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Sea turtles exhibit high migratory rates and occupy a broad range of habitats, which in turn makes monitoring these taxa challenging. Applying deep learning (DL) models to vast image datasets collected from citizen science programs can offer promising solutions to overcome the challenge of monitoring the wide habitats of wildlife, particularly sea turtles. Among DL models, object detection models, such as the You Only Look Once (YOLO) series, have been extensively employed for wildlife classification. Despite their successful application in this domain, detecting objects in images with complex backgrounds, including underwater environments, remains a significant challenge. Recently, instance segmentation models have been developed to address this issue by providing more accurate classification of complex images compared to traditional object detection models. This study compared the performance of two state-of-the-art DL methods namely; the object detection model (YOLOv5) and instance segmentation model (YOLOv5-seg), to detect and classify sea turtles. The images were collected from iNaturalist and Google and then divided into 64% for training, 16% for validation, and 20% for test sets. Model performance during and after finishing training was evaluated by loss functions and various indexes, respectively. Based on loss functions, YOLOv5-seg demonstrated a lower error rate in detecting rather than classifying sea turtles than the YOLOv5. According to mean Average Precision (mAP) values, which reflect precision and recall, the YOLOv5-seg model showed superior performance than YOLOv5. The mAP0.5 and mAP0.5:0.95 for the YOLOv5 model were 0.885 and 0.795, respectively, whereas for the YOLOv5-seg, these values were 0.918 and 0.831, respectively. In particular, based on the loss functions and classification results, the YOLOv5-seg showed improved performance for detecting rather than classifying sea turtles compared to the YOLOv5. The results of this study may help improve sea turtle monitoring in the future. [ABSTRACT FROM AUTHOR]

In this study, we suggest a method to amplify spin waves (SWs) in antiferromagnets (AFMs). By introducing a non-uniform Dzyaloshinskii–Moriya (DM) interaction, the potential barrier forms a resonant cavity. SWs with an opposite chirality undergo scattering and are resonantly amplified at a phase-matching condition. The calculation is performed in the insulating AFMs where the electric-field-induced DM interaction and pseudo-dipole anisotropy broaden the parabolic-like SW band for multiple resonant modes. Using a transfer matrix method, we also show numerically that scattering between SWs contributes significantly to the SW amplification. Since the electric field selectively amplifies the SWs with resonant frequencies, the proposed device works as an SW transistor and rectifier. This finding will contribute to insulating AFM-based magnon devices where Joule heating is, in principle, avoided. [ABSTRACT FROM AUTHOR]

Since the first imported case of coronavirus disease (COVID-19) was confirmed in South Korea on January 20, 2020, a sharp increase in the number of COVID-19 cases has been observed, [...]

South Korea had 10,801 confirmed cases of coronavirus disease (COVID-19) by May 4, 2020 (1). The epidemic curve of the cumulative number of cases had plateaued in April (Appendix Figure [...]

Simple Summary: Sialocele-related concurrent diseases or factors in dogs are not well documented, and occasionally, dogs with sialocele have been found to have concurrent hypercortisolism (HC) or a history of long-term glucocorticoid (GC) treatment. In this retrospective case–control study, we investigated the association between HC, long-term GC treatment, and the diagnosis of sialocele in dogs. The occurrence of sialocele was higher in dogs with HC and those receiving long-term GC treatment, that is, treatment lasting for more than 5 months. This suggests that endogenous and exogenous GCs may influence sialocele formation. Therefore, we recommend regular monitoring for sialocele occurrence in dogs with HC or those receiving long-term GC treatment. Dogs with sialocele often have concurrent hypercortisolism or are receiving long-term glucocorticoid treatment. However, their association has not been investigated. This retrospective matched case–control study investigated the association between hypercortisolism, long-term glucocorticoid treatment, and sialocele in dogs. We retrospectively reviewed the records from 1 January 2018 to 31 December 2022. Records of 19 dogs diagnosed with sialocele were investigated for hypercortisolism and long-term glucocorticoid treatment. Two age- and breed-matched controls for each sialocele dog (38 dogs) were investigated for the same concurrent diseases. Logistic regression analysis was used. The odds of sialocele in dogs with hypercortisolism were 15.56 times those of dogs without hypercortisolism (p = 0.02; 95% CI: 1.54–156.79). The odds of sialocele in dogs with long-term glucocorticoid treatment (median, 8 months; range, 5–13) were 7.78 times those of dogs without long-term glucocorticoid treatment (p = 0.03; 95% CI: 1.23–49.40). No associations were found between age, sex, body weight, and the presence of sialocele. The results indicate that sialocele was significantly associated with hypercortisolism and long-term glucocorticoid treatment in dogs. Therefore, dogs with hypercortisolism or receiving long-term glucocorticoid therapy should be screened for possible sialocele. Additionally, dogs with sialocele should be identified for concurrent hypercortisolism and prolonged glucocorticoid exposure. [ABSTRACT FROM AUTHOR]

Layered nanomaterials with in‐plane anisotropy exhibit unique orientation‐dependent responses to external stimuli, enabling the development of novel devices with additional degrees of freedom. In particular, their anisotropic optical properties enable ultrafast nanophotonic modulators to be controlled by light polarization. However, achieving high controllability is still challenging due to incomplete optical anisotropy in most materials. Here, this work presents a completely anisotropic, ultrafast optical modulation in zirconium pentatelluride (ZrTe5), a layered nanomaterial that has recently attracted renewed attention. The transient absorption (TA) microscopy reveals anisotropic ultrafast picosecond optical modulation in a broad range of 1.2–2.2 eV. In particular, at a certain photon‐energy of 1.62 eV, complete on/off switching with a near‐unity degree of anisotropy is achieved solely by changing the light polarization, suggesting that ZrTe5 is a promising material for polarization‐selective high‐speed optical modulators. The theoretical analysis of the transition dipole moments attributes this sharp anisotropy to strongly polarization‐dependent excited‐state absorption. Furthermore, this work directly observes direction‐dependent photocarrier transport using scanning TA microscopy. It yields the anisotropic diffusivity, mobility, and diffusion lengths of the photocarriers, which are essential parameters for designing devices. Therefore, this work provides a comprehensive understanding of the anisotropic optical characteristics of ZrTe5 on ultrafast timescales. [ABSTRACT FROM AUTHOR]

The performance of a 10-vane strapped magnetron oscillator used in microwave ovens was benchmarked using the three-dimensional particle-in-cell (PIC) code MAGIC3D. The formation of the five electron spokes in the oscillation region confirms the [pie]-mode oscillation of a 10-vane strapped resonator showing its mode separation with the adjacent mode to be 82%. The measured operating frequency of 2.465 GHz and the saturated output power of 1.04 kW are in good agreement with the simulated values of 2.470 GHz and 1.07 kW, respectively. The magnetron with an efficiency of 75 % is operated at the beam voltage of 4.3 kV, the anode current of 0.33 A, and the cathode current of 1.08 A when the external axial magnetic field of 0.19 T is applied. In addition, the measured harmonic components of the radiated output are compared with the simulated one estimated by Fourier transformation of an induced radio-frequency voltage signal, showing good agreement. Index Terms--MAGIC3D, oscillator, PIC code, 10-vane strapped magnetron.