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Low-grade wind with airspeed Vwind < 5 m/s, while distributed far more abundantly, is still challenging to extract because current turbine-based technologies require particular geography (e.g., wide-open land or off-shore regions) with year-round Vwind > 5 m/s to effectively rotate the blades. Here, we report that low-speed airflow can sensitively enable directional flow within nanowire-anchored ionic liquid (IL) drops. Specifically, wind-induced air/liquid friction continuously raises directional leeward fluid transport in the upper portion, whereas three-phase contact line (TCL) pinning blocks further movement of IL. To remove excessive accumulation of IL near TCL, fluid dives, and headwind flow forms in the lower portion, as confirmed by microscope observation. Such stratified circulating flow within single drop can generate voltage output up to ~0.84 V, which we further scale up to ~60 V using drop "wind farms". Our results demonstrate a technology to tap the widespread low-grade wind as a reliable energy resource.
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Moso bamboo (Phyllostachys edulis) shows remarkably rapid growth (114.5 cm/day), but the underlying biological mechanisms remain unclear. After examining more than 12,750 internodes from more than 510 culms from 17 Moso populations, we identified internode 18 as a representative internode for rapid growth. This internode includes a 2-cm cell division zone (DZ), a cell elongation zone up to 12 cm, and a secondary cell wall (SCW) thickening zone. These zones elongated 11.8 cm, produced approximately 570,000,000 cells, and deposited â¼28 mg g-1 dry weight (DW) lignin and â¼44 mg g-1 DW cellulose daily, far exceeding vegetative growth observed in other plants. We used anatomical, mathematical, physiological, and genomic data to characterize development and transcriptional networks during rapid growth in internode 18. Our results suggest that (1) gibberellin may directly trigger the rapid growth of Moso shoots, (2) decreased cytokinin and increased auxin accumulation may trigger cell DZ elongation, and (3) abscisic acid and mechanical pressure may stimulate rapid SCW thickening via MYB83L. We conclude that internode length involves a possible tradeoff mediated by mechanical pressure caused by rapid growth, possibly influenced by environmental temperature and regulated by genes related to cell division and elongation. Our results provide insight into the rapid growth of Moso bamboo.
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Giberelinas , Transcriptoma , Ácido Abscísico/farmacología , Citocininas , Regulación de la Expresión Génica de las Plantas , Ácidos Indolacéticos , Lignina , Poaceae/genética , Transcriptoma/genéticaRESUMEN
Selective attention is thought to involve target enhancement and distractor inhibition processes. Here, we recorded simultaneous electroencephalographic (EEG) and functional near-infrared spectroscopy (fNIRS) data from human adults when they were pre-cued by the visual field of coming target, distractor, or both of them. From the EEG data, we found alpha power relatively decreased contralaterally to the to-be-attended target, as reflected by the positive-going alpha modulation index. Late alpha power relatively increased contralaterally to the to-be-suppressed distractor, as reflected by the negative-going alpha modulation index. From the fNIRS data, we found enhancements of hemodynamic activity over the contralateral hemisphere in response to both the target and the distractor anticipation but within nonoverlapping posterior brain regions. More importantly, we described the specific neurovascular modulation between alpha power and oxygenated hemoglobin signal, which showed a positive coupling effect during target anticipation and a negative coupling effect during distractor anticipation. Such flexible neurovascular couplings between EEG oscillation and hemodynamic activity seem to play an essential role in the final behavioral outcomes. These results provide unique neurovascular evidence for the dissociation of the mechanisms of target enhancement and distractor inhibition. Individual behavioral differences can be related to individual differences in neurovascular coupling.
