Qualitative Action Recognition by Wireless Radio Signals in Human–Machine Systems

Human-machine systems required a deep understanding of human behaviors. Most existing research on action recognition has focused on discriminating between different actions, however, the quality of executing an action has received little attention thus far. In this paper, we study the quality assessment of driving behaviors and present WiQ, a system to assess the quality of actions based on radio signals. This system includes three key components, a deep neural network based learning engine to extract the quality information from the changes of signal strength, a gradient-based method to detect the signal boundary for an individual action, and an activity-based fusion policy to improve the recognition performance in a noisy environment. By using the quality information, WiQ can differentiate a triple body status with an accuracy of 97%, whereas for identification among 15 drivers, the average accuracy is 88%. Our results show that, via dedicated analysis of radio signals, a fine-grained action characterization can be achieved, which can facilitate a large variety of applications, such as smart driving assistants

CYK-4 functions independently of its centralspindlin partner ZEN-4 to cellularize oocytes in germline syncytia

International audienceThroughout metazoans, germ cells undergo incomplete cytokinesis to form syncytia connected by intercellular bridges. Gamete formation ultimately requires bridge closure, yet how bridges are reactivated to close is not known. The most conserved bridge component is centralspindlin, a complex of the Rho family GTPase-activating protein (GAP) CYK-4/MgcRacGAP and the microtubule motor ZEN-4/kinesin-6. Here, we show that oocyte production by the syncytial Caenorhabditis elegans germline requires CYK-4 but not ZEN-4, which contrasts with cytokinesis, where both are essential. Longitudinal imaging after conditional inactivation revealed that CYK-4 activity is important for oocyte cellularization, but not for the cytokinesis-like events that generate syncytial compartments. CYK-4's lipid-binding C1 domain and the GTPase-binding interface of its GAP domain were both required to target CYK-4 to intercellular bridges and to cellularize oocytes. These results suggest that the conserved C1-GAP region of CYK-4 constitutes a targeting module required for closure of intercellular bridges in germline syncytia

The kinetochore-microtubule coupling machinery is repurposed in sensory nervous system morphogenesis

Dynamic coupling of microtubule ends to kinetochores, built on the centromeres of chromosomes, directs chromosome segregation during cell division. Here, we report that the evolutionarily ancient kinetochore-microtubule coupling machine, the KMN (Knl1/Mis12/Ndc80-complex) network, plays a critical role in neuronal morphogenesis. We show that the KMN network concentrates in microtubule-rich dendrites of developing sensory neurons that collectively extend in a multicellular morphogenetic event that occurs during C. elegans embryogenesis. Post-mitotic degradation of KMN components in sensory neurons disrupts dendritic extension, leading to patterning and functional defects in the sensory nervous system. Structure-guided mutations revealed that the molecular interface that couples kinetochores to spindle microtubules also functions in neuronal development. These results identify a cell-division-independent function for the chromosome-segregation machinery and define a microtubule-coupling-dependent event in sensory nervous system morphogenesis

The dynamic change of microbial communities in crude oil contaminated soils from oilfields in China

To study the biodegradability of microbial communities in crude oil contamination, crude oil-contaminated soil samples from different areas of China were collected. Using polyphasic approach, this study explored the dynamic change of the microbial communities during natural accumulation in oilfield and how the constructed bioremediation systems reshape the composition of microbial communities. The abundance of oil-degrading microbes was highest when oil content was 3%–8%. This oil content is potentially optimal for oil-degrading bacteria proliferate. During a ∼12 months natural accumulation, the quantity of oil-degrading microbes increased from 105 to 108 cells/g of soil. A typical sample of Liaohe (LH, oil-contaminated site near Liaohe river, Liaoning Province, China) was remediated for 50 days to investigate the dynamic change of microbial communities. The average FDA (a fluorescein diacetate approach) activities reached 0.25 abs/h·g dry soil in the artificially enhanced repair system, 32% higher than the 0.19 abs/h·g dry soil in natural circumstances. The abundance of oil-degrading microbes increased steadily from 0.001 to 0.068. During remediation treatment, oil content in the soil sample was reduced from 6.0% to 3.7%. GC-MS analysis indicated up to 67% utilization of C10–C20 normal paraffin hydrocarbons, the typical compounds that undergo microbial degradation

Assembly and function of non-centrosomal microtubule arrays /

In contrast to the radial microtubule arrays organized by centrosomes in dividing cells, many differentiated cells assemble non-centrosomal microtubule arrays adapted for specific cellular functions, including nuclear positioning and migration, maintenance of tissue architecture and intracellular transportation. In an RNAi screen in C. elegans, we identified NOCA-1 as a novel protein that does not contribute to centrosome-driven embryonic cell divisions but is required to form microtubule arrays in the germline that are essential for organismal fertility. In this dissertation, I focused on NOCA-1 to study the assembly mechanism and cellular function of non- centrosomal microtubule arrays. The noca-1 gene encodes 8 isoforms expressed in a variety of tissues. Two distinct long isoforms control assembly of microtubule arrays in the germline and embryonic epidermis, respectively. In contrast, a short isoform functions in parallel to the microtubule minus end-binding protein Patronin (PTRN-1) to control assembly of microtubule arrays in the post- embryonic epidermis. Evidence for the redundant activity of NOCA-1 and PTRN-1 includes synthetic lethality and early larval stage dye permeability of noca-1[Delta];ptrn- 1[Delta] double mutants, both of which are rescued by selectively expressing PTRN-1 in the post-embryonic epidermis. In support of the genetic interaction, NOCA-1 co-sediments with taxol-stabilized microtubules from worm lysates and purified recombinant NOCA-1, like PTRN-1, binds to microtubule ends in a microtubule-anchoring assay. We conclude that NOCA-1 represents a new class of microtubule end-binding proteins with essential functions of its own, as well as parallel functions with Patronin, in the assembly of non-centrosomal microtubule arrays in multiple C. elegans tissues. Non-centrosomal microtubule arrays in embryonic epidermis contribute to elongation, the process that converts the oval-shaped embryo into an elongated worm. By using two different means of disrupting microtubules, we showed that disrupting microtubules alone does not affect elongation. However, when acto-myosin contractility is compromised by a partial loss-of-function mutant of let-502 (a Rho kinase), disrupting microtubules results in elongation arrests and causes embryonic lethality. Intact microtubules and normal LET-502 activity are required for E-cadherin clustering at adherens junctions and the maturation of hemidesmosomes, possibly explaining the elongation defects we observed. We conclude that microtubules in the embryonic epidermis contribute to elongation, but only is required when actomyosin contractility is reduce

