533 research outputs found

    Fermionic T-duality in the pp-wave limit

    Full text link
    AdS5 X S5 and its pp-wave limit are self-dual under transformations involving eight fermionic T-dualities, a property which accounts for symmetries seen in scattering amplitudes in N=4 super-Yang-Mills. Despite strong evidence for similar symmetries in the amplitudes of three-dimensional N=6 ABJM theory, a corresponding self-duality in the dual geometry AdS4 X CP3 currently eludes us. Here, working with the type IIA pp-wave limit of AdS4 X CP3 preserving twenty four supercharges, we show that the pp-wave is self-dual with respect to eight commuting fermionic T-dualities and not the six expected. In addition, we show the same symmetry can be found in a superposition pp-wave and a generic pp-wave with twenty and sixteen unbroken supersymmetries respectively, strongly suggesting that self-duality under fermionic T-duality may be a symmetry of all pp-waves.Comment: 21 pages, typos fixe

    Tripartite interactions between two phase qubits and a resonant cavity

    Full text link
    The creation and manipulation of multipartite entangled states is important for advancements in quantum computation and communication, and for testing our fundamental understanding of quantum mechanics and precision measurements. Multipartite entanglement has been achieved by use of various forms of quantum bits (qubits), such as trapped ions, photons, and atoms passing through microwave cavities. Quantum systems based on superconducting circuits have been used to control pair-wise interactions of qubits, either directly, through a quantum bus, or via controllable coupling. Here, we describe the first demonstration of coherent interactions of three directly coupled superconducting quantum systems, two phase qubits and a resonant cavity. We introduce a simple Bloch-sphere-like representation to help one visualize the unitary evolution of this tripartite system as it shares a single microwave photon. With careful control and timing of the initial conditions, this leads to a protocol for creating a rich variety of entangled states. Experimentally, we provide evidence for the deterministic evolution from a simple product state, through a tripartite W-state, into a bipartite Bell-state. These experiments are another step towards deterministically generating multipartite entanglement in superconducting systems with more than two qubits

    Preferential regulation of stably expressed genes in the human genome suggests a widespread expression buffering role of microRNAs

    Get PDF
    In this study, we comprehensively explored the stably expressed genes (SE genes) and fluctuant genes (FL genes) in the human genome by a meta-analysis of large scale microarray data. We found that these genes have distinct function distributions. miRNA targets are shown to be significantly enriched in SE genes by using propensity analysis of miRNA regulation, supporting the hypothesis that miRNAs can buffer whole genome expression fluctuation. The expression-buffering effect of miRNA is independent of the target site number within the 3'-untranslated region. In addition, we found that gene expression fluctuation is positively correlated with the number of transcription factor binding sites in the promoter region, which suggests that coordination between transcription factors and miRNAs leads to balanced responses to external perturbations

    A Systematic Review of Mosquito Coils and Passive Emanators: Defining Recommendations for Spatial Repellency Testing Methodologies.

    Get PDF
    Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propose scientific consensus on terminologies and methodologies used for evaluation of product formats that could contain spatial chemical actives, including indoor residual spraying (IRS), long lasting insecticide treated nets (LLINs) and insecticide treated materials (ITMs). PubMed, (National Centre for Biotechnology Information (NCBI), U.S. National Library of Medicine, NIH), MEDLINE, LILAC, Cochrane library, IBECS and Armed Forces Pest Management Board Literature Retrieval System search engines were used to identify studies of pyrethroid based coils and emanators with key-words "Mosquito coils" "Mosquito emanators" and "Spatial repellents". It was concluded that there is need to improve statistical reporting of studies, and reach consensus in the methodologies and terminologies used through standardized testing guidelines. Despite differing evaluation methodologies, data showed that coils and emanators induce mortality, deterrence, repellency as well as reduce the ability of mosquitoes to feed on humans. Available data on efficacy outdoors, dose-response relationships and effective distance of coils and emanators is inadequate for developing a target product profile (TPP), which will be required for such chemicals before optimized implementation can occur for maximum benefits in disease control

    Quantification of Alternative Splicing Variants of Human Telomerase Reverse Transcriptase and Correlations with Telomerase Activity in Lung Cancer

