36 research outputs found
Topic Detection and Tracking with Time-Aware Document Embeddings
The time at which a message is communicated is a vital piece of metadata in
many real-world natural language processing tasks such as Topic Detection and
Tracking (TDT). TDT systems aim to cluster a corpus of news articles by event,
and in that context, stories that describe the same event are likely to have
been written at around the same time. Prior work on time modeling for TDT takes
this into account, but does not well capture how time interacts with the
semantic nature of the event. For example, stories about a tropical storm are
likely to be written within a short time interval, while stories about a movie
release may appear over weeks or months. In our work, we design a neural method
that fuses temporal and textual information into a single representation of
news documents for event detection. We fine-tune these time-aware document
embeddings with a triplet loss architecture, integrate the model into
downstream TDT systems, and evaluate the systems on two benchmark TDT data sets
in English. In the retrospective setting, we apply clustering algorithms to the
time-aware embeddings and show substantial improvements over baselines on the
News2013 data set. In the online streaming setting, we add our document encoder
to an existing state-of-the-art TDT pipeline and demonstrate that it can
benefit the overall performance. We conduct ablation studies on the time
representation and fusion algorithm strategies, showing that our proposed model
outperforms alternative strategies. Finally, we probe the model to examine how
it handles recurring events more effectively than previous TDT systems
THE PERSUASIVE IMPACT OF EMOTICONS IN ONLINE WORD-OF-MOUTH COMMUNICATION
The present research proposes a conceptual framework to examine the effect of emoticons on online WOM persuasion. Using a laboratory experiment, we demonstrate that emoticons enhance recipients’ empathy for the communicator, and this effect is moderated by message valence. Enhanced empathy heightens perceived trustworthiness of the communicator and perceived quality of the message, both of which lead to an increase in the persuasiveness of the WOM message. We conclude by discussing the contributions of this research and identifying the directions for future research
Slit2N and Robo4 regulate lymphangiogenesis through the VEGF-C/VEGFR-3 pathway
Background: Signaling through vascular endothelial growth factor C (VEGF–C) and VEGF receptor 3 (VEGFR-3) plays a central role in lymphangiogenesis and the metastasis of several cancers via the lymphatics. Recently, the Slit2/Robo4 pathway has been recognized as a modulator of vascular permeability and integrity. Signaling via the Robo receptor inhibits VEGF-mediated effects; however, its effects on lymphatic endothelial cell function have not been well characterized. Results: We found that pretreatment with Slit2N, an active fragment of Slit2, inhibited VEGF-C-mediated lung-derived lymphatic endothelial cell (L-LEC) proliferation, migration, and in vitro tube formation. Slit2N induced the internalization of VEGFR-3, which blocked its activation, and inhibited the activation of the PI3K/Akt pathway by VEGF-C in L-LECs. Moreover, we found that inhibition of VEGF-C-induced effects by Slit2N was Robo4-dependent. Conclusion: These results indicate that Slit2N/Robo4 modulates several key cellular functions, which contribute to lymphangiogenesis, and identify this ligand-receptor pair as a potential therapeutic target to inhibit lymphatic metastasis of VEGF-C-overexpressing cancers and manage lymphatic dysfunctions characterized by VEGF-C/VEGFR-3 activation
Come Rain and Shine? Exploring the Effects of Mobile Weather Applications on Users’ Movements
All Weather conditions affect human behaviors and the growing number of Mobile Weather Applications (MWAs) has amplified this effect. Yet, little is known about how human seek to actively control their behavior by appropriating mobile technology to anticipate changing weather conditions. Guided by Anticipatory Behavioral Control Theory (ABCT), this study endeavors to bride the abovementioned knowledge gap by investigating how the interface design and usage of MWAs would impact the relationship between abnormal weather conditions and users’ movement patterns. From analyzing panel data collected on the hourly movement trajectories of over 1.95 million anonymous mobile phone users over a 2-month period, we strive to shed light on the moderating influence of content representation and usage intensity of MWAs on the relationship between weather conditions and human behaviors
Attentive Mask CLIP
Image token removal is an efficient augmentation strategy for reducing the
cost of computing image features. However, this efficient augmentation strategy
has been found to adversely affect the accuracy of CLIP-based training. We
hypothesize that removing a large portion of image tokens may improperly
discard the semantic content associated with a given text description, thus
constituting an incorrect pairing target in CLIP training. To address this
issue, we propose an attentive token removal approach for CLIP training, which
retains tokens with a high semantic correlation to the text description. The
correlation scores are computed in an online fashion using the EMA version of
the visual encoder. Our experiments show that the proposed attentive masking
approach performs better than the previous method of random token removal for
CLIP training. The approach also makes it efficient to apply multiple
augmentation views to the image, as well as introducing instance contrastive
learning tasks between these views into the CLIP framework. Compared to other
CLIP improvements that combine different pre-training targets such as SLIP and
MaskCLIP, our method is not only more effective, but also much more efficient.
