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11 pages, 790 KiB

Open AccessArticle

Serological Distribution of Salmonella enterica subsp. Isolated from Feces of Domesticated Crested Gecko (Correlophus ciliates) in Busan Province, South Korea

by Il Kwon Bae, Yon-koung Park, So Hyun Park and Jun Sung Hong

Life 2025, 15(3), 405; https://doi.org/10.3390/life15030405 - 5 Mar 2025

Viewed by 792

Abstract

Geckos are often considered to be reservoirs of zoonotic pathogens. This study was conducted to describe the prevalence and characteristics of pathogens isolated from fecal samples of crested geckos in South Korea. A total of 76 fecal samples were collected from 76 domesticated crested geckos in independent captivity. To determine bacterial profiles, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), the disk diffusion method, PCR and direct sequencing, and the Kauffmann–White scheme for serotyping Salmonella species were performed. A total of 107 Gram-negative isolates were identified as belonging to 50 Citrobacter species, 33 Salmonella enterica subsp., 8 Serratia marcescens, 8 Klebsiella species, 3 Morganella morganii, 2 Enterobacter cloacae, 2 Pseudomonas aeruginosa, and 1 Acinetobacter species. Most of the isolates were susceptible to antibiotics tested in this study. The chloramphenicol acetyltransferase (cat) gene was detected in one M. morganii isolate, and the class C beta-lactamase (AZECL-14) gene was detected in one E. cloacae. The most prevalent somatic (O) antigens of the groups were C (n = 23) and D (n = 7), and 8 different serotypes were identified among the 33 Salmonella enterica subsp. isolates. Five of eight Salmonella serotypes have not been previously reported among clinical isolates in South Korea. Our results reveal that enteric bacteria have not been shared between crested geckos and humans, at least in South Korea. Full article

(This article belongs to the Special Issue Latest Updates on Clinical Microbiology and Antimicrobial Resistant Infection)

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17 pages, 8026 KiB

Open AccessArticle

Altimetry Method for an Interferometric Radar Altimeter Based on a Phase Quality Evaluation

by Jong-Soo Ha and Sung-Yong Hong

Sensors 2023, 23(12), 5508; https://doi.org/10.3390/s23125508 - 12 Jun 2023

Cited by 1 | Viewed by 2049

Abstract

A radar altimeter (RA) is useful to improve autonomous functions such as landing guidance or navigation control of an aircraft. To ensure more precise and safer flights by aircraft, an interferometric RA (IRA) capable of measuring the angle of a target is required. However, the phase-comparison monopulse (PCM) technique used in IRAs has a problem in that an angular ambiguity arises with respect to a target with multiple reflection points, such as terrain. In this paper, we propose an altimetry method for IRAs that reduces the angular ambiguity by evaluating the quality of the phase. The altimetry method as introduced here is sequentially described based on synthetic aperture radar, a delay/Doppler radar altimeter, and PCM techniques. Finally, a phase quality evaluation method is proposed for use in the azimuth estimation process. Aircraft captive flight test results are presented and analyzed, and the validity of the proposed method is examined. Full article

(This article belongs to the Section Radar Sensors)

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12 pages, 1156 KiB

Open AccessArticle

Enclosure Background Preferences Differ between Sexes and Color Morphs in the Gouldian Finch

by Robert I. Moise, Georgina R. Eccles and Claudia Mettke-Hofmann

Animals 2023, 13(8), 1353; https://doi.org/10.3390/ani13081353 - 15 Apr 2023

Cited by 1 | Viewed by 2463

Abstract

Most wild animals camouflage well into their environment, providing protection from predators, whereas captive animals often contrast with their background. This can cause stress for the animal, which may perceive it as being exposed. Theory suggests that prey is more difficult to detect in front of complex backgrounds; hence, animals should prefer complex over simple backgrounds. We tested this in the polymorphic Gouldian finch by providing a complex background pattern in one half of the flight cage and a simple background pattern in the other half for 10 days (phase 1). Patterns were then swapped and presented for another week (phase 2). Groups of four birds consisting of either pure black-headed or red-headed or mixed head color (two black-headed and two red-headed) pairings were tested. Gouldian finches spent significantly more time in front of the simple background in phase 1 but not in phase 2. Specifically, females preferred the simple background in phase 1 significantly more than males. Moreover, red-headed birds consistently perched in front of the simple background, whereas black-headed birds used both backgrounds, particularly in phase 2. Results indicate that background preferences differ between sexes and morphs, which should be considered when designing backgrounds. Moreover, natural habitat preferences need consideration. Full article

(This article belongs to the Special Issue Effects of Enclosure Complexity and Design on Behavior and Physiology in Captive Animals)

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23 pages, 3659 KiB

Open AccessArticle

A Pragmatic Approach to the Design of Advanced Precision Terrain-Aided Navigation for UAVs and Its Verification

by Jungshin Lee, Chang-Ky Sung, Juhyun Oh, Kyungjun Han, Sangwoo Lee and Myeong-Jong Yu

Remote Sens. 2020, 12(9), 1396; https://doi.org/10.3390/rs12091396 - 28 Apr 2020

Cited by 9 | Viewed by 3991

Abstract

Autonomous unmanned aerial vehicles (UAVs) require highly reliable navigation information. Generally, navigation systems with the inertial navigation system (INS) and global navigation satellite system (GNSS) have been widely used. However, the GNSS is vulnerable to jamming and spoofing. The terrain referenced navigation (TRN) technique can be used to solve this problem. In this study, to obtain reliable navigation information even if a GNSS is not available or the degree of terrain roughness is not determined, we propose a federated filter based INS/GNSS/TRN integrated navigation system. We also introduce a TRN system that combines batch processing and an auxiliary particle filter to ensure stable flight of UAVs even in a long-term GNSS-denied environment. As an altimeter sensor for the TRN system, an interferometric radar altimeter (IRA) is used to obtain reliable navigation accuracy in high altitude flight. In addition, a parallel computing technique with general purpose computing on graphics processing units (GPGPU) is applied to process a high resolution terrain database and a nonlinear filter in real-time on board. Finally, the performance of the proposed system is verified through software-in-the-loop (SIL) tests and captive flight tests in a GNSS unavailable environment. Full article

(This article belongs to the Section Engineering Remote Sensing)

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