3,807 research outputs found

    A role of corazonin receptor in larval-pupal transition and pupariation in the oriental fruit fly Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

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    Corazonin (Crz) is a neuropeptide hormone, but also a neuropeptide modulator that is internally released within the CNS, and it has a widespread distribution in insects with diverse physiological functions. Here, we identified and cloned the cDNAs of Bactrocera dorsalis that encode Crz and its receptor CrzR. Mature BdCrz has 11 residues with a unique Ser11 substitution (instead of the typical Asn) and a His in the evolutionary variable position 7. The BdCrzR cDNA encodes a putative protein of 608 amino acids with 7 putative transmembrane domains, typical for the structure of G-protein-coupled receptors. When expressed in Chinese hamster ovary (CHO) cells, the BdCrzR exhibited a high sensitivity and selectivity for Crz (EC50 approximate to 52.5 nM). With qPCR, the developmental stage and tissue-specific expression profiles in B. dorsalis demonstrated that both BdCrz and BdCrzR were highly expressed in the larval stage, and BdCrzR peaked in 2-day-old 3rd-instar larvae, suggesting that the BdCrzR may play an important role in the larval-pupal transition behavior. Immunochemical localization confirmed the production of Crz in the central nervous system (CNS), specifically by a group of three neurons in the dorso-lateral protocerebrum and eight pairs of lateral neurons in the ventral nerve cord. qPCR analysis located the BdCrzR in both the CNS and epitracheal gland, containing the Inka cells. Importantly, dsRNA-BdCrzR-mediated gene-silencing caused a delay in larval-pupal transition and pupariation, and this phenomenon agreed with a delayed expression of tyrosine hydroxylase and dopa-decarboxylase genes. We speculate that CrzR-silencing blocked dopamine synthesis, resulting in the inhibition of pupariation and cuticular melanization. Finally, injection of Crz in head-ligated larvae could rescue the effects. These findings provide a new insight into the roles of Crz signaling pathway components in B. dorsalis and support an important role of CrzR in larval-pupal transition and pupariation behavior

    Exploring f(T)f(T) Gravity via strongly lensed fast radio bursts

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    This study aims to investigate the strong gravitational lensing effects in f(T)f(T) gravity. We present the theoretical analytic expressions for the lensing effects in f(T)f(T) gravity, including deflection angle, magnification, and time delay. On this basis, we also take the plasma lensing effect into consideration. We compare the lensing effects between the General Relativity in a vacuum environment and the f(T)f(T) gravity in a plasma environment. From a strongly lensed fast radio burst, the results indicate that in a plasma environment, General Relativity and f(T)f(T) gravity can generate indistinguishable image positions, but the magnification and time delay on these positions are significantly different, which can be distinguished by current facilities in principle. Therefore, the discrepancies between observational results and theoretical expectations can serve as clues for a modified gravity theory and provide constraints on f(T)f(T) gravity

    Strong decays of the ϕ(2170)\phi(2170) as a fully-strange tetraquark state

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    We study strong decays of the ϕ(2170)\phi(2170), along with its possible partner X(2436)X(2436), as two fully-strange tetraquark states of JPC=1J^{PC} = 1^{--}. We consider seven decay channels: ϕη\phi \eta, ϕη\phi \eta^\prime, ϕf0(980)\phi f_0(980), ϕf1(1420)\phi f_1(1420), h1(1415)ηh_1(1415) \eta, h1(1415)ηh_1(1415) \eta^\prime, and h1(1415)f1(1420)h_1(1415) f_1(1420). Some of these channels are kinematically possible, and we calculate their relative branching ratios through the Fierz rearrangement. Future experimental measurements on these ratios can be useful in determining the nature of the ϕ(2170)\phi(2170) and X(2436)X(2436). The ϕ(2170)\phi(2170) has been observed in the ϕf0(980)\phi f_0(980), ϕη\phi \eta, and ϕη\phi \eta^\prime channels, and we propose to further examine it in the h1(1415)ηh_1(1415) \eta channel. Evidences of the X(2436)X(2436) have been observed in the ϕf0(980)\phi f_0(980) channel, and we propose to verify whether this structure exists or not in the ϕη\phi \eta, ϕη\phi \eta^\prime, h1(1415)ηh_1(1415) \eta, and h1(1415)ηh_1(1415) \eta^\prime channels.Comment: 10 pages, 3 figures, 1 table, suggestions and comments are welcom

    Decoupling Optimization for Complex PDN Structures using Deep Reinforcement Learning

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    This Article Presents a New Optimization Method for Complex Power Distribution Networks (PDNs) with Irregular Shapes and Multilayer Structures using Deep Reinforcement Learning (DRL), Which Has Not Been Considered Before. a Fast Boundary Integration Method is Applied to Compute the Impedance Matrix of a PDN Structure. Subsequently, a New DRL Algorithm based on Proximal Policy Optimization (PPO) is Proposed to Optimize the Decoupling Capacitor (Decap) Placement by Minimizing the Number of Decaps While Satisfying the Desired Target Impedance. in the Proposed Approach, the PDN Structure Information is Encoded into Matrices and Serves as the Input of the DRL Algorithm, Which Increases the Flexibility of the Method to Be Extended and Generalized to Different PDN Configurations. Also, the Output of the Algorithm Determines the Selection of Decap Types and Locations Collaboratively, Making It Easier to Find the Optimal Solution in a Huge Search Space. the Proposed Method is Compared with the State-Of-The-Art Approaches and Shows Consistent Advantages in Reducing the Number of Decaps in Different Testing Cases

    2,5-Bis(9H-carbazol-9-yl)thio­phene

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    The mol­ecules of the title compound, C28H18N2S, are built up from two triply-fused rings and one five-membered ring, with dihedral angles of 66.12 (8) and 70.96 (7)° between the central thio­phene ring and the two triply-fused rings
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