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Acoplamiento Neurovascular , Adulto , Humanos , Acoplamiento Neurovascular/fisiología , Atención/fisiología , Electroencefalografía/métodos , Hemodinámica/fisiología , Señales (Psicología)RESUMEN
Sodium nitroprusside (SNP), as a single minuscule signaling molecule, has been employed to alleviate plant stress in recent years. This approach has a beneficial effect on the biological and physiological processes of plants. As a result, an in vitro tissue culture experiment was carried out to investigate the effect of high and low levels of SNP on the amelioration of manganese (Mn) and chromium (Cr) toxicity in a one-year-old bamboo plant, namely Pleioblastus pygmaea L. Five different concentrations of SNP were utilized as a nitric oxide (NO) donor (0, 50, 80, 150, 250, and 400 µM) in four replications of 150 µM Mn and 150 µM Cr. The results revealed that while 150 µM Mn and 150 µM Cr induced an over-generation of reactive oxygen species (ROS) compounds, enhancing plant membrane injury, electrolyte leakage (EL), and oxidation in bamboo species, the varying levels of SNP significantly increased antioxidant and non-antioxidant activities, proline (Pro), glutathione (GSH), and glycine betaine (GB) content, photosynthesis, and plant growth parameters, while also reducing heavy metal accumulation and translocation in the shoot and stem. This resulted in an increase in the plant's tolerance to Mn and Cr toxicity. Hence, it is inferred that NO-induced mechanisms boosted plant resistance to toxicity by increasing antioxidant capacity, inhibiting heavy metal accumulation in the aerial part of the plant, restricting heavy metal translocation from root to leaves, and enhancing the relative water content of leaves.
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Antioxidantes , Manganeso , Nitroprusiato/farmacología , Manganeso/toxicidad , Cromo/toxicidad , Agua , Glutatión , Donantes de Óxido NítricoRESUMEN
Molten alkali metal salt effectively promotes the performance of calcium looping (CaL). Deep insight into the nonequilibrium phase-transition characteristic of alkali metal salt is better for the control of the temperature in CaL, which not only ensures the complete melting of metal salt but also prevents the reaction from inhibiting caused by higher temperatures. In this work, therefore, the molecular dynamics simulation method is used to explore the nonequilibrium phase-transition characteristic of Na2SO4. The results show that the equilibrium melting temperature of nanosodium sulfate on the calcium oxide surface is 810 K, which is lower than the macroscopic melting temperature. Meanwhile, the high heating rates led to the atoms in Na2SO4 unable to break through the thermal stability limit, resulting in overheating of the crystal. Both the surface premelting and overheating melting temperature of the crystal are increased. When the heating rates are 0.25, 0.5, and 1.0 K/ps, the overheating melting temperatures are 845, 885, and 930 K, respectively. More than that, the surface defects enhance the interaction between CaO and Na2SO4 because of the surface being charged. The increases in the interaction not only effectively break the stability of the crystal lattice of Na2SO4 on the defective surfaces but also promote the energy transport inside Na2SO4. Therefore, as the defect concentration increases from 0 to 3% and 5%, the overheating melting temperature of Na2SO4 gradually decreases from 845 to 836 and 815 K.
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Bamboo differentiates a cell division zone (DZ) and a cell elongation zone (EZ) to promote internode elongation during rapid growth. However, the biological mechanisms underlying this sectioned growth behavior are still unknown. Using histological, physiological, and genomic data, we found that the cell wall and other subcellular organelles such as chloroplasts are more developed in the EZ. Abundant hydrogen peroxide accumulated in the pith cells of the EZ, and stomata formed completely in the EZ. In contrast, most cells in the DZ were in an undifferentiated state with wrinkled cell walls and dense cytoplasm. Hormone detection revealed that the levels of gibberellin, auxin, cytokinin, and brassinosteroid were higher in the DZ than in the EZ. However, the levels of salicylic acid and jasmonic acid were higher in the EZ than in the DZ. Transcriptome analysis with qRT-PCR quantification revealed that the transcripts for cell division and primary metabolism had higher expression in the DZ, whereas the genes for photosynthesis, cell wall growth, and secondary metabolism were dramatically upregulated in the EZ. Overexpression of a MYB transcription factor, BmMYB83, promotes cell wall lignification in transgenic plants. BmMYB83 is specifically expressed in cells that may have lignin deposits, such as protoxylem vessels and fiber cells. Our results indicate that hormone gradient and transcriptome reprogramming, as well as specific expression of key genes such as BmMYB83, may lead to differentiation of cell growth in the bamboo internode.
