The United States COVID-19 Forecast Hub dataset

Academic researchers, government agencies, industry groups, and individuals have produced forecasts at an unprecedented scale during the COVID-19 pandemic. To leverage these forecasts, the United States Centers for Disease Control and Prevention (CDC) partnered with an academic research lab at the University of Massachusetts Amherst to create the US COVID-19 Forecast Hub. Launched in April 2020, the Forecast Hub is a dataset with point and probabilistic forecasts of incident cases, incident hospitalizations, incident deaths, and cumulative deaths due to COVID-19 at county, state, and national, levels in the United States. Included forecasts represent a variety of modeling approaches, data sources, and assumptions regarding the spread of COVID-19. The goal of this dataset is to establish a standardized and comparable set of short-term forecasts from modeling teams. These data can be used to develop ensemble models, communicate forecasts to the public, create visualizations, compare models, and inform policies regarding COVID-19 mitigation. These open-source data are available via download from GitHub, through an online API, and through R packages

Experimental Study of Deformation Measurement of Bored Pile Using OFDR and BOTDR Joint Optical Fiber Sensing Technology

Pile foundation is the most common foundation form in geotechnical engineering; it is very important for engineering safety. In order to accurately grasp the deformation of pile foundation, OFDR (optical frequency domain reflectometer) and BOTDR (Brillouin optical time domain reflectometer) optical fiber sensing technologies are used to measure the strain variation of pile foundation. The measurement results of the two technologies are analyzed, and different data processing methods are used. The ability of the two methods to measure the strain of pile foundation is evaluated. The results show that OFDR technology can achieve high-precision and distributed measurement of strain of pile; BOTDR technology can achieve the monitoring effect of OFDR to a certain extent using appropriate data processing methods; the combination of the two methods can make up for the shortcomings of the short monitoring distance of the OFDR technique and the low accuracy of the BOTDR technique; by comparing the application effect with the two technologies in geotechnical engineering, the application prospect of OFDR–BOTDR joint optical fiber sensing technology in geotechnical engineering is discussed

Molecular Characterization and Antimicrobial Activity Analysis of Liver-Expressed Antimicrobial Peptide 2 (LEAP-2) Gene in Russian Sturgeon (Acipenser gueldenstaedti)

