In the last decade, community detection in dynamic networks has received increasing attention, because it can not only uncover the community structure of the network at any time but also reveal the regularity of dynamic networks evolution. Although methods based on the framework of evolutionary clustering are promising for dynamic community detection, there is still room for further improvement in the snapshot quality and the temporal cost. In this study, a dynamic community detection algorithm based on optional pathway guide pity beetle algorithm (DYN-OPGPBA), which is a novel dynamic community detection method based on the framework of evolutionary clustering, is proposed. We propose an improved PBA for community detection of the network at the first time step, including a discrete search strategy based on adjacent nodes, a closeness-based community modification strategy and a crowded community split strategy. Compared with many representative static community detection methods, the proposed method has some superior detection accuracy. A neighbour vector competition-based individual update strategy and an external population size restriction mechanism are also proposed for community detection at subsequent time steps. Results show that DYN-OPGPBA has a better balance between snapshot quality and temporal cost than two representative dynamic community detection methods.
Accumulating findings during the past decades have demonstrated that the hypothalamic arcuate kisspeptin neurons are supposed to be responsible for pulsatile release of gonadotropin-releasing hormone (GnRH) to regulate gametogenesis and steroidogenesis in mammals. The arcuate kisspeptin neurons express neurokinin B (NKB) and dynorphin A (Dyn), thus, the neurons are also referred to as KNDy neurons. In the present article, we mainly focus on the cellular and molecular mechanisms underlying GnRH pulse generation, that is focused on the action of NKB and Dyn and an interaction between KNDy neurons and astrocytes to control GnRH pulse generation. Then, we also discuss the factors that modulate the activity of KNDy neurons and consequent pulsatile GnRH/LH release in mammals.
Endothelial cells are sensitive to mechanical stress and respond differently to oscillatory flow versus unidirectional flow. This review highlights the mechanisms by which a wide range of unidirectional laminar shear stress induces activation of the redox sensitive antioxidant transcription factor nuclear factor-E2-related factor 2 (Nrf2) in cultured endothelial cells. We propose that fibroblast growth factor-2 (FGF-2), brain-derived neurotrophic factor (BDNF) and 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) are potential Nrf2 activators induced by laminar shear stress. Shear stress-dependent secretion of FGF-2 and its receptor-mediated signaling is tightly controlled, requiring neutrophil elastase released by shear stress, αvβ3 integrin and the cell surface glycocalyx. We speculate that primary cilia respond to low laminar shear stress (15 dyn/cm2) induces vesicular exocytosis of BDNF from endothelial cells, and we propose that BDNF via the p75NTR receptor could induce CK2-mediated Nrf2 activation. Unidirectional laminar shear stress upregulates gene expression of FGF-2 and BDNF and generation of 15d-PGJ2, which cooperate in sustaining Nrf2 activation to protect endothelial cells against oxidative damage.
Purpose This study aims to examine how the relative importance of a search versus a credence attribute, strategically addressed in a flu vaccination advertisement, varies as a function of message sidedness. A search attribute was designed to highlight the affordability of flu shots, and a credence attribute addressed the potential health benefits of flu vaccination. Design/methodology/approach Two experiments were designed to explore how the relative persuasiveness of search versus credence attributes varies as a function of message sidedness in the context of flu vaccination advertising. In Experiment 1, the search–credence attribute type was manipulated by addressing either the affordability (e.g. “Get free flu shots”) or indirect health benefits of flu vaccines (e.g. “Improve herd immunity/community health”). In Experiment 2, an individual-level credence attribute (e.g. “Strengthen your immune system”) was created and compared to the other two attribute conditions used in Experiment 1: a search versus a societal credence versus an individual credence attribute. Findings Experiment 1 (N = 114) revealed the relative advantage of a search attribute (free flu shots) in the two-sided persuasion. Experiment 2 (N = 193) indicated that the persuasive impact of a societal credence attribute (herd immunity/community health) was greater in the two-sided message condition (vs one-sided message condition). Originality/value Relatively little research has examined how consumers respond to strategic flu prevention and vaccination messages promoting either credence or search attributes. Motivated by the need to investigate the relative effectiveness of stressing “herd immunity” versus “free flu shots” in flu vaccination advertising, this study examines how the effects of these distinct attributes on flu vaccination judgments differ between two-sided (e.g. “No vaccine is 100% effective”) and one-sided persuasion.
We report far-field approximations to the derivatives and integrals of the Green's function for the Ffowcs Williams and Hawkings equation in the frequency domain. The approximations are based on the far-field asymptotic of the Green's function. The details of the derivations of the proposed formulations are provided.
Indication: Qualitative detection of the nucleocapsid protein antigen from SARS-CoV-2 in nasopharyngeal aspirate specimens directly or after the aspirate have been added to viral transport media from individuals who are suspected of COVID-19 by their healthcare provider. Emergency use of this test is limited to authorized laboratories and other authorized testing locations.
Abstract There is an important emerging role for the endogenous opioid dynorphin (DYN) and the kappa‐opioid receptor (KOR) in the treatment of alcohol dependence. Evidence suggests that the DYN/KOR system in the bed nucleus of the stria terminalis (BNST) contributes to maladaptive behavioral regulation during withdrawal in alcohol dependence. The current experiments were designed to assess dysregulation of the BNST DYN/KOR system by evaluating alcohol dependence‐induced changes in DYN/KOR gene expression (Pdyn and Oprk1, respectively), and the sensitivity of alcohol self‐administration, negative affective‐like behavior and physiological withdrawal to intra‐BNST KOR antagonism during acute withdrawal. Wistar rats trained to self‐administer alcohol, or not trained, were subjected to an alcohol dependence induction procedure (14 h alcohol vapor/10 h air) or air‐exposure. BNST micropunches from air‐ and vapor‐exposed animals were analyzed using RT‐qPCR to quantify dependence‐induced changes in Pdyn and Oprk1 mRNA expression. In addition, vapor‐ and air‐exposed groups received an intra‐BNST infusion of a KOR antagonist or vehicle prior to measurement of alcohol self‐administration. A separate cohort of vapor‐exposed rats was assessed for physiological withdrawal and negative affective‐like behavior signs following intra‐BNST KOR antagonism. During acute withdrawal, following alcohol dependence induction, there was an upregulation in Oprk1 mRNA expression in alcohol self‐administering animals, but not non‐alcohol self‐administering animals, that confirmed dysregulation of the KOR/DYN system within the BNST. Furthermore, intra‐BNST KOR antagonism attenuated escalated alcohol self‐administration and negative affective‐like behavior during acute withdrawal without reliably impacting physiological symptoms of withdrawal. The results confirm KOR system dysregulation in the BNST in alcohol dependence, illustrating the therapeutic potential of targeting the KOR to treat alcohol dependence. HighlightsOprk1 mRNA expression was increased in the BNST of alcohol self‐administering dependent animals.BNST KOR antagonism ameliorated escalated alcohol self‐administration during acute withdrawal.BNST KOR antagonism did not reliably alter symptoms of physiological withdrawal.BNST KOR antagonism attenuated withdrawal‐induced negative affective‐like behavior.22‐kHz USVs may be a more sensitive index of negative affective‐like behavior than EPM performance.
Behavioral, biological, and social sequelae that lead to drug addiction differ between men and women. Our efforts to understand addiction on a mechanistic level must include studies in both males and females. Stress, anxiety, and depression are tightly linked to addiction, and whether they precede or result from compulsive drug use depends on many factors, including biological sex. The neuropeptide dynorphin (DYN), an endogenous ligand at kappa opioid receptors (KORs), is necessary for stress-induced aversive states and is upregulated in the brain after chronic exposure to drugs of abuse. KOR agonists produce signs of anxiety, fear, and depression in laboratory animals and humans, findings that have led to the hypothesis that drug withdrawal-induced DYN release is instrumental in negative reinforcement processes that drive addiction. However, these studies were almost exclusively conducted in males. Only recently is evidence available that there are sex differences in the effects of KOR activation on affective state. This review focuses on sex differences in DYN and KOR systems and how these might contribute to sex differences in addictive behavior. Much of what is known about how biological sex influences KOR systems is from research on pain systems. The basic molecular and genetic mechanisms that have been discovered to underlie sex differences in KOR function in pain systems may apply to sex differences in KOR function in reward systems. Our goals are to discuss the current state of knowledge on how biological sex contributes to KOR function in the context of pain, mood, and addiction and to explore potential mechanisms for sex differences in KOR function. We will highlight evidence that the function of DYN-KOR systems is influenced in a sex-dependent manner by: polymorphisms in the prodynorphin (pDYN) gene, genetic linkage with the melanocortin-1 receptor (MC1R), heterodimerization of KORs and mu opioid receptors (MORs), and gonadal hormones. Finally, we identify several gaps in our understanding of “if” and “how” DYN and KORs modulate addictive behavior in a sex-dependent manner. Future work may address these gaps by building on the mechanistic studies outlined in this review. Ultimately this will enable the development of novel and effective addiction treatments tailored to either males or females.