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Regulación de la Expresión Génica de las Plantas , Giberelinas , Lignina/metabolismo , Brasinoesteroides , Peróxido de Hidrógeno/metabolismo , Ácidos Indolacéticos , Factores de Transcripción/metabolismo , Citocininas , Ácido Salicílico , Hormonas , Diferenciación Celular/genéticaRESUMEN
BACKGROUND: Acupuncture has promising effects on chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), but high-quality evidence is scarce. OBJECTIVE: To assess the long-term efficacy of acupuncture for CP/CPPS. DESIGN: Multicenter, randomized, sham-controlled trial. (ClinicalTrials.gov: NCT03213938). SETTING: Ten tertiary hospitals in China. PARTICIPANTS: Men with moderate to severe CP/CPPS, regardless of prior exposure to acupuncture. INTERVENTION: Twenty sessions of acupuncture or sham acupuncture over 8 weeks, with 24-week follow-up after treatment. MEASUREMENTS: The primary outcome was the proportion of responders, defined as participants who achieved a clinically important reduction of at least 6 points from baseline on the National Institutes of Health Chronic Prostatitis Symptom Index at weeks 8 and 32. Ascertainment of sustained efficacy required the between-group difference to be statistically significant at both time points. RESULTS: A total of 440 men (220 in each group) were recruited. At week 8, the proportions of responders were 60.6% (95% CI, 53.7% to 67.1%) in the acupuncture group and 36.8% (CI, 30.4% to 43.7%) in the sham acupuncture group (adjusted difference, 21.6 percentage points [CI, 12.8 to 30.4 percentage points]; adjusted odds ratio, 2.6 [CI, 1.8 to 4.0]; P < 0.001). At week 32, the proportions were 61.5% (CI, 54.5% to 68.1%) in the acupuncture group and 38.3% (CI, 31.7% to 45.4%) in the sham acupuncture group (adjusted difference, 21.1 percentage points [CI, 12.2 to 30.1 percentage points]; adjusted odds ratio, 2.6 [CI, 1.7 to 3.9]; P < 0.001). Twenty (9.1%) and 14 (6.4%) adverse events were reported in the acupuncture and sham acupuncture groups, respectively. No serious adverse events were reported. LIMITATION: Sham acupuncture might have had certain physiologic effects. CONCLUSION: Compared with sham therapy, 20 sessions of acupuncture over 8 weeks resulted in greater improvement in symptoms of moderate to severe CP/CPPS, with durable effects 24 weeks after treatment. PRIMARY FUNDING SOURCE: China Academy of Chinese Medical Sciences and the National Administration of Traditional Chinese Medicine.
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Terapia por Acupuntura , Dolor Pélvico/terapia , Prostatitis/terapia , Terapia por Acupuntura/métodos , Adulto , Enfermedad Crónica , Humanos , Masculino , Dimensión del Dolor , Dolor Pélvico/etiología , Prostatitis/complicacionesRESUMEN
Nowadays, accurate localization plays an essential role in many fields, such as target tracking and path planning. The challenges of indoor localization include inadequate localization accuracy, unreasonable anchor deployment in complex scenarios, lack of stability, and the high cost. So, the universal positioning technologies cannot meet the real application requirements scarcely. To overcome these shortcomings, a comprehensive ultra wide-band (UWB)-based real-time localization system (RTLS) is presented in this paper. We introduce the architecture of a real-time localization system, then propose a new wireless clock synchronization (WCS) scheme, and finally discuss the time difference of arrival (TDoA) algorithm. We define the time-base selection strategy for the TDoA algorithm, and we analyze the relationship between anchor deployment and positioning accuracy. The extended Kalman filter (EKF) method is presented for non-linear dynamic localization estimation, and it performs well in terms of stability and accuracy on moving targets.
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Algoritmos , Fenómenos Biológicos , Sistemas de ComputaciónRESUMEN
SQUAMOSA Promoter-Binding Protein-Like (SPL) family is well-known for playing an important role in plant growth and development, specifically in the reproductive process. Bamboo plants have special reproductive characteristics with a prolonged vegetative phase and uncertain flowering time. However, the underlying functions of SPL genes in reproductive growth are undisclosed in bamboo plants. In the study, a total of 28 SPLs were screened from an ornamental dwarf bamboo species, Pleioblastus pygmaeus. Phylogenetic analysis indicates that 183 SPLs from eight plant species can be classified into nine subfamilies, and the 28 PpSPLs are distributed among eight subfamilies. Homologous analysis shows that as many as 32 pairs of homologous genes were found between P. pygmaeus and rice, and 83 pairs were found between P. pygmaeus and Moso bamboo, whose Ka/Ks values are all <1. MiRNA target prediction reveals that 13 out of the 28 PpSPLs have recognition sites complementary to miRNA156. To screen the SPLs involved in the reproductive growth of bamboo plants, the mRNA abundance of the 28 PpSPLs was profiled in the different tissues of flowering P. pygmaeus and non-flowering plants by RNA-Seq. Moreover, the relative expression level of eight PpSPLs is significantly higher in flowering P. pygmaeus than that in non-flowering plants, which was also validated by RT-qPCR. Combined with phylogenetic analysis and homologous analysis, the eight significant, differentially expressed PpSPLs were identified to be associated with the reproductive process and flower organ development. Among them, there are four potential miRNA156-targeting PpSPLs involved in the flowering process. Of significant interest in the study is the identification of 28 SPLs and the exploration of four key flowering-related SPLs from P. pygmaeus, which provides a theoretic basis for revealing the underlying functions of SPLs in the reproductive growth of bamboo plants.
