos
Herbivoria , Insetos , Folhas de Planta , Plântula , Plântula/fisiologia , Animais , Insetos/fisiologia , Folhas de Planta/fisiologia , Estações do Ano , Altitude , Florestas
2.
Theor Appl Genet ; 135(6): 1909-1921, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35357526

RESUMO

KEY MESSAGES: Genetic analysis revealed that CmCLV3 is a candidate gene for the variation in melon carpel number. Carpel number (CN) is an important trait in melon. Three-CN melon fruit is oval, while 5-CN melon fruit has a round or flat shape. Herein, a genetic analysis of a population in which the CN locus was segregated indicated that 3-CN is controlled by a major dominant effective gene. Bulked segregant analysis and initial linkage mapping placed the CN locus in a 6.67 Mb region on chromosome 12, and it was narrowed to 882.19 kb with molecular markers and recombinant plants. Fine mapping with a large F2 population containing 1026 individuals further narrowed the locus to an 83.98 kb region harboring five annotated genes. Gene structure alignment between the parental lines revealed MELO3C035640.2 (annotated as CLAVATA3, CmCLV3) as the best candidate gene for the CN trait. CmCLV3 was more highly expressed in 3- than 5-CN lines and specifically expressed in terminal buds rather than in young leaves, hypocotyls, and roots. The CmCLV3 coding region was cloned from eight 3- or 5-CN melon accessions, and a nonsynonymous SNP site was highly correlated with CN variation. This SNP site was also related to CN variations among 40 melon lines according to their resequencing data, causing a helix alteration in the CmCLV3 protein. Promoter region sequence alignment and activity analysis showed that, unlike in cucumber and tomato, CmCLV3 promoter variation and activity were not the main reasons for CN alteration. Overall, this study provides a genetic resource for melon fruit development research and molecular breeding tools for melon CN improvement.


Assuntos
Cucumis melo , Genes de Plantas , Mapeamento Cromossômico , Cucumis melo/genética , Cucumis sativus/genética , Análise de Sequência de DNA
3.
Sensors (Basel) ; 18(10)2018 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-30360444

RESUMO

This paper presents a novel sensing mode for using mobile robots to collect disaster ground information when the ground traffic from the rescue center to disaster site is disrupted. Traditional sensing modes which use aerial robots or ground robots independently either have limited ability to access disaster site or are only able to provide a bird's eye view of the disaster site. To illustrate the proposed sensing mode, the authors have developed a Multi-robot System with Air Dispersal Mode (MSADM) by combining the unimpeded path of aerial robots with the detailed view of ground robots. In the MSADM, an airplane carries some minimal reconnaissance ground robots to overcome the paralyzed traffic problem and deploys them on the ground to collect detailed scene information using parachutes and separation device modules. In addition, the airplane cruises in the sky and relays the control and reported information between the ground robots and the human operator. This means that the proposed sensing mode is able to provide more reliable communication performance when there are obstacles between the human operators and the ground robots. Additionally, the proposed sensing mode can easily make use of different kinds of ground robots, as long as they have a compatible interface with the separation device. Finally, an experimental demonstration of the MSADM is presented to show the effectiveness of the proposed sensing mode.

4.
Sensors (Basel) ; 17(10)2017 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-29065560

RESUMO

This paper introduces a search-and-rescue robot system used for remote sensing of the underground coal mine environment, which is composed of an operating control unit and two mobile robots with explosion-proof and waterproof function. This robot system is designed to observe and collect information of the coal mine environment through remote control. Thus, this system can be regarded as a multifunction sensor, which realizes remote sensing. When the robot system detects danger, it will send out signals to warn rescuers to keep away. The robot consists of two gas sensors, two cameras, a two-way audio, a 1 km-long fiber-optic cable for communication and a mechanical explosion-proof manipulator. Especially, the manipulator is a novel explosion-proof manipulator for cleaning obstacles, which has 3-degree-of-freedom, but is driven by two motors. Furthermore, the two robots can communicate in series for 2 km with the operating control unit. The development of the robot system may provide a reference for developing future search-and-rescue systems.

