278 research outputs found
A Review of Adversarial Attacks in Computer Vision
Deep neural networks have been widely used in various downstream tasks,
especially those safety-critical scenario such as autonomous driving, but deep
networks are often threatened by adversarial samples. Such adversarial attacks
can be invisible to human eyes, but can lead to DNN misclassification, and
often exhibits transferability between deep learning and machine learning
models and real-world achievability. Adversarial attacks can be divided into
white-box attacks, for which the attacker knows the parameters and gradient of
the model, and black-box attacks, for the latter, the attacker can only obtain
the input and output of the model. In terms of the attacker's purpose, it can
be divided into targeted attacks and non-targeted attacks, which means that the
attacker wants the model to misclassify the original sample into the specified
class, which is more practical, while the non-targeted attack just needs to
make the model misclassify the sample. The black box setting is a scenario we
will encounter in practice
A Reduction in Video Gaming Time Produced a Decrease in Brain Activity
This study examines whether a decrease in brain development is observable after players have reduced their video gaming time over a period of 1 year. Both video gaming experts and non-experts were recruited, whose resting-state functional MRI (fMRI) data were collected at the beginning and the end of the study. Immediately after the first scan, the participants were instructed to spend no more than 3 h on video gaming weekly for 1 year. The results showed decreased self-reported video gaming skills and decreased amplitude of low-frequency fluctuation (ALFF) in the experts at the end of the study, demonstrating that a reduction in video gaming time over a period of 1 year produced a decrease in brain development. The non-experts served as a control group and had no significant changes. The findings support the adaptive effect of video gaming experience on brain and cognitive development
FedHM: Efficient Federated Learning for Heterogeneous Models via Low-rank Factorization
One underlying assumption of recent federated learning (FL) paradigms is that
all local models usually share the same network architecture and size, which
becomes impractical for devices with different hardware resources. A scalable
federated learning framework should address the heterogeneity that clients have
different computing capacities and communication capabilities. To this end,
this paper proposes FedHM, a novel heterogeneous federated model compression
framework, distributing the heterogeneous low-rank models to clients and then
aggregating them into a full-rank model. Our solution enables the training of
heterogeneous models with varying computational complexities and aggregates
them into a single global model. Furthermore, FedHM significantly reduces the
communication cost by using low-rank models. Extensive experimental results
demonstrate that FedHM is superior in the performance and robustness of models
of different sizes, compared with state-of-the-art heterogeneous FL methods
under various FL settings. Additionally, the convergence guarantee of FL for
heterogeneous devices is first theoretically analyzed
SKP2 and OTUD1 govern non-proteolytic ubiquitination of YAP that promotes YAP nuclear localization and activity
Dysregulation of signaling pathways that control organ size, such as the AKT-mTOR and Hippo-YAP pathways, often leads to tumorigenesis and metastasis. The Hippo pathway effector YAP is a transcriptional co-activator overexpressed or activated in human tumors. Accumulating evidence has demonstrated that YAP promotes tumor initiation and/or progression in various types of cancer. YAP shuttles between the nucleus and the cytoplasm of the cell. When in the nucleus, YAP binds to transcription factors, such as SMAD, p73, RUNX, and the TEA domain (TEAD) family members, to activate gene transcription. The nuclear localization of YAP can be inhibited by the Hippo phosphorylation cascade and the cytoplasmic binding partners of YAP. In addition, YAP has previously been shown to be ubiquitinated by the SCFβ-TRCP complex and degraded by the proteasome. Recently, we discovered a novel mechanism by which non-proteolytic, K63-linked polyubiquitination of YAP promotes its nuclear localization, transcriptional activity, and growth-promoting function (Yao et al. Nat Commun 9:2269). Moreover, by screening ubiquitin E3 ligases implicated in K63-linked ubiquitination and a human deubiquitinase (DUB) library, we identified the SCFSKP2 complex and OTUD1, respectively, as the E3 ligase and the DUB that regulate this non-proteolytic ubiquitination without altering YAP protein level. Interestingly, this ubiquitination-mediated regulation of YAP is independent of Hippo pathway-mediated phosphorylation of YAP
Mechanisms of angiogenesis in tumour
Angiogenesis is essential for tumour growth and metastasis. Antiangiogenic factor-targeting drugs have been approved as first line agents in a variety of oncology treatments. Clinical drugs frequently target the VEGF signalling pathway during sprouting angiogenesis. Accumulating evidence suggests that tumours can evade antiangiogenic therapy through other angiogenesis mechanisms in addition to the vascular sprouting mechanism involving endothelial cells. These mechanisms include (1) sprouting angiogenesis, (2) vasculogenic mimicry, (3) vessel intussusception, (4) vascular co-option, (5) cancer stem cell-derived angiogenesis, and (6) bone marrow-derived angiogenesis. Other non-sprouting angiogenic mechanisms are not entirely dependent on the VEGF signalling pathway. In clinical practice, the conversion of vascular mechanisms is closely related to the enhancement of tumour drug resistance, which often leads to clinical treatment failure. This article summarizes recent studies on six processes of tumour angiogenesis and provides suggestions for developing more effective techniques to improve the efficacy of antiangiogenic treatment
BOLD-fMRI activity informed by network variation of scalp EEG in juvenile myoclonic epilepsy