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Flores , Regulación de la Expresión Génica de las Plantas , Flores/metabolismo , Proteínas Portadoras/metabolismo , Filogenia , Poaceae/metabolismoRESUMEN
The influence of the vacancy defect of the CaO surface on the wettability of molten alkali metal salt was studied by molecular dynamics simulations. The results indicated that in the temperature range of 800-1100 K, the molten Na2SO4 on both VDcalcium and VDoxygen defect surfaces presented a poor wettability compared to that on the complete surface. Measurement of the density profile and the contact angle of the molten Na2SO4 showed that the higher the temperature and defect concentration, the worse the wettability. The micromechanism was revealed by calculating the polarization intensity that the vacancy defect surface led to the formation of the induced dipole moment in the molten Na2SO4. Induced polarization caused by defect surfaces reduces the wettability of Na2SO4. More importantly, as the temperature and defect concentration increase, various defect surfaces form loose and local weak liquidity structures. These structures are beneficial for the diffusion of carbon dioxide into the solid, but the reduction in the spreading area caused by poor wettability causes the efficiency of the CaL to decline. The vibration difference between Na2SO4 and CaO increases with the increased temperature and defect concentration. This means that the thermal energy transportability at the interface is suppressed by poor wettability.
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BACKGROUND: The vegetative growth is an important stage for plants when they conduct photosynthesis, accumulate and collect all resources needed and prepare for reproduction stage. Bamboo is one of the fastest growing plant species. The rapid growth of Phyllostachys edulis results from the expansion of intercalary meristem at the basal part of nodes, which are differentiated from the apical meristem of rhizome lateral buds. However, little is known about the major signaling pathways and players involved during this rapid development stage of bamboo. To study this question, we adopted the high-throughput sequencing technology and compared the transcriptomes of Moso bamboo rhizome buds in germination stage and late development stage. RESULTS: We found that the development of Moso bamboo rhizome lateral buds was coordinated by multiple pathways, including meristem development, sugar metabolism and phytohormone signaling. Phytohormones have fundamental impacts on the plant development. We found the evidence of several major hormones participating in the development of Moso bamboo rhizome lateral bud. Furthermore, we showed direct evidence that Gibberellic Acids (GA) signaling participated in the Moso bamboo stem elongation. CONCLUSION: Significant changes occur in various signaling pathways during the development of rhizome lateral buds. It is crucial to understand how these changes are translated to Phyllostachys edulis fast growth. These results expand our knowledge on the Moso bamboo internodes fast growth and provide research basis for further study.
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Germinación , Brotes de la Planta/crecimiento & desarrollo , Poaceae/genética , Rizoma/metabolismo , Transcriptoma , Perfilación de la Expresión Génica , Redes y Vías Metabólicas , Reguladores del Crecimiento de las Plantas/metabolismo , Brotes de la Planta/genética , Brotes de la Planta/metabolismo , Poaceae/crecimiento & desarrollo , Poaceae/metabolismo , Rizoma/crecimiento & desarrolloRESUMEN
Bamboo is one of the fastest growing plants in the world, but their shoot buds develop very slowly. Information about the sugar storage and metabolism during the shoot growth is lacking. In the present study, we determined the activity of sucrose and starch metabolizing enzymes during the developmental period of Fargesia yunnanensis from shoot buds to the young culms that have achieved their full height. The soluble sugars and starch contents were also determined and analyzed in shoot buds and shoots at different developmental stages. The results showed that there were higher sucrose contents in shoot buds than shoots, which coincides with the sweeter taste of shoot buds. As the shoot buds sprouted out of the ground, the starch and sucrose were depleted sharply. Coupled with this, the activity of soluble acid invertase (SAI), cell wall-bound invertase (CWI), sucrose synthase at cleavage direction (SUSYC) and starch phosphorylase (STP) increased significantly in the rapidly elongating internodes. These enzymes dominated the rapid elongation of internodes. The activities of SAI, CWI, SUSYC and STP and adenosine diphosphate-glucose pyrophosphorylase were higher as compared to other enzymes in the shoot buds, but were far lower than those in the developing shoots. The slow growth of shoot buds was correlated with the low activity of these enzymes. These results complement our understanding of the physiological differences between shoot buds and elongating shoots and ascertain the physiological mechanism for the rapid growth of bamboo shoots.
