Spatiotemporal patterns of leaf nutrients of wild apples in a wild fruit forest plot in the Ili Valley, China.

Malus sieversii, commonly known as wild apples, represents a Tertiary relict plant species and serves as the progenitor of globally cultivated apple varieties. Unfortunately, wild apple populations are facing significant degradation in localized areas due to a myriad of factors. To gain a comprehensive understanding of the nutrient status and spatiotemporal variations of M. sieversii, green leaves were collected in May and July, and the fallen leaves were collected in October. The concentrations of leaf nitrogen (N), phosphorus (P), and potassium (K) were measured, and the stoichiometric ratios as well as nutrient resorption efficiencies were calculated. The study also explored the relative contributions of soil, topographic, and biotic factors to the variation in nutrient traits. The results indicate that as the growing period progressed, the concentrations of N and P in the leaves significantly decreased (P < 0.05), and the concentration of K in October was significantly lower than in May and July. Throughout plant growth, leaf N-P and N-K exhibited hyperallometric relationships, while P-K showed an isometric relationship. Resorption efficiency followed the order of N < P < K (P < 0.05), with all three ratios being less than 1; this indicates that the order of nutrient limitation is K > P > N. The resorption efficiencies were mainly regulated by nutrient concentrations in fallen leaves. A robust spatial dependence was observed in leaf nutrient concentrations during all periods (70.1-97.9% for structural variation), highlighting that structural variation, rather than random factors, dominated the spatial variation. Nutrient resorption efficiencies (NRE, PRE, and KRE) displayed moderate structural variation (30.2-66.8%). The spatial patterns of nutrient traits varied across growth periods, indicating they are influenced by multifactorial elements (in which, soil property showed the highest influence). In conclusion, wild apples manifested differentiated spatiotemporal variability and influencing factors across various leaf nutrient traits. These results provide crucial insights into the spatiotemporal patterns and influencing factors of leaf nutrient traits of M. sieversii at the permanent plot scale for the first time. This work is of great significance for the ecosystem restoration and sustainable management of degrading wild fruit forests.

Broadband lens and graphene/silicon photodiode for wide spectral imaging.

We designed a broadband lens along with a graphene/silicon photodiode for wide spectral imaging ranging from ultraviolet to near-infrared wavelengths. By using five spherical glass lenses, the broadband lens, with the modulation transfer function of 0.38 at 100 lp/mm, corrects aberrations ranging from 340 to 1700 nm. Our design also includes a broadband graphene/silicon Schottky photodiode with the highest responsivity of 0.63 A/W ranging from ultraviolet to near-infrared. By using the proposed broadband lens and the broadband graphene/silicon photodiode, several single-pixel imaging designs in ultraviolet, visible, and near-infrared wavelengths are demonstrated. Experimental results show the advantages of integrating the lens with the photodiode and the potential to realize broadband imaging with a single set of lens and a detector.

CIP2A deficiency promotes depression-like behaviors in mice through inhibition of dendritic arborization.

Major depressive disorder (MDD) is a severe mental illness. Decreased brain plasticity and dendritic fields have been consistently found in MDD patients and animal models; however, the underlying molecular mechanisms remain to be clarified. Here, we demonstrate that the deletion of cancerous inhibitor of PP2A (CIP2A), an endogenous inhibitor of protein phosphatase 2A (PP2A), leads to depression-like behaviors in mice. Hippocampal RNA sequencing analysis of CIP2A knockout mice shows alterations in the PI3K-AKT pathway and central nervous system development. In primary neurons, CIP2A stimulates AKT activity and promotes dendritic development. Further analysis reveals that the effect of CIP2A in promoting dendritic development is dependent on PP2A-AKT signaling. In vivo, CIP2A deficiency-induced depression-like behaviors and impaired dendritic arborization are rescued by AKT activation. Decreased CIP2A expression and impaired dendrite branching are observed in a mouse model of chronic unpredictable mild stress (CUMS). Indicative of clinical relevance to humans, CIP2A expression is found decreased in transcriptomes from MDD patients. In conclusion, we discover a novel mechanism that CIP2A deficiency promotes depression through the regulation of PP2A-AKT signaling and dendritic arborization.

Proteomics and transcriptomics profiling reveals distinct aspects of kidney stone related genes in calculi rats.

