Cloning and expression of pineapple sucrosephosphate synthase gene during fruit development

A 1132-base pairs (bp) polymerase-chain-reaction product of sucrose-phosphate synthase (SPS) (EC 2.3.1.14) from pineapple (Ananas comosus cv. Comte de paris) fruit was cloned and nominated as Ac- SPS1. The sequence encodes a putative 377 amino acids protein containing two serine conserved features that had been found in other plant SPS genes: the presence of a 14-3-3 protein special binding domain and an activated site of osmosis stress, which can been activated by phosphorylation and dephosphorylation. The Neighbour-joining tree revealed that Ac-SPS1 belonged to the first kind of sucrose phosphate synthase gene. The results indicated that, the Ac-SPS1 expression was low in the earlier period of fruit growth, then, increasing from 20 days after anthesis and gradually a falling on 40 days, reached the peak with the highest value around 70 days. The SPS activity and sucrose content reached their maximum 80 days after anthesis. It proved that the  accumulation of sucrose was correlated with SPS activity and mRNA content and it maximally occurred at 10 d after SPS mRNA and activity had reached its maxima. These results indicated that Ac-SPS1 gene played a key role in sucrose accumulation during the pineapple fruit development and transcriptional activation with increase in Ac- SPS1 expression might be important regulatory events of sugar during pineapple fruit maturation.Key words: Pineapple fruit, sucrose phosphate synthase, gene cloning, expression

Feature extraction of vibration signal using OMP-NWE method

Feature extraction is one of the core problems in condition monitoring and fault diagnosis of mechanical equipment. In this study, an OMP-NWE method of feature extraction is proposed, aiming at the problem of low accuracy of existing feature extraction method. The OMP-NWE method integrates the strengths of orthogonal matching pursuit (OMP) algorithm with the benefits of nonparametric waveform estimation (NWE). Signal feature extraction model is constructed by design of filter bank and adaptive template signal. Then the vibration signal is linearly decomposed into a set of best matching waveform, which solves the problem that the basis function must be chosen in advance in OMP algorithm. The OMP-NWE method is applied to the feature extraction of the simulation and experimental vibration signal of rolling bearing, compared with the traditional OMP algorithm. Results show that the SNR of the extracted feature signal using OMP-NWE method increased by 19.22 % compared with that using the OMP method, which illustrates that OMP-NWE method has a higher accuracy in the feature extraction of unknown complex vibration signals. This work provides a new idea and a successful example for the feature extraction of vibration signal in the condition monitoring and fault diagnosis of mechanical equipment

LPI-IBNRA: Long Non-coding RNA-Protein Interaction Prediction Based on Improved Bipartite Network Recommender Algorithm

According to the latest research, lncRNAs (long non-coding RNAs) play a broad and important role in various biological processes by interacting with proteins. However, identifying whether proteins interact with a specific lncRNA through biological experimental methods is difficult, costly, and time-consuming. Thus, many bioinformatics computational methods have been proposed to predict lncRNA-protein interactions. In this paper, we proposed a novel approach called Long non-coding RNA-Protein Interaction Prediction based on Improved Bipartite Network Recommender Algorithm (LPI-IBNRA). In the proposed method, we implemented a two-round resource allocation and eliminated the second-order correlations appropriately on the bipartite network. Experimental results illustrate that LPI-IBNRA outperforms five previous methods, with the AUC values of 0.8932 in leave-one-out cross validation (LOOCV) and 0.8819 ± 0.0052 in 10-fold cross validation, respectively. In addition, case studies on four lncRNAs were carried out to show the predictive power of LPI-IBNRA

Anaerobic copper toxicity and iron-sulfur cluster biogenesis in Escherichia coli

© 2017 American Society for Microbiology. While copper is an essential trace element in biology, pollution of groundwater from copper has become a threat to all living organisms. Cellular mechanisms underlying copper toxicity, however, are still not fully understood. Previous studies have shown that iron-sulfur proteins are among the primary targets of copper toxicity in Escherichia coli under aerobic conditions. Here, we report that, under anaerobic conditions, iron-sulfur proteins in E. coli cells are even more susceptible to copper in medium. Whereas addition of 0.2 mM copper(II) chloride to LB (Luria-Bertani) medium has very little or no effect on iron-sulfur proteins in wild-type E. coli cells under aerobic conditions, the same copper treatment largely inactivates iron-sulfur proteins by blocking iron-sulfur cluster biogenesis in the cells under anaerobic conditions. Importantly, proteins that do not have iron-sulfur clusters (e.g., fumarase C and cysteine desulfurase) in E. coli cells are not significantly affected by copper treatment under aerobic or anaerobic conditions, indicating that copper may specifically target iron-sulfur proteins in cells. Additional studies revealed that E. coli cells accumulate more intracellular copper under anaerobic conditions than under aerobic conditions and that the elevated copper content binds to the iron-sulfur cluster assembly proteins IscU and IscA, which effectively inhibits iron-sulfur cluster biogenesis. The results suggest that the copper-mediated inhibition of iron-sulfur proteins does not require oxygen and that iron-sulfur cluster biogenesis is the primary target of anaerobic copper toxicity in cells

