Automated Ortho-Rectification of UAV-Based Hyperspectral Data over an Agricultural Field Using Frame RGB Imagery

Low-cost Unmanned Airborne Vehicles (UAVs) equipped with consumer-grade imaging systems have emerged as a potential remote sensing platform that could satisfy the needs of a wide range of civilian applications. Among these applications, UAV-based agricultural mapping and monitoring have attracted significant attention from both the research and professional communities. The interest in UAV-based remote sensing for agricultural management is motivated by the need to maximize crop yield. Remote sensing-based crop yield prediction and estimation are primarily based on imaging systems with different spectral coverage and resolution (e.g., RGB and hyperspectral imaging systems). Due to the data volume, RGB imaging is based on frame cameras, while hyperspectral sensors are primarily push-broom scanners. To cope with the limited endurance and payload constraints of low-cost UAVs, the agricultural research and professional communities have to rely on consumer-grade and light-weight sensors. However, the geometric fidelity of derived information from push-broom hyperspectral scanners is quite sensitive to the available position and orientation established through a direct geo-referencing unit onboard the imaging platform (i.e., an integrated Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS). This paper presents an automated framework for the integration of frame RGB images, push-broom hyperspectral scanner data and consumer-grade GNSS/INS navigation data for accurate geometric rectification of the hyperspectral scenes. The approach relies on utilizing the navigation data, together with a modified Speeded-Up Robust Feature (SURF) detector and descriptor, for automating the identification of conjugate features in the RGB and hyperspectral imagery. The SURF modification takes into consideration the available direct geo-referencing information to improve the reliability of the matching procedure in the presence of repetitive texture within a mechanized agricultural field. Identified features are then used to improve the geometric fidelity of the previously ortho-rectified hyperspectral data. Experimental results from two real datasets show that the geometric rectification of the hyperspectral data was improved by almost one order of magnitude

Enhanced high cycle fatigue resistance of Ti-17 titanium alloy after multiple laser peening without coating

High cycle fatigue failure of titanium alloy components on the aircraft is a serious problem that affects the flight safety. The low energy laser peening without coating (LPwC) has been demonstrated for the improved fatigue resistance of metallic materials via the introduction of compressive residual stress and microstructure modifications. Therefore, in the present study, LPwC with different impacts were conducted on the Ti-17 titanium alloy using the Mianna-Q laser with the wavelength of 532 nm and energy of 85 mJ. The surface and depth-wise residual stress and micro-hardness distribution were presented on the samples with and without LPwC treatment. High amplitude compressive residual stress was introduced, and the hardness was significantly improved. The microstructures of the Ti-17 samples after LPwC was characterized using the X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). Furthermore, high cycle fatigue performance of the as-cast, LPwCed sample with 1 impact and LPwCed sample with 3 impacts were evaluated via the tension-compression fatigue test. The fatigue strength of the LPwCed specimen was increased from 390 MPa to 475.4 MPa (1 impact) and 490.3 MPa (3 impacts). Then the fracture morphology of all the specimens were characterized by the SEM. Finally, the strengthening mechanism was discussed based on the microstructural evolution and residual stress distribution. It was concluded that the enhancement of high cycle fatigue strength was attributed to the combined effects of LPwC induced compressive residual stress and high-density dislocations

Host-range shift of H3N8 canine influenza virus: a phylodynamic analysis of its origin and adaptation from equine to canine host

International audiencePrior to the emergence of H3N8 canine influenza virus (CIV) and the latest avian-origin H3N2 CIV, there was no evidence of a circulating canine-specific influenza virus. Molecular and epidemiological evidence suggest that H3N8 CIV emerged from H3N8 equine influenza virus (EIV). This host-range shift of EIV from equine to canine hosts and its subsequent establishment as an enzootic CIV is unique because this host-range shift was from one mammalian host to another. To further understand this host-range shift, we conducted a comprehensive phylodynamic analysis using all the available whole-genome sequences of H3N8 CIV. We found that (1) the emergence of H3N8 CIV from H3N8 EIV occurred in approximately 2002; (2) this interspecies transmission was by a reassortant virus of the circulating Florida-1 clade H3N8 EIV; (3) once in the canine species, H3N8 CIV spread efficiently and remained an enzootic virus; (4) H3N8 CIV evolved and diverged into multiple clades or sublineages, with intra and inter-lineage reassortment. Our results provide a framework to understand the molecular basis of host-range shifts of influenza viruses and that dogs are potential “mixing vessels” for the establishment of novel influenza viruses

HVEM Promotes the Osteogenesis of allo-MSCs by Inhibiting the Secretion of IL-17 and IFN-γ in Vγ4T Cells

Bone defects are a common orthopaedic concern, and an increasing number of tissue-engineered bones (TEBs) are used to repair bone defects. Allogeneic mesenchymal stem cells (allo-MSCs) are used as seed cells in many approaches to develop TEB constructs, but the immune response caused by allogeneic transplantation may lead to transplant failure. V gamma 4 T (Vγ4T) cells play an important role in mediating the immune response in the early stage after transplantation; therefore, we wanted to verify whether suppressing Vγ4T cells by herpesvirus entry mediator (HVEM)/B and T lymphocyte attenuator (BTLA) signalling can promote MSCs osteogenesis in the transplanted area. In vitro experiments showed that the osteogenic differentiation of MSCs and Vγ4T cells was weakened after co-culture, and an increase in interleukin-17 (IL-17) and interferon-γ (IFN-γ) levels was detected in the culture supernatant. HVEM-transfected MSCs (MSCs-HVEM) still exhibited osteogenic differentiation activity after co-culture with Vγ4T cells, and the levels of IL-17 and IFN-γ in the co-culture supernatant were significantly reduced. In vivo experiments revealed that inflammation in the transplanted area was reduced and osteogenic repair was enhanced after Vγ4T cells were removed. MSCs-HVEM can also consistently contribute to reduced inflammation in the transplanted area and enhanced bone repair in wild-type (WT) mice. Therefore, our experiments verified that HVEM can promote the osteogenesis of allo-MSCs by inhibiting IL-17 and IFN-γ secretion from Vγ4T cells

Development of 15kA/cm2^2 Fabrication Process for Superconducting Integrated Digital Circuits

A new fabrication process for superconducting integrated digital circuits is reported. We have developed the "SIMIT Nb04" fabrication technique for superconducting integrated circuits with Nb-based Josephson junctions based on the validated "SIMIT Nb03" process and Chemical Mechanical Planarization (CMP) technology. Seven Nb superconducting layers and one Mo resistor layer are included in the "SIMIT Nb04" process with 19 mask levels. The device structure is composed of active layers including junctions at the bottom, two passive transmission line (PTL) layers in the middle and a DC power layer at the top. The circuit fabrication started with the fabrication of Mo resistors with a target sheet resistance Rsh of 3 $\Omega$, followed by the deposition of Nb/Al-AlO$_x$/Nb trilayer Josephson-junction with a target critical current density Jc at 15 kA/cm$^2$. To increase the Al-AlO$_x$ barrier layer etching's repeatability, an additional barrier protection layer was applied. To accomplish high-quality planarization, we created a planarization procedure coupled with dummy filling. To assess the process dependability and controllability, a set of process control monitors (PCMs) for monitoring fabrication and design parameters was designed and monitored. The successful manufacturing and testing of a few small-scale circuits, like our standard library cells, further attests to the viability of our fabrication process for superconducting integrated circuits

Effect of high-intensity interval training protocol on abdominal fat reduction in overweight chinese women: a randomized controlled trial

The objective of the study was to compare the whole-body and abdominal fat loss resulting from high-intensity interval training (HIIT) with that from moderate-intensity continuous training (MICT) with equivalent oxygen cost in overweight women. Forty-three overweight women with matched anthropometric characteristics were randomly assigned to participate in: (1) HIIT [4 x 4-minute running at 85–95% HRpeak, 10-minute recovery], (2) MICT [33-minute running at 60–70% HRpeak] with oxygen cost equivalent to HIIT, and (3) no training [control], for 12 weeks, 4 d·wk-1. Dietary energy intake and habitual energy expenditure were not altered during the intervention. After the intervention, whole-body fat reduction and serum lipid profile modification were similar in the HIIT and MICT groups. With regard to the abdominal visceral (AVFA) and subcutaneous (ASFA) fat areas revealed by computed tomography scans, a greater reduction in ASFA was found in the HIIT than in the MICT group (p=.038). Moreover, a significant reduction in AVFA was found only in the HIIT group. No variables were changed in the control group. Twelve-week HIIT and MICT programmes with equivalent oxygen cost resulted in similar whole-body fat loss in overweight women. Nonetheless, HIIT appears to be more effective than MICT for controlling abdominal visceral and subcutaneous fat