33 research outputs found

    Genetic algorithm optimization for storing arbitrary multimode transverse images in thermal atomic vapor

    Get PDF
    Storing multimode transverse images in atomic media is crucial in constructing large-scale quantum networks. A major obstacle of storing transverse images in the thermal atomic vapor is the distortion of the retrieved images caused by atomic diffusion. Here, we demonstrate the combination of genetic algorithm with the phase-shift lithography method to construct the optimal phase for an arbitrary transverse image that can diminish the effect of diffusion. Theoretical simulations and experimental results manifest that the retrieved images' resolution can be substantially improved when carrying the optimal phases. Our scheme is efficient and straightforward and can be extensively applied in storing complex transverse multimodes in diffusion media

    Neuronal lack of PDE7a disrupted working memory, spatial learning, and memory but facilitated cued fear memory in mice

    Get PDF
    12 p.-5 fig.Background: PDEs regulate cAMP levels which is critical for PKA activity-dependent activation of CREB-mediated transcription in learning and memory. Inhibitors of PDEs like PDE4 and Pde7 improve learning and memory in rodents. However, the role of PDE7 in cognition or learning and memory has not been reported yet.Methods:Therefore, we aimed to explore the cognitive effects of a PDE7 subtype, PDE7a, using combined pharmacological and genetic approaches.Results: PDE7a-nko mice showed deficient working memory, impaired novel object recognition, deficient spatial learning & memory, and contextual fear memory, contrary to enhanced cued fear memory, highlighting the potential opposite role of PDE7a in the hippocampal neurons. Further, pharmacological inhibition of PDE7 by AGF2.20 selectively strengthens cued fear memory in C57BL/6 J mice, decreasing its extinction but did not affect cognitive processes assessed in other behavioral tests. The further biochemical analysis detected deficient cAMP in neural cell culture with genetic excision of the PDE7a gene, as well as in the hippocampus of PDE7a-nko mice in vivo. Importantly, we found overexpression of PKA-R and the reduced level of pPKA-C in the hippocampus of PDE7a-nko mice, suggesting a novel mechanism of the cAMP regulation by PDE7a. Consequently, the decreased phosphorylation of CREB, CAMKII, eif2a, ERK, and AMPK, and reduced total level of NR2A have been found in the brain of PDE7a-nko animals. Notably, genetic excision of PDE7a in neurons was not able to change the expression of NR2B, BDNF, synapsin1, synaptophysin, or snap25.Conclusion: Altogether, our current findings demonstrated, for the first time, the role of PDE7a in cognitive processes. Future studies will untangle PDE7a-dependent neurobiological and molecular-cellular mechanisms related to cAMP-associated disorders.This work was supported by the Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions No: 2022SHIBS0004: Basic research and free exploration project of Shenzhen Science and technology innovation Commission (JCYJ20190808113007570).Peer reviewe

    Examining the Interactome of Huperzine A by Magnetic Biopanning

    Get PDF
    Huperzine A is a bioactive compound derived from traditional Chinese medicine plant Qian Ceng Ta (Huperzia serrata), and was found to have multiple neuroprotective effects. In addition to being a potent acetylcholinesterase inhibitor, it was thought to act through other mechanisms such as antioxidation, antiapoptosis, etc. However, the molecular targets involved with these mechanisms were not identified. In this study, we attempted to exam the interactome of Huperzine A using a cDNA phage display library and also mammalian brain tissue extracts. The drugs were chemically linked on the surface of magnetic particles and the interactive phages or proteins were collected and analyzed. Among the various cDNA expressing phages selected, one was identified to encode the mitochondria NADH dehydrogenase subunit 1. Specific bindings between the drug and the target phages and target proteins were confirmed. Another enriched phage clone was identified as mitochondria ATP synthase, which was also panned out from the proteome of mouse brain tissue lysate. These data indicated the possible involvement of mitochondrial respiratory chain matrix enzymes in Huperzine A's pharmacological effects. Such involvement had been suggested by previous studies based on enzyme activity changes. Our data supported the new mechanism. Overall we demonstrated the feasibility of using magnetic biopanning as a simple and viable method for investigating the complex molecular mechanisms of bioactive molecules

    Rubber Identification Based on Blended High Spatio-Temporal Resolution Optical Remote Sensing Data: A Case Study in Xishuangbanna

