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Asgard archaea are considered to be the closest known relatives of eukaryotes. Their genomes contain hundreds of eukaryotic signature proteins (ESPs), which inspired hypotheses on the evolution of the eukaryotic cell1–3. A role of ESPs in the formation of an elaborate cytoskeleton and complex cellular structures has been postulated4–6, but never visualized. Here we describe a highly enriched culture of ‘Candidatus Lokiarchaeum ossiferum’, a member of the Asgard phylum, which thrives anaerobically at 20 °C on organic carbon sources. It divides every 7–14 days, reaches cell densities of up to 5 × 107 cells per ml and has a significantly larger genome compared with the single previously cultivated Asgard strain7. ESPs represent 5% of its protein-coding genes, including four actin homologues. We imaged the enrichment culture using cryo-electron tomography, identifying ‘Ca. L. ossiferum’ cells on the basis of characteristic expansion segments of their ribosomes. Cells exhibited coccoid cell bodies and a network of branched protrusions with frequent constrictions. The cell envelope consists of a single membrane and complex surface structures. A long-range cytoskeleton extends throughout the cell bodies, protrusions and constrictions. The twisted double-stranded architecture of the filaments is consistent with F-actin. Immunostaining indicates that the filaments comprise Lokiactin—one of the most highly conserved ESPs in Asgard archaea. We propose that a complex actin-based cytoskeleton predated the emergence of the first eukaryotes and was a crucial feature in the evolution of the Asgard phylum by scaffolding elaborate cellular structures.Culture and analysis of ‘Candidatus Lokiarchaeum ossiferum’—a member of the Asgard phylum—reveals an elaborate cell architecture with extensive membranous protrusions. [ABSTRACT FROM AUTHOR]

Frequency diverse array (FDA)-multiple-input and multiple-output (MIMO) radar is characterized with a range-angle-dependent transceive beampattern by introducing incremental frequencies among the transmit array elements and separating the transmitted waveforms with matched filtering in the receiver. In this respect, the paper aims to control the range-angle-dependent transceive beampattern for FDA-MIMO radar by designing the weight vector according to the desired response. At the design stage, the weight vectors to control the beampattern responses of different regions are devised by performing the orthogonal decomposition technique. Then, a filtering matrix using the oblique projection operator is constructed to filter the weight vectors for different regions, where two iterative algorithms are developed either considering concurrent or successive control of multiple regions. In such a way, a desired range-angle-dependent transceive beampattern is formed with simultaneously broadened nulls and a flat-top mainlobe. At the analysis stage, the method has been applied to interference mitigation in FDA-MIMO radar, where the mismatch exists both in the sidelobes and mainlobe. Simulated and measured results are provided to corroborate the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]

A series of Zn-incorporated nano-ZSM-5 zeolites were synthesized by a dry gel conversion (DGC) method using tetrapropylammonium hydroxide (TPAOH) as a single template, and their activity in methanol to aromatics (MTA) process was investigated. The characterization results revealed that the introduction of Zn species slightly decreased the crystal size with the formation of some agglomerated particles. We also demonstrated that new Lewis acid sites formed in Zn-incorporated nano-ZSM-5 zeolite at the expense of Brønsted acid sites. The amount of medium acid sites in Zn-modified samples increased with increasing of Zn contents. Catalytic evaluation results revealed that the selectivity of BTX and aromatics for the sample synthesized via direct synthesis (Zn-NZ5-3) is increased from 24.0% and 37.9% to 27.9% and 46.4%, respectively. In addition, the lifetime of the sample prepared by the direct synthesis (Zn-NZ5-3) was 33% longer than that of the impregnated sample, while the selectivity of BTX and aromatics was slightly higher. [ABSTRACT FROM AUTHOR]

Purpose: Previous population studies on the associations between dietary fatty acids (FAs), plasma FAs levels, and the risk of age-related macular degeneration (AMD) have yielded inconclusive results. Herein, we conducted a dose–response meta-analysis to quantitatively evaluate the associations between specific type of dietary FAs, plasma FAs on early and advanced AMD risk. Methods: PubMed, Web of Science, and EMBASE were systematically searched for observational cohort studies published through May 2020. For highest versus lowest comparison and dose–response analyses, the relative risk (RR) estimates with a 95% confidence interval (CI) were analyzed using random effects model. Results: 11 studies with 167,581 participants were included in the meta-analysis. During the follow-up periods (ranging from 3 to 28 years), 6,318 cases of AMD were recorded. Dietary intake of docosahexaenoic acid (DHA) and eicosatetraenoic acid (EPA) combined (per 1 g/day increment) were found to be negatively associated with early AMD (RR: 0.67, 95% CI [0.51, 0.88]). Each 1 g/day increment of DHA (RR: 0.50, 95% CI [0.32, 0.78]) and EPA (RR: 0.40, 95% CI [0.18, 0.87]) was associated with a 50% and 60% reduction of early AMD risk, respectively. Plasma DHA (RR: 0.72, 95% CI [0.55, 0.95]) and EPA (RR: 0.57, 95% CI [0.40, 0.81]) indicated significant negative relationship with advanced AMD. Conclusion: Increasing dietary intake of ω-3 polyunsaturated fatty acids (PUFAs), specifically DHA and EPA, were associated with a reduced risk of early subtype of AMD, while other types of FAs did not present significant results. Further research is warranted to explore the potential association between dietary FA, plasma FA levels, and advanced subtype of AMD. [ABSTRACT FROM AUTHOR]

Septins are cytoskeletal proteins that assemble into hetero-oligomeric complexes and sense micron-scale membrane curvature. During infection with Shigella flexneri, an invasive enteropathogen, septins restrict actin tail formation by entrapping bacteria in cage-like structures. Here, we reconstitute septin cages in vitro using purified recombinant septin complexes (SEPT2-SEPT6-SEPT7), and study how these recognize bacterial cells and assemble on their surface. We show that septin complexes recognize the pole of growing Shigella cells. An amphipathic helix domain in human SEPT6 enables septins to sense positively curved membranes and entrap bacterial cells. Shigella strains lacking lipopolysaccharide components are more efficiently entrapped in septin cages. Finally, cryo-electron tomography of in vitro cages reveals how septins assemble as filaments on the bacterial cell surface. Septins are cytoskeletal proteins that assemble into complexes and contribute to immunity by entrapping intracellular bacteria in cage-like structures. Here, Lobato-Márquez et al. reconstitute septin cages in vitro using purified recombinant complexes, and study how these recognize bacterial cells and assemble as filaments on their surface. [ABSTRACT FROM AUTHOR]

Video prediction is challenging as real-world motion dynamics are usually multi-modally distributed. Existing stochastic methods commonly formulate random noise input with simple prior distribution, which is insufficient to model highly complex motion dynamics. This work proposes a progressive multiple granularity analysis framework to tackle the above difficulty. Firstly, to achieve coarse alignment, the input sequence is matched to prototype motion dynamics in the training set, based on self-supervised auto-encoder learning via motion/appearance disentanglement. Secondly, motion dynamics is transferred from the matched prototype sequence to input sequence via adaptively learned kernel, and the predicted frames are further refined through a motion-aware prediction model. Extensive qualitative and quantitative experiments on three widely used video prediction datasets demonstrate that: (1) the proposed framework essentially decomposes the hard task into a series of more approachable sub-tasks where a better solution is easier to be sought and (2) our proposed method performs favorably against state-of-the-art prediction methods. [ABSTRACT FROM AUTHOR]

The performance of the regional atmosphere-ocean coupled model ROM (REMO-OASIS-MPIOM) is compared with its atmospheric component REMO in simulating the East Asian summer monsoon (EASM) during the time period 1980–2012 with the following results being obtained. (1) The REMO model in the standalone configuration with the prescribed sea surface conditions produces stronger low-level westerlies associated with the South Asian summer monsoon, an eastward shift of the western Pacific subtropical high (WPSH) and a wetter lower troposphere, which jointly lead to moisture pathways characterized by stronger westerlies with convergence eastward to the western North Pacific (WNP). As a consequence, the simulated precipitation in REMO is stronger over the ocean and weaker over the East Asian continent than in the observational datasets. (2) Compared with the REMO results, lower sea surface temperatures (SSTs) feature the ROM simulation with enhanced air-sea exchanges from the intensified low-level winds over the subtropical WNP, generating an anomalous low-level anticyclone and hence improving simulations of the low-level westerlies and WPSH. With lower SSTs, ROM produces less evaporation over the ocean, inducing a drier lower troposphere. As a result, the precipitation simulated by ROM is improved over the East Asian continent but with dry biases over the WNP. (3) Both models perform fairly well for the upper level circulation. In general, compared with the standalone REMO model, ROM improves simulations of the circulation associated with the moisture transport in the lower- to mid-troposphere and reproduces the observed EASM characteristics, demonstrating the advantages of the regionally coupled model ROM in regions where air-sea interactions are highly relevant for the East Asian climate. [ABSTRACT FROM AUTHOR]

To perform the integration of radar and communication in waveform, we design an integrated system combining multiple-input multiple-output radar with orthogonal frequency division multiplexing (OFDM) communication. In this system, each antenna transmits the integrated waveform with a nonoverlapping block sub-frequency band. The utilized waveform is a variation of the classical OFDM communication waveform. In order to sufficiently exploit the entire system bandwidth and array aperture, a joint time and space processing approach is proposed, and hence the range and angle estimations with high resolution are obtained, whereas the range and angle are coupled. Moreover, the loss in processing gain and the Cramér–Rao bounds of range and angle estimates based on integrated waveform are derived, respectively. Theoretical analysis validates that the designed system is capable of implementing the radar and communication functions simultaneously. Finally, numerical results are presented to verify the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

The Hengduan Mountains and Tibetan Plateau possess unique topographical characteristics that serve as an effective blocking of the movement of the westerly wind in the middle and lower troposphere towards East China. This study examines results from a regional climate model (REMO) at the resolutions of 25 and 50 km for the period 1980–2012. The model is run using lateral boundary conditions from ERA-Interim (European Centre for Medium-Range Weather Forecasts interim reanalysis). There are only a few differences between 25 and 50 km in land surface/vegetation characteristics, but the major differences in this region are due to the orography. Results show that the high-resolution simulation performance is poor in winter, when southwesterly wind prevails, whereas it performs well in summer, when the westerly wind is substantially weakened in southern China. In comparison to the ERA-Interim wind field, the high-resolution simulation overestimates the air flow over the Hengduan Mountains near the ground surface, which influences the transport of atmospheric water vapor in the downstream region, i.e., over southern China. Specifically, with the help of the overestimated southwesterly wind, the amount of atmospheric water vapor transported increases considerably perennially by up to 20% in southern China, while it decreases remarkably by more than 5% throughout the year in a large area of Central and North China. These features lead to excessive precipitation and underestimated cloud cover in southern China, which probably causes the overestimated 2-m temperature in southern China. Our study emphasizes that, in such high-resolution-model studies for East Asia, special attention should be paid to the near-surface winds over the Hengduan Mountains. [ABSTRACT FROM AUTHOR]

A number of studies have shown that added value is obtained by increasing the horizontal resolution of a regional climate model to capture additional fine-scale weather processes. However, the mechanisms leading to this added value are different over areas with complicated orographic features, such as the Tibetan Plateau (TP). To determine the role that horizontal resolution plays over the TP, a detailed comparison was made between the results from the REMO regional climate model at resolutions of 25 and 50 km for the period 1980-2007. The model was driven at the lateral boundaries by the European Centre for Medium-Range Weather Forecasts Interim Reanalysis data. The experiments differ only in representation of topography, all other land parameters (e.g., vegetation characteristics, soil texture) are the same. The results show that the high-resolution topography affects the regional air circulation near the ground surface around the edge of the TP, which leads to a redistribution of the transport of atmospheric water vapor, especially over the Brahmaputra and Irrawaddy valleys—the main water vapor paths for the southern TP—increasing the amount of atmospheric water vapor transported onto the TP by about 5%. This, in turn, significantly decreases the temperature at 2 m by > 1.5 °C in winter in the high-resolution simulation of the southern TP. The impact of topography on the 2 m temperature over the TP is therefore by influencing the transport of atmospheric water vapor in the main water vapor paths. [ABSTRACT FROM AUTHOR]

Digital beamforming with non-uniformly distributed array radar can make full use of resources and enhance the target detection capability. However, it encounters severe grating lobes and high false alarm probability. In this paper, a novel range-angle pencil-beamforming with the non-uniformly distributed frequency diverse array (FDA) is proposed. FDA is referred to as an array transmitting linearly increased carrier frequencies with the array elements. The FDA is capable of providing controllable degrees-of-freedom in range domain, which is superior to the conventional phased array. In our approach, the frequency increments and element positions are optimally determined via particle swarm optimization algorithm to focus the transmit power within a particular range and angle region. With the proposed method, the range-angle pencil-beampattern is obtained and its side-lobes in range-angle domains can be further lowered down. Numerical simulation examples are provided to verify the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