5.
Sci Total Environ ; 946: 174103, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-38908603

RESUMO

To fulfill the industrial requirements of salt fractionation and recovery from saline wastewater, a two-chamber selective electrodialysis (SED) stack incorporating commercial monovalent selective anion exchange membranes was employed and investigated in this study. Three different initial concentration ratios of NaCl/Na2SO4, namely 1:1 (10 g/L:10 g/L), 3:1 (30 g/L:10 g/L), and 5:1 (50 g/L:10 g/L) were examined to simulate various scenarios of saline wastewater. The influence of applied current density on membrane selectivity and overall system efficiency was further evaluated. The results indicated that an increase in the NaCl fraction within the feed solution directly correlates with enhanced concentration and purity of Na2SO4 in the product, achieving purities exceeding 92 %. A lower current density contributed to improved concentration and purity of Na2SO4, whereas higher current densities were conducive to augmenting the concentration and purity of NaCl. Additionally, a linear correlation was observed between the volumetric water transport and NaCl migration. Through numerical simulations, the concentrations of Na2SO4 and NaCl in the effluent were predicted, facilitating a comparative analysis with the salt fractionation efficiency of commercial nanofiltration membranes. Subsequent assessments of energy consumption and current efficiency revealed that the SED system ensured high product concentration and purity at reasonably low energy consumption (0.22-0.28 kWh per kg NaCl) alongside a high current efficiency (83-89 %). These findings offer critical insights into the optimization of salt fractionation process and highlight its economic and technical feasibility for the sustainable management of industrial saline wastewater.

6.
Front Microbiol ; 15: 1364339, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38559355

RESUMO

Introduction: Matrine (MT) is a potential resistance reversal agent. However, it remains unclear whether MT can reverse the resistance of Haemophilus parasuis (H. parasuis) to ß-lactams, and, if so, by what mechanism MT works. Methods: We screened one cefaclor (CEC)-resistant strain (clinical strain C7) from eight clinical (H. parasuis) strains and determined the underlying resistance mechanism. Then, we investigated the reversal effect of MTon the resistance of this strain to CEC. Results and Discussion: The production of ß-lactamase, overexpression of AcrAB-TolC system, and formation of biofilm might not be responsible for the resistance of clinical strain C7 to CEC. Fourteen mutation sites were found in four PBP genes (ftsI, pbp1B, mrcA, and prcS) of clinical strain C7, among which the mutation sites located in ftsI (Y103D and L517R) and mrcA (A639V) genes triggered the resistance to CEC. The minimum inhibitory concentration (MIC) of CEC against clinical strain C7 was reduced by two to eight folds after MT treatment, accompanied by the significant down-regulated expression of mutated ftsI and mrcA genes. Based on such results, we believed that MT could reverse the resistance of H. parasuis to CEC by inhibiting the mutations in ftsI and mrcA genes. Our research would provide useful information for restoring the antimicrobial activity of ß-lactams and improving the therapeutic efficacy of Glässer's disease.

7.
Sci Rep ; 12(1): 13558, 2022 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-35945423

RESUMO

The rigid-flexible coupling cable system under large deformation is studied, and the beam element from absolute node coordinate formulation is used to establish flexible cable body of the system. Different numerical integral algorithms are discussed for solving the rigid-flexible cable system and an integration strategy which combines Implicit Euler with Minimum Residual Method (MINRES) is proposed. The influence of the position and number of rigid components and different the lengths of the flexible elements on the system dynamics are analyzed. With constant total mass of the system, higher number of rigid components and their uniform distribution contribute to stabilization of the swing of the flexible cable body. When the total length of the cable is constant, increasing the number of beam elements enhances the nonlinear characteristics of the swing motion and damages the stability. The influence of different factors on the movement of large deformation flexible cable body is obtained through modeling and simulation of the rigid-flexible coupling cable system.