BACKGROUNDS: Kidney stone also known as urolithiasis or nephrolithiasis, is one of the oldest diseases known to medicine, however, the gene expression changes and related kidney injury remains unclear. METHODS: A calculi rat model was developed via ethylene glycol- and ammonium chloride-induction. Integrated proteomic and transcriptomic analysis was performed to characterize the distinct gene expression profiles in the kidney of calculi rat. Differential expressed genes (DEGs) were sub-clustered into distinct groups according to the consistency of transcriptome and proteome. Gene Ontology and KEGG pathway enrichment was performed to analyze the functions of each sub-group of DEGs. Immunohistochemistry was performed to validated the expression of identified proteins. RESULTS: Five thousand eight hundred ninety-seven genes were quantified at both transcriptome and proteome levels, and six distinct gene clusters were identified, of which 14 genes were consistently dysregulated. Functional enrichment analysis showed that the calculi rat kidney was increased expression of injured & apoptotic markers and immune-molecules, and decreased expression of solute carriers & transporters and many metabolic related factors. CONCLUSIONS: The present proteotranscriptomic study provided a data resource and new insights for better understanding of the pathogenesis of nephrolithiasis, will hopefully facilitate the future development of new strategies for the recurrence prevention and treatment in patients with kidney stone disease.

Efficacy of various surgical approaches in treating hematospermia using transurethral seminal vesiculoscopy.

PURPOSE: To explore the efficacy of different approaches of seminal vesiculoscopy surgery and the predictive factors of good treatment outcome. MATERIALS AND METHODS: A retrospective analysis of 68 patients who underwent seminal vesiculoscopy for hematospermia in our hospital from January 2015 to January 2021. According to different surgical approaches, they were divided into three groups: natural ejaculatory ducts (method A, 45 cases), assisted transurethral resection/incision of ejaculatory ducts (method B, 14 cases), fenestration in prostatic utricle (method C, 9 cases). We analyzed the recurrence rate of the three surgical approaches and the predictive factors of treatment efficacy. RESULTS: The total recurrence rate after the seminal vesiculoscopy for hematospermia in this group was 32.35%. The postoperative recurrence rates of the three methods were 24.44% for method A, 50.00% for method B and 44.44% for method C, and there was no significant difference among the three methods (P > 0.05). The data of five predictors of 45 cases in method A group were included in the Univariate Logistic analysis, the results suggest that whether complicated with seminal tract stones/cysts was an effective predictor (OR 0.250, P = 0.022), which was still an effective predictor in the Multivariate Logistic analysis model (OR 0.244, P = 0.010). CONCLUSIONS: The Transurethral seminal vesiculoscopy technique demonstrates a low postoperative recurrence rate in treating hematospermia. Among the various approaches, the intraoperative use of natural orifices through the ejaculatory duct exhibits the lowest recurrence rate. Additionally, seminal tract stones/cysts effectively predict favorable postoperative outcomes.

[Nomographic Model for Predicting Severe Foot Pain in Nurses from Tertiary Hospitals in China].

Objective: To investigate the prevalence and common sites of severe foot pain among nurses, to define the risk factors of severe foot pain in nurses in tertiary hospital in China, and to construct a nomograph model for predicting individuals' risks for severe foot pain. Methods: Between August 2019 and December 2019, a stratified global sampling method was used to select 10691 nurses from 351 tertiary hospitals in China to investigate the incidence of severe foot pain among them. The variables that may affect the occurrence of severe foot pain were analyzed by single factor analysis to identify the influencing factors of severe foot pain in nurses. Furthermore, the independent risk factors of severe foot pain were analyzed by stepwise logistic regression analysis. The statistically significant factors identified in the multivariate regression analysis were incorporated into the nomograph prediction model. The predictive performance of the nomograph was measured by the consistency index (C-index) and calibrated with 1000 Bootstrap samples. Results: A total of 3419 nurses out of the 10691 had foot pain, resulting in an incidence of 31.98%. The incidence of severe pain (VAS score 7-10) was 2.27% (243 of 10691). The locations of severe pain were more commonly found in the soles and heels of both feet. Six factors, including age, education, the material of the work shoes, comfortableness of the work shoes, number of complications, and foot injure history, were incorporated in the nomograph predicting model. The C-index value was 0.706 and the standard curve fitted well with the calibrated prediction curve. Conclusion: The risk prediction model constructed in this study showed sound performance in predicting the risk of severe foot pain in nurses, and all the indicators involved are simple and the relevant data are easily obtained. The model can provide reference for preventing severe foot pain in nurses.

Effects of short daylight and mild low temperature on mitochondrial degeneration in the testis of Cricetulus barabensis.