Antimicrobial peptides (AMPs) are an important part of the innate immune defense system; they can effectively kill viruses, fungi, and bacteria, preventing infection (and even sepsis). AMPs also have other functional roles in immune regulation, anti-tumor activity, angiogenesis, and wound healing. Liver-expressed antimicrobial peptide 2 (LEAP-2) is an AMP that has been extensively studied in mammals, birds, and fishes. The earliest fish LEAP-2 study reported the cloning of LEAP-2A and LEAP-2B of rainbow trout. So far, LEAP-2 has been studied in various fishes, including blunt snout bream, grass carp, golden pompano, ayu, and large yellow croaker. These studies found that LEAP-2 generally contains four highly conserved cysteine residues and two disulfide bonds; it can disrupt the structural integrity of bacterial cell membrane, revealing its antibacterial activity with an important role in the innate immune system of fishes. Russian sturgeon (Acipenser gueldenstaedtii) is cultivated on a certain scale in China, and Aeromonas hydrophila is its main pathogen. Hemorrhagic ascites and tissue hemorrhage appear after infection, causing huge economic losses to Russian sturgeon aquaculture. As an important innate immunity component, LEAP-2 research is of great significance. At present, studies on AgLEAP-2 have not been reported. To study the molecular characteristics and the transcriptional expression patterns of AgLEAP-2, as well as its antibacterial activity in vitro, the full-length AgLEAP-2 cDNA sequence was obtained by RACE. AgLEAP-2 was cloned and its sequence characteristics were analyzed by bioinformatics. The qRT-PCR method was used to detect AgLEAP-2 in 13 different tissues (liver, intestine, spleen, head kidney, blood, gill, skin, ovary, brain, heart, stomach, metanephros, and muscle) of healthy Russian sturgeon, and the AgLEAP-2 transcriptional expression pattern in immune tissues after infection with A. hydrophila. The AgLEAP-2 prokaryotic expression vector was constructed and the recombinant AgLEAP-2 protein (designated rAgLEAP-2) was purified. The antibacterial activity of rAgLEAP-2 was preliminarily detected by the agar dilution method. The results showed that the full-length cDNA of the AgLEAP-2 gene was 622 bp in length, of which the 5'-UTR was 184 bp, the 3'-UTR was 192 bp, and the ORF was 246 bp in length, encoding an 81-amino acid peptide. The molecular mass of the rAgLEAP-2 protein was predicted to be 11.2 kDa, and the theoretical isoelectric point was 9.15. AgLEAP-2 contained a signal peptide (1~25 aa) and a mature peptide (26~81 aa). The mature peptide contained four conserved cysteine residues and formed a core structure is consistent with two disulfide bonds between the Cys58-Cys69 and Cys64-Cys74. The AgLEAP-2 structure agreed with the LEAP-2 family characteristics. Moreover, the results showed that the AgLEAP-2 sequence was highly evolutionary conserved. Amino acid sequence alignment and phylogenetic analysis showed that AgLEAP-2 was clustered into a clade with the LEAP-2C of fishes, with the highest similarity with the LEAP-2C of Yangtze sturgeon and Chinese sturgeon. The qRT-PCR analysis showed that AgLEAP-2 was widely expressed in all healthy tissues, with the highest expression level in the liver, followed by the intestine and muscle, with the lowest expression in the gill. The expression patterns of LEAP-2 in different fish species were slightly different, with the highest expression level in the liver of Russian sturgeon and the intestine of large yellow croaker. The similar LEAP-2 expression patterns in different species suggested that its functions may be consistent, although it also had tissue and species specificity. The AgLEAP-2 expression reached its maximum within 72 h in the liver, spleen, head kidney, gill, and blood immune tissues. Among them, the expression AgLEAP-2 changed most significantly on the gill, which increased 5 000-fold compared with 0 h. The highest relative expression level was observed in the spleen at 72 h, corresponding to a 1500-fold induction relative to 0 h, and in the intestine at 48 h, with a 900-fold induction compared to 0 h kept constant until 72 h. In addition, the rAgLEAP-2 protein exhibited good antibacterial effects against both Gram-positive bacteria (Streptococcus sp. and S. aureus) and Gram-negative bacteria (E. coli, Vibrio anguillarum, and Shewanella spp.) in a dose-dependent manner in vitro. The rAgLEAP-2 protein at 500 μg/mL could inhibit the growth of most bacteria, significantly reducing the number of colonies on the plate. In conclusion, cloning and homology analysis revealed that AgLEAP-2 was closely related to LEAP-2C. AgLEAP-2 plays an important role in the immune response of Russian sturgeon against bacterial infection, and the rAgLEAP-2 protein could inhibit the growth of Gram-positive and Gram-negative bacteria in vitro. This study enhanced our current understanding of the nonspecific immune response in fish and provided a research basis for further studies on the antibacterial mechanism of LEAP-2 found in Russian sturgeon

Throughput Multiplexing Efficiency for High-Order Handset MIMO Antennas

In multipath environments, multiple-input multiple-output (MIMO) terminals typically suffer from non-zero correlations due to limited handset space and power imbalances due to different antenna efficiencies or partial hand blockage. These antenna–channel impairments can lead to significant throughput performance degradation of MIMO terminals. The multiplexing efficiency was proposed to quantitatively assess this performance degradation. Previous work only derived the analytical expression of the throughput-based multiplexing efficiency of two-port MIMO antennas for user equipment (UE). However, the fifth-generation (5G) UE dictates four or more antennas. In this paper, we extend the multiplexing efficiency metric to high-order MIMO UEs. Both correlation-based channel models and geometry-based stochastic channel models were used for validation. Besides dipole antennas, two representative terminal antennas were also employed for simulation verifications in this work

