Yawning is a ubiquitous stereotyped action in vertebrates. Yawning may induce behavioral state changes in animals through its arousal function, but no studies have explicitly examined this ...state-change hypothesis in fish. This study examined the state-change hypothesis in juvenile white-spotted char,
Salvelinus leucomaenis
. We observed 48 yawns in 23 out of 41 juveniles during 600 s of observation in the laboratory. Thirty-two of these yawns occurred while juveniles were stationary on the substrate, and they were concentrated immediately before the behavioral transition from stationary to active. These results support the state-change hypothesis. Sixteen yawns were observed after the behavioral transition, and their durations were longer than those before the transition. Although we suspected that this prolonged yawning after the transition would be associated with feeding and thermoregulation in the juveniles, we could not determine the cause of this difference. Further studies are needed to understand fish yawning and the origin of animal yawning.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a pandemic threat worldwide and causes severe health and economic burdens. Contaminated environments, such as personal items and ...room surfaces, are considered to have virus transmission potential. Ultraviolet C (UVC) light has demonstrated germicidal ability and removes environmental contamination. UVC has inactivated SARS-CoV-2; however, the underlying mechanisms are not clear. It was confirmed here that UVC 253.7 nm, with a dose of 500 μW/cm
, completely inactivated SARS-CoV-2 in a time-dependent manner and reduced virus infectivity by 10
-fold within 30 s. Immunoblotting analysis for viral spike and nucleocapsid proteins showed that UVC treatment did not damage viral proteins. The viral particle morphology remained intact even when the virus completely lost infectivity after UVC irradiation, as observed by transmission electronic microscopy. In contrast, UVC irradiation-induced genome damage was identified using the newly developed long reverse-transcription quantitative-polymerase chain reaction (RT-qPCR) assay, but not conventional RT-qPCR. The six developed long RT-PCR assays that covered the full-length viral genome clearly indicated a negative correlation between virus infectivity and UVC irradiation-induced genome damage (R
ranging from 0.75 to 0.96). Altogether, these results provide evidence that UVC inactivates SARS-CoV-2 through the induction of viral genome damage.
Abstract
The development of mid-infrared (mid-IR) tunable lasers has been driving various laser spectroscopic technologies. Herein, we report wavelength-scanning cavity ring-down spectroscopy ...(WS-CRDS) in the mid-IR region using an electronically tuned Cr:ZnSe (ET-Cr:ZnSe) laser, which could achieve a nanosecond pulse operation, with broad wavelength tuning of 2–3 µm. This allowed WS-CRDS-induced trace detection of the refrigerant, CH
2
F
2
. A CH
2
F
2
detection limit of 0.66 ppm (3σ), and the detection of trace H
2
O in CH
2
F
2
was realized using the broad wavelength-tuning range feature, demonstrating the effectiveness of the ET-Cr:ZnSe laser in WS-CRDS. We believe that our method would accelerate the development of various trace-gas detection technologies.
We describe a novel foraging technique of the blue bat star Patiria pectinifera that we call “standing-on-tiptoe” behavior. We examined whether the starfish uses this technique to catch shore crab ...Gaetice depressus in laboratory experiments. Patiria pectinifera in an aquarium with live crabs showed standing-on-tiptoe behavior at a significantly higher frequency (20 out of 47 cases) than those with dead crabs (one out of 23 cases) or no crabs (one out of 23 cases). Nine out of the twenty starfish showing this behavior succeeded in catching and consuming the shore crabs. This behavior could be a tactic for foraging for agile prey, such as shore crabs.
•A single vision sensor based laser welding monitoring platform is set up for monitor multiple target.•The welding images are divided into two, three and four categories.•Feature extraction is ...performed using convolution neural network.•Effectiveness of the proposed method is verified by the various laser welding parameters.
