Leveraging Social Foci for Information Seeking in Social Media

The rise of social media provides a great opportunity for people to reach out to their social connections to satisfy their information needs. However, generic social media platforms are not explicitly designed to assist information seeking of users. In this paper, we propose a novel framework to identify the social connections of a user able to satisfy his information needs. The information need of a social media user is subjective and personal, and we investigate the utility of his social context to identify people able to satisfy it. We present questions users post on Twitter as instances of information seeking activities in social media. We infer soft community memberships of the asker and his social connections by integrating network and content information. Drawing concepts from the social foci theory, we identify answerers who share communities with the asker w.r.t. the question. Our experiments demonstrate that the framework is effective in identifying answerers to social media questions.Comment: AAAI 201

Attributed Network Embedding for Learning in a Dynamic Environment

Network embedding leverages the node proximity manifested to learn a low-dimensional node vector representation for each node in the network. The learned embeddings could advance various learning tasks such as node classification, network clustering, and link prediction. Most, if not all, of the existing works, are overwhelmingly performed in the context of plain and static networks. Nonetheless, in reality, network structure often evolves over time with addition/deletion of links and nodes. Also, a vast majority of real-world networks are associated with a rich set of node attributes, and their attribute values are also naturally changing, with the emerging of new content patterns and the fading of old content patterns. These changing characteristics motivate us to seek an effective embedding representation to capture network and attribute evolving patterns, which is of fundamental importance for learning in a dynamic environment. To our best knowledge, we are the first to tackle this problem with the following two challenges: (1) the inherently correlated network and node attributes could be noisy and incomplete, it necessitates a robust consensus representation to capture their individual properties and correlations; (2) the embedding learning needs to be performed in an online fashion to adapt to the changes accordingly. In this paper, we tackle this problem by proposing a novel dynamic attributed network embedding framework - DANE. In particular, DANE first provides an offline method for a consensus embedding and then leverages matrix perturbation theory to maintain the freshness of the end embedding results in an online manner. We perform extensive experiments on both synthetic and real attributed networks to corroborate the effectiveness and efficiency of the proposed framework.Comment: 10 page

MOGU LI STRUKTURALNE PRILAGODBE VLADINOG UPRAVLJANJA POBOLJŠATI EKONOMSKE UČINKE? SLUČAJ WUHANSKOG VELEGRADSKOG PODRUČJA U KINI

The paper employs M-form and U-form organization theory to analyze the structural innovation of government governance, and tries to study the resources integration and economic performances among different cities in a metropolis circle by using the example of Wuhan metropolis circle in China. Specifically, we focus on analyzing the difference between economic performance before and after the formation of Wuhan metropolis circle. The research result shows that, on the one hand, the formation of Wuhan metropolis circle can make full use of the U-form organization; on the other hand, different cities also benefit from coordinated regional development and rational resources allocation thanks to the formation of metropolis circle. Furthermore, each city has individual characteristics and complementary to other cities. Consequently, the economic performance of theses cities greatly differs from each other.Rad koristi organizacijsku teoriju M-forme i U-forme za analizu strukturalnih inovacija vladinog upravljanja, te pokušava proučiti integraciju resursa i ekonomske učinke vladinog upravljanja među raznim gradovima velegradskog područja koristeći primjer wuhanskog velegradskog područja u Kini. Posebno je usredotočen na analizu razlike između ekonomskih učinaka prije i nakon stvaranja wuhanskog velegradskog područja. Rezultati istraživanja pokazuju da, s jedne strane, stvaranje wuhanskog velegradskog područja može u potpunosti iskoristiti U-formu organizacije, dok s druge strane, različiti gradovi također profitiraju radi koordiniranog područnog razvoja i racionalne raspodjele resursa zahvaljujući stvaranju velegradskog područja. Osim toga, svaki grad ima individualne karakteristike i one komplementarne drugim gradovima. Stoga se ekonomski učinci ovih gradova uvelike razlikuju jedni od drugih

On the performance of an integrated communication and localization system: an analytical framework

Quantifying the performance bound of an integrated localization and communication (ILAC) system and the trade-off between communication and localization performance is critical. In this letter, we consider an ILAC system that can perform communication and localization via time-domain or frequency-domain resource allocation. We develop an analytical framework to derive the closed-form expression of the capacity loss versus localization Cramer-Rao lower bound (CRB) loss via time-domain and frequency-domain resource allocation. Simulation results validate the analytical model and demonstrate that frequency-domain resource allocation is preferable in scenarios with a smaller number of antennas at the next generation nodeB (gNB) and a larger distance between user equipment (UE) and gNB, while time-domain resource allocation is preferable in scenarios with a larger number of antennas and smaller distance between UE and the gNB.Comment: 5 pages, 3 figure