Epilepsy is marked by hypersynchronous bursts of neuronal activity, and seizures can propagate variably to any and all areas, leading to brain network dynamic organization. However, the relationship between the network characteristics of scalp EEG and blood oxygenation level-dependent (BOLD) responses in epilepsy patients is still not well known. In this study, simultaneous EEG and fMRI data were acquired in 18 juvenile myoclonic epilepsy (JME) patients. Then, the adapted directed transfer function (ADTF) values between EEG electrodes were calculated to define the time-varying network. The variation of network information flow within sliding windows was used as a temporal regressor in fMRI analysis to predict the BOLD response. To investigate the EEG-dependent functional coupling among the responding regions, modulatory interactions were analyzed for network variation of scalp EEG and BOLD time courses. The results showed that BOLD activations associated with high network variation were mainly located in the thalamus, cerebellum, precuneus, inferior temporal lobe and sensorimotor-related areas, including the middle cingulate cortex (MCC), supplemental motor area (SMA), and paracentral lobule. BOLD deactivations associated with medium network variation were found in the frontal, parietal, and occipital areas. In addition, modulatory interaction analysis demonstrated predominantly directional negative modulation effects among the thalamus, cerebellum, frontal and sensorimotor-related areas. This study described a novel method to link BOLD response with simultaneous functional network organization of scalp EEG. These findings suggested the validity of predicting epileptic activity using functional connectivity variation between electrodes. The functional coupling among the thalamus, frontal regions, cerebellum and sensorimotor-related regions may be characteristically involved in epilepsy generation and propagation, which provides new insight into the pathophysiological mechanisms and intervene targets for JME
Quantitative analysis of the risk of hydrogen sulfide release from gas hydrates
The role that H2S plays in the global sulfur cycle has been studied extensively in recent years. This paper focuses on the influence of H2S released from gas hydrates on sulfur cycle and establishes a one-dimensional mathematical model to calculate the amount of H2S released from the dissociation of gas hydrates present in multiple layers in the Qiongdongnan Basin China. The results show that the sulfate and methane transition zone that covers an area of about 100 km2in the Qiongdongnan Basin contains 2.3 × 1012 g of pyrite, which requires 4.06 × 1011 mol of H2S for its formation. The H2S released from the dissociation of gas hydrates is 5.4 ×1011 mol, which is about 1.3 times that needed for the formation of pyrite. Therefore, the H2S released from the gas hydrates is an important source of H2S for the formation of pyrite in the sulfate-methane transition zone of Qiongdongnan Basin. According to the flux of H2S and the partial pressure of O2 (PO2) in the atmosphere, the critical value of the balance between the flux of H2S and PO2 turns out to be 0.13 mol kg−1∙bar−1. Furthermore, considering the effect of global sea-level changes, three risk modes are identified to categorize the amount of H2S released from the dissociation of gas hydrate into the atmosphere. We classify the periods from 5–12 Ma BP, 25–29 Ma BP, 47–52 Ma, and 57–61 Ma BP into the high-risk mode. Furthermore, the results show that a part of the H2S released from the gas hydrate dissociation is oxidized by the Fe (III) oxide metal, with much of the metal ions being released into the pore water. Another part of the H2S is re-oxidized by the O2 in the ocean, with much of SO42- released into the seawater. Therefore, the process also provides metal ions and SO42- to pore water or seawater when the H2S released from gas hydrate diffuses from the bottom. This paper provides new insights into the source of H2S in the ocean and shows that the H2S contained in gas hydrates plays an important role in the global sulfur cycle
Action Real-Time Strategy Gaming Experience Related to Increased Attentional Resources: An Attentional Blink Study
Action real-time strategy gaming (ARSG) is a cognitively demanding task which requires attention, sensorimotor skills, team cooperation, and strategy-making abilities. A recent study found that ARSG experts had superior visual selective attention (VSA) for detecting the location of a moving object that could appear in one of 24 different peripheral locations (Qiu et al., 2018), suggesting that ARSG experience is related to improvements in the spatial component of VSA. However, the influence of ARSG experience on the temporal component of VSA—the detection of an item among a sequence of items presented consecutively and quickly at a single location—still remains understudied. Using behavioral and electrophysiological measures, this study examined whether ARSG experts had superior temporal VSA performance compared to non-experts in an attentional blink (AB) task, which is typically used to examine temporal VSA. The results showed that the experts outperformed the non-experts in their detection rates of targets. Furthermore, compared to the non-experts, the experts had faster information processing as indicated by earlier P3 peak latencies in an AB period, more attentional resources distributed to targets as indicated by stronger P3 amplitudes, and a more flexible deployment of attentional resources. These findings suggest that experts were less prone to the AB effect. Thus, long-term ARSG experience is related to improvements in temporal VSA. The current findings support the benefit of video gaming experience on the development of VSA
The Influence of Action Video Gaming Experience on the Perception of Emotional Faces and Emotional Word Meaning
Action video gaming (AVG) experience has been found related to sensorimotor and attentional development. However, the influence of AVG experience on the development of emotional perception skills is still unclear. Using behavioral and ERP measures, this study examined the relationship between AVG experience and the ability to decode emotional faces and emotional word meanings. AVG experts and amateurs completed an emotional word-face Stroop task prior to (the pregaming phase) and after (the postgaming phase) a 1 h AVG session. Within-group comparisons showed that after the 1 h AVG session, a more negative N400 was observed in both groups of participants, and a more negative N170 was observed in the experts. Between-group comparisons showed that the experts had a greater change of N170 and N400 amplitudes across phases than the amateurs. The results suggest that both the 1 h and long-term AVG experiences may be related to an increased difficulty of emotional perception. Furthermore, certain behavioral and ERP measures showed neither within- nor between-group differences, suggesting that the relationship between AVG experience and emotional perception skills still needs further research
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