In this paper, an innovative monitoring system capable of diagnosing the penetration state during the laser welding process is introduced, which consists of two main blocks: a coaxial visual monitoring platform and a penetration state diagnosis unit. The platform can capture coaxial images of the interaction zone during the laser welding through a partially transmitting mirror and a high-speed camera. An image dataset representing four welding states was created for training and validation. The unit mainly consists of an embedded power-efficient computing TX2 and image processing algorithms based on a convolution neural network (CNN). Experiment results show that the platform can stably capture state-of-the-art welding images. The CNN used for a diagnosis of the penetration state is optimized using an optimal network structure and hyperparameters, applying a super-Gaussian function to initialize the weights of the convolutional layer. Its latency on TX2 is less than 2 ms, satisfying the real-time requirement. During the real laser welding of tailor-rolled blanks, a penetration state diagnosis with an accuracy of 94.6 % can be achieved even if the illumination changes significantly. The similar accuracy between the validating set and a real laser welding demonstrates that the proposed monitoring system has strong robustness. The precision and recall ratios of the CNN are higher than those of other methods such as a histogram of oriented gradients and local binary pattern.
Many plants, including fruits and vegetables, release biogenic gases containing various volatile organic compounds such as ethylene (C
H
), which is a gaseous phytohormone. Non-destructive and ...in-situ gas sampling technology to detect trace C
H
released from plants in real time would be attractive for visualising the ageing, ripening, and defence reactions of plants. In this study, we developed a C
H
detection system with a detection limit of 0.8 ppb (3σ) using laser absorption spectroscopy. The C
H
detection system consists of a mid-infrared quantum cascade laser oscillated at 10.5 µm, a multi-pass gas cell, a mid-IR photodetector, and a gas sampling system. Using non-destructive and in-situ gas sampling, while maintaining the internal pressure of the multi-pass gas cell at low pressure, the change in trace C
H
concentration released from apples (Malus domestica Borkh.) can be observed in real time. We succeeded in observing C
H
concentration changes with a time resolution of 1 s, while changing the atmospheric gas and surface temperature of apples from the 'Fuji' cultivar. This technique allows the visualisation of detailed C
H
dynamics in plant environmental response, which may be promising for further progress in plant physiology, agriculture, and food science.
Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis, the most common neoplastic disease of cattle, which is closely related to human T‐cell leukemia viruses. BLV has spread ...worldwide and causes a serious problem for the cattle industry. The cellular receptor specifically binds with viral envelope glycoprotein (Env), and this attachment mediates cell fusion to lead virus entry. BLV Env reportedly binds to cationic amino acid transporter 1 (CAT1)/solute carrier family 7 member 1 (SLC7A1), but whether the CAT1/SLC7A1 is an actual receptor for BLV remains unknown. Here, we showed that CAT1 functioned as an infection receptor, interacting with BLV particles. Cells expressing undetectable CAT1 levels were resistant to BLV infection but became highly susceptible upon CAT1 overexpression. CAT1 exhibited specific binding to BLV particles on the cell surface and colocalized with the Env in endomembrane compartments and membrane. Knockdown of CAT1 in permissive cells significantly reduced binding to BLV particles and BLV infection. Expression of CAT1 from various species demonstrated no species specificity for BLV infection, implicating CAT1 as a functional BLV receptor responsible for its broad host range. These findings provide insights for BLV infection and for developing new strategies for treating BLV and preventing its spread.—Bai, L., Sato, H., Kubo, Y., Wada, S., Aida, Y. CAT1/SLC7A1 acts as a cellular receptor for bovine leukemia virus infection. FASEB J. 33, 14516‐14527 (2019). www.fasebj.org
(K0.5Na0.5)NbO3 (KNN) + x (= 1, 0.5, 0.05, and 0) wt%Co3O4 single crystals were fabricated by a solid-state crystal growth method with a KTaO3 seed crystal and a KNN atmosphere powder, and the ...effects of the sintering aid content x and the addition of Co3O4 to the atmosphere powder on the growth of the single crystals were investigated. The formation of pores in the single crystals was suppressed by a decrease of x, which, however, decreased the crystal growth length. On the other hand, dense and large KNN single crystals could be fabricated by sintering with a KNN + 5 wt%Co3O4 atmosphere at x = 0. The dielectric, ferroelectric, and piezoelectric properties of the KNN single crystals were comparable to those of reported (K,Na)NbO3 single crystals. These results would be useful for fabricating dense and large single crystals by the solid-state crystal growth method.
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