Performance evaluation of AODV, DSR and DSDV in mobile ad-hoc network using NS-2

Mobile ad-hoc network (MANET) is a set of movable hosts established without existing network infrastructure and can be self-organized dynamically. MANET protocols have faced big challenges due to dynamic changing network topology and asymmetric network link. In this paper, we simulate AODV, DSDV, DSR routing protocols in network simulator NS-2 and evaluate and compare the performance metrics for each routing protocol using packet delivery ratio, average end to end delay of packets and normalized routing overhead. We conduct the simulation by varying the sending rate of source node (2 packets/s and 4 packets/s) with different pause time using node movement model and cbr source traffic model

Generalized Parametric Contrastive Learning

In this paper, we propose the Generalized Parametric Contrastive Learning (GPaCo/PaCo) which works well on both imbalanced and balanced data. Based on theoretical analysis, we observe that supervised contrastive loss tends to bias high-frequency classes and thus increases the difficulty of imbalanced learning. We introduce a set of parametric class-wise learnable centers to rebalance from an optimization perspective. Further, we analyze our GPaCo/PaCo loss under a balanced setting. Our analysis demonstrates that GPaCo/PaCo can adaptively enhance the intensity of pushing samples of the same class close as more samples are pulled together with their corresponding centers and benefit hard example learning. Experiments on long-tailed benchmarks manifest the new state-of-the-art for long-tailed recognition. On full ImageNet, models from CNNs to vision transformers trained with GPaCo loss show better generalization performance and stronger robustness compared with MAE models. Moreover, GPaCo can be applied to the semantic segmentation task and obvious improvements are observed on the 4 most popular benchmarks. Our code is available at https://github.com/dvlab-research/Parametric-Contrastive-Learning.Comment: TPAMI 2023. arXiv admin note: substantial text overlap with arXiv:2107.1202

Astragaloside IV Ameliorates Airway Inflammation in an Established Murine Model of Asthma by Inhibiting the mTORC1 Signaling Pathway

Astragaloside IV (AS-IV), a main active constituent of Astragalus membranaceus, has been confirmed to have antiasthmatic effects. However, it remained unclear whether the beneficial effects of AS-IV on asthma were attributed to the mTOR inhibition; this issue was the focus of the present work. BALB/c mice were sensitized and challenged with ovalbumin followed with 3 weeks of rest/recovery and then reexposure to ovalbumin. AS-IV was administrated during the time of rest and reexposure. The characteristic features of allergic asthma, including airway hyperreactivity, histopathology, cytokines (IL-4, IL-5, IL-13, IL-17, and INF-γ), and CD4+CD25+Foxp3+Treg cells in bronchoalveolar lavage fluid (BALF), and downstream proteins of mTORC1/2 signaling were examined. AS-IV markedly suppressed airway hyperresponsiveness and reduced IL-4, IL-5, and IL-17 levels and increased INF-γ levels in the BALF. Histological studies showed that AS-IV markedly decreased inflammatory infiltration in the lung tissues. Notably, AS-IV inhibited mTORC1 activity, whereas it had limited effects on mTORC2, as assessed by phosphorylation of mTORC1 and mTORC2 substrates S6 ribosomal protein, p70 S6 Kinase, and Akt, respectively. CD4+CD25+Foxp3+Treg cells in BALF were not significantly changed by AS-IV. Together, these results suggest that the antiasthmatic effects of AS-IV were at least partially from inhibiting the mTORC1 signaling pathway

Macrolide Derivatives Reduce Proinflammatory Macrophage Activation and Macrophage‐Mediated Neurotoxicity

Introduction: Azithromycin (AZM) and other macrolide antibiotics are applied as immunomodulatory treatments for CNS disorders. The immunomodulatory and antibiotic properties of AZM are purportedly independent. Aims: To improve the efficacy and reduce antibiotic resistance risk of AZM‐based therapies, we evaluated the immunomodulatory and neuroprotective properties of novel AZM derivatives. We semisynthetically prepared derivatives by altering sugar moieties established as important for inhibiting bacterial protein synthesis. Bone marrow‐derived macrophages (BMDMs) were stimulated in vitro with proinflammatory, M1, stimuli (LPS + INF‐gamma) with and without derivative costimulation. Pro‐ and anti‐inflammatory cytokine production, IL‐12 and IL‐10, respectively, was quantified using ELISA. Neuron culture treatment with BMDM supernatant was used to assess derivative neuroprotective potential. Results: Azithromycin and some derivatives increased IL‐10 and reduced IL‐12 production of M1 macrophages. IL‐10/IL‐12 cytokine shifts closely correlated with the ability of AZM and derivatives to mitigate macrophage neurotoxicity. Conclusions: Sugar moieties that bind bacterial ribosomal complexes can be modified in a manner that retains AZM immunomodulation and neuroprotection. Since the effects of BMDMs in vitro are predictive of CNS macrophage responses, our results open new therapeutic avenues for managing maladaptive CNS inflammation and support utilization of IL‐10/12 cytokine profiles as indicators of macrophage polarization and neurotoxicity

5-Amino-7-(4-bromo­phen­yl)-3,7-di­hydro-2H-thieno[3,2-b]pyran-6-carbo­nitrile 1,1-dioxide

In the title compound, C14H11BrN2O3S, the 2,3-dihydro­thio­phene ring is almost planar [maximum deviation = 0.006 (1) Å]. The pyran ring is in an envelope conformation [puckering parameters Q = 0.115 (2) Å, θ = 77.5 (10), ϕ = 172.9 (10)°]. The pyran and phenyl rings are approximately perpendicular, making a dihedral angle of −76.4 (2)°. The crystal packing is stabilized by inter­molecular N—H⋯O hydrogen bonds, with the sulfone O atoms acting as acceptors