Centrality anomalies for the domestic air transportation networks in the USA: an empirical benchmark.

Air transportation systems are a foundational infrastructure for the human's society. The lack of systematic and detailed investigation on a large amount of records for air flights has blocked seriously the deep understanding of the systems. By using the American domestic passenger flight records from 1995 to 2020, we constructed the air transportation networks and calculated the betweenness and the eigenvector centralities for the airports. It is found that in terms of eigenvector centrality, 15-30% airports in the unweighted and undirected networks behave anomalous. The anomalies disappear after considering the information of link weights or directionalites. Five widely used models for air transportation networks are evaluated, results for which tell us that the spatial constraints are required to eliminate the anomalies detected by the eigenvector centrality, and provide us some references for selecting the parameters in the models. We hope the empirical benchmarks reported in this paper can stimulate much more works on theoretical models for air transportation systems.

Functional map of the macroglomerular complex of male Helicoverpa armigera.

The mechanism of sex pheromone reception in the male cotton bollworm Helicoverpa armigera has been extensively studied because it has become an important model system for understanding insect olfaction. However, the pathways of pheromone processing from the antenna to the primary olfactory center in H. armigera have not yet been clarified. Here, the physiology and morphology of male H. armigera olfactory sensory neurons (OSNs) were studied using single sensillum recording along with anterograde filling and intracellular recording with retrograde filling. OSNs localized in type A sensilla responded to the major pheromone component cis-11-hexadecenal, and the axonal terminals projected to the cumulus (Cu) of the macroglomerular complex (MGC). The OSNs in type B sensilla responded to the behavioral antagonist cis-9-tetradecenal, and the axonal terminals projected to the dorsomedial anterior (DMA) unit of the MGC. In type C sensilla, there were 2 OSNs: one that responded to cis-9-tetradecenal and cis-11-hexadecenol with the axonal terminals projecting to the DMA, and another that responded to the secondary pheromone components cis-9-hexadecenal and cis-9-tetradecenal with the axonal terminals projecting to the dorsomedial posterior (DMP) unit of the MGC. Type A and type B sensilla also housed the secondary OSNs, which were silent neurons with axonal terminals projected to the glomerulus G49 and DMP. Overall, the neural pathways that carry information on attractiveness and aversiveness in response to female pheromone components in H. armigera exhibit distinct projections to the MGC units.

Serotonergic Neurons in the Brain and Gnathal Ganglion of Larval Spodoptera frugiperda.

The fall armyworm Spodoptera frugiperda (S. frugiperda) (Lepidoptera: Noctuidae) is a worldwide, disruptive, agricultural pest species. The larvae of S. frugiperda feed on seedling, leave, and kernel of crops with chewing mouthparts, resulting in reduced crop yields. Serotonin is an important biogenic amine acting as a neural circuit modulator known to mediate lots of behaviors including feeding in insects. In order to explore the serotonergic neural network in the nervous system of larval S. frugiperda, we performed immunohistochemical experiments to examine the neuropil structure of the brain and the gnathal ganglion with antisynapsin and to examine their serotonergic neurons with antiserotonin serum. Our data show that the brain of larval S. frugiperda contains three neuromeres: the tritocerebrum, the deutocerebrum, and the protocerebrum. The gnathal ganglion also contains three neuromeres: the mandibular neuromere, the maxillary neuromere, and the labial neuromere. There are about 40 serotonergic neurons in the brain and about 24 serotonergic neurons in the gnathal ganglion. Most of these neurons are wide-field neurons giving off processes in several neuropils of the brain and the gnathal ganglion. Serotonergic neuron processes are mainly present in the protocerebrum. A pair of serotonergic neurons associated with the deutocerebrum has arborizations in the contralateral antennal lobe and bilateral superior lateral protocerebra. In the gnathal ganglion, the serotonergic neuron processes are also widespread throughout the neuropil and some process projections extend to the tritocerebrum. These findings on the serotonergic neuron network in larval S. frugiperda allow us to explore the important roles of serotonin in feeding and find a potential approach to modulate the feeding behavior of the gluttonous pest and reduce its damage.

Identification of Odorant-Binding and Chemosensory Protein Genes in Mythimna separata Adult Brains Using Transcriptome Analyses.

