8 research outputs found

    Optimization of culturing conditions for isolated Arthrobacter sp. ZXY-2, an effective atrazine-degrading and salt-adaptive bacterium

    No full text
    The increasing salinity in aquatic environments has had a negative impact on the biodegradation of atrazine, an extensively used herbicide which has been proven to pollute soil and water ecosystems. In the present study, a novel atrazine-degrading strain (ZXY-2) was isolated from industrial wastewater and identified as the Arthrobacter genus with the 16S rRNA gene. Results indicated that the strain showed a high salinity tolerance, and was able to tolerate NaCl concentrations up to 10% (w/w). Plackett–Burman (PB) multifactorial design and response surface methodology (RSM) were then employed to optimize the culturing conditions. Results showed that among the selected fifteen factors, six contributing factors were obtained. Subsequently, by employing the RSM to model and optimize atrazine degradation, a biodegradation efficiency of 12.73 mg L−1 h−1 was reached under optimal conditions (34.04 °C, pH 9.0, inoculum size 10% (v/v), 2.212 g L−1 of sucrose, 6 g L−1 of Na2HPO4·12H2O, and 50 mg L−1 of atrazine). In addition, a statistically quadratic polynomial mathematical model was suggested (R2 = 0.9873). In contrast to other atrazine-degrading bacteria, ZXY-2 appears to be adapted to life under high salinity conditions and sustains excellent atrazine degradation performance. Therefore it could potentially be applied in atrazine bioremediation.Sanitary Engineerin

    Asymmetric Excitation of Surface Plasmon Polaritons via Paired Slot Antennas for Angstrom Displacement Sensing

    No full text
    Optical antennas enable efficient coupling between propagating light and bonding electromagnetic waves like surface plasmon polaritons (SPPs). Under the illumination of inhomogeneous optical fields, propagating SPPs mediated by multimode antennas could be spatially asymmetric and the asymmetry strongly depends on the position of the antennas relative to the illumination field. Here we develop such asymmetric excitation of SPPs through illuminating a pair of slot antennas with the (1,0) mode Hermite-Gaussian beam. The physical scenario of the interaction between the illumination optical field and the paired slot antennas are elaborated by full-wave electromagnetic simulations. We also carry out experiments to monitor the asymmetric SPPs propagation with a back-focal plane imaging technique. By retrieving the asymmetric intensity ratio of the SPP pattern in the back-focal plane image, lateral displacement of the antennas down to angstrom level is demonstrated. ImPhys/Optic

    A Self-Bias-Flip with Charge Recycle Interface Circuit with No External Energy Reservoir for Piezoelectric Energy Harvesting Array

    No full text
    This article presents a piezoelectric energy harvesting (PEH) interface circuit using a new self-bias-flip with the charge recycle (SBFR) technique without employing any additional energy reservoir. Traditional designs, including synchronous-switch harvesting on inductor (SSHI), synchronous-switch harvesting on capacitor (SSHC), synchronous electric charge extraction (SECE), etc., require additional capacitors or inductors to reverse the voltage on the PEH at the zero-crossing point. This design innovatively uses the inherent capacitors of the piezoelectric harvesters as the flipping capacitors. In order to improve the extract efficiency of the interface, the zero-crossing state is split into a charge recycle stage and a voltage-flip stage. For a piezoelectric array with 2^n PEHs, a configuration with (n-1) phases in the charge recycle stage is adopted to reduce the loss caused by direct charge neutralization. The charge redistribution loss is reduced by employing (2n+1) phases in the voltage-flip stage. The proposed principle has been implemented with discrete components and is verified by three different prototypes. The measurement results show that a flipping efficiency of 67% is achieved by utilizing SBFR with four PEHs. And the proposed interface can provide up to 5.2x improvement when compared with the full-bridge rectifier (FBR).Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Instrumentatio

    Hyunsoonleella rubra sp nov., isolated from coastal sediment

    No full text
    A novel Gram-stain-negative, aerobic, rod-shaped, non-flagellated and non-gliding bacterium, designated FA042 T, was isolated from a marine sediment sample collected from the coast of Weihai, China ( 37 degrees 32' 02 '' N 122 degrees 03' 44 '' E). Optimal growth occurred at 33 degrees C, pH 7.0-7.5 and in the presence of 2-3% ( w/ v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain FA042 T belonged to the genus Hyunsoonleella. The closest described neighbour, in terms of 16S rRNA gene sequence identity, was Hyunsoonleella jejuensis ( 95.0 %). The major fatty acids were iso-C-15 : 0, iso-C-15 : 1 G, C15 : 0, iso-C-17 : 0 3-OH and iso-C-15 : 0 3-OH. The major respiratory quinone was MK-6. The major polar lipids of strain FA042(T) were phosphatidylethanolamine, three unidentified lipids and two unidentified aminolipids. The DNA G+ C content was 38.5 mol%. Based on its phylogenetic and phenotypic characteristics, strain FA042 T is presented as a representative of a novel species, for which the name Hyunsoonleella rubra sp. nov. is proposed. The type strain of Hyunsoonleella rubra sp. nov. is FA042(T) (= KCTC 42398(T) = MCCC 1H00110(T))

    BDgene: A Genetic Database for Bipolar Disorder and Its Overlap With Schizophrenia and Major Depressive Disorder

