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Windsor, CT, United States

Kowshik H.,Next Generation Systems | Kumar P.R.,Texas A&M University
IEEE Transactions on Information Theory | Year: 2012

We consider the problem of information aggregation in sensor networks, where one is interested in computing a function of the sensor measurements. We allow for block processing and study in-network function computation in directed graphs and undirected graphs. We study how the structure of the function affects the encoding strategies and the effect of interactive information exchange. Depending on the application, there could be a designated collector node, or every node might want to compute the function. We begin by considering a directed graph G = (V,E) on the sensor nodes, where the goal is to determine the optimal encoders on each edge which achieve function computation at the collector node. Our goal is to characterize the rate region in R |E|, i.e., the set of points for which there exist feasible encoders with given rates which achieve zero-error computation for asymptotically large block length. We determine the solution for directed trees, specifying the optimal encoder and decoder for each edge. For general directed acyclic graphs, we provide an outer bound on the rate region by finding the disambiguation requirements for each cut, and describe examples where this outer bound is tight. Next, we address the scenario where nodes are connected in an undirected tree network, and every node wishes to compute a given symmetric Boolean function of the sensor data. Undirected edges permit interactive computation, and we therefore study the effect of interaction on the aggregation and communication strategies. We focus on sum-threshold functions and determine the minimum worst case total number of bits to be exchanged on each edge. The optimal strategy involves recursive in-network aggregation which is reminiscent of message passing. In the case of general graphs, we present a cut-set lower bound and an achievable scheme based on aggregation along trees. For complete graphs, we prove that the complexity of this scheme is no more than twice that of the optimal scheme. © 2012 IEEE. Source

Imaizumi Y.,Keio University | Imaizumi Y.,Next Generation Systems | Okano H.,Keio University
Journal of Neurochemistry | Year: 2014

Human induced pluripotent stem (iPS) cells obtained by reprogramming technology are a source of great hope, not only in terms of applications in regenerative medicine, such as cell transplantation therapy, but also for modeling human diseases and new drug development. In particular, the production of iPS cells from the somatic cells of patients with intractable diseases and their subsequent differentiation into cells at affected sites (e.g., neurons, cardiomyocytes, hepatocytes, and myocytes) has permitted the in vitro construction of disease models that contain patient-specific genetic information. For example, disease-specific iPS cells have been established from patients with neuropsychiatric disorders, including schizophrenia and autism, as well as from those with neurodegenerative diseases, including Parkinson's disease and Alzheimer's disease. A multi-omics analysis of neural cells originating from patient-derived iPS cells may thus enable investigators to elucidate the pathogenic mechanisms of neurological diseases that have heretofore been unknown. In addition, large-scale screening of chemical libraries with disease-specific iPS cells is currently underway and is expected to lead to new drug discovery. Accordingly, this review outlines the progress made via the use of patient-derived iPS cells toward the modeling of neurological disorders, the testing of existing drugs, and the discovery of new drugs. © 2013 International Society for Neurochemistry. Source

Zhou Q.,Scripps Research Institute | Gui J.,Scripps Research Institute | Pan C.-M.,Scripps Research Institute | Albone E.,Morphotek Inc. | And 5 more authors.
Journal of the American Chemical Society | Year: 2013

A general C-H functionalization method for the tagging of natural products and pharmaceuticals is described. An azide-containing sulfinate reagent allows the appendage of azidoalkyl chains onto heteroaromatics, the product of which can then be attached to a monoclonal antibody by a "click" reaction. This strategy expands the breadth of bioactive small molecules that can be linked to macromolecules in a manner that is beyond the scope of existing methods in bioconjugation to permit tagging of the "seemingly untaggable". © 2013 American Chemical Society. Source

Next Generation Systems | Date: 2013-02-28

A pump in fluid communication with the outlet of a fluid purification apparatus. A pump may furthermore provide fluid to the inlet of the fluid purification apparatus. An embodiment includes a fluid driven rotating inlet device in fluid communication with the inlet of the fluid purification apparatus and an outlet impeller in fluid communication with the outlet of the fluid purification apparatus.

Next Generation Systems | Date: 2011-06-01

Apparatuses and methods for removing volatiles from fluid systems. The apparatuses and methods include evaporator sections. The apparatuses and methods may furthermore include a heater disposed at least in part in the evaporator section, which may have a ridge on its surface. The apparatuses and methods may furthermore include an evaporation tube positioned around the heater, which may have a conically shaped outer surface. The apparatuses and methods may also include an air inlet and an air outlet in the evaporator section.

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