Large numbers of chemosensory genes have been identified in the peripheral sensory organs of the pest Mythimna separata (Walker) to increase our understanding of chemoreception-related molecular mechanisms and to identify molecular targets for pest control. Chemosensory-related genes are expressed in various tissues, including non-sensory organs, and they play diverse roles. To better understand the functions of chemosensory-related genes in non-sensory organs, transcriptomic analyses of M. separata brains were performed. In total, 29 odorant-binding proteins (OBPs) and 16 chemosensory proteins (CSPs) putative genes were identified in the transcriptomic data set. The further examination of sex- and tissue-specific expression using RT-PCR suggested that eight OBPs (OBP5, -7, -11, -13, -16, -18, -21, and -24) and eight CSPs (CSP2-4, -8, CSP10-12, and -15) genes were expressed in the brain. Furthermore, bands representing most OBPs and CSPs could be detected in antennae, except for a few that underwent sex-biased expression in abdomens, legs, or wings. An RT-qPCR analysis of the expression profiles of six OBPs (OBP3-5, -9, -10, and -16) and two CSPs (CSP3 and CSP4) in different tissues and sexes indicated that OBP16 was highly expressed in male brain, and CSP3 and CSP4 were female-biased and highly expressed in brain. The expression levels of OBP5 and OBP10 in brain were not significantly different between the sexes. The findings expand our current understanding of the expression patterns of OBPs and CSPs in M. separata sensory and non-sensory tissues. These results provide valuable reference data for exploring novel functions of OBPs and CSPs in M. separata and may help in developing effective biological control strategies for managing this pest by exploring novel molecular targets.

Neuronal architecture and functional mapping of the taste center of larval Helicoverpa armigera (Lepidoptera: Noctuidae).

The sense of taste plays a crucial role in herbivorous insects by discriminating nutrients from complex plant metabolic compounds. The peripheral coding of taste has been thoroughly studied in many insect species, but the central gustatory pathways are poorly described. In the present study, we characterized single neurons in the gnathal ganglion of Helicoverpa armigera larvae using the intracellular recording/staining technique. We identified different types of neurons, including sensory neurons, interneurons, and motor neurons. The morphologies of these neurons were largely diverse and their arborizations seemingly covered the whole gnathal ganglion. The representation of the single neurons responding to the relevant stimuli of sweet and bitter cues showed no distinct patterns in the gnathal ganglion. We postulate that taste signals may be processed in a manner consistent with the principle of population coding in the gnathal ganglion of H. armigera larvae.

LncRNA-MALAT1 promotes tumorogenesis of infantile hemangioma by competitively binding miR-424 to stimulate MEKK3/NF-κB pathway.

AIMS: Infantile hemangioma (IH) is the most common vascular neoplasm in infant and young children. Long non-coding RNAs (lncRNAs) are known to be associated with IH. This study aims to investigate the role and underlying mechanism of lncRNA-MALAT1 in IH. MAIN METHODS: qRT-PCR was used to quantify the expressions of MALAT1, miR-424, and MEKK3 in IH tissues. The cell proliferation, apoptosis, migration, invasion, and tube formation ability were assessed by MTT assay, colony formation assay, flow cytometric analysis, transwell assay and tube formation assay, respectively. The interaction among MALAT1, miR-424 and MEKK3 was evaluated by luciferase reporter assay. Immunohistochemistry (IHC) and Western blotting were utilized to evaluate the expression levels of MEKK3, Ki-67 and NF-κB pathway-related proteins both in vitro and in vivo. KEY FINDINGS: In IH tissues, MALAT1 and MEKK3 were overexpressed while miR-424 was down-regulated. Silencing MALAT1 or overexpression of miR-424 significantly inhibited the IH cell proliferation, migration and tube formation, but promoted the cell apoptosis. Knockdown of MALAT1 suppressed the expression of MEKK3 and inactivated the IKK/NF-κB pathway by sponging miR-424. Overexpression of MEKK3 in HemEcs reversed the impact of knockdown of MALAT1 and overexpression of miR-424 on the cell proliferation, apoptosis, migration, invasion and tube formation rate. The tumor xenografts experiments demonstrated that silencing MALAT1 significantly inhibited the tumor growth in vivo and Ki-67 in the tumor tissues was also significantly suppressed. SIGNIFICANCE: MALAT1 promoted the IH progression through inhibiting miR-424 to activate MEKK3-mediated IKK/NF-κB pathway, suggesting that MALAT1, miR-424 and MEKK3 could be used as potential targets to improve IH treatment efficiency.