Generic User Behavior: A User Behavior Similarity-Based Recommendation Method.

Recommender system (RS) plays an important role in Big Data research. Its main idea is to handle huge amounts of data to accurately recommend items to users. The recommendation method is the core research content of the whole RS. However, the existing recommendation methods still have the following two shortcomings: (1) Most recommendation methods use only one kind of information about the user's interaction with items (such as Browse or Purchase), which makes it difficult to model complete user preference. (2) Most mainstream recommendation methods only consider the final consistency of recommendation (e.g., user preferences) but ignore the process consistency (e.g., user behavior), which leads to the biased final result. In this article, we propose a recommendation method based on the Entity Interaction Knowledge Graph (EIKG), which draws on the idea of collaborative filtering and innovatively uses the similarity of user behaviors to recommend items. The method first extracts fact triples containing interaction relations from relevant data sets to generate the EIKG; then embeds the entities and relations in the EIKG; finally, uses link prediction techniques to recommend items for users. The proposed method is compared with other recommendation methods on two publicly available data sets, Scholat and Lizhi, and the experimental result shows that it exceeds the state of the art in most metrics, verifying the effectiveness of the proposed method.

8-OH-DPAT enhances dopamine D2-induced maternal disruption in rats.

Recent evidence indicates that 5-HT1A receptors play a significant role in mediating maternal behavior in rats. Given that they also modulate the mesocortical dopamine system, we hypothesized that 5-HT1A receptors may mediate maternal behavior, possibly by interacting with the D2 receptor. To address this issue, we used a combination of 5-HT1A agonist (8-OH-DPAT, 0.5 mg/kg) and two D2 drugs (an agonist quinpirole, QUIN, 1.0 mg/kg; a potent D2 antagonist haloperidol, HAL, 0.1 mg/kg) on rat maternal behavior in the home-cage maternal behavior and pup preference tests. We replicated the findings that acute QUIN, HAL, and 8-OH-DPAT disrupted home-cage maternal behavior. When administered in combination, pretreatment with HAL and QUIN worsened 8-OH-DPAT-induced maternal disruption and induced a decrease in the pup preference ratio. Accordingly, 8-OH-DPAT enhanced QUIN' and HAL's disruption of pup retrieval and pup preference, reversed the increase in hovering over pups induced by HAL. These findings suggest that activation of 5-HT1A receptors enhances D2-mediated maternal disruption. Furthermore, given that the combination of D2 drugs and 5-HT1A agonists only produced an additive effect on maternal disruption, 5-HT1A receptors may have a direct effect on maternal behavior independent of their interaction with D2 receptors.

Predator odor exposure increases social contact in adolescents and parental behavior in adulthood in Brandt's voles.

Research suggests that predation risk during adolescence can program adult stress response and emotional behavior; however, little is known about the short-term and lasting residual effects of this experience on social behavior. We explored this concept in social Brandt's voles (Lasiopodomys brandtii). Adolescent male and female voles were exposed to distilled water, rabbit urine (as a non-predator stimulus), and cat urine for 60 min daily from postnatal day (PND) 28-49. Social play tests were conducted immediately following exposure on PND 28, 35, 42, and 49. In the social play test, repeated cat odor (CO) exposure enhanced the contact behavior of voles with their cagemate. Adolescent exposure to CO did not affect behavioral responses toward unrelated pups in the alloparental behavior test or same-sex individuals in the social interaction test. However, exposure to CO significantly enhanced the licking/grooming behavior of voles towards their own pups in the home cage parental behavior test. Repeated CO exposure significantly inhibited weight gain in male voles during adolescence. This effect was transmitted to the next generation, with lower weight gain in offspring before weaning. Following repeated CO exposure, males tended to have more female offspring whereas females produced more offspring, suggesting an adaptive strategy to increase inclusive fitness under predatory risk. These findings demonstrate that adolescent exposure to predatory risk augments adolescent social contact and adult parental behavior and suggest a role for improved inclusive fitness in mediating long-term outcomes.