8 research outputs found

    Data quality influences the predicted distribution and habitat of four southern-hemisphere albatross species

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    Few studies have assessed the influence of data quality on the predicted probability of occurrence and preferred habitat of marine predators. We compared results from four species distribution models (SDMs) for four southern-hemisphere albatross species, Buller’s (Thalassarche bulleri), Campbell (T. impavida), grey-headed (T. chrysostoma), and white-capped (T. steadi), based on datasets of differing quality, ranging from no location data to twice-daily locations of individual birds collected by geolocation devices. Two relative environmental suitability (RES) models were fit using minimum and maximum preferred and absolute values for each environmental variable based on (1) monthly 50% kernel density contours and background environmental data, and (2) primary literature or expert opinion. Additionally, two boosted regression tree (BRT) models were fit using (1) opportunistic sightings data, and (2) geolocation data from bird-borne electronic tags. Using model-specific threshold values, habitat was quantified for each species and model. Model variables included distance from land, bathymetry, sea surface temperature, and chlorophyll-a concentration. Results from both RES models and the BRT model fit with opportunistic sightings were compared to those from the BRT model fit using geolocation data to assess the influence of data quality on predicted occupancy and habitat. For all species, BRT models outperformed RES models. BRT models offer a predictive advantