271 research outputs found
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Structure of the AAA protein Msp1 reveals mechanism of mislocalized membrane protein extraction.
The AAA protein Msp1 extracts mislocalized tail-anchored membrane proteins and targets them for degradation, thus maintaining proper cell organization. How Msp1 selects its substrates and firmly engages them during the energetically unfavorable extraction process remains a mystery. To address this question, we solved cryo-EM structures of Msp1-substrate complexes at near-atomic resolution. Akin to other AAA proteins, Msp1 forms hexameric spirals that translocate substrates through a central pore. A singular hydrophobic substrate recruitment site is exposed at the spiral's seam, which we propose positions the substrate for entry into the pore. There, a tight web of aromatic amino acids grips the substrate in a sequence-promiscuous, hydrophobic milieu. Elements at the intersubunit interfaces coordinate ATP hydrolysis with the subunits' positions in the spiral. We present a comprehensive model of Msp1's mechanism, which follows general architectural principles established for other AAA proteins yet specializes Msp1 for its unique role in membrane protein extraction
BBR-induced Stark shifts and level broadening in helium atom
The precise calculations of blackbody radiation (BBR)-induced Stark shifts
and depopulation rates for low-lying states of helium atom with the use of
variational approach are presented. An effect of the BBR-induced induced
Stark-mixing of energy levels is considered. It is shown that this effect leads
to a significant reduction of lifetimes of helium excited states. As a
consequence the influence of Stark-mixing effect on the decay rates of
metastable states in helium is discussed in context of formation processes of
the cosmic microwave background
Emotion Analysis for Personality Inference from EEG Signals
The stable relationship between personality and EEG ensures the feasibility of personality inference from brain activities. In this paper, we recognize an individual’s personality traits by analyzing brain waves when he or she watches emotional materials. Thirty-seven participants took part in this study and watched 7 standardized film clips that characterize real-life emotional experiences and target seven discrete emotions. Features extracted from EEG signals and subjective ratings enter the SVM classifier as inputs to predict five dimensions of personality traits. Our model achieves better classification performance for Extraversion (81.08%), Agreeableness (86.11%), and Conscientiousness (80.56%) when positive emotions are elicited than negative ones, higher classification accuracies for Neuroticism (78.38-81.08%) when negative emotions, except disgust, are evoked than positive emotions, and the highest classification accuracy for Openness (83.78%) when a disgusting film clip is presented. Additionally, the introduction of features from subjective ratings increases not only classification accuracy in all five personality traits (ranging from 0.43% for Conscientiousness to 6.3% for Neuroticism) but also the discriminative power of the classification accuracies between five personality traits in each category of emotion. These results demonstrate the advantage of personalit
The androgen receptor plays different roles in macrophage-induced proliferation in prostate stromal cells between transitional and peripheral zones of benign prostatic hypertrophy
Macrophages play a critical role in the process of excessive stromal proliferation of benign prostatic hyperplasia (BPH). In our previous study, we used a BPH mouse model to elucidate a potential mechanism whereby macrophage infiltration promotes stromal cell proliferation in the prostate via the androgen receptor (AR)/inflammatory cytokine CCL3-dependent pathway. In our present study, we used the co-culture system of human macrophages and various prostatic zone stromal cells to further demonstrate that infiltrating macrophages promote prostatic stromal cell proliferation through stromal AR-dependent pathways, and we show that the stroma of TZ and PZ respond to macrophages differently because of differences in stromal AR signaling; this could possibly be one of the key pathways for stromal expansion during BPH development and progression. We hypothesize that AR and different downstream inflammatory mediators between TZ and PZ could serve as potential targets for the future design of therapeutic agents for BPH and our results provide significant insights into the search for targeted therapeutic approaches to battle BPH
Dynamic Circular Network-Based Federated Dual-View Learning for Multivariate Time Series Anomaly Detection
Multivariate time-series data exhibit intricate correlations in both temporal and spatial dimensions. However, existing network architectures often overlook dependencies in the spatial dimension and struggle to strike a balance between long-term and short-term patterns when extracting features from the data. Furthermore, industries within the business community are hesitant to share their raw data, which hinders anomaly prediction accuracy and detection performance. To address these challenges, the authors propose a dynamic circular network-based federated dual-view learning approach. Experimental results from four open-source datasets demonstrate that the method outperforms existing methods in terms of accuracy, recall, and F1_score for anomaly detection
Multi-decadal trends in global terrestrial evapotranspiration and its components
Evapotranspiration (ET) is the process by which liquid water becomes water vapor and energetically this accounts for much of incoming solar radiation. If this ET did not occur temperatures would be higher, so understanding ET trends is crucial to predict future temperatures. Recent studies have reported prolonged declines in ET in recent decades, although these declines may relate to climate variability. Here, we used a well-validated diagnostic model to estimate daily ET during 1981–2012, and its three components: transpiration from vegetation (Et), direct evaporation from the soil (Es) and vaporization of intercepted rainfall from vegetation (Ei). During this period, ET over land has increased significantly (p < 0.01), caused by increases in Et and Ei, which are partially counteracted by Es decreasing. These contrasting trends are primarily driven by increases in vegetation leaf area index, dominated by greening. The overall increase in Et over land is about twofold of the decrease in Es. These opposing trends are not simulated by most Coupled Model Intercomparison Project phase 5 (CMIP5) models, and highlight the importance of realistically representing vegetation changes in earth system models for predicting future changes in the energy and water cycle
Monolayer Excitonic Laser
Recently, two-dimensional (2D) materials have opened a new paradigm for
fundamental physics explorations and device applications. Unlike gapless
graphene, monolayer transition metal dichalcogenide (TMDC) has new optical
functionalities for next generation ultra-compact electronic and
opto-electronic devices. When TMDC crystals are thinned down to monolayers,
they undergo an indirect to direct bandgap transition, making it an outstanding
2D semiconductor. Unique electron valley degree of freedom, strong light matter
interactions and excitonic effects were observed. Enhancement of spontaneous
emission has been reported on TMDC monolayers integrated with photonic crystal
and distributed Bragg reflector microcavities. However, the coherent light
emission from 2D monolayer TMDC has not been demonstrated, mainly due to that
an atomic membrane has limited material gain volume and is lack of optical mode
confinement. Here, we report the first realization of 2D excitonic laser by
embedding monolayer tungsten disulfide (WS2) in a microdisk resonator. Using a
whispering gallery mode (WGM) resonator with a high quality factor and optical
confinement, we observed bright excitonic lasing in visible wavelength. The
Si3N4/WS2/HSQ sandwich configuration provides a strong feedback and mode
overlap with monolayer gain. This demonstration of 2D excitonic laser marks a
major step towards 2D on-chip optoelectronics for high performance optical
communication and computing applications.Comment: 15 pages, 4 figure
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