Flow-based microfluidic biochips have emerged as a promising platform for biochemical experiments. These chips contain transportation channels and operational devices that are controlled by microvalves, which are actu...
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Flow-based microfluidic biochips have emerged as a promising platform for biochemical experiments. These chips contain transportation channels and operational devices that are controlled by microvalves, which are actuated by external controllers. As the complexity of experiments conducted on these chips continues to increase, control multiplexers (MUXes) have become essential for actuating a large number of valves. However, current binary-coding-based MUXes do not fully utilize the coding capacity and suffer from reliability issues due to long total length of channels and high control channel density. In this article, we propose the combinatorial coding, a novel MUX coding strategy, along with an algorithm to synthesize combinatorial-coding-based MUXes (CoMUXes) of arbitrary sizes with the theoretical maximum coding capacity. We also develop a simplification method to reduce the number of valves and the total length of control channels in CoMUXes, thereby improving their reliability. Additionally, we develop a reliability-aware adaptation method to reliably integrate the CoMUXes into the main functional part of the designs. We compare CoMUX with state-of-the-art MUXes under different control demands with up to 10 x 2(13) independent control channels. Experimental results show that CoMUXes can reliably address more independent control channels with fewer resources. For instance, when the number of control channels to be controlled is up to 10x 2(13) , compared to a state-of-the-art MUX, the optimized CoMUX reduces the number of required flow channels by 44% and the number of valves by 90%. The proposed adaptation method is also tested to be capable of significantly reducing area usage, total length of control channels, and the risk of having defects.
In this paper, we present a method that reduces the decoding complexity of an entropy encoding technique, namely, combinatorial coding, in order to increase compression efficiency without suffering from intolerable de...
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ISBN:
(纸本)9781728175652
In this paper, we present a method that reduces the decoding complexity of an entropy encoding technique, namely, combinatorial coding, in order to increase compression efficiency without suffering from intolerable decoding latency. Performance of the proposed method is empirically evaluated on randomly generated bit strings for variable lengths and Hamming weights. As a result, it is made possible that combinatorial coding may practically be applied in larger sized blocks, producing higher throughput than the naive implementation.
High-level neural activity often exhibits mixed selectivity to multivariate signals. How such representations arise and modulate natural behavior is poorly understood. We addressed this question in weakly electric fis...
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High-level neural activity often exhibits mixed selectivity to multivariate signals. How such representations arise and modulate natural behavior is poorly understood. We addressed this question in weakly electric fish, whose social behavior is relatively low dimensional and can be easily reproduced in the laboratory. We report that the preglomerular complex, a thalamic region exclusively connecting midbrain with pallium, implements a mixed selectivity strategy to encode interactions related to courtship and rivalry. We discuss how this code enables the pallial recurrent networks to control social behavior, including dominance in male male competition and female mate selection. Notably, response latency analysis and computational modeling suggest that corollary discharge from premotor regions is implicated in flagging outgoing communications and thereby disambiguating self-versus non-self-generated signals. These findings provide new insights into the neural substrates of social behavior, multi-dimensional neural representation, and its role in perception and decision making.
There is increasing appreciation that G-protein-coupled receptors (GPCRs) can initiate diverse cellular responses by activating multiple G proteins, arrestins, and other biochemical effectors. Structurally different l...
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There is increasing appreciation that G-protein-coupled receptors (GPCRs) can initiate diverse cellular responses by activating multiple G proteins, arrestins, and other biochemical effectors. Structurally different ligands targeting the same receptor are thought to stabilize the receptor in multiple distinct active conformations such that specific subsets of signaling effectors are engaged at the exclusion of others, creating a bias toward a particular outcome, which has been referred to as ligand-induced selective signaling, biased agonism, ligand-directed signaling, and functional selectivity, among others. The potential involvement of functional selectivity in mammalian olfactory signal transduction has received little attention, notwithstanding the fact that mammalian olfactory receptors comprise the largest family of mammalian *** position review considers the possibility that, although such complexity in G-protein function may have been lost in the specialization of olfactory receptors to serve as sensory receptors, the ability of olfactory receptor neurons (ORNs) to function as signal integrators and growing appreciation that this functionality is widespread in the receptor population suggest otherwise. We pose that functional selectivity driving 2 opponent inputs have the potential to generate an output that reflects the balance of ligand-dependent signaling, the direction of which could be either suppressive or synergistic and, as such, needs to be considered as a mechanistic basis for signal integration in mammalian ORNs.
Olfactory GPCRs (ORs) in mammalian olfactory receptor neurons (ORNs) mediate excitation through the G alpha(s) family member G alpha(olf). Here we tentatively associate a second G protein, G alpha(o), with inhibitory ...
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Olfactory GPCRs (ORs) in mammalian olfactory receptor neurons (ORNs) mediate excitation through the G alpha(s) family member G alpha(olf). Here we tentatively associate a second G protein, G alpha(o), with inhibitory signaling in mammalian olfactory transduction by first showing that odor evoked phosphoinositide 3-kinase (PI3K)-dependent inhibition of signal transduction is absent in the native ORNs of mice carrying a conditional OMP-Cre based knockout of G alpha(o). We then identify an OR from native rat ORNs that are activated by octanol through cyclic nucleotide signaling and inhibited by citral in a PI3K-dependent manner. We show that the OR activates cyclic nucleotide signaling and PI3K signaling in a manner that reflects its functionality in native ORNs. Our findings lay the groundwork to explore the interesting possibility that ORs can interact with two different G proteins in a functionally identified, ligand-dependent manner to mediate opponent signaling in mature mammalian ORNs.
