45 research outputs found

    Wpływ tributylocyny na przyjmowanie pokarmu i ekspresję neuropeptydów w mózgu szczurów

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    Introduction: Tributyltin (TBT) is a largely diffused environmental pollutant. Several studies have demonstrated that TBT is involved in the development of obesity. However, few studies addressing the effects of TBT on the brain neuropeptides involved in appetite and body weight homeostasis have been published.Material and methods: Experiments were carried out on female and male Sprague-Dawley rats. Animals were exposed to TBT (0.5 μg/kg body weight) for 54 days. The hepatic triglyceride and total cholesterol were determined using commercial enzyme kits. The NPY, AgRP, POMC and CART mRNA expression in brains were quantified by real-time PCR.Results: TBT exposure resulted in significant increases in the hepatic total cholesterol and triglyceride concentration of both male and female rats. Interestingly, increases in body weight and fat mass were only found in the TBT-treated male rats. TBT exposure also led to a significant increase in food intake by the female rats, while no change was observed in the male rats. Moreover, the neuropeptides expression was different between males and females after TBT exposure. TBT induced brain NPY expression in the female rats, and depressed brain POMC, AgRP and CART expression in the males.Conclusions: TBT can increase food intake in female rats, which is associated with the disturbance of NPY in brains. TBT had sex-different effects on brain NPY, AgRP, POMC and CART mRNA expression, which indicates a complex neuroendocrine mechanism of TBT. (Endokrynol Pol 2014; 65 (6): 485–490)Wstęp: Tributylocyna (TBT) jest powszechnie występującym w środowisku zanieczyszczeniem. Prowadzone dotychczas badania wykazały, że obecność TBT może mieć związek z rozwojem otyłości. Niewiele jest jednak doniesień na temat wpływu TBT na układ neuropeptydów w mózgowiu regulujących łaknienie i utrzymanie masy ciała. Materiał i metody: Doświadczenia przeprowadzono na szczurach obu płci szczepu Sprague-Dawley. Zwierzętom podawano przez 54 dni TBT w dawce 0,5 μg/kg masy ciała. Stężenie triglicerydów i całkowite stężenie cholesterolu w wątrobie oznaczano przy użyciu komercyjnych zestawów analitycznych. Obecność mRNA NPY, AgRP, POMC i CART w mózgach szczurów oznaczano metodą PCR w czasie rzeczywistym (real time-PCR).Wyniki: Ekspozycja na TBT powodowała istotne zwiększenie całkowitego stężenia cholesterolu i trójglicerydów w wątrobie zarówno samców, jak i samic szczura. Co ciekawe, zwiększenie masy ciała i masy tkanki tłuszczowej odnotowano jedynie u samców, którym podawano TBT. Stwierdzono także istotne zwiększenie ilości pokarmu przyjmowanego przez samice, natomiast nie obserwowano takich zmian u samców. Ponadto, odnotowano różnice w ekspresji neuropeptydów w mózgowiu samic i samców szczura, którym podawano TBT. Ekspozycja na TBT nasilała ekspresję NPY w mózgach samic, ale równocześnie zmniejszała ekspresję POMC, AgRP i CART w mózgach samców szczura.Wnioski: Ekspozycja na TBT może zwiększać ilość pokarmu spożywanego przez samice szczura, co wiąże się z zaburzeniem układu NPY w mózgowiu. Trybutylocyna wywiera odmienny wpływ na ekspresję mRNA NPY, AgRP, POMC i CART w mózgach samców i samic szczura, co wskazuje na istnienie złożonego mechanizmu działania tej substancji na układ neuroendokrynny. (Endokrynol Pol 2014; 65 (6): 485–490

    Efficient Behavior-consistent Calibration for Multi-agent Market Simulation

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    Order-driven market simulation mimics the trader behaviors to generate order streams to support interactive studies of financial strategies. In market simulator, the multi-agent approach is commonly adopted due to its explainability. Existing multi-agent systems employ heuristic search to generate order streams, which is inefficient for large-scale simulation. Furthermore, the search-based behavior calibration often leads to inconsistent trader actions under the same general market condition, making the simulation results unstable and difficult to interpret. We propose CaliSim, the first search-free calibration approach multi-agent market simulator which achieves large-scale efficiency and behavior consistency. CaliSim uses meta-learning and devises a surrogate trading system with a consistency loss function for the reproducibility of order stream and trader behaviors. Extensive experiments in the market replay and case studies show that CaliSim achieves state-of-the-art in terms of order stream reproduction with consistent trader behavior and can capture patterns of real markets

