12 research outputs found

    Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

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    Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

    Pest Responses to Odors From Predators Fed a Diet of Target Species Conspecifics and Heterospecifics

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    Research into the use of predator-odor–based repellents as a management tool has gained momentum during the past 30 years. Some studies have suggested that odors from a predator whose diet includes the target species are more effective than odors from a predator that does not consume the species. To evaluate this management tool in the Australian context and to determine the effect, if any, of predator diet on odor repellence, we tested eutherian and metatherian, predator fecal odors on phylogenetically separated pest species that currently occur in Australia. We evaluated fecal odors from tigers (Panthera tigris) and Tasmanian devils (Sarcophilus harrisii) as repellents for goats (Capra hircus) and eastern grey kangaroos (Macropus giganteus). We fed tigers and Tasmanian devils 2 diets: one of goat and one of eastern grey kangaroo. The test fecal odors were more effective than a control odor of carrier material and solvent at deterring goats (P < 0.001) and kangaroos (P = 0.02) from food. Tiger fecal odor was more effective than Tasmanian devil odor in deterring both goats (P 5 0.001) and kangaroos (P = 0.03). We observed a decrease in the number of feeding events for goats when they were exposed to the odor from a tiger fed goat compared with all other predator–diet combinations (P < 0.001). We also observed a decrease in feeding events for kangaroos when exposed to the odor from a tiger fed kangaroo compared with all other predator–diet combinations. We observed signs of desensitization to the test odors in goats and habituation to the test odors in kangaroos over the experimental period. A better understanding of the factors involved in desensitization and habituation may increase the effectiveness of fecal odor–based repellents as a humane and nonlethal management tool for managers

    Automated detection of animals in low-resolution airborne thermal imagery

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    Detecting animals to estimate abundance can be difficult, particularly when the habitat is dense or the target animals are fossorial. The recent surge in the use of thermal imagers in ecology and their use in animal detections can increase the accuracy of population estimates and improve the subsequent implementation of management programs. However, the use of thermal imagers results in many hours of captured flight videos which require manual review for confirmation of species detection and identification. Therefore, the perceived cost and efficiency trade-off often restricts the use of these systems. Additionally, for many off-the-shelf systems, the exported imagery can be quite low resolution (<9 Hz), increasing the difficulty of using automated detections algorithms to streamline the review process. This paper presents an animal species detection system that utilises the cost-effectiveness of these lower resolution thermal imagers while harnessing the power of transfer learning and an enhanced small object detection algorithm. We have proposed a distant object detection algorithm named Distant-YOLO (D-YOLO) that utilises YOLO (You Only Look Once) and improves its training and structure for the automated detection of target objects in thermal imagery. We trained our system on thermal imaging data of rabbits, their active warrens, feral pigs, and kangaroos collected by thermal imaging researchers in New South Wales and Western Australia. This work will enhance the visual analysis of animal species while performing well on low, medium and high-resolution thermal imagery

    Automated Detection of Animals in Low-Resolution Airborne Thermal Imagery

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    Detecting animals to estimate abundance can be difficult, particularly when the habitat is dense or the target animals are fossorial. The recent surge in the use of thermal imagers in ecology and their use in animal detections can increase the accuracy of population estimates and improve the subsequent implementation of management programs. However, the use of thermal imagers results in many hours of captured flight videos which require manual review for confirmation of species detection and identification. Therefore, the perceived cost and efficiency trade-off often restricts the use of these systems. Additionally, for many off-the-shelf systems, the exported imagery can be quite low resolution (&lt;9 Hz), increasing the difficulty of using automated detections algorithms to streamline the review process. This paper presents an animal species detection system that utilises the cost-effectiveness of these lower resolution thermal imagers while harnessing the power of transfer learning and an enhanced small object detection algorithm. We have proposed a distant object detection algorithm named Distant-YOLO (D-YOLO) that utilises YOLO (You Only Look Once) and improves its training and structure for the automated detection of target objects in thermal imagery. We trained our system on thermal imaging data of rabbits, their active warrens, feral pigs, and kangaroos collected by thermal imaging researchers in New South Wales and Western Australia. This work will enhance the visual analysis of animal species while performing well on low, medium and high-resolution thermal imagery

    Do Fecal Odors from Native and Non-native Predators Cause a Habitat Shift Among Macropods?

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    Predator-odor-based repellents have benefits as humane, non-lethal management tools that may reduce the need for lethal control in some areas. Macropods (such as kangaroos and wallabies) are iconic Australian native marsupials; however, some are considered important rangeland pests, and their presence in the urban and peri-urban environment often results in conflict. The management of these macropods is a contentious and volatile issue. We evaluated lion (Panthera leo), Sumatran tiger (P. tigris sumatrae), and dingo (Canis lupus dingo) fecal odors as short-term odor-based repellents for wild eastern grey kangaroos (Macropus giganteus) and red-necked wallabies (M. rufogriseus). These odors were used to 'protect' highly palatable food sources; with any food not consumed (residue) collected and weighed each day. Trials were conducted at Long Grass Nature Reserve in Queensland, Australia from 9-29 January 2009. Both eastern grey kangaroos and red-necked wallabies relocated a minimum of 100 m away from the food station treated with lion odors on the first day of the trial. As a result of this spatial shift, more food was consumed at the control food stations than at any food station treated with predator odors (regardless of predator). In particular, eastern grey kangaroos never fed from a single predator-odor food station. An increase in vigilance behaviors was observed for both macropod species, and red-necked wallabies were more likely to exhibit vigilance behaviors than feeding behaviors at predator odor food stations. There was no difference in food residue between any predator odors and these food stations were only visited on the first day of the study. Use of predator fecal odors may repel macropods from highly palatable food sources, and predator fecal odors also may be useful for macropod relocation

    Wildlife conservation management on inhabited islands

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    Islands are critically important sites for the conservation and restoration of biodiversity because they are home to a disproportionate amount of the world’s biodiversity and are often free from many of the causes of species decline found on mainlands (Myers et al. 2000; Courchamp et al. 2014; Tershy et al. 2015). Although there have been substantial conservation gains on small uninhabited islands (Jones et al. 2016; Moro et al. 2018), islands of substantial size are typically inhabited. Wildlife conservation management on inhabited islands thus entails both ecological and socio-economic dimensions. The social sciences have much experience to bring to the challenge of wildlife conservation management (Bennett et al. 2017), and inhabited islands may be a test case for applying them. Although human communities on islands tend to have unique characteristics as a result of their isolation and the nature of their existence, they also tend to be more engaged with their environment through their livelihoods. Management of conservation conflict on such islands is as much about ecology as it is sociology, psychology and stakeholder engagement and management (Van der Werff et al. 2013; Redpath et al. 2015). Indeed, recent extinctions of three faunal species in Australia have been as much about human processes as they have ecological processes (Woinarski et al. 2017). This special issue brings together selected works presented at a symposium of the Australasian Wildlife Management Society (AWMS) Conference held in Brisbane, December 2014. It focuses on the role of humans on islands, and therefore the importance of human dimensions in wildlife management. Wildlife management on islands is explored through this lens for a number of Australasian and international case studies. Crandall et al. (2018) first outline the diverse toolkit the social sciences bring to bear on these challenges. Russell et al. (2018) then highlight the importance of social impact assessment in conjunction with environmental impact assessment, and the important application it is likely to have in the future for wildlife management on inhabited islands. Several additional case studies are then presented
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