In this study, we investigated the mitochondrial energy supply capacity and molecular mechanisms of apoptosis, mitochondrial fission, and mitophagy in regulating mitochondrial degeneration in testis of striped dwarf hamsters (Cricetulus barabensis) under mild low temperature (15°C) and short daylight (10 h:14 h) conditions. Results showed that under moderate daylight and mild low temperature (ML), short daylight and moderate temperature (SM), short daylight and mild low temperature (SL) conditions, the mitochondria were swollen and cristae were disrupted. Compared with the moderate daylight & moderate temperature group (MM; 12 h:12 h, 22°C), the number of mitochondria was significantly decreased in the SM and SL groups. Both short daylight and mild low temperature reduced the protein expression of citrate synthase, thus the energy supply capacity of mitochondria may be weakened. Compared with the MM group, bax/bcl2 protein expression was higher in three treatment groups, and caspase3 activity increased in SM and SL groups, suggesting that short daylight can induce apoptosis. DRP1 protein expression showed no difference in four groups, while the FIS1 protein expression was significantly decreased in three treatment groups, this indicates that short daylight and mild low temperature can increase mitochondrial fission level. PINK1 protein expression was significantly increased in ML and SL groups, indicates that mild low temperature will lead to increased mitophagy level. Generally, short daylight induced degeneration of mitochondria in the testis of hamsters mainly by increasing apoptosis, while under mild low temperature, balanced regulation of mitophagy and mitochondrial fission appear to contribute to the protection of mitochondria.

Coumarin-monoterpenes from Gerbera anandria (Linn.) Sch.-Bip and their neuroprotective activity.

Thirty-two undescribed coumarin-monoterpenes, including the first report of six pairs of enantiomeric and twenty congeners, were isolated from the petroleum ether extract of the stems of Gerbera anandria (Linn.) Sch.-Bip. Structurally, these compounds represented C3-substituted 5-methyl-4-hydroxycoumarin-monoterpenes. Among them, 1-7 and 10-24 were rare 5-methylcoumarin-monoterpenes formed through a furan ring. Their chemical structures and absolute configurations were determined by comprehensive analysis of spectroscopic data, including HRESIMS, 1D and 2D NMR spectroscopic data, Mosher's method, ECD calculations and single crystal X-ray diffraction. Furthermore, biological studies revealed that compounds 1-3, 3a, 5, 5a, 11-12, 21-22 and 26 had the neuroprotective effects on scopolamine-induced injury in PC12 cells. Notably, 3 exhibited the strongest neuroprotective activity with the cell viability values of 77.24%. Meanwhile, pretreatment with 3 significantly downregulate apoptosis and reactive oxygen species (ROS) production, as well as strengthen antioxidant enzyme activities (MDA and SOD). Moreover, pretreatment with 3 also could attenuate the down-regulation of HO-1 and Nrf2 induced by scopolamine. In conclusion, these results demonstrated that these compounds possessed the protective effects on scopolamine-injured PC12 cells through anti-apoptotic and anti-oxidant activities.

Leaf-root-soil N:P stoichiometry of ephemeral plants in a temperate desert in Central Asia.

Ephemeral plants are a crucial vegetation component in temperate deserts of Central Asia, and play an important role in biogeochemical cycle and biodiversity maintenance in desert ecosystems. However, the nitrogen (N) and phosphorus (P) status and interrelations of leaf-root-soil of ephemeral plants remain unclear. A total of 194 leaf-root-soil samples of eight ephemeral species at 37 sites in the Gurbantunggut Desert, China were collected, and then the corresponding N and P concentrations, and the N:P ratio were measured. Results showed that soil parameters presented no significant difference among the eight species. The total soil N:P was only 0.116 (geomean), indicating limited soil N, while the available soil N:P (4.896, geomean) was significantly larger than the total N:P. The leaf N (averagely 30.995 mg g-1) and P (averagely 1.523 mg g-1) concentrations were 2.64-8.46 and 0.93-3.99 times higher than the root N (averagely 8.014 mg g-1) and P (averagely 0.802 mg g-1) concentrations, respectively. Thus, leaf N:P (averagely 21.499) was 1.410-2.957 times higher than root N:P (averagely 11.803). Meanwhile, significant interspecific differences existed in plant stoichiometric traits. At the across-species level, N content scaled as the 3/4-power of P content in both leaves and roots. Leaf and root N:P ratios were mainly influenced by P; however, the leaf-to-root N or P ratio was dominated by roots. Leaf and root N, P contents and N:P were generally unrelated to soil nutrients, and the former presented lower variation than the latter, indicating a strong stoichiometric homeostasis for ephemerals. These results demonstrate that regardless of soil nutrient supply capacity in this region, the fast-growing ephemeral plants have formed a specific leaf-root-soil stoichiometric relation and nutrient use strategy adapting to the extreme desert environment.