The sewers have the function of carbon removal, which has been proven. But if the effect of nitrogen removal can be enhanced at the same time of carbon removal, it can lay a foundation for the realization of “sewer’s working as a reactor.” This paper investigated the effects of shear stress and C/N ratio on nitrogen removal through biofilms on the sewer inner wall and nitrogen transfer. The main conclusions are as follows: (1) nitrogen could be partially removed in sewers after a series of reactions; (2) the anaerobic, anoxic, aerobic environment and some bacteria related to nitrogen metabolism, which exist in the biofilm, promote the nitrification and denitrification; (3) a total of 722 functional genes involved in nitrogen metabolism were detected in the biofilm (C/N ratio of 10, shear stress of 1.4 Pa), accounting for 0.67% of all genes, and the functional genes related to denitrification were dominant.ᅟ [ABSTRACT FROM AUTHOR]

The function of sewer as reactors must rely on the biofilm in it. In this paper, the formation, structure, oxygen transfer, and activity of the biofilm under different hydraulic conditions were studied by the microelectrode technology, oxygen uptake rate (OUR) technology, and 454 high-throughput pyrosequencing technology. Results showed that when the wall-shear stresses were 1.12, 1.29, and 1.45 Pa, the porosity of the steady-state biofilm were 69.1, 64.4, and 55.1 %, respectively. The maximum values of OUR were 0.033, 0.027, and 0.022 mg/(L*s), respectively, and the COD removal efficiency in the sewers reached 40, 35, and 32 %, respectively. The research findings had an important significance on how to improve the treatment efficiency of the sewers. [ABSTRACT FROM AUTHOR]

This paper presents a novel asynchronous design approach for multiple input multiple output (MIMO) satellite communication (SatCom) systems. One of the main challenges for MIMO SatCom systems is that these are prone to transient faults that typically are attributable to radiation hazards. Hence, instead of using conventional synchronous circuits, we conceive our design using asynchronous circuits since it inherently has a high tolerance to transient fault. Additionally, we adopt accelerated dual paths (ADP) design into our system. By carefully arranging the data flow between the two paths, the ADP design approach can help to further accelerate the asynchronous system and increase the reliability of the system by circumventing transient faults induced delay, as well as tolerating latch-ups and other permanent faults. The numerical results show that this design approach provides promising results. For example, the proposed design can decrease the delay overhead of the entire system from 43.5 to 19.8 % at the fault rate of 400/clock cycle. [ABSTRACT FROM AUTHOR]

Feeling is stable and implicit and can be explicated in concrete situations in the form of emotion. To map the time course of feeling processing, the present study explored electrophysiological responses relevant to inner feeling by creating situations to evoke the explicit response of feeling. Fourteen mothers were asked to listen to TS and NS. Although the early event-related potential components (P1, N1 and P2) elicited by story pictures were not affected by the emotional valence of stories, the pictures relevant to TS elicited larger P3 and late positive potential (LPP) components than did neutral story pictures, indicating that feeling processing occurred at the post-perceptual stage. Feeling-related positive potential was separated using the difference wave analysis technique, which consisted of two sub-components: FRBB1 and FRBB2 based on P3 and LPP modulations, respectively. These data provide new electrophysiological evidence for the time course of feeling processing related to maternal love. [ABSTRACT FROM AUTHOR]

Rigid polyurethane foams were fabricated with five kinds of liquefied sugarcane bagasse polyols (LBP). The foams derived from sugarcane bagasse were investigated by thermogravimetric analysis (TGA), and the thermal degradation data were analyzed using the Coast-Redfern method and Ozawa method to obtain the reaction order and activation energy. The results indicate that the sugarcane bagasse-foams exhibit an excellent heat-resistant property, whereas their pyrolysis procedures are quite complicated. The reaction as first order only takes place from 250 to 400 °C, and the pyrolysis activation energies vary from 20 to 140 kJ/mol during the whole pyrolysis process. [ABSTRACT FROM AUTHOR]

Working principles of silicon double P-N junction color sensor are introduced and a color measurement system to distinguish tooth color difference is designed in this paper. This system consists of silicon double P-N junction, a small optical fiber probe, signal process circuit and an MSP430FG439 single-chip system. Small in size, this system can measure different parts of the tooth in a fast and convenient way with high-accuracy. Thus, this system will be very promising in building prosthodontics and tooth fabrication. [ABSTRACT FROM AUTHOR]