    Differentiation in stem and leaf traits among sympatric lianas, scandent shrubs and trees in a subalpine cold temperate forest

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    The scandent shrub plant form is a variant of liana that has upright and self-supporting stems when young but later becomes a climber. We aimed to explore the associations of stem and leaf traits among sympatric lianas, scandent shrubs and trees, and the effects of growth form and leaf habit on variation in stem or leaf traits. We measured 16 functional traits related to stem xylem anatomy, leaf morphology and nutrient stoichiometry in eight liana, eight scandent shrub and 21 tree species co-occurring in a subalpine cold temperate forest at an elevation of 2600–3200 m in Southwest China. Overall, lianas, scandent shrubs and trees were ordered along a fast-slow continuum of stem and leaf functional traits, with some traits overlapping. We found a consistent pattern of lianas > scandent shrubs > trees for hydraulically weighted vessel diameter, maximum vessel diameter and theoretical hydraulic conductivity. Vessel density and sapwood density showed a pattern of lianas = scandent shrubs < trees, and lianas < scandent shrubs = trees, respectively. Lianas had significantly higher specific leaf area and lower carbon concentration than co-occurring trees, with scandent shrubs showing intermediate values that overlapped with lianas and trees. The differentiation among lianas, scandent shrubs and trees was mainly explained by variation in stem traits. Additionally, deciduous lianas were positioned at the fast end of the trait spectrum, and evergreen trees at the slow end of the spectrum. Our results showed for the first time clear differentiation in stem and leaf traits among sympatric liana, scandent shrub and tree species in a subalpine cold temperate forest. This work will contribute to understanding the mechanisms responsible for variation in ecological strategies of different growth forms of woody plants

    Effects of increased phosphorus fertilizer on C, N, and P stoichiometry in different organs of bluegrass (Poa L.) at different growth stages

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    IntroductionThe application of phosphorus (P) fertilizer can promote photosynthesis in forage grasses and accelerate their establishment.MethodsTo improve the utilization efficiency of P fertilizer for bluegrass (Poa L.) in alpine regions, the effects of P fertilizer on their growth, and carbon (C), nitrogen (N) and P distribution in their different organs of them are tested at six P fertilization levels (3, 6, 9, 12, 15, 18 g·m−2).Results(1) The nutrient content in each organ of bluegrass varies during different growth stages, with the lowest nutrient content occurring in the wilt stage. (2) The response of the nutrient content and ratio of each organ of bluegrass to different P fertilization levels varies. When the P application rate was 15 g·m−2, the contents of N and P in roots were the highest, and their C/N and C/P ratios were the lowest. When the P application rate was 12 g·m−2, the contents of N and P in the stems were the highest, and their C/N and C/P ratios were the lowest. When the P application rate was 9 g·m−2, the contents of N and P in leaves were the highest, and their C/N and C/P ratios were the lowest. When the P application rate was 6 g·m−2 the contents of N and P in the panicle were the highest, and their C/N and C/P ratios were the lowest.DiscussionThese results provide a better understanding of the effect of P fertilization in the nutrient partitioning pattern of perennial forage plant organs in alpine regions. The information from this study can support a more reasonable P fertilization for the establishment of early grassland. For example, in artificial forage grassland, the application of low-concentration P fertilizer (6~9 g·m−2) can promote the nutrient content in spikes and stems of forage grass; for ecological management, the application of high-concentration P fertilizer (15 g·m−2) can promote the nutrient content in roots and enhance the ecological benefits of forage grassland

    Hijacking common mycorrhizal networks for herbivore-induced defence signal transfer between tomato plants

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    Common mycorrhizal networks (CMNs) link multiple plants together. We hypothesized that CMNs can serve as an underground conduit for transferring herbivore-induced defence signals. We established CMN between two tomato plants in pots with mycorrhizal fungus Funneliformis mosseae, challenged a ‘donor' plant with caterpillar Spodoptera litura, and investigated defence responses and insect resistance in neighbouring CMN-connected ‘receiver' plants. After CMN establishment caterpillar infestation on ‘donor' plant led to increased insect resistance and activities of putative defensive enzymes, induction of defence-related genes and activation of jasmonate (JA) pathway in the ‘receiver' plant. However, use of a JA biosynthesis defective mutant spr2 as ‘donor' plants resulted in no induction of defence responses and no change in insect resistance in ‘receiver' plants, suggesting that JA signalling is required for CMN-mediated interplant communication. These results indicate that plants are able to hijack CMNs for herbivore-induced defence signal transfer and interplant defence communication