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Metabolismo de los Hidratos de Carbono , Brotes de la Planta/crecimiento & desarrollo , Poaceae/metabolismo , Almidón/metabolismo , Sacarosa/metabolismo , Glucosiltransferasas/metabolismo , Brotes de la Planta/metabolismo , Poaceae/crecimiento & desarrollo , Almidón Fosforilasa/metabolismo , beta-Fructofuranosidasa/metabolismoRESUMEN
Bamboo forests are undoubtedly one of the most abundant nontimber plants on Earth and cover a wide area of tropical and subtropical regions around the world. This amazing plant has unique rapid growth and can play an important role in protecting our planet from pollution and improving the soil. Bamboo can be used as a biofuel, food, and for architecture and construction applications and plays a large role in the local economy by creating job opportunities. The aim of this paper is to review the extraordinary tropical plant bamboo by explaining the mechanisms related to the growth and strength of bamboo and identifying ways to utilize bamboo in industry, employment, climate change mitigation, and soil erosion reduction.
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Ecología , Ecosistema , Sasa/fisiología , Biocombustibles , Dióxido de Carbono/química , Oxígeno/química , Desarrollo de la Planta , Plantas Comestibles , SueloRESUMEN
BACKGROUND: Fargesia macclureana (Poaceae) is a woody bamboo species found on the Qinghai-Tibet Plateau (QTP) approximately 2000 ~ 3800 m above sea level. It rarely blossoms in the QTP, but it flowered 20 days after growing in our lab, which is in a low-altitude area outside the QTP. To date, little is known regarding the molecular mechanism of bamboo flowering, and no studies of flowering have been conducted on wild bamboo plants growing in extreme environments. Here, we report the first de novo transcriptome sequence for F. macclureana to investigate the putative mechanisms underlying the flowering time control used by F. macclureana to adapt to its environment. RESULTS: Illumina deep sequencing of the F. macclureana transcriptome generated 140.94 Gb of data, assembled into 99,056 unigenes. A comprehensive analysis of the broadly, specifically and differentially expressed unigenes (BEUs, SEUs and DEUs) indicated that they were mostly involved in metabolism and signal transduction, as well as DNA repair and plant-pathogen interactions, which may be of adaptive importance. In addition, comparison analysis between non-flowering and flowering tissues revealed that expressions of FmFT and FmHd3a, two putative F. macclureana orthologs, were differently regulated in NF- vs F- leaves, and carbohydrate metabolism and signal transduction were two major KEGG pathways that DEUs were enriched in. Finally, we detected 9296 simple sequence repeats (SSRs) that may be useful for further molecular marker-assisted breeding. CONCLUSIONS: F. macclureana may have evolved specific reproductive strategies for flowering-related pathways in response to photoperiodic cues to ensure long vegetation growing period. Our findings will provide new insights to future investigations into the mechanisms of flowering time control and adaptive evolution in plants growing at high altitudes.