Comprehensive Analysis Strategy of Nervous-Endocrine-Immune-Related Metabolites to Evaluate Arachidonic Acid as a Novel Diagnostic Biomarker in Depression.

Depression is one of the most complex multifactorial diseases affected by genetic and environmental factors. The molecular mechanism underlying depression remains largely unclear. To address this issue, a novel nervous-endocrine-immune (NEI) network module was used to find the metabolites and evaluate the diagnostic ability of patients with depression. During this process, metabolites were acquired from a professional depression metabolism database. Over-representation analysis was performed using IMPaLA. Then, the metabolite-metabolite interaction (MMI) network of the NEI system was used to select key metabolites. Finally, the receiver operating characteristic curve analysis was evaluated for the diagnostic ability of arachidonic acid. The results show that the numbers of the nervous system, endocrine system, and immune system pathways are 10, 19, and 12 and the numbers of metabolites are 38, 52, and 13, respectively. The selected shared metabolite-enriched pathways can be 97.56% of the NEI-related pathways. Arachidonic acid was extracted from the NEI system network by using an optimization formula and validated by in vivo experiments. It was indicated that the proposed model was good at screening arachidonic acid for the diagnosis of depression. This method provides reliable evidences and references for the diagnosis and mechanism research of other related diseases.

Transcriptomes analysis reveals novel insight into the molecular mechanisms of somatic embryogenesis in Hevea brasiliensis.

BACKGROUND: Somatic embryogenesis (SE) is a promising technology for plant vegetative propagation, which has an important role in tree breeding. Though rubber tree (Hevea brasiliensis Muell. Arg.) SE has been founded, few late SE-related genes have been identified and the molecular regulation mechanisms of late SE are still not well understood. RESULTS: In this study, the transcriptomes of embryogenic callus (EC), primary embryo (PE), cotyledonary embryo (CE), abnormal embryo (AE), mature cotyledonary embryo (MCE) and withered abnormal embryo (WAE) were analyzed. A total of 887,852,416 clean reads were generated, 85.92% of them were mapped to the rubber tree genome. The de novo assembly generated 36,937 unigenes. The differentially expressed genes (DEGs) were identified in the pairwise comparisons of CE vs. AE and MCE vs. WAE, respectively. The specific common DEGs were mainly involved in the phytohormones signaling pathway, biosynthesis of phenylpropanoid and starch and sucrose metabolism. Among them, hormone signal transduction related genes were significantly enriched, especially the auxin signaling factors (AUX-like1, GH3.1, SAUR32-like, IAA9-like, IAA14-like, IAA27-like, IAA28-like and ARF5-like). The transcription factors including WRKY40, WRKY70, MYBS3-like, MYB1R1-like, AIL6 and bHLH93-like were characterized as molecular markers for rubber tree late SE. CML13, CML36, CAM-7, SERK1 and LEAD-29-like were also related to rubber tree late SE. In addition, histone modification had crucial roles during rubber tree late SE. CONCLUSIONS: This study provides important information to elucidate the molecular regulation during rubber tree late SE.

Tobacco rattle virus-induced gene silencing in Hevea brasiliensis.

Virus-induced gene silencing (VIGS) is a powerful gene-silencing tool that has been intensively applied in plants. To data, the application of VIGS in rubber tree has not yet been reported. In this study, we described the efficient gene silencing in rubber tree by VIGS. The gene encoding Hevea brasiliensis phytoene desaturase (HbPDS) was identified in rubber tree genome. Small interfering RNAs from HbPDS and the silencing gene fragment were predicted and a length of 399 bp was selected to be tested. We showed that the tobacco rattle virus (TRV)-VIGS could induce effective HbPDS silencing in rubber tree. This study was the first to report VIGS in rubber tree. The present TRV-VIGS method could be used to perform reverse genetic approaches to identify unknown gene functions and might be further applied to produce gene silenced rubber tree plants, to advance functional gene of rubber tree.

Estrogen receptor 2 mediates intraspecific aggressive behaviors of the female Cricetulus barabensis in the estrous cycle.