    No full text
    As an important economic resource, rubber has rapidly grown in Xishuangbanna of Yunnan Province, China, since the 1990s. Tropical rainforests have been replaced by extensive rubber plantations, which has resulted in ecological problems such as the loss of biodiversity and local water shortages. It is vitally important to accurately map the rubber plantations in this region. Although several rubber mapping methods have been proposed, few studies have investigated methods based on optical remote sensing time series data with high spatio-temporal resolution due to the cloudy and foggy weather conditions in this area. This study presented a rubber plantation identification method that used spatio-temporal optical remote sensing data fusion technology to obtain vegetation index data at high spatio-temporal resolution within the optical remote sensing window in Xishuangbanna. The analysis of the proposed method shows that (1) fused optical remote sensing data with high spatio-temporal resolution could map the rubber distribution with high accuracy (overall accuracy of up to 89.51% and kappa of 0.86). (2) Fused indices have high R2 (R2 greater than 0.8, where R is the correlation coefficient) with the indices that were derived from the Landsat observed data, which indicates that fusion results are dependable. However, the fusion accuracy is affected by terrain factors including elevation, slope, and slope aspects. These factors have obvious negative effects on the fusion accuracy of high spatio-temporal resolution optical remote sensing data: the highest fusion accuracy occurred in areas with elevations between 1201 and 1400 m.a.s.l., and the lowest accuracy occurred in areas with elevations less than 600 m.a.s.l. For the 5 fused time series indices (normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), normalized difference moisture index (NDMI), normalized burn ratio (NBR), and tasseled cap angle (TCA)), the fusion accuracy decreased with increasing slope, and increasing slope had the least impact on the EVI, but the greatest negative impact on the NDVI; the slope aspect had a limited influence on the fusion accuracies of the 5 time series indices, but fusion accuracy was lowest on the northwest slope. (3) EVI had the highest accuracy of rubber plantation classification among the 5 time series indices, and the overall classification accuracies of the time series EVI for the four different years (2000, 2005, 2010, and 2015) reached 87.20% (kappa 0.82), 86.91% (kappa 0.81), 88.85% (kappa 0.84), and 89.51% (kappa 0.86), respectively. The results indicate that the method is a promising approach for rubber plantation mapping and the detection of changes in rubber plantations in this tropical area

    Construction of quality evaluation indicator system for diamond discrete global grid systems

    No full text
    Although the uniformity of diamond discrete global grid is essential for calculations and searches, geometric deformations increase with the level of divisions. The Goodchild Criteria provides a basis for evaluating the quality of the global grid. However, some indicators in the criteria are redundant and contradictory, and the existing indicator system has limitations. Directly using the indicator system may render the evaluation of the diamond grid unreliable. In this study, we summarized the evaluation indicators for grid quality based on the Goodchild Criteria, calculated the correlations between these indicators using different diamond grid systems, and constructed reliable evaluation systems based on similarities and differences. The selected grid systems are classified into two groups: non-equal-area and equal-area grids. Their quality evaluation systems are composed of Size-Shape-Topology Factor and Geometry-Topology Factor, respectively. The proposed quality evaluation systems utilize a minimal number of indicators selected from each factor to provide a comprehensive description of the diamond grid’s characteristics. This approach simplifies the complexity of the evaluations while improving their reliability and credibility

    Phenomenon and Mechanism of Capsule Shrinking in Alkaline Solution Containing Calcium Ions

    No full text
    Shrinking phenomenon of poly­(allylamine hydrochloride) (PAH)/poly­(styrene sulfonate, sodium salt) (PSS) multilayer microcapsules was observed when they were incubated in alkaline solutions containing Ca<sup>2+</sup>. The shrinking was universal to those polyelectrolyte multilayer capsules regardless of the wall thickness and wall compositions suppose the conditions were proper. The shrinking extent increased along with the increase of solution pH and Ca<sup>2+</sup> concentration, and reached to a maximum value of 70% (from 7.4 to 2.3 μm). The shrunk capsules with a hollow structure and thick wall could well maintain their spherical shape in a dry state. During the capsule shrinking partial loss of the polyelectrolytes especially PSS took place, and the loss amount increased along with the increase of solution pH although the alteration patterns were different at lower Ca<sup>2+</sup> concentration. The complexation of PSS with Ca<sup>2+</sup>, which is believed one of the major reasons governing the capsule shrinking, was demonstrated by X-ray photoelectron spectroscopy and turbidity experiment. The mechanism is proposed, which relies on the synergistic effects of deprotonation of PAH and screening of PSS by Ca<sup>2+</sup> leading to the thermodynamically favored-capsule shrinking

    Genetic algorithm optimization for storing arbitrary multimode transverse images in thermal atomic vapor

    No full text
    Storing multimode transverse images in atomic media is crucial in constructing large-scale quantum networks. A major obstacle of storing transverse images in the thermal atomic vapor is the distortion of the retrieved images caused by atomic diffusion. Here, we demonstrate the combination of genetic algorithm with the phase-shift lithography method to construct the optimal phase for an arbitrary transverse image that can diminish the effect of diffusion. Theoretical simulations and experimental results manifest that the retrieved images' resolution can be substantially improved when carrying the optimal phases. Our scheme is efficient and straightforward and can be extensively applied in storing complex transverse multimodes in diffusion media
    corecore