Size- and speed-dependent mechanical behavior in living mammalian cytoplasm

Active transport in the cytoplasm plays critical roles in living cell physiology. However, the mechanical resistance that intracellular compartments experience, which is governed by the cytoplasmic material property, remains elusive, especially its dependence on size and speed. Here we use optical tweezers to drag a bead in the cytoplasm and directly probe the mechanical resistance with varying size a and speed V. We introduce a method, combining the direct measurement and a simple scaling analysis, to reveal different origins of the size- and speed-dependent resistance in living mammalian cytoplasm. We show that the cytoplasm exhibits size-independent viscoelasticity as long as the effective strain rate V/a is maintained in a relatively low range (0.1 s −1 < V/a < 2 s −1 ) and exhibits size-dependent poroelasticity at a high effective strain rate regime (5 s −1 < V/a < 80 s −1 ). Moreover, the cytoplasmic modulus is found to be positively correlated with only V/a in the viscoelastic regime but also increases with the bead size at a constant V/a in the poroelastic regime. Based on our measurements, we obtain a full-scale state diagram of the living mammalian cytoplasm, which shows that the cytoplasm changes from a viscous fluid to an elastic solid, as well as from compressible material to incompressible material, with increases in the values of two dimensionless parameters, respectively. This state diagram is useful to understand the underlying mechanical nature of the cytoplasm in a variety of cellular processes over a broad range of speed and size scales. Keywords: cell mechanics; poroelasticity; viscoelasticity; cytoplasmic state diagra

Long noncoding RNA NEAT1 (nuclear paraspeckle assembly transcript 1) is critical for phenotypic switching of vascular smooth muscle cells

In response to vascular injury, vascular smooth muscle cells (VSMCs) may switch from a contractile to a proliferative phenotype thereby contributing to neointima formation. Previous studies showed that the long noncoding RNA (lncRNA) NEAT1 is critical for paraspeckle formation and tumorigenesis by promoting cell proliferation and migration. However, the role of NEAT1 in VSMC phenotypic modulation is unknown. Herein we showed that NEAT1 expression was induced in VSMCs during phenotypic switching in vivo and in vitro. Silencing NEAT1 in VSMCs resulted in enhanced expression of SM-specific genes while attenuating VSMC proliferation and migration. Conversely, overexpression of NEAT1 in VSMCs had opposite effects. These in vitro findings were further supported by in vivo studies in which NEAT1 knockout mice exhibited significantly decreased neointima formation following vascular injury, due to attenuated VSMC proliferation. Mechanistic studies demonstrated that NEAT1 sequesters the key chromatin modifier WDR5 (WD Repeat Domain 5) from SM-specific gene loci, thereby initiating an epigenetic "off" state, resulting in down-regulation of SM-specific gene expression. Taken together, we demonstrated an unexpected role of the lncRNA NEAT1 in regulating phenotypic switching by repressing SM-contractile gene expression through an epigenetic regulatory mechanism. Our data suggest that NEAT1 is a therapeutic target for treating occlusive vascular diseases

Novel Myh11 Dual Reporter Mouse Model Provides Definitive Labeling and Identification of Smooth Muscle Cells—Brief Report

Objective: Myh11 encodes a myosin heavy chain protein that is specifically expressed in smooth muscle cells (SMCs) and is important for maintaining vascular wall stability. The goal of this study is to generate a Myh11 dual reporter mouse line for definitive visualization of MYH11+ SMCs in vivo. Approach and Results: We generated a Myh11 knock-in mouse model by inserting LoxP-nlacZ-4XpolyA-LoxP-H2B-GFP-polyA-FRT-Neo-FRT reporter cassette into the Myh11 gene locus. The nuclear (n) lacZ-4XpolyA cassette is flanked by 2 LoxP sites followed by H2B-GFP (histone 2B fused green fluorescent protein). Upon Cre-mediated recombination, nlacZ-stop cassette is removed thereby permitting nucleus localized H2B-GFP expression. Expression of the nuclear localized lacZ or H2B-GFP is under control of the endogenous Myh11 promoter. Nuclear lacZ was expressed specifically in SMCs at embryonic and adult stages. Following germline Cre-mediated deletion of nuclear lacZ, H2B-GFP was specifically expressed in the nuclei of SMCs. Comparison of nuclear lacZ expression with Wnt1Cre and Mef2cCre mediated-H2B-GFP expression revealed heterogenous origins of SMCs from neural crest and second heart field in the great arteries and coronary vessels adjacent to aortic root. Conclusions: The Myh11 knock-in dual reporter mouse model offers an exceptional genetic tool to visualize and trace the origins of SMCs in mice

CAM : a Combined Attention Model for natural language inference.

Natural Language Inference (NLI) is a fundamental step towards natural language understanding. The task aims to detect whether a premise entails or contradicts a given hypothesis. NLI contributes to a wide range of natural language understanding applications such as question answering, text summarization and information extraction. Recently, the public availability of big datasets such as Stanford Natural Language Inference (SNLI) and SciTail, has made it feasible to train complex neural NLI models. Particularly, Bidirectional Long Short-Term Memory networks (BiLSTMs) with attention mechanisms have shown promising performance for NLI. In this paper, we propose a Combined Attention Model (CAM) for NLI. CAM combines the two attention mechanisms: intraattention and inter-attention. The model first captures the semantics of the individual input premise and hypothesis with intra-attention and then aligns the premise and hypothesis with inter-sentence attention. We evaluate CAM on two benchmark datasets: Stanford Natural Language Inference (SNLI) and SciTail, achieving 86.14% accuracy on SNLI and 77.23% on SciTail. Further, to investigate the effectiveness of individual attention mechanism and in combination with each other, we present an analysis showing that the intra- and inter-attention mechanisms achieve higher accuracy when they are combined together than when they are independently used