Innate immune sentinel cells must initiate and orchestrate appropriate immune responses for myriad pathogens. These stimulus-specific gene expression responses are mediated by combinatorial and temporal coding within ...
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Sensory coding represents a basic principle of all phyla in nature: species attempt to perceive their natural surroundings and to make sense of them. Ultimately, sensory coding is the only way to allow a species to ma...
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Sensory coding represents a basic principle of all phyla in nature: species attempt to perceive their natural surroundings and to make sense of them. Ultimately, sensory coding is the only way to allow a species to make the kinds of crucial decisions that lead to a behavioral response. In this manner, animals are able to detect numerous parameters, ranging from temperature and humidity to light and sound to volatile or non-volatile chemicals. Most of these environmental cues represent a clearly defined stimulus array that can be described along a single physical parameter, such as wavelength or frequency;odorants, in contrast, cannot. The odor space encompasses an enormous and nearly infinite number of diverse stimuli that cannot be classified according to their positions along a single dimension. Hence, the olfactory system has to encode and translate the vast odor array into an accurate neural map in the brain. In this review, we will outline the relevant steps of the olfactory code and describe its progress along the olfactory pathway, i.e., from the peripheral olfactory organs to the first olfactory center in the brain and then to the higher processing areas where the odor perception takes place, enabling an organism to make odor guided decisions. We will focus mainly on studies from the vinegar fly Drosophila melanogaster, but we will also indicate similarities to and differences from the olfactory system of other invertebrate species as well as of the vertebrate world. (C) 2017 The Authors. Published by Elsevier Ireland Ltd.
Background: Honeybees are well established models of neural correlates of sensory function, learning and memory formation. Here we report a novel approach allowing to record high-order mushroom body-extrinsic interneu...
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Background: Honeybees are well established models of neural correlates of sensory function, learning and memory formation. Here we report a novel approach allowing to record high-order mushroom body-extrinsic interneurons in the brain of worker bees within a functional colony. New method The use of two 100 cm long twisted copper electrodes allowed recording of up to four units of mushroom body-extrinsic neurons simultaneously for up to 24 h in animals moving freely between members of the colony. Every worker, including the recorded bee, hatched in the experimental environment. The group consisted of 200 animals in average. Results: Animals explored different regions of the comb and interacted with other colony members. The activities of the units were not selective for locations on the comb, body directions with respect to gravity and olfactory signals on the comb, or different social interactions. However, combinations of these parameters defined neural activity in a unit-specific way. In addition, units recorded from the same animal co-varied according to unknown factors. Comparison with existing method(s): All electrophysiological studies with honey bees were performed so far on constrained animals outside their natural behavioral contexts. Yet no neuronal correlates were measured in a social context. Free mobility of recoded insects over a range of a quarter square meter allows addressing questions concerning neural correlates of social communication, planning of tasks within the colony and attention-like processes. Conclusions: The method makes it possible to study neural correlates of social behavior in a near-natural setting within the honeybee colony. (C) 2015 Elsevier B.V. All rights reserved.
"Sweet-" and "bitter-" tasting substances distinctively support attractive and aversive choice behavior, respectively, and therefore are thought to be processed by distinct pathways. Interestingly,...
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"Sweet-" and "bitter-" tasting substances distinctively support attractive and aversive choice behavior, respectively, and therefore are thought to be processed by distinct pathways. Interestingly, electrophysiological recordings in adult Drosophila suggest that bitter and salty tastants, in addition to activating bitter, salt, or bitter/salt sensory neurons, can also inhibit sweet-sensory neurons. However, the behavioral significance of such a potential for combinatorial coding is little understood. Using larval Drosophila as a study case, we find that the preference towards fructose is inhibited when assayed in the background of the bitter tastant quinine. When testing the influence of quinine on the preference to other, equally preferred sweet tastants, we find that these sweet tastants differ in their susceptibility to be inhibited by quinine. Such stimulus specificity argues that the inhibitory effect of quinine is not due to general effects on locomotion or nausea. In turn, not all bitter tastants have the same potency to inhibit sweet preference;notably, their inhibitory potency is not determined by the strength of the avoidance of them. Likewise, equally avoided concentrations of sodium chloride differ in their potency to inhibit sugar preference. Furthermore, Gr33a-Gal4-positive neurons, while being necessary for bitter avoidance, are dispensable for inhibition of the sweet pathway. Thus, interactions across taste modalities are behaviorally significant and, as we discuss, arguably diverse in mechanism. These results suggest that the coding of tastants and the organization of gustatory behavior may be more combinatorial than is generally acknowledged.
In C-RAN, the baseband units (BBU) and the remote radio heads (RRH) are separated, using the Common Public Radio Interface (CPRI) to transport data to each other. It is based on centralized processing and Real-time Cl...
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ISBN:
(纸本)9781479959709
In C-RAN, the baseband units (BBU) and the remote radio heads (RRH) are separated, using the Common Public Radio Interface (CPRI) to transport data to each other. It is based on centralized processing and Real-time Cloud Infrastructure, which requires significant transport network resources. A low latency compression scheme of LTE downlink baseband signal based on clustering algorithm is presented in this paper to reduce the CPRI transmission bandwidth in C-RAN. The main procedure of algorithm is removing redundant bandwidth I/Q data in frequency domain, clustering and quantifying the points on the constellation, and finally selecting an appropriate coding scheme adaptively. The Matlab simulation and FPGA-based performance analysis are presented in this paper to verify the compression algorithm. Under the premise of that EVM is less than 0.025%, especially in low throughput scenarios, the data compression ratio can reach about 4%. Moreover, the compression scheme has a strong independence and versatility, and can be used as a standalone module directly added to the current LTE system.
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