8.
Micromachines (Basel) ; 13(12)2022 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-36557437

RESUMO

During the test of microelectromechanical system (MEMS) devices, calibration of test cables, loads and test instruments is an indispensable step. Calibration kits with high accuracy, great operability and small loss can reduce the systematic errors in the test process to the greatest extent and improve the measurement accuracy. Aiming at the issues of the conventional discrete calibration piece unit, which presents cumbersome calibration steps and large system loss, an integrated electronic calibration chip based on frequency microelectromechanical system (RF MEMS) switches is designed and fabricated. The short-open-load-through (SOLT) calibration states can be completed on a single chip, step by step, by adjusting the on-off state of the RF MEMS switches. The simulation results show that the operating frequency of the electronic calibration piece covers the range of DC~26.5 GHz, the insertion loss in through (thru) state is less than 0.2 dB, the return loss is less than 1.0 dB in short-circuit and open-circuit states, the return loss under load-circuit state is less than 20 dB and its size is only 2.748 mm × 2.2 mm × 0.5 mm. This novel calibration chip design has certain esteem for advancing calibration exactness and effectiveness.

9.
Front Plant Sci ; 13: 828287, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35463445

RESUMO

The melon fruit surface groove (fsg) not only affects peel structure and causes stress-induced fruit cracking but also fits consumers' requirements in different regions. In this study, genetic inheritance analysis of three F2 populations derived from six parental lines revealed that the fsg trait is controlled by a simple recessive inherited gene. Through bulked segregant analysis sequencing (BSA-seq), the Cmfsg locus was detected in an 8.96 Mb interval on chromosome 11 and then initially mapped to a region of approximately 1.15 Mb. Further fine mapping with a large F2 population including 1,200 plants narrowed this region to 207 kb containing 11 genes. A genome-wide association study (GWAS) with 187 melon accessions also produced the same chromosome region for the Cmfsg locus. Due to the rare molecular markers and lack of mutations in the coding and promoter regions of the 11 candidate genes in the fine-mapped interval, we conducted in silico BSA to explore the natural melon panel to predict candidate genes for the Cmfsg locus. A 1.07 kb segment upstream of MELO3C019694.2 (annotated as the AGAMOUS MADS-box transcription factor) exhibited a correlation with the grooved and non-grooved accessions among the F2 individuals, and a natural panel consisted of 17 melon accessions. The expression level of MELO3C019694.2 in the pericarp was higher in grooved lines than in non-grooved lines and was specifically expressed in fruit compared with other tissues (female flower, male flower, root, and leaf). This work provides fundamental information for further research on melon fsg trait formation and molecular markers for melon breeding.

10.
Int J Biol Macromol ; 187: 272-280, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34303739

RESUMO

The aim of this study was to explore the indirect immunomodulatory activities and its mechanism of enzymatic hydrolysis of Hericium erinaceus polysaccharides (EHEP) in the MODE-K/DCs co-culture model. According to the TEER value, transmission of phenol red and AKP activity of MODE-K cells, single model was established in order to evaluate the eligibility of MODE-K cells monolayer. Then the MODE-K/DCs co-culture model was set up and HEP and EHEP were added into the apical chamber, DCs were obtained for the expression of key surface markers, the ability of phagocytosis, the morphology, the secretion of cytokines and the production of target proteins. We found that after 21 d of culture, the MODE-K cells monolayer became intact and dense, which can be used for the MODE-K/DCs co-culture model. Under the treatment of HEP and EHEP, immature DCs become into mature DCs with the high expression of CD86 and MHCII, the low antigens up-taking, the typical morphology, the more content of IL-12 and TNF-α and the high level of TLR4, MyD88 and NF-κB proteins. However, compared with HEP, EHEP showed the better immunomodulatory activities. These findings indicated that EHEP could indirectly affect the immune function of DCs in the MODE-K/DCs co-culture model.


Assuntos
Células Dendríticas/efeitos dos fármacos , Polissacarídeos Fúngicos/farmacologia , Hericium/metabolismo , Agentes de Imunomodulação/farmacologia , Animais , Antígeno B7-2/metabolismo , Células Cultivadas , Técnicas de Cocultura , Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Impedância Elétrica , Enzimas/metabolismo , Células Epiteliais/metabolismo , Polissacarídeos Fúngicos/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Hidrólise , Agentes de Imunomodulação/metabolismo , Masculino , Camundongos Endogâmicos ICR , Fagocitose/efeitos dos fármacos
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