The social behavior mechanisms have not been thoroughly reported in the solitary female striped dwarf hamster (Cricetulus barabensis). In this study, the handling bag test and neutral arena measurements were used to detect the changes of aggression in the face of rivals of different genders of wild striped dwarf hamsters. We found that female hamsters had the highest aggressive performance in proestrus, followed by estrus, and the lowest in metestrus and the dioestrus, and the increased aggression during the proestrus or estrus period was low-intensity aggression such as intimidation, shock, boxing and counterattack, or even ritualized non-harmful behaviors to drive away opponents. When confronted with male individuals, aggression in females decreased significantly during estrus. The concentration of plasma estradiol was the highest in estrus and the lowest in metestrus and dioestrus. In contrast, estrogen receptor 2 relative expression in the hypothalamus is the lowest in proestrus and highest in metestrus and dioestrus. Besides, both estradiol levels in plasma and estrogen receptor 2 mRNA in the hypothalamus were associated with aggression. These results will broaden our understanding of the molecular mechanism of how breeding phenotype is an essential driver in changing the social behavior of female Cricetulus barabensis.

Robustness improvement for cyber physical system based on an optimization model of interdependent constraints.

With the rapid development of information technology, traditional infrastructure networks have evolved into cyber physical systems (CPSs). However, this evolution has brought along with it cyber failures, in addition to physical failures, which can affect the safe and stable operation of the whole system. In light of this, in this paper, we propose an interdependence-constrained optimization model to improve the robustness of the cyber physical system. The proposed model includes not only the realistic physical law but also the interdependence between the physical network and the cyber network. However, this model is highly nonlinear and cannot be solved directly. Therefore, we transform the model into a bi-level mixed integer linear programming problem, which can be easily and effectively solved in polynomial time. We conduct the simulation based on standard Institute of Electrical and Electronics Engineers test cases and study the impact of the disaster level and coupling strength on the robustness of the whole system. The simulation results show that our proposed model can effectively improve the robustness of the cyber physical system. Moreover, we compare the performance of the power supply in different CPSs, which have different network structures of the cyber network. Our work can provide useful instructions for system operators to improve the robustness of CPSs after extreme events happen in them.

Fluoride absorption, transportation and tolerance mechanism in Camellia sinensis, and its bioavailability and health risk assessment: a systematic review.

Tea is the one of the most popular non-alcoholic caffeinated beverages in the world. Tea is produced from the tea plant (Camellia sinensis (L.) O. Kuntze), which is known to accumulate fluoride. This article systematically analyzes the literature concerning fluoride absorption, transportation and fluoride tolerance mechanisms in tea plants. Fluoride bioavailability and exposure levels in tea infusions are also reviewed. The circulation of fluoride within the tea plantation ecosystems is in a positive equilibrium, with greater amounts of fluoride introduced to tea orchards than removed. Water extractable fluoride and magnesium chloride (MgCl2 ) extractable fluoride in plantation soil are the main sources of absorption by tea plant root via active trans-membrane transport and anion channels. Most fluoride is readily transported through the xylem as F- /F-Al complexes to leaf cell walls and vacuole. The findings indicate that tea plants employ cell wall accumulation, vacuole compartmentalization, and F-Al complexes to co-detoxify fluoride and aluminum, a possible tolerance mechanism through which tea tolerates higher levels of fluoride than most plants. Furthermore, dietary and endogenous factors influence fluoride bioavailability and should be considered when exposure levels of fluoride in commercially available dried tea leaves are interpreted. The relevant current challenges and future perspectives are also discussed. © 2020 Society of Chemical Industry.

Wavefront reconstruction based on deep transfer learning for microscopy.

The application of machine learning in wavefront reconstruction has brought great benefits to real-time, non-invasive, deep tissue imaging in biomedical research. However, due to the diversity and heterogeneity of biological tissues, it is difficult to train the dataset with a unified model. In general, the utilization of some unified models will result in the specific sample falling outside the training set, leading to low accuracy of the machine learning model in some real applications. This paper proposes a sensorless wavefront reconstruction method based on transfer learning to overcome the domain shift introduced by the difference between the training set and the target test set. We build a weights-sharing two-stream convolutional neural network (CNN) framework for the prediction of Zernike coefficient, in which a large number of labeled randomly generated samples serve as the source-domain data and the unlabeled specific samples serve as the target-domain data at the same time. By training on massive labeled simulated data with domain adaptation to unlabeled target-domain data, the network shows better performance on the target tissue samples. Experimental results show that the accuracy of the proposed method is 18.5% higher than that of conventional CNN-based method and the peak intensities of the point spread function (PSF) are more than 20% higher with almost the same training time and processing time. The better compensation performance on target sample could have more advantages when handling complex aberrations, especially the aberrations caused by various histological characteristics, such as refractive index inhomogeneity and biological motion in biological tissues.

