789 research outputs found

    Microbial community pattern detection in human body habitats via ensemble clustering framework

    Full text link
    The human habitat is a host where microbial species evolve, function, and continue to evolve. Elucidating how microbial communities respond to human habitats is a fundamental and critical task, as establishing baselines of human microbiome is essential in understanding its role in human disease and health. However, current studies usually overlook a complex and interconnected landscape of human microbiome and limit the ability in particular body habitats with learning models of specific criterion. Therefore, these methods could not capture the real-world underlying microbial patterns effectively. To obtain a comprehensive view, we propose a novel ensemble clustering framework to mine the structure of microbial community pattern on large-scale metagenomic data. Particularly, we first build a microbial similarity network via integrating 1920 metagenomic samples from three body habitats of healthy adults. Then a novel symmetric Nonnegative Matrix Factorization (NMF) based ensemble model is proposed and applied onto the network to detect clustering pattern. Extensive experiments are conducted to evaluate the effectiveness of our model on deriving microbial community with respect to body habitat and host gender. From clustering results, we observed that body habitat exhibits a strong bound but non-unique microbial structural patterns. Meanwhile, human microbiome reveals different degree of structural variations over body habitat and host gender. In summary, our ensemble clustering framework could efficiently explore integrated clustering results to accurately identify microbial communities, and provide a comprehensive view for a set of microbial communities. Such trends depict an integrated biography of microbial communities, which offer a new insight towards uncovering pathogenic model of human microbiome.Comment: BMC Systems Biology 201

    Design and Testing of an Online Fertilizing Amount Detection Device Based on the Moment Balance Principle

    Get PDF
    Based on the principle of moment balance, this paper designs a fertilizer application amount online detection device, which is mainly composed of two major parts: the fertilizer guide mechanism and the fertilizer metering and discharging mechanism.Under the electromagnetic reversing and buffering of the fertilizer guide mechanism, the fertilizer discharged into the device falls alternately into the storage box of the two metering units of the metering and discharging mechanism. Once the gravity of the fertilizer in the storage box is greater than the suction of the electromagnetic sucker, the fertilizer discharging board is automatically opened for fertilizer discharge, and the metering pulse signal is accumulated once. Meanwhile, the fertilizer guide plate is driven by the electromagnetic commutator to reverse the material, and then another storage box is started for fertilizer storage and metering. In this approach, online detection of fertilizer flow can be realized by repeatedly guiding and reversing and metering the incoming fertilizer. According to the single metering fertilizer quality and the number of metering pulse signals, the fertilization amount can be calculated in real-time.The performance of the device was verified by bench test. The test results indicated that: The established fertilizer application detection model is a quadratic function (R2>0.98), and the verification error was less than 3.73% in the detection of alternating cycle fertilizer discharge; the coefficient of determination (R2) and the root mean square error (RMSE) reached 0.992 and 9.858 respectively, indicating high detection accuracy of the device is

    Performance of Arrhenotokous and Thelytokous Thrips tabaci (Thysanoptera: Thripidae) on Onion and Cabbage and Its Implications on Evolution and Pest Management

    Get PDF
    Onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), is an important pest on onion and cabbage. Two reproductive modes—arrhenotoky and thelytoky—are found in this species and co-occur in the field. We compared life table traits between arrhenotokous and thelytokous T. tabaci on cabbage and onion. Experiments were conducted in cages to determine which reproductive mode is more competitive. Additionally, host adaption of the arrhenotokous and thelytokous T. tabaci between onion and cabbage was investigated. On onion, arrhenotokous T. tabaci performed better than thelytokous T. tabaci, while on cabbage the opposite occurred. When comparing life table and demographic growth parameters (net reproductive rates R0, mean generation time T, the intrinsic rate of natural increase rm, finite rate of increase λ, and population doubling time Td) on different host plants, we found that arrhenotokous T. tabaci performed better on onion than on cabbage, whereas thelytokous T. tabaci performed better on cabbage than on onion. Host-related performance differences in this species suggest that the divergence between two reproductive modes might be associated with host adaption. Pest management strategies for this global pest should recognize that the two reproductive modes can impact population dynamics on different crop

    Posterior Nutcracker Syndrome Associated with Interrupted Left Inferior Vena Cava with Azygos Continuation and Retroaortic Right Renal Vein

    Get PDF
    Various anatomic anomalies have been considered the causes of nutcracker syndrome (NCS). Posterior NCS refers to the condition, in which vascular narrowing was secondary to the compression of the retroaortic left renal vein while it is crossing between the aorta and the vertebral column. Here, we report an unusual case of posterior NCS associated with a complicated malformation of the interrupted left inferior vena cava with azygos continuation and retroaortic right renal vein, diagnosed by both color Doppler ultrasonography and CT angiography
    corecore