Encephalitic alphaviruses exploit caveola-mediated transcytosis at the blood-brain barrier for central nervous system entry

Venezuelan and western equine encephalitis viruses (VEEV and WEEV, respectively) invade the central nervous system (CNS) early during infection, via neuronal and hematogenous routes. While viral replication mediates host shutoff, including expression of type I interferons (IFN), few studies have addressed how alphaviruses gain access to the CNS during established infection or the mechanisms of viral crossing at the blood-brain barrier (BBB). Here, we show that hematogenous dissemination of VEEV and WEEV into the CNS occurs via caveolin-1 (Cav-1)-mediated transcytosis (Cav-MT) across an intact BBB, which is impeded by IFN and inhibitors of RhoA GTPase. Use of reporter and nonreplicative strains also demonstrates that IFN signaling mediates viral restriction within cells comprising the neurovascular unit (NVU), differentially rendering brain endothelial cells, pericytes, and astrocytes permissive to viral replication. Transmission and immunoelectron microscopy revealed early events in virus internalization and Cav-1 association within brain endothelial cells. Cav-1-deficient mice exhibit diminished CNS VEEV and WEEV titers during early infection, whereas viral burdens in peripheral tissues remained unchanged. Our findings show that alphaviruses exploit Cav-MT to enter the CNS and that IFN differentially restricts this process at the BBB

A Hybrid Mechanism Forming a 2:1 Librating-Circulating Resonant Configuration in the Planetary System

A diversity of resonance configurations may be formed under different migration of two giant planets. And the researchers show that the HD 128311 and HD 73526 planetary systems are involved in a 2:1 mean motion resonance but not in apsidal corotation, because one of the resonance argument circulates over the dynamical evolution. In this paper, we investigate potential mechanisms to form the 2:1 librating-circulating resonance configuration. In the late stage of planetary formation, scattering or colliding among planetesimals and planetary embryos can frequently occur. Hence, in our model, we consider a planetary configuration of two giants together with few terrestrial planets. We find that both colliding or scattering events at very early stage of dynamical evolution can influence the configurations trapped into resonance. A planet-planet scattering of a moderate terrestrial planet, or multiple scattering of smaller planets in a crowded planetary system can change the resonant configuration. In addition, collision or merging can alter the masses and location of the giant planets, which also play an important role in shaping the resonant configuration during the dynamical evolution. In this sense, the librating-circulating resonance configuration is more likely to form by a hybrid mechanism of scattering and collision.Comment: 8 pages, 5 figures, 2 Tables, accepted for publication in MNRA

Difference between arterial and venous peak optical density after thrombectomy is associated with functional outcomes

BackgroundThe density of contrast medium in digital subtraction angiography (DSA) have been used to evaluate the cerebral circulation function. Our aim was to study the effect of difference in arteriovenous peak optical density (POD) after thrombectomy on functional outcomes.MethodsConsecutive patients with acute ischemic stroke due to large vessel occlusion who underwent thrombectomy were reviewed. We processed DSA images with ImageJ software to measure the POD of internal carotid artery (ICA) and cortical veins. The average POD of cortical veins (PODVA) and the POD difference between ICA and cortical veins (PODICA-CV) were calculated. Primary outcome was good functional outcome (modified Rankin scale score of 0–2 at 90 days).ResultsOne hundred sixty-six patients were finally included in the study. Patients with good functional outcome had lower ipsilateral PODVA (median [interquartile range (IQR)], 257.198 [216.623–296.631] vs. 290.944 [248.647–338.819], p < 0.001) and lower ipsilateral PODICA-CV (median [IQR], 128.463 [110.233–153.624] vs. 182.01 [146.621–211.331], p < 0.001). Multivariable logistic regression analyses showed that ipsilateral PODVA (odds ratio [OR] 0.991, 95% confidence interval [CI] 0.984–0.999, p = 0.019) and ipsilateral PODICA-CV (OR 0.975, 95% CI 0.963–0.986, p < 0.001) were associated with good functional outcome. The predictive ability was significantly enhanced in the model including ipsilateral PODICA-CV (0.893 vs. 0.842, p = 0.027). No correlation was found between ipsilateral PODICA-CV and expanded Thrombolysis in Cerebral Infarction grades (r = −0.133, p = 0.099).ConclusionIpsilateral PODICA-CV is an additional indicator of cerebral reperfusion status and predicts functional outcomes after thrombectomy