    Get PDF
    Telomerase plays important roles in the development and progression of malignant tumors, and its activity is primarily determined by transcriptional regulation of human telomerase reverse transcriptase (hTERT). Several mRNA alternative splicing variants (ASVs) for hTERT have been identified, but it remains unclear whether telomerase activity is directly associated with hTERT splicing transcripts. In this study, we developed novel real-time PCR protocols using molecular beacons and applied to lung carcinoma cell lines and cancerous tissues for quantification of telomerase activity and three essential hTERT deletion transcripts respectively. The results showed that lung carcinoma cell lines consistently demonstrated telomerase activity (14.22–31.43 TPG units per 100 cells) and various hTERT alternative splicing transcripts. For 165 lung cancer cases, telomerase activity showed significant correlation with tumor differentiation (poorly->moderately->well-differentiated, P<0.01) and with histotypes (combined small cell and squamous cell carcinoma>squamous cell carcinoma>adenosquamous carcinoma>adenocarcinoma, P<0.05). Although the overall hTERT transcripts were detected in all the samples, they were not associated with telomerase activity (r = 0.092, P = 0.24). Telomerase activity was significantly correlated with the transcriptional constituent ratio of α-deletion (r = -0.267, P = 0.026), β-deletion (r = -0.693, P = 0.0001) and γ-deletion (r = –0.614, P = 0.001). The positive rate and average constituent ratio of β-deletion transcripts (92.12%, 0.23) were higher than those of α-deletion (41.82%, 0.12) or γ-deletion (16.36%, 0.18) transcripts. The combined small-cell and squamous cell carcinomas expressed less deletion transcripts, especially β-deletion, than other histotypes, which might explain their higher telomerase activity. In conclusion, the molecular beacon-based real-time PCR protocols are rapid, sensitive and specific methods to quantify telomerase activity and hTERT ASVs. Telomerase activity may serve as a reliable and effective molecular marker to assist the evaluation of histological subtype and differentiation of lung carcinomas. Further studies on hTERT deletion splicing transcripts, rather than the overall hTERT transcripts, may improve our understanding of telomerase regulation

    Effect of 1,25-(OH)2D3 on proliferation of fibroblast-like synoviocytes and expressions of pro-inflammatory cytokines through regulating MicroRNA-22 in a rat model of rheumatoid arthritis

    Get PDF
    Objective: This study aims to investigate the regulatory mechanism of 1,25-(OH)2D3 on the proliferation of fibroblast-like synoviocytes (FLS) and expressions of pro-inflammatory cytokines in rheumatoid arthritis (RA) rats via microRNA-22 (miR-22).Methods: A rat model of RA was established with a subcutaneous injection of type II collagen. After treated with different concentrations of 1,25-(OH)2D3 the proliferation of FLS was estimated by the MTT method, and the optimal concentration of 1,25-(OH)2D3 was selected for further experiments. Cell proliferation was detected by MTT. Cell cycle and apoptosis were analyzed by FCM. The IL-1β, IL-6, IL-8, and PGE2 protein expressions were determined by ELISA, and MMP-3, INOS, and Cox-2 mRNA expressions were measured by qRT-PCR.Results: The rat model of RA was successfully established. Compared with the blank group, the 1,25-(OH)2D3 and miR-22 inhibitors groups exhibited higher proliferation inhibition and apoptosis rates, lower levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, and PGE2), and decreased mRNA expressions of MMP-3, INOS, and Cox-2. The miR-22 mimics group had lower proliferation inhibition and apoptosis rates, elevated expressions of pro-inflammatory cytokines and MMP-3, INOS, and Cox-2 than the blank group. In contrast to the 1,25-(OH)2D3 group, the proliferation inhibition and apoptosis rates were down-regulated, and the expressions of pro-inflammatory cytokines and MMP-3, INOS, and Cox-2 were up-regulated in the 1,25-(OH)2D3 + miR-22 mimics group.Conclusion: Our study demonstrated that 1,25-(OH)2D3 inhibits the proliferation of FLS and alleviates inflammatory response in RA rats by down-regulating miR-22

    Towards High Capacity Li-ion Batteries Based on Silicon-Graphene Composite Anodes and Sub-micron V-doped LiFePO4 Cathodes

    Get PDF
    Lithium iron phosphate, LiFePO4 (LFP) has demonstrated promising performance as a cathode material in lithium ion batteries (LIBs), by overcoming the rate performance issues from limited electronic conductivity. Nano-sized vanadium-doped LFP (V-LFP) was synthesized using a continuous hydrothermal process using supercritical water as a reagent. The atomic % of dopant determined the particle shape. 5 at. % gave mixed plate and rod-like morphology, showing optimal electrochemical performance and good rate properties vs. Li. Specific capacities of >160 mAh g−1 were achieved. In order to increase the capacity of a full cell, V-LFP was cycled against an inexpensive micron-sized metallurgical grade Si-containing anode. This electrode was capable of reversible capacities of approximately 2000 mAh g−1 for over 150 cycles vs. Li, with improved performance resulting from the incorporation of few layer graphene (FLG) to enhance conductivity, tensile behaviour and thus, the composite stability. The cathode material synthesis and electrode formulation are scalable, inexpensive and are suitable for the fabrication of larger format cells suited to grid and transport applications
    corecore