Specifically, using ViT-B and YFCC-15M dataset, our approach achieves
top-1 accuracy on ImageNet-1K zero-shot classification, as well as
and I2T/T2I retrieval accuracy on Flickr30K and MS COCO, which are
, , and higher than the SLIP method, while being
faster. An efficient version of our approach running
faster than the plain CLIP model achieves significant gains of ,
, and on these benchmarks
Overexpressed transient receptor potential vanilloid 1 (TRPV1) in lung adenocarcinoma harbours a new opportunity for therapeutic targeting
The specific biological function of transient receptor potential vanilloid 1 (TRPV1) in pathogenesis of lung adenocarcinoma (LUAD) remains unclear. In this study, TRPV1 expression in tumor tissues, primary cells and cell lines of LUAD, as well as the mechanism mediating its hyperexpression were systematically studied. Multiple models and techniques were adopted to elucidate the
relationship between TRPV1 hyperexpression and tumor recurrence and metastasis. Results showed that TRPV1 expression was increased in tumor tissues and primary tumor cells of LUAD patients. The increased expression was associated with worse overall survival outcome and raised HIF1α levels. TRPV1 expression in A549 and NCI-H292 cells was increased after pretreatment with cigarette smoke extract or spermine NONOate. Moreover, A549 cells with TRPV1 overexpression has enhanced tumor growth rates
in subcutaneous grafted tumor models, and increased intrapulmonary metastasis after tail vein infusion in nude BALB/c nude mice. Mechanistically, TRPV1 overexpression in A549 cells promoted HIF1α expression and nuclear translocation by promoting CREB phosphorylation and activation of NOS1-NO pathway, ultimately leading to accelerated cell proliferation and stronger invasiveness.
In addition, based on photothermal effects, CuS-TRPV1 mAb effectively targeted and induced apoptosis of TRPV1-A549 cells both in vivo and in vitro, thereby mitigating tumor growth and metastasis induced by xenotransplantation of TRPV1-A549 cells. In conclusion, TRPV1 hyperexpression in LUAD is a risk factor for tumor progression and is involved in proliferation and migration of tumor cells through activation of HIF1α. Our study also attempted a new strategy inhibiting the recurrence and metastasis of LUAD: by CuS-TRPV1 mAb precisely kill TRPV1 hyperexpression cells through photothermal effects
Facile Synthesis and Optical Properties of Small Selenium Nanocrystals and Nanorods
Abstract Selenium is an important element for human’s health, small size is very helpful for Se nanoparticles to be absorbed by human's body. Here, we present a facile approach to fabrication of small selenium nanoparticles (Nano-Se) as well as nanorods by dissolving sodium selenite (Na2SeO3) in glycerin and using glucose as the reduction agent. The as-prepared selenium nanoparticles have been characterized by X-ray diffraction (XRD), UV-Vis absorption spectroscopy and high resolution transmission electron microscope (HRTEM). The morphology of small Se nanoparticles and nanorods have been demonstrated in the TEM images. A small amount of 3-mercaptoproprionic acid (MPA) and glycerin play a key role on controlling the particle size and stabilize the dispersion of Nano-Se in the glycerin solution. In this way, we obtained very small and uniform Se nanoparticles; whose size ranges from 2 to 6 nm. This dimension is much smaller than the best value (>20 nm) ever reported in the literatures. Strong quantum confinement effect has been observed upon the size-dependent optical spectrum of these Se nanoparticles
Sharp turns and gyrotaxis modulate surface accumulation of microorganisms.
The accumulation of swimming microorganisms at surfaces is an essential feature of various physical, chemical, and biological processes in confined spaces. To date, this accumulation is mainly assumed to depend on the change of swimming speed and angular velocity caused by cell-wall contact and hydrodynamic interaction. Here, we measured the swimming trajectories of Heterosigma akashiwo (a biflagellate marine alga) near vertical and horizontal rigid boundaries. We observed that the probability of sharp turns is greatly increased near a vertical wall, resulting in significant changes in the distributions of average swimming speed, angular velocity, and rotational diffusivity near the wall (a quantity that has not previously been investigated) as functions of both distance from the wall and swimming orientation. These cannot be satisfactorily explained by standard hydrodynamic models. Detailed examination of an individual cell trajectory shows that wall contact by the leading flagellum triggers complex changes in the behavior of both flagella that cannot be incorporated in a mechanistic model. Our individual-based model for predicting cell concentration using the measured distributions of swimming speed, angular velocity, and rotational diffusivity agrees well with the experiment. The experiments and model are repeated for a cell suspension in a vertical plane, bounded above by a horizontal wall. The cell accumulation beneath the wall, expected from gyrotaxis, is considerably amplified by cell-wall interaction. These findings may shed light on the prediction and control of cell distribution mediated by gyrotaxis and cell-wall contact