    No full text
    Background: Bipolar disorder (BD) is a common psychiatric disorder with complex genetic architecture. It shares overlapping genetic influences with schizophrenia (SZ) and major depressive disorder (MDD). Large numbers of genetic studies of BD and cross-disorder studies between BD and SZ/MDD have accumulated numerous genetic data. There is a growing need to integrate the data to provide a comprehensive data set to facilitate the genetic study of BD and its highly relevant diseases. Methods: BDgene database was developed to integrate BD-related genetic factors and shared ones with SZ/MDD from profound literature reading. On the basis of data from the literature, in-depth analyses were performed for further understanding of the data, including gene prioritization, pathway-based analysis, intersection analysis of multidisease candidate genes, and pathway enrichment analysis. Results: BDgene includes multiple types of literature-reported genetic factors of BD with both positive and negative results, including 797 genes, 3119 single nucleotide polymorphisms, and 789 regions. Shared genetic factors such as single nucleotide polymorphisms, genes, and regions from published cross-disorder studies among BD and SZ/MDD were also presented. In-depth data analyses identified 43 BD core genes; 70 BD candidate pathways; and 127, 79, and 107 new potential cross-disorder genes for BD-SZ, BD-MDD, and BD-SZ-MDD, respectively. Conclusions: As a central genetic database for BD and the first cross-disorder database for BD and SZ/MDD, BDgene provides not only a comprehensive review of current genetic research but also high-confidence candidate genes and pathways for understanding of BD mechanism and shared etiology among its relevant diseases. BDgene is freely available at http://bdgene.psych.ac.cn

    ADHDgene: a genetic database for attention deficit hyperactivity disorder

    No full text
    With a worldwide prevalence of similar to 5%, attention deficit hyperactivity disorder (ADHD) has become one of the most common psychiatric disorders. The polygenetic nature of ADHD indicates that multiple genes jointly contribute to the development of this complex disease. Studies aiming to explore genetic susceptibility of ADHD have been increasing in recent years. There is a growing need to integrate the genetic data from various genetic studies to provide a comprehensive data set and uniform access for convenience of in-depth data mining. So far, there has been no such effort for ADHD. To address the genetic complexity of ADHD, we developed the ADHDgene database by integrating ADHD-related genetic factors by profound literature reading. Based on the data from the literature, extended functional analysis, including linkage disequilibrium analysis, pathway-based analysis and gene mapping were performed to provide new insights into genetic causes of ADHD. Moreover, powerful search tools and a graphical browser were developed to facilitate the navigation of the data and data connections. As the first genetic database for ADHD, ADHDgene aims to provide researchers with a central genetic resource and analysis platform for ADHD and is freely available at http://adhd.psych.ac.cn/

    Community-weighted mean traits but not functional diversity determine the changes in soil properties during wetland drying on the Tibetan Plateau

    No full text
    Climate change and human activities have caused a shift in vegetation composition and soil biogeochemical cycles of alpine wetlands on the Tibetan Plateau. The primary goal of this study was to test for associations between community-weighted mean (CWM) traits, functional diversity, and soil properties during wetland drying. We collected soil samples and investigated the aboveground vegetation in swamp, swamp meadow, and typical meadow environments. Four CWM trait values (specific leaf area is SLA, leaf dry matter content is LDMC, leaf area is LA, and mature plant height is MPH) for 42 common species were measured across the three habitats; three components of functional diversity (functional richness, functional evenness, and functional divergence) were also quantified at these sites. Our results showed that the drying of the wetland dramatically altered plant community and soil properties. There was a significant correlation between CWM of traits and soil properties, but not a significant correlation between functional diversity and soil properties. Our results further showed that CWM-LA, CWM-SLA, and CWM-LDMC had positive correlations with soil readily available nutrients (available nitrogen, AN; available phosphorus, AP), but negative correlations with total soil nutrients (soil organic carbon is SOC, total nitrogen is TN, and total phosphorus is TP). Our study demonstrated that simple, quantitative plant functional traits, but not functional diversity, are directly related to soil C and N properties, and they likely play an important role in plant-soil interactions. Our results also suggest that functional identity of species may be more important than functional diversity in influencing ecosystem processes during wetland drying

    Community-level trait responses and intra-specific trait variability play important roles in driving community productivity in an alpine meadow on the Tibetan Plateau

    No full text
    Aims Human activities have dramatically increased nutrient inputs to ecosystems, impacting plant community diversity, composition and functioning. Extensive research has shown that a decrease in species diversity and an increase in productivity are a common phenomenon following fertilization in grasslands ecosystem. The magnitude of the response of species diversity and above-ground net primary productivity (ANPP) to fertilization mainly depends on species traits (mean trait values) and traits variability (plasticity). Our aim of this study was to examine (i) changes of species diversity (species richness and Shannon-Wiener index) and ANPP following fertilization; (ii) which species traits or community-weighted mean (CWM) traits can determine ANPP, as expected from the 'biomass ratio hypothesis'; and (iii) the relative role of intra-specific and inter-specific trait variability in this process following fertilization. Methods We measured ANPP and four key plant functional traits: specific leaf area (SLA), leaf dry matter content (LDMC), mature plant height (MPH) and leaf nitrogen concentration (LNC) for 25 component species along a fertilization gradient in an alpine meadow on the Tibetan Plateau. In addition, trait variation of species was assessed using coefficients of variation (CV), and we calculated the ratio of the CVintra to the CVinter. Important Findings Our results showed that: (i) fertilization significantly reduced species richness and Shannon-Weiner diversity index, but significantly increased ANPP; (ii) there was a significant positive correlation between ANPP and CWM-SLA and CWM-MPH, yet there was no significant relationship between ANPP and CWM-LNC or CWM-LDMC; (iii) intra-specific variability in SLA and MPH was found to be much greater than inter-specific variability, especially at the higher fertilization levels. We concluded that CWM-SLA and CWM-MPH can be used to assess the impacts of species changes on ecosystem functioning, and dominant species can maximize resource use through intra-specific variability in SLA and MPH to compensate for the loss of species following fertilization, therefore maintaining high community productivity
    corecore