Assembly and function of non-centrosomal microtubule arrays /

In contrast to the radial microtubule arrays organized by centrosomes in dividing cells, many differentiated cells assemble non-centrosomal microtubule arrays adapted for specific cellular functions, including nuclear positioning and migration, maintenance of tissue architecture and intracellular transportation. In an RNAi screen in C. elegans, we identified NOCA-1 as a novel protein that does not contribute to centrosome-driven embryonic cell divisions but is required to form microtubule arrays in the germline that are essential for organismal fertility. In this dissertation, I focused on NOCA-1 to study the assembly mechanism and cellular function of non- centrosomal microtubule arrays. The noca-1 gene encodes 8 isoforms expressed in a variety of tissues. Two distinct long isoforms control assembly of microtubule arrays in the germline and embryonic epidermis, respectively. In contrast, a short isoform functions in parallel to the microtubule minus end-binding protein Patronin (PTRN-1) to control assembly of microtubule arrays in the post- embryonic epidermis. Evidence for the redundant activity of NOCA-1 and PTRN-1 includes synthetic lethality and early larval stage dye permeability of noca-1[Delta];ptrn- 1[Delta] double mutants, both of which are rescued by selectively expressing PTRN-1 in the post-embryonic epidermis. In support of the genetic interaction, NOCA-1 co-sediments with taxol-stabilized microtubules from worm lysates and purified recombinant NOCA-1, like PTRN-1, binds to microtubule ends in a microtubule-anchoring assay. We conclude that NOCA-1 represents a new class of microtubule end-binding proteins with essential functions of its own, as well as parallel functions with Patronin, in the assembly of non-centrosomal microtubule arrays in multiple C. elegans tissues. Non-centrosomal microtubule arrays in embryonic epidermis contribute to elongation, the process that converts the oval-shaped embryo into an elongated worm. By using two different means of disrupting microtubules, we showed that disrupting microtubules alone does not affect elongation. However, when acto-myosin contractility is compromised by a partial loss-of-function mutant of let-502 (a Rho kinase), disrupting microtubules results in elongation arrests and causes embryonic lethality. Intact microtubules and normal LET-502 activity are required for E-cadherin clustering at adherens junctions and the maturation of hemidesmosomes, possibly explaining the elongation defects we observed. We conclude that microtubules in the embryonic epidermis contribute to elongation, but only is required when actomyosin contractility is reduce

End-to-End Mandarin Speech Recognition Combining CNN and BLSTM

Since conventional Automatic Speech Recognition (ASR) systems often contain many modules and use varieties of expertise, it is hard to build and train such models. Recent research show that end-to-end ASRs can significantly simplify the speech recognition pipelines and achieve competitive performance with conventional systems. However, most end-to-end ASR systems are neither reproducible nor comparable because they use specific language models and in-house training databases which are not freely available. This is especially common for Mandarin speech recognition. In this paper, we propose a CNN+BLSTM+CTC end-to-end Mandarin ASR. This CNN+BLSTM+CTC ASR uses Convolutional Neural Net (CNN) to learn local speech features, uses Bidirectional Long-Short Time Memory (BLSTM) to learn history and future contextual information, and uses Connectionist Temporal Classification (CTC) for decoding. Our model is completely trained on the by-far-largest open-source Mandarin speech corpus AISHELL-1, using neither any in-house databases nor external language models. Experiments show that our CNN+BLSTM+CTC model achieves a WER of 19.2%, outperforming the exiting best work. Because all the data corpora we used are freely available, our model is reproducible and comparable, providing a new baseline for further Mandarin ASR research

An Overview of End-to-End Automatic Speech Recognition

Automatic speech recognition, especially large vocabulary continuous speech recognition, is an important issue in the field of machine learning. For a long time, the hidden Markov model (HMM)-Gaussian mixed model (GMM) has been the mainstream speech recognition framework. But recently, HMM-deep neural network (DNN) model and the end-to-end model using deep learning has achieved performance beyond HMM-GMM. Both using deep learning techniques, these two models have comparable performances. However, the HMM-DNN model itself is limited by various unfavorable factors such as data forced segmentation alignment, independent hypothesis, and multi-module individual training inherited from HMM, while the end-to-end model has a simplified model, joint training, direct output, no need to force data alignment and other advantages. Therefore, the end-to-end model is an important research direction of speech recognition. In this paper we review the development of end-to-end model. This paper first introduces the basic ideas, advantages and disadvantages of HMM-based model and end-to-end models, and points out that end-to-end model is the development direction of speech recognition. Then the article focuses on the principles, progress and research hotspots of three different end-to-end models, which are connectionist temporal classification (CTC)-based, recurrent neural network (RNN)-transducer and attention-based, and makes theoretically and experimentally detailed comparisons. Their respective advantages and disadvantages and the possible future development of the end-to-end model are finally pointed out. Automatic speech recognition is a pattern recognition task in the field of computer science, which is a subject area of Symmetry