Immersion in various media has different effect on the properties of dental composites, such as sorption, solubility, elution of unreacted monomers, flexural strength, and flexural elastic modulus. In the present work, the effect of immersion in various media and the relationship between the variation of these properties and the components of dental composite were investigated. Two model dental composites were immersed in three different media—distilled water, artificial saliva, and ethanol/water, respectively, for a certain time. Their sorption, solubility, flexural strength, and flexural elastic modulus were tested according to the international standard. Elution of unreacted monomers was analyzed by using high performance liquid chromatography (HPLC) and the surface morphology of samples after immersion was observed using scanning electron microscope (SEM). The results showed that the effect on properties depended on the immersion media where ethanol/water had the most significant effect and these properties were related to the components of dental composite. [ABSTRACT FROM AUTHOR]

The mature virion of the tailed bacteriophage ϕ29 is an ~33 MDa complex that contains more than 450 subunits of seven structural proteins assembling into a prolate head and a short non-contractile tail. Here, we report the near-atomic structures of the ϕ29 pre-genome packaging head (prohead), the mature virion and the genome-emptied virion. Structural comparisons suggest local rotation or oscillation of the head-tail connector upon DNA packaging and release. Termination of the DNA packaging occurs through pressure-dependent correlative positional and conformational changes in the connector. The funnel-shaped tail lower collar attaches the expanded narrow end of the connector and has a 180-Å long, 24-strand β barrel narrow stem tube that undergoes conformational changes upon genome release. The appendages form an interlocked assembly attaching the tail around the collar. The membrane active long loops at the distal end of the tail knob exit during the late stage of infection and form the cone-shaped tip of a largely hydrophobic helix barrel, prepared for membrane penetration. Mature particles of bacteriophage ϕ29 consist of a 33-MDa complex formed by over 450 subunits, assembled into a head and a short tail. Here, Xu et al. report the near-atomic structures of the ϕ29 prohead, the mature virion and the genome-emptied virion, providing insights into DNA packaging and release. [ABSTRACT FROM AUTHOR]

Sewer system is an important source of methane formation and emission. Although some models were developed to predict methane production in sewers, the impact of microorganism amount was indicated indirectly. Here, seven laboratory scale sewers with varied wall-shear stresses were established. The biofilm thickness, microorganism amount, DO distribution, microorganism community in the biofilms and methane production in the sewers were measured. Based on experimental data, an empirical model was developed to directly describe the relationship between methane production, microorganism amount and wall-shear stress. The results showed that DO concentration decreased significantly along the biofilm depth under varied wall-shear stress, and the DO reduction rate was positively related to the intensity of wall-shear stress. The dominant archaea species in mature biofilms were similar whereas the proportions showed remarkable differences. The abundance of Methanospirillum in biofilms cultured at 2.0 Pa wall-shear stress was 53.08% more than that at 1.29 Pa. The maximum methane production rate, 2.04 mg/L wastewater day, was obtained when the wall-shear stress kept at 1.45 Pa, which was 1.2-fold higher than the minimum in sewer at 0.5 Pa. The R2 value of the established model was 0.95, the difference between the measurement and simulation was in the rage of 1.5-13.0%. [ABSTRACT FROM AUTHOR]

Microglia are intrinsic immune cells in the central nervous system (CNS). The under controlled microglia activation plays important roles in inflammatory demyelination diseases, such as multiple sclerosis (MS). However, the means to modulate microglia activation as a therapeutic modality and the underlying mechanisms remain elusive. Here we show that administration of 18β-glycyrrhetinic acid (GRA), by using both preventive and therapeutic treatment protocols, significantly suppresses disease severity of experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice. The treatment effect of GRA on EAE is attributed to its regulatory effect on microglia. GRA-modulated microglia significantly decreased pro-inflammatory profile in the CNS through suppression of MAPK signal pathway. The ameliorated CNS pro-inflammatory profile prevented the recruitment of encephalitogenic T cells into the CNS, which alleviated inflammation-induced demyelination. In addition, GRA treatment promoted remyelination in the CNS of EAE mice. The induced remyelination can be mediated by the overcome of inflammation-induced blockade of brain-derived neurotrophic factor expression in microglia, as well as enhancing oligodendrocyte precursor cell proliferation. Collectively, our results demonstrate that GRA-modulated microglia suppresses EAE through inhibiting microglia activation-mediated CNS inflammation, and promoting neuroprotective effect of microglia, which represents a potential therapeutic strategy for MS and maybe other neuroinflammatory diseases associated with microglia activation. [ABSTRACT FROM AUTHOR]