A class of singularly perturbed semi-linear boundary value problems with discontinuous functions is examined in this article.Using the boundary layer function method,the asymptotic solution of such a problem is given and shown to be uniformly effective.The existence and uniqueness of the solution for the system is also proved.Numerical result is presented as an illustration to the theoretical result.
To proceed from sensation to movement, integration and transformation of information from different senses and reference frames are required. Several brain areas are involved in this transformation process, but previous neuroanatomical and neurophysiological studies have implicated the caudal area 7b as one particular component of this transformation system. In this study, we present the first quantitative report on the spatial coding properties of caudal area 7b. The results showed that neurons in this area had intermediate component characteristics in the transformation system; the area contained bimodal neurons, and neurons in this area encode spatial information using a hybrid reference frame. These results provide evidence that caudal area 7b may belong to the reference frame transformation system, thus contributing to our general understanding of the transformation system.
Hui-Hui JIANGYing-Zhou HUJian-Hong WANGYuan-Ye MAXin-Tian HU
Within the postpartum period, both mothers and infants are susceptible; but because PPD typically occurs for short durations and has moderate symptoms, there exists challenges in exploring and addressing the underlying cause of the depression. This fact highlights the need for relevant animal models. In the present study, postpartum adult female cynomolgus monkeys(Macaca fascicularis) living in breeding groups were observed for typical depressive behavior. The huddle posture behavior was utilized as an indicator of behavioral depression postpartum(BDP) as it has been established as the core depressive-like behavior in primates. Monkeys were divided into two groups: A BDP group(n=6), which were found to spend more time huddling over the first two weeks postpartum than other individuals that formed a non-depression control group(n=4). The two groups were then further analyzed for locomotive activity, stressful events, hair cortisol levels and for maternal interactive behaviors. No differences were found between the BDP and control groups in locomotive activity, in the frequencies of stressful events experienced and in hair cortisol levels. These findings suggested that the postpartum depression witnessed in the monkeys was not related to external factors other than puerperium period. Interestingly, the BDP monkeys displayed an abnormal maternal relationship consisting of increased infant grooming. Taken together, these findings suggest that the adult female cynomolgus monkeys provide a natural model of behavioral postpartum depression that holds a number of advantages over commonly used rodent systems in PPD modeling. The cynomolgus monkeys have a highly-organized social hierarchy and reproductive characteristics without seasonal restriction—similar to humans—as well as much greater homology to humans than rodents. As such, this model may provide a greater translational efficiency and research platform for systematically investigating the etiology, treatment, prevention of PPD.
Xun-Xun CHUJoshua Dominic RizakShang-Chuan YANGJian-Hong WANGYuan-Ye MAXin-Tian HU
The fruit fly,Drosophila melanogaster,is able to discriminate visual landmarks and form visual long-term memory in a flight simulator.Studies focused on the molecular mechanism of long-term memory have shown that memory formation requires mRNA transcription and protein synthesis.However,little is known about the molecular mechanisms underlying the visual learning paradigm.The present study demonstrated that both spaced training procedure(STP)and consecutive training procedure(CTP)would induce long-term memory at 12 hour after training,and STP caused significantly higher 12-h memory scores compared with CTP.Labelfree quantification of liquid chromatography-tandem mass spectrometry(LC-MS/MS)and microarray were utilized to analyze proteomic and transcriptomic differences between the STP and CTP groups.Proteomic analysis revealed 30 up-regulated and 27 down-regulated proteins;Transcriptomic analysis revealed 145 up-regulated and 129 down-regulated genes.Among them,five candidate genes were verified by quantitative PCR,which revealed results similar to microarray.These results provide insight into the molecular components influencing visual long-term memory and facilitate further studies on the roles of identified genes in memory formation.
To proceed from sensation to movement,integration and transformation of information from different senses and reference frames are required.Several brain areas are involved in this transformation process,but previous neuroanatomical and neurophysiological studies have implicated the caudal area 7b as one particular component of this transformation system.In this study,we present the first quantitative report on the spatial coding properties of caudal area 7b.The results showed that neurons in this area had intermediate component characteristics in the transformation system;the area contained bimodal neurons,and neurons in this area encode spatial information using a hybrid reference frame.These results provide evidence that caudal area 7b may belong to the reference frame transformation system,thus contributing to our general understanding of the transformation system.
Hui-Hui JIANGYing-Zhou HUJian-Hong WANGYuan-Ye MAXin-Tian HU
The human visual system is tuned to the motions of biological entities, which provide potentially vital information for survival. The current study examines the interplay between motion speed and motion direction perception. Following a brief presentation of a point-light walker walking straight ahead or slightly leftward or rightward, observers were asked to quickly judge the walking direction (left or right). Participants showed better direction discrimination when the walker walked at a fast pace compared to a natural or slow pace, and this was not simply due to a difference in motion cycles. Moreover, walking direction sensitivity could be enhanced by increasing the feet motion speed alone, so long as the direction of feet movement was consistent with that of the other body parts. These findings demonstrate that our perception of walking direction is influenced by local motion speed, and highlight the role of the feet in biological motion perception.
