Hebei Province was affected by two coronavirus disease 2019 (COVID-19) outbreak waves during the period 22 January 2020 through 27 February 2020 (wave 1) and 2 January 2021 through 14 February 2021 (wave 2). To evaluate and compare the epidemiological characteristics, containment delay, cluster events and social activity, as well as non-pharmaceutical interventions of the two COVID-19 outbreak waves, we examined real-time update information on all COVID-19-confirmed cases from a publicly available database. Wave 1 was closely linked with the COVID-19 pandemic in Wuhan, whereas wave 2 was triggered, to a certain extent, by the increasing social activities such as weddings, multi-household gatherings and church events during the slack agricultural period. In wave 2, the epidemic spread undetected in the rural areas, and people living in the rural areas had a higher incidence rate than those living in the urban areas (5.3 vs. 22.0 per 1 000 000). Furthermore, Rt was greater than 1 in the early stage of the two outbreak waves, and decreased substantially after massive non-pharmaceutical interventions were implemented. In China's ‘new-normal’ situation, development of targeted and effective intervention remains key for COVID-19 control in consideration of the potential threat of new coronavirus strains.

Saetaspongia so far cannot be confidently assigned to any class-level crown group. Clarifying its phylogenetic position requires new information provided by more detailed studies of previously described and/or new material. Some sponge fossils with the typical skeletal architecture of Saetaspongia have recently been recognized in the Cambrian (Stage 4) Balang Biota of Guizhou, China, including S. jianhensis new species and S. cf. S. densa. The new taxon is characterized by the following features: spicules are fine monaxons and are inclined to be loosely to densely arranged into plumose arrays; skeleton is composed primarily of one major plumose bundle, with an uncertain number (perhaps two) of small plumose arrays; and primary skeleton is occasionally interspersed with some irregularly oriented individual spicules. An additional specimen consisting of large monaxons, with plumose structures and overlying irregular coarse monaxons, closely fits the description and illustrations of previously described S. cf. S. densa. By combining information from previous studies and the present research, fossil evidence indicates that the plumose architecture is a critical feature diagnostic of Saetaspongia and that there are no hexactine-based spicules in this genus. The new material from the Balang Biota further supports the notion that Saetaspongia has a protomonaxonid rather than a hexactinellid affinity. Fossil evidence suggests that Saetaspongia had a wide biogeographic distribution during the early Cambrian and the stratigraphic distribution of this genus extends up to Stage 4.

UUID: http://zoobank.org/e9ca5e4a-134c-4daa-9266-19085e32614f.

Real-time localization is an important mission for self-driving cars and it is difficult to achieve precise pose information in dynamic environments. In this paper, a novel localization method is proposed to estimate the pose of self-driving cars using a 3D-LiDAR sensor. First, the multi-frame curb features and laser intensity features are extracted. Meanwhile, based on the high-precision curb map generated offline, obstacles on road are detected using region segmentation methods and their features are removed. Furthermore, a map-matching method is proposed to match the features to the map, a robust iterative closest point algorithm is utilized to deal with curb features along with a probability search method dealing with intensity features. Finally, two separate Kalman filters are used to fuse the low-cost global positioning systems and map-matching results. Both offline and online experiments are carried out in dynamic environments and the results demonstrate the accuracy and robustness of the proposed method.

The surface topology of biomaterial has a definite effect on the growth behavior of nerve cells for peripheral nerve regeneration. In this study, the silk fibroin (SF) film with different anisotropic microgroove/ridge was constructed by micropatterning technology. The effects of topologies width on the directional growth of dorsal root ganglion (DRG) neurons were evaluated. The results showed that the topological structure of the SF film with higher SF concentration was more clear and complete. The microtopography of the SF film with a concentration of 15% and a groove width of around 30 μm could effectively guide the directional growth of the nerve fibers of DRG. And nerve fibers could obviously form nerve fiber bundles which may have a certain pavement effect on the recovery of nerve function. The study indicated that the SF film with a specific width of the topological structure may have potential applications in the field of directional nerve regeneration.

Yushu Prefecture in Qinghai Province provides some of the largest known stretches of habitat for the Vulnerable snow leopard Panthera uncia in China. People living in these areas are dependent on agropastoralism. Support from local communities is necessary for effective long-term conservation action for snow leopards, but loss of livestock to snow leopards can create financial burdens that induce negative attitudes and encourage retaliatory killing. We assessed factors driving herders' attitudes towards snow leopards and their conservation. We found that herders had higher agreement with positive than with negative statements about snow leopards despite nearly half reporting livestock loss to snow leopards within the last 5 years. No retaliatory killing was reported. Herders with more years of formal education and fewer livestock losses were more likely to have positive attitudes whereas those with lower importance of snow leopards to their religion, fewer livestock losses, and fewer years of education were more likely to have negative attitudes. Understanding the multifaceted mechanisms responsible for positive views towards species is imperative for reaching conservation goals. Our findings ascribe to the importance of increased education and adherence to Tibetan beliefs in promoting conservation tolerance towards snow leopards in Qinghai Province, but also indicate a need for further research into the impact of livestock loss.

