Magnetoencephalography was used to investigate the effect of directed attention on changes in sensorimotor mu (8-12Hz) response (mu reactivity) to non-painful electrical stimulation of the median nerve in healthy adults. Results indicated attention-related sex differences in mu reactivity, with females showing i) prolonged mu suppression when attending to somatosensory stimuli indicating active processing of the sensory stimuli; ii) task-dependent attentional modulation of the mu response, which was absent in males, and iii) a trend for greater neuronal excitability of the primary somatosensory region suggesting greater physiological responsiveness to stimulation overall. Sex-related differences in attentional modulation of sensorimotor rhythms suggest that females and males use different top-down control strategies when processing somatosensory information. These sex differences in attention may underlie well-documented sex-related biases in pain processing wherein females typically report greater sensitivity to experimental and clinical pain.

This paper presents the research on the robust control of micromachined accelerometers. First, we present different micromaching techniques and compare, analyze the accelerometers with different methods of signal pick-off. Besides the different methods of signal pick-off(the position detection of the seismic mass) and structure designs, we can enhance the performance such as stability, bandwidth, sensitivity, resolution and dynamic range etc. by suitable feedback controllers. So inside the front part of the paper are the analyses for the controllers of different types of accelerometers so far. Moreover, we design the controllers by robust control in different methods with the model of one specific type of micromachined tunneling accelerometer. Because of the robust controllers, the accelerometers can be stable and have good performance under different environments and uncertainties. At last we analyze and compare the controllers designed by -synthesis and gap metric.

Abstract This thesis presents that the closed-loop sensitivity function shaping combined with -synthesis applies to design the controller with structured uncertainties. The sensitivity function shaping is directly based on the indices of the closed-loop performances. The closed-loop frequency response and the robust stability for the system could approach the designed performances by adjusting weighting functions. Since the robust performance of the closed-loop systems bases on the index of the open-loop function in the loop shaping, it may not accomplish the requirement of the designer. The loop shaping can¡¦t be applied to design controllers for the system with structured uncertainties. Therefore, using the closed-loop sensitivity function shaping to design controller will contain the system with structured uncertainties and satisfy the closed-loop performance.

Thesis--University of Chicago. / Includes texts in Chinese and Japanese. Includes bibliographical references (leaves 219-235).

Thesis--Guo li zheng zhi da xue. / Reproduced from ms. copy. Errata slip inserted. Includes bibliographical references (p. 833-859).

Phage Mu transposes by two distinct pathways depending on the specific stage of its life cycle. A common θ strand transfer intermediate is resolved differentially in the two pathways. During lytic growth, the θ intermediate is resolved by replication of Mu initiated within the flanking target DNA; during integration of infecting Mu, it is resolved without replication, by removal and repair of DNA from a previous host that is still attached to the ends of the incoming Mu genome. Our studies show that the cryptic endonuclease activity reported for the isolated C-terminal domain of the transposase MuA, which is not observed in the full-length protein or in the assembled transpososome in vitro, is required in vivo for removal of the attached host DNA or “5’flap” after the infecting Mu genome has integrated into the E. coli chromosome. I have identified additional phage and host factors required for flap removal in vivo, which include an early Mu protein called Ner, and the E. coli protein ClpX. Ner regulates bidirectional transcription through the Mu transposition enhancer, while ClpX, a molecular chaperone, is known to interact with the C-terminus of MuA to remodel the transpososome for replication. The transpososome is a multi-subunit MuA complex assembled on the two paired ends of Mu. The enhancer DNA segment serves as an essential scaffold for transpososome assembly, and remains stably associated with θ strand transfer MuA complexes. I hypothesize that Ner-regulated transcription through the enhancer remodels transpososome conformation in the presence of ClpX, promoting activation of the MuA endonuclease, which resects flanking DNA during the repair pathway of Mu transposition. / text

Half-Duplex Multiuser Multiple-Input Multiple-Output (HD MU-MIMO) systemscurrently employed in communication systems are not experiencing the selfinterference(SI) problem but they are not optimal in terms of efficiency and interms of resources used (time and frequency resources). Ignoring the effect of largescalefading, we start by explaining the uplink (UL) and downlink (DL) parts ofthe MU-MIMO system and how the sum-rate is calculated. We also introduce thethree linear receivers/precoders, Maximum-Ratio Combining (MRC)/Maximum-Ratio Transmission (MRT), Zero-Forcing (ZF), and Minimum Mean-Square Error(MMSE) and which of the three types is going to be used in the study of Full-Duplex Multiuser Multiple-input Multiple-output (FD MU-MIMO) system. Thenwe introduce FD MU-MIMO system, and how the equation used to calculate thesum-rate of the UL part changes when the SI occurs, and why SI problem is notpresent in the DL part. Next, we introduce the spectral efficiency (SE), and howto calculate it and why it is taken as a parameter to compare HD and FD systems.Also the effect of SI on FD MU-MIMO system is presented through simulationgraphs, then we move to show how to reduce SI effect by increasing the number ofantennas in the base-station (BS). Lastly, we take the effect of large scale fading inorder to reach a simple statistical model in the form cumulative distribution function(CDF) graph for different values of SI and compare those of FD MU-MIMOsystem to HD MU-MIMO. The results show that FD MU-MIMO together withmassive MIMO technology is very promising and would save time and frequencyresources which means an increase in the SE but SI must be below a certain level.

Recently we have begun to investigate a novel role of EphB receptors in opiate-dependant analgesia. EphB2-β-galactosidase knockins demonstrate that EphB2 is persistently expressed within a number of neural pathways involved in MOR-mediated nociception in vivo and that EphB2 colocalizes with markers of the MOR at the cellular level in the spinal cord and dorsal root ganglia. Despite demonstrating wild-type levels of sensory and motor activity, EphB2 null mice exhibit a significantly altered analgesic response to repeated (but not naive) opiate exposure compared to controls. Investigation of EphB2 null mice and wild type animals revealed no differences in MOR protein levels or affinity. Analysis of this opiate-mediated tolerance suggests that associative phenomena play a substantial role in mediating the analgesic effects observed, possibly due to defeciencies in CA1-mediated learning. Therefore, loss of EphB2 may diminish context-dependent learning and that such learning plays a substantial role in regulating morphine-dependent tolerance.

Recently we have begun to investigate a novel role of EphB receptors in opiate-dependant analgesia. EphB2-β-galactosidase knockins demonstrate that EphB2 is persistently expressed within a number of neural pathways involved in MOR-mediated nociception in vivo and that EphB2 colocalizes with markers of the MOR at the cellular level in the spinal cord and dorsal root ganglia. Despite demonstrating wild-type levels of sensory and motor activity, EphB2 null mice exhibit a significantly altered analgesic response to repeated (but not naive) opiate exposure compared to controls. Investigation of EphB2 null mice and wild type animals revealed no differences in MOR protein levels or affinity. Analysis of this opiate-mediated tolerance suggests that associative phenomena play a substantial role in mediating the analgesic effects observed, possibly due to defeciencies in CA1-mediated learning. Therefore, loss of EphB2 may diminish context-dependent learning and that such learning plays a substantial role in regulating morphine-dependent tolerance.

Thesis--Guo li zheng zhi da xue. / Reproduced from ms. copy. Errata slip inserted. Includes bibliographical references (p. 833-859).