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Flores/fisiología , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Desarrollo de la Planta/genética , Poaceae/fisiología , Transcriptoma , Secuencia de Aminoácidos , Biología Computacional/métodos , Ontología de Genes , Anotación de Secuencia Molecular , Filogenia , Poaceae/clasificaciónRESUMEN
In covert visual attention, one fundamental question is how advance knowledge facilitates subsequent neural processing and behavioral performance. In this study, with a rapid event-related simultaneous electroencephalography (EEG) and functional near infrared spectroscopy recording in humans, we explored the potential contribution of anticipatory electrophysiological activation and hemodynamic activation by examining how anticipatory low-frequency oscillations and changes in oxygenated hemoglobin (HbO) concentration influence the subsequent event-related potential (ERP) marker of attentional selection. We found that expecting a target led to both a posterior lateralization of alpha-band (8-12 Hz) oscillation power and a lateralization of HbO response over the visual cortex. Importantly, the magnitude of cue-induced alpha lateralization was positively correlated with the nearby HbO lateralization in the visual cortex, and such a cue-induced alpha lateralization predicted the subsequent target-evoked N2pc amplitudes assumed to reflect attentional selection. Our results suggest that each individual's attentional selection biomarker as reflected by N2pc is predictable in advance via the anticipation-induced alpha lateralization, and such cue-induced alpha lateralization seems to play an important role in the functional coupling effects between the low-frequency EEG and the nearby hemodynamic activation.
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Ritmo alfa/fisiología , Anticipación Psicológica/fisiología , Atención/fisiología , Hemodinámica/fisiología , Percepción Espacial/fisiología , Corteza Visual/fisiología , Adulto , Electroencefalografía/métodos , Femenino , Predicción , Humanos , Masculino , Estimulación Luminosa/métodos , Corteza Visual/diagnóstico por imagen , Adulto JovenRESUMEN
Pith cavity formation is critical for bamboo to overcome the bending force during its fast growth; however, the underlying molecular mechanisms remain largely unknown. Multiple approaches, including anatomical dissection, mathematical modelling and transcriptome profiling, were employed in this study to investigate the biology of pith cavity formation in bamboo Pseudosasa japonica. We found that the corruption of pith tissue occurred sequentially and asymmetrically from the top-centre of the internode down to the bottom, which might be caused by the combined effects of asymmetrical radial and axial tensile forces during shoot-wall cell elongation and spiral growth of bamboo internodes. Programmed cell death (PCD) in pitch manifested by TUNEL positive nuclei, DNA cleavage and degraded organelles, and potentially regulated by ethylene and calcium signalling pathway, ROS burst, cell wall modification, proteolysis and nutrient recycle genes, might be responsible for pith tissue corruption of Ps. japonica. Although similar physiological changes and transcriptome profiles were found in different bamboo species, different formation rates of pith cavity were observed, which might be caused by different pith cells across the internode that were negatively correlated with the culm diameter. These findings provided a systematical view on the formation of bamboo pith cavity and revealed that PCD plays an important role in the bamboo pith cavity formation.
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Apoptosis/genética , Genes de Plantas/genética , Poaceae/genética , Transcriptoma/genética , División del ADN , Perfilación de la Expresión Génica , Genes de Plantas/fisiología , Etiquetado Corte-Fin in Situ , Microscopía Electrónica de Transmisión , Poaceae/anatomía & histología , Poaceae/crecimiento & desarrollo , Poaceae/metabolismo , ARN de Planta/metabolismo , Transcriptoma/fisiologíaRESUMEN
Little is known about the mechanisms underlying the development of bamboo culm. Using anatomical, mathematical modeling, and genomics methods, we investigated the role of shoot apical meristem (SAM) in the development of the transverse morphology of bamboo culm and explored the underlying cellular and molecular processes. We discovered that maintenance of SAM morphology that can produce circular culm and increase in SAM cell numbers, especially corpus cells, is the means by which bamboo makes a larger culm with a regular pith cavity and culm wall during development. A less cellular form of SAM with a lower proportion of corpus cells causes an abnormal higher ratio of wall component cells to pith cells, which breaks the balance of their interaction and triggers the random invasion of wall component cells into pith tissues during development, and finally results in the various thick culm walls of Phyllostachys nidularia f. farcta. The smaller SAM also results in a lower level of hormones such as cytokinin and auxin, and down-regulates hormone signaling and the downstream functional genes such as those related to metabolism, which finally results in a dwarf and smaller diameter culm with lower biomass. These results provide an important perspective on the culm development of bamboo, and support a plausible mechanism causing the size-reduced culm and various thick culm walls of P. nidularia f. farcta.