Intelligent control of friction and adhesion has attracted much attention for use in soft robotics, human-sensor interfaces, and bionics. Here we introduce a shape memory photonic crystal (SMPC) polymer that can be programmed and recovered by solvent to realize switchable surface friction. Micro sliding test show that the friction coefficient on this SMPC in the programmed and recovered state can vary by three times. We also show that the mechanism behind this switchable friction coefficient is the surface roughness related adhesion.

Passive daytime radiative cooling (PDRC) is an electricity-free method for cooling terrestrial entities. In PDRC, a surface has a solar reflectance of nearly 1 to avoid solar heating and a high emittance close to 1 in the long-wavelength infrared (LWIR) transparent window of the atmosphere (wavelength λ = 8–13 μm) for radiating heat to the cold sky. This allows the surface to passively achieve sub-ambient cooling. PDRC requires careful tuning of optical reflectance in the wide optical spectrum, and various strategies have been proposed in the last decade, some of which are under commercialization. PDRC can be used in a variety of applications, such as building envelopes, containers, and vehicles. This perspective describes the principle and applications of various PDRC strategies and analyzes the cost, and economic and environmental consequences. Potential challenges and possible future directions are also discussed.

Annexin A2 (ANXA2) is reported to be associated with cancer development. To investigate the roles ANXA2 plays during the development of cancer, the RNAi method was used to inhibit the ANXA2 expression in caco2 (human colorectal cancer cell line) and SMMC7721 (human hepatocarcinoma cell line) cells. The results showed that when the expression of ANXA2 was efficiently inhibited, the growth and motility of both cell lines were significantly decreased, and the development of the motility relevant microstructures, such as pseudopodia, filopodia, and the polymerization of microfilaments and microtubules were obviously inhibited. The cancer cell apoptosis was enhanced without obvious significance. The possible regulating pathway in the process was also predicted and discussed. Our results suggested that ANXA2 plays important roles in maintaining the malignancy of colorectal and hepatic cancer by enhancing the cell proliferation, motility, and development of the motility associated microstructures of cancer cells based on a possible complicated signal pathway.

AlMg alloys have widespread industrial applications. Grain refinement techniques have been frequently used to achieve high strength in these alloys. Here, we report on the fabrication of epitaxial co-sputtered AlMg thin films with high-density growth twins. The microstructure evolution with varying Mg composition has been characterized. Nanoindentation and in-situ micropillar compression tests show that the strength of AlMg alloys increases with increasing Mg composition. The flow stress of epitaxial nanotwinned Al–10 at.% Mg thin film exceeds 800 MPa. The modified Hall–Petch plots incorporating the solid solution strengthening effect suggest that, compared to high angle grain boundaries, incoherent twin boundaries are equivalent barriers to the transmission of dislocations in nanotwinned AlMg alloys.

Specific roles of individual CDPKs vary, but in general they mediate essential biological functions necessary for parasite survival. A comparative analysis of the structure-activity relationships (SAR) of Neospora caninum, Eimeria tenella and Babesia bovis calcium-dependent protein kinases (CDPKs) together with those of Plasmodium falciparum, Cryptosporidium parvum and Toxoplasma gondii was performed by screening against 333 bumped kinase inhibitors (BKIs). Structural modelling and experimental data revealed that residues other than the gatekeeper influence compound–protein interactions resulting in distinct sensitivity profiles. We subsequently defined potential amino-acid structural influences within the ATP-binding cavity for each orthologue necessary for consideration in the development of broad-spectrum apicomplexan CDPK inhibitors. Although the BKI library was developed for specific inhibition of glycine gatekeeper CDPKs combined with low inhibition of threonine gatekeeper human SRC kinase, some library compounds exhibit activity against serine- or threonine-containing CDPKs. Divergent BKI sensitivity of CDPK homologues could be explained on the basis of differences in the size and orientation of the hydrophobic pocket and specific variation at other amino-acid positions within the ATP-binding cavity. In particular, BbCDPK4 and PfCDPK1 are sensitive to a larger fraction of compounds than EtCDPK1 despite the presence of a threonine gatekeeper in all three CDPKs.

The atomic force microscope (AFM) has been used to observe and characterize for the first time surface steps and grooves on the faces of Cr2O3 grains formed as an oxide scale on Ni−30Cr and Ni−30Cr−0.5Y alloys during high temperature oxidation. The very high spatial resolution of the AFM is required to characterize these features. We propose that these surface features, whose dimensions are in the range of nanometers and tens of nanometers, may be interpreted as evidence of highly localized plastic deformation of the oxide scale. The size and spacing of the steps and grooves are consistent with models of plastic deformation based on slip bands derived from dislocation climb or dislocation glide. Mechanical twinning and the models for stress-driven surface instability are also possibly responsible for some surface features. The addition of yttrium to the alloy seemed to enable enhanced plastic deformation of the scale. The strain corresponding to the observed features, estimated by simple models, could relax a significant part of oxide growth and thermal stresses.