Node-Level Energy Management for Sensor Networks in the Presence of Multiple Applications

Wireless Networks - Energy related research in wireless ad hoc sensor networks (WASNs) is focusing on energy saving techniques in the application-, protocol-, service-, or hardware-level. Little...     

Lentiviral-Induced Spinal Cord Gliomas in Rat Model

Intramedullary spinal cord tumors are a rare and understudied cancer with poor treatment options and prognosis. Our prior study used a combination of PDGF-B, HRAS, and p53 knockdown to induce the development of high-grade glioma in the spinal cords of minipigs. In this study, we evaluate the ability of each vector alone and combinations of vectors to produce high-grade spinal cord gliomas. Eight groups of rats (n = 8/group) underwent thoracolumbar laminectomy and injection of lentiviral vector in the lateral white matter of the spinal cord. Each group received a different combination of lentiviral vectors expressing PDGF-B, a constitutively active HRAS mutant, or shRNA targeting p53, or a control vector. All animals were monitored once per week for clinical deficits for 98 days. Tissues were harvested and analyzed using hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining. Rats injected with PDGF-B+HRAS+sh-p53 (triple cocktail) exhibited statistically significant declines in all behavioral measures (Basso Beattie Bresnahan scoring, Tarlov scoring, weight, and survival rate) over time when compared to the control. Histologically, all groups except the control and those injected with sh-p53 displayed the development of tumors at the injection site, although there were differences in the rate of tumor growth and the histopathological features of the lesions between groups. Examination of immunohistochemistry revealed rats receiving triple cocktail displayed the largest and most significant increase in the Ki67 proliferation index and GFAP positivity than any other group. PDGF-B+HRAS also displayed a significant increase in the Ki67 proliferation index. Rats receiving PDGF-B alone and PDGF-B+ sh-p53 displayed more a significant increase in SOX2-positive staining than in any other group. We found that different vector combinations produced differing high-grade glioma models in rodents. The combination of all three vectors produced a model of high-grade glioma more efficiently and aggressively with respect to behavioral, physiological, and histological characteristics than the rest of the vector combinations. Thus, the present rat model of spinal cord glioma may potentially be used to evaluate therapeutic strategies in the future.     

Improved capillary electrophoretic separation of glycosylated oligopeptides through addition of poly(vinyl alcohol), and analysis by electrospray mass spectrometry

A method for the analysis of O-glycosylation of peptides has been developed, combining capillary electrophoretic (CE) separation and electrospray ionization mass spectrometry. Synthetic peptides with apomucin 'tandem repeat' sequences which present potential O-glycosylation sites on threonine and serine residues were used as model system. In vitro O-glycosylated peptide samples were obtained by incubation of the peptides with human gastric microsomal homogenates containing N-acetylgalactosamine transferase activity in the presence of uridyl diphosphate N-acetylgalactosamine (UDP-GalNAc). CE was carried out in the presence of the linear polymer poly(vinyl alcohol) in the electrophoresis solvent, resulting in a greatly improved separation of the up to five different glycoforms of peptides with lengths of 8, 16 or 23 amino acids, and the unglycosylated peptides. After separation and peak collection, the number of modifications with N-acetyl galactosamine (GalNAc) could be determined by electrospray ionization mass spectrometry. The glycosylation pattern was shown to depend on the amino acid sequence of the peptides.     

Footshock-induced sensitization of electrically elicited startle reflexes.

Acoustic startle is a short-latency reflex mediated by a neural circuit consisting of the ventral cochlear nucleus (VCN), ventral nucleus of the lateral lemniscus (VLL), the nucleus reticularis pontis caudalis (RPC), and the spinal cord. The present study sought to determine the point along this pathway where footshocks might ultimately alter neural transmission to affect startle response. Rats were implanted bilaterally with stimulating electrodes in either the VCN, VLL, or RPC. Startle could be elicited acoustically with a noise burst or electrically with a single-pulse stimulus to either the VCN, VLL, or RPC before and after a train of ten 0.6-mA, 500-ms shocks presented at a rate of 1 shock/s. Startle elicited acoustically or electrically in the VCN or VLL was significantly elevated following shocks. Data suggest that footshock sensitization ultimately alters transmission in the startle circuit at the RPC. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative learning modifies the shortening reflex in the semi-intact leech Hirudo medicinalis: Effects of pairing, predictability, and CS preexposure.

Three experiments addressed the importance of the inter-event relationships of contiguity and contingency for associative learning in the semi-intact leech. It was found that both of these relationships are important for the leech to acquire a learned association between a CS (touch) and unconditioned stimulus (UCS; shock). The learning can be extinguished if training is followed by explicitly unpaired presentations of the CS and UCS, which removes the contiguity between the stimuli. Learning is degraded by the introduction of unpredicted UCSs, as well as by unreinforced presentations of the CS (CS preexposure); both manipulations reduce the contingency between the CS and UCS. These results suggest that the associative process in both vertebrates and invertebrates share considerable functional similarity in the inter-event relationships important to learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Speech and Language Processing for Multimodal Human-Computer Interaction

In this paper, we describe our recent work at Microsoft Research, in the project codenamed Dr. Who, aimed at the development of enabling technologies for speech-centric multimodal human-computer interaction. In particular, we present in detail MiPad as the first Dr. Who's application that addresses specifically the mobile user interaction scenario. MiPad is a wireless mobile PDA prototype that enables users to accomplish many common tasks using a multimodal spoken language interface and wireless-data technologies. It fully integrates continuous speech recognition and spoken language understanding, and provides a novel solution to the current prevailing problem of pecking with tiny styluses or typing on minuscule keyboards in today's PDAs or smart phones. Despite its current incomplete implementation, we have observed that speech and pen have the potential to significantly improve user experience in our user study reported in this paper. We describe in this system-oriented paper the main components of MiPad, with a focus on the robust speech processing and spoken language understanding aspects. The detailed MiPad components discussed include: distributed speech recognition considerations for the speech processing algorithm design; a stereo-based speech feature enhancement algorithm used for noise-robust front-end speech processing; Aurora2 evaluation results for this front-end processing; speech feature compression (source coding) and error protection (channel coding) for distributed speech recognition in MiPad; HMM-based acoustic modeling for continuous speech recognition decoding; a unified language model integrating context-free grammar and N-gram model for the speech decoding; schema-based knowledge representation for the MiPad's personal information management task; a unified statistical framework that integrates speech recognition, spoken language understanding and dialogue management; the robust natural language parser used in MiPad to process the speech recognizer's output; a machine-aided grammar learning and development used for spoken language understanding for the MiPad task; Tap & Talk multimodal interaction and user interface design; back channel communication and MiPad's error repair strategy; and finally, user study results that demonstrate the superior throughput achieved by the Tap & Talk multimodal interaction over the existing pen-only PDA interface. These user study results highlight the crucial role played by speech in enhancing the overall user experience in MiPad-like human-computer interaction devices.