Throughput Multiplexing Efficiency for High-Order Handset MIMO Antennas

In multipath environments, multiple-input multiple-output (MIMO) terminals typically suffer from non-zero correlations due to limited handset space and power imbalances due to different antenna efficiencies or partial hand blockage. These antenna–channel impairments can lead to significant throughput performance degradation of MIMO terminals. The multiplexing efficiency was proposed to quantitatively assess this performance degradation. Previous work only derived the analytical expression of the throughput-based multiplexing efficiency of two-port MIMO antennas for user equipment (UE). However, the fifth-generation (5G) UE dictates four or more antennas. In this paper, we extend the multiplexing efficiency metric to high-order MIMO UEs. Both correlation-based channel models and geometry-based stochastic channel models were used for validation. Besides dipole antennas, two representative terminal antennas were also employed for simulation verifications in this work

Highly Ordered Thermoplastic Polyurethane/Aramid Nanofiber Conductive Foams Modulated by Kevlar Polyanion for Piezoresistive Sensing and Electromagnetic Interference Shielding

Abstract Highly ordered and uniformly porous structure of conductive foams is a vital issue for various functional purposes such as piezoresistive sensing and electromagnetic interference (EMI) shielding. With the aids of Kevlar polyanionic chains, thermoplastic polyurethane (TPU) foams reinforced by aramid nanofibers (ANF) with adjustable pore-size distribution were successfully obtained via a non-solvent-induced phase separation. In this regard, the most outstanding result is the in situ formation of ANF in TPU foams after protonation of Kevlar polyanion during the NIPS process. Furthermore, in situ growth of copper nanoparticles (Cu NPs) on TPU/ANF foams was performed according to the electroless deposition by using the tiny amount of pre-blended Ti3C2Tx MXene as reducing agents. Particularly, the existence of Cu NPs layers significantly promoted the storage modulus in 2,932% increments, and the well-designed TPU/ANF/Ti3C2Tx MXene (PAM-Cu) composite foams showed distinguished compressive cycle stability. Taking virtues of the highly ordered and elastic porous architectures, the PAM-Cu foams were utilized as piezoresistive sensor exhibiting board compressive interval of 0–344.5 kPa (50% strain) with good sensitivity at 0.46 kPa−1. Meanwhile, the PAM-Cu foams displayed remarkable EMI shielding effectiveness at 79.09 dB in X band. This work provides an ideal strategy to fabricate highly ordered TPU foams with outstanding elastic recovery and excellent EMI shielding performance, which can be used as a promising candidate in integration of satisfactory piezoresistive sensor and EMI shielding applications for human–machine interfaces. Graphical Abstrac

C/SiO2 meta-composite: Overcoming the λ/a relationship limitation in metamaterials

Metamaterials usually require that the unit size a should be comparable to the wavelength λ. Although the λ/a relationship could tell us what size of unit we need and which method we should choose for the fabrication, it limits the application of metamaterials in the kHz and MHz frequency range, as the unit size would be on the order of 10 2 m, making the overall size of the metamaterial too large for practical application. In this paper, we firstly demonstrate that the λ/a relationship limitation could be overcome by a new kind of composite, which we have called carbon-based \u27meta-composite\u27. A SiO 2 matrix with periodic microstructure is fabricated by using self-assembly of SiO 2 microspheres, and amorphous carbon fills in the gaps to form a three-dimensional periodic carbon network. The experimental results indicate that the carbon network will introduce tunable electromagnetic properties, which could be precisely tailored by controlling the geometric size of the carbon network. It is worth pointing out that the unit size of the periodic carbon network is on the sub-micrometre level, but the wavelength is on the order of 10 2 m. This means that the meta-composite overcomes the λ/a relationship limitation in the kHz and MHz frequency range, which shows great potential for the miniaturization of electronic devices