    Vomiting and wasting disease associated with hemagglutinating encephalomyelitis viruses infection in piglets in jilin, china

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    One coronavirus strain was isolated from brain tissues of ten piglets with evident clinical manifestations of vomiting, diarrhea and dyskinesia in Jilin province in China. Antigenic and genomic characterizations of the virus (isolate PHEV-JLsp09) were based on multiplex PCR and negative staining electron microscopy and sequence analysis of the Hemagglutinin-esterase (HE) gene. These piglets were diagnosed with Porcine hemagglutinating encephalomyelitis virus (PHEV)

    Draft genome sequence of the mulberry tree Morus notabilis

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    Human utilization of the mulberry–silkworm interaction started at least 5,000 years ago and greatly influenced world history through the Silk Road. Complementing the silkworm genome sequence, here we describe the genome of a mulberry species Morus notabilis. In the 330-Mb genome assembly, we identify 128 Mb of repetitive sequences and 29,338 genes, 60.8% of which are supported by transcriptome sequencing. Mulberry gene sequences appear to evolve ~3 times faster than other Rosales, perhaps facilitating the species’ spread worldwide. The mulberry tree is among a few eudicots but several Rosales that have not preserved genome duplications in more than 100 million years; however, a neopolyploid series found in the mulberry tree and several others suggest that new duplications may confer benefits. Five predicted mulberry miRNAs are found in the haemolymph and silk glands of the silkworm, suggesting interactions at molecular levels in the plant–herbivore relationship. The identification and analyses of mulberry genes involved in diversifying selection, resistance and protease inhibitor expressed in the laticifers will accelerate the improvement of mulberry plants

    Stability Precision Error Correction of Photoelectric Detection by Unmanned Aerial Vehicle

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    For getting clear images and overcoming shaking caused by various disturbances, real-time compensation of pointing errors will improve the overall stability performance of photoelectric detection by unmanned aerial vehicle. However, the compensation will be greatly deteriorated by error-causing sources, and the error correction process is of great importance. In this research, the problem of stability precision error correction is comprehensively studied. First, by modeling overall kinematics, error-causing sources, and error compensation, the error correction process is mathematically modeled and simulated. Then, by using simulation data regression, error correction models including the global function model and parametric model are established. The models are validated by carrying out both simulations and validation experiments. At last, the performances of the error correction models are compared and analyzed, which concerns the factors of parameter identification, model simplicity, and final improvement effect. Results show that the final stability precision can be greatly improved over 20%, and the parametric model outperforms the global function model comprehensively. It can be concluded that, either in simulation environment or real application scenarios, the obtained models and related analysis results are effective in improving the system stability performance

    Analysis of Multi-Objective Optimization of Machining Allowance Distribution and Parameters for Energy Saving Strategy

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    Machining allowance distribution and related parameter optimization of machining processes have been well-discussed. However, for energy saving purposes, the optimization priorities of different machining phases should be different. There are often significant incoherencies between the existing research and real applications. This paper presents an improved method to optimize machining allowance distribution and parameters comprehensively, considering energy-saving strategy and other multi-objectives of different phases. The empirical parametric models of different machining phases were established, with the allowance distribution problem properly addressed. Based on previous analysis work of algorithm performance, non-dominated sorting genetic algorithm II and multi-objective evolutionary algorithm based on decomposition were chosen to obtain Pareto solutions. Algorithm performances were compared based on the efficiency of finding the Pareto fronts. Two case studies of a cylindrical turning and a face milling were carried out. Results demonstrate that the proposed method is effective in trading-off and finding precise application scopes of machining allowances and parameters used in real production. Cutting tool life and surface roughness can be greatly improved for turning. Energy consumption of rough milling can be greatly reduced to around 20% of traditional methods. The optimum algorithm of each case is also recognized. The proposed method can be easily extended to other machining scenarios and can be used as guidance of process planning for meeting various engineering demands
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