Novel ultrastructural findings on cardiac mitochondria of huddling Brandt's voles in mild cold environment.

Reduced ambient temperature has a damaging effect on mammalian myocardium. Huddling as a cooperative behavior has evolved in social mammals as a strategy to maximize adaptation to environmental cooling. Here, we studied the effects of huddling behavior on mitochondrial morphology, number, and function in the myocardia of Brandt's voles (Lasiopodomys brandtii) under cool environmental temperatures (15 °C). Results showed (1) mitochondrial swelling and cristae disruption in the cool huddling group (CH) and cool separated group (CS). Compared to the control group (CON, 22 °C), damaged mitochondria in the cool huddling and separated groups reached >90%; however, total number of mitochondria in the CH group was similar to that in the CON group. (2) ATP synthase activity was lowest in the CS group, whereas citrate synthetase activity was maintained among the three treatment groups. (3) Bax/bcl2 protein expression in the CH and CS groups was higher than that in the CON group, whereas DNA fragmentation, nuclear number, and caspase3 activity showed no significant differences among the three groups. (4) The protein expression levels of dynamin-related protein1 and mitochondrial fission factor were highest in the CH group. (5) Both protein expression of PINK1 and phosphorylation ratio of Parkin showed the pattern CS > CH > CON. (6) Total number of mitochondria was higher in males than in females. In general, the increased mitochondrial fission level observed in huddling voles partially counteracted the decrease in myocardial mitochondria caused by the increase in autophagy.

The first report of Cryptosporidium testudinis in Chinese alligators (Alligator sinensis) in China.

Several Cryptosporidium species that infect reptiles, especially squamates, are well described, but there is limited data about Cryptosporidium species infecting crocodilians. In this study, we assess the occurrence of intestinal parasites using traditional microscopic examination and describe the prevalence and Cryptosporidium species in the captive-bred Chinese alligators (Alligator sinensis) in eastern China using molecular methods. The results of microscopic examination showed that no intestinal parasites were detected among the 491 fecal samples examined from the Chinese alligators. The overall prevalence for Cryptosporidium was 0.41% (2/491) by PCR detection using the SSU rRNA locus. Sequence and phylogenetic analysis of the SSU rRNA, COWP, and actin genes revealed the presence of Cryptosporidium testudinis, which has been isolated primarily from chelonians. This is the first detection of the specific DNA of C. testudinis in the feces of the Chinese alligator. This study expands our knowledge of the Cryptosporidium species involved in crocodiles, and more extensive studies are necessary to confirm the validity of C. testudinis in crocodiles.

An asymmetric interdependent networks model for cyber-physical systems.

Cyber-physical systems (CPSs) are integrations of information technology and physical systems, which are more and more significant in society. As a typical example of CPSs, smart grids integrate many advanced devices and information technologies to form a safer and more efficient power system. However, interconnection with the cyber network makes the system more complex, so that the robustness assessment of CPSs becomes more difficult. This paper proposes a new CPS model from a complex network perspective. We try to consider the real dynamics of cyber and physical parts and the asymmetric interdependency between them. Simulation results show that coupling with the communication network makes better robustness of power system. But since the influences between the power and communication networks are asymmetric, the system parameters play an important role to determine the robustness of the whole system.

Positron-emitting tracer imaging of fluoride transport and distribution in tea plant.

BACKGROUND: Tea (Camellia sinensis (L.) O. Kuntze) is a hyper-accumulator of fluoride (F). To understand F uptake and distribution in living plants, we visually evaluated the real-time transport of F absorbed by roots and leaves using a positron-emitting (18 F) fluoride tracer and a positron-emitting tracer imaging system. RESULTS: F arrived at an aerial plant part about 1.5 h after absorption by roots, suggesting that tea roots had a retention effect on F, and then was transported upward mainly via the xylem and little via the phloem along the tea stem, but no F was observed in the leaves within the initial 8 h. F absorbed via a cut petiole (leaf 4) was mainly transported downward along the stem within the initial 2 h. Although F was first detected in the top and ipsilateral leaves, it was not detected in tea roots by the end of the monitoring. During the monitoring time, F principally accumulated in the node. CONCLUSION: F uptake by the petiole of excised leaf and root system was realized in different ways. The nodes indicated that they may play pivotal roles in the transport of F in tea plants. © 2020 Society of Chemical Industry.