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Regulación de la Expresión Génica de las Plantas/fisiología , Meristema/citología , Meristema/fisiología , Brotes de la Planta/citología , Brotes de la Planta/fisiología , Poaceae/citología , Poaceae/fisiología , Citocininas/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Meristema/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotes de la Planta/metabolismo , Poaceae/metabolismoRESUMEN
The fundamental role of covert spatial attention is to enhance the processing of attended items while simultaneously ignoring irrelevant items. However, relatively little is known about how brain electrophysiological activities associated with target selection and distractor suppression are involved as they develop and become fully functional. The current study aimed to identify the neurophysiological bases of the development of covert spatial attention, focusing on electroencephalographic (EEG) markers of attentional selection (N2pc) and suppression (PD ). EEG data were collected from healthy young adults and typically developing children (9-15 years old) as they searched for a shape singleton target in either the absence or the presence of a salient-but-irrelevant color singleton distractor. The ERP results showed that a lateral shape target elicited a smaller N2pc in children compared with adults regardless of whether a distractor was present or not. Moreover, the target-elicited N2pc was always followed by a similar positivity in both age groups. Counterintuitively, a lateral salient-but-irrelevant distractor elicited a large PD in children with low behavioral accuracy, whereas high-accuracy children exhibited a small and "adult-like" PD . More importantly, we found no evidence for a correlation between the target-elicited N2pc and the distractor-elicited PD in either age group. Our results provide neurophysiological evidence for the developmental differences between target selection and distractor suppression. Compared with adults, 9-15-year-old children deploy insufficient attentional selection resources to targets but use "adult-like" or even more attentional suppression resources to resist irrelevant distractors. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=NhWapx0d75I.
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Atención/fisiología , Desarrollo Infantil/fisiología , Adolescente , Adulto , Encéfalo/fisiología , Niño , Electroencefalografía/métodos , Fenómenos Electrofisiológicos , Humanos , Inhibición Psicológica , Percepción Espacial/fisiología , Adulto JovenRESUMEN
Visual attention can be attracted automatically by salient simple features, but whether and how nonsalient complex stimuli such as shapes may capture attention in humans remains unclear. Here, we present strong electrophysiological evidence that a nonsalient shape presented among similar shapes can provoke a robust and persistent capture of attention as a consequence of extensive training in visual search (VS) for that shape. Strikingly, this attentional capture that followed perceptual learning (PL) was evident even when the trained shape was task-irrelevant, was presented outside the focus of top-down spatial attention, and was undetected by the observer. Moreover, this attentional capture persisted for at least 3-5 months after training had been terminated. This involuntary capture of attention was indexed by electrophysiological recordings of the N2pc component of the event-related brain potential, which was localized to ventral extrastriate visual cortex, and was highly predictive of stimulus-specific improvement in VS ability following PL. These findings provide the first evidence that nonsalient shapes can capture visual attention automatically following PL and challenge the prominent view that detection of feature conjunctions requires top-down focal attention.
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Atención/fisiología , Encéfalo/fisiología , Potenciales Evocados Visuales/fisiología , Aprendizaje/fisiología , Percepción Visual/fisiología , Potenciales Evocados/fisiología , Femenino , Humanos , Masculino , Estimulación Luminosa/métodos , Tiempo de Reacción/fisiologíaRESUMEN
Investigating factors involved in the alleviation of the toxic effects of heavy metals (HMs) on plants is regarded as one of the important research concerns in the environmental field. The southern regions of China are severely impacted by human-induced heavy metal (HM) contamination, which poses an impediment to growth and productivity of bamboo (Indocalamus latifolius) plants. This necessitates the investigation of the effects of HMs on growth and physiological properties of bamboo. Therefore, the aim of the study was to evaluate some gas exchange and growth parameters in two-year-old bamboo species under HMs stress. A greenhouse-based experiment was conducted at Nanjing Forestry University, where the bamboo plant was treated with three HMs (Cu, Pb, and Zn) at four different concentrations (0, 500, 1000, and 2000 mg kg-1). The results illustrated that excessive HMs (1000 and 2000 mg kg-1) triggered a decline in a number of photosynthetic-related indices including the rate of photosynthesis (µmol CO2 m-2 s-1), intercellular CO2 concentration (µmol CO2 mol-1), conductance to H2O (mol H2O m-2 s-1), and net assimilation as well as transpiration. Morphological indices were also depressed as a result of the adverse influence of HMs, leading to decreased shoot length (10 to 73%) and reduced number of emerged plants (6 to 57%). Also, the results indicated that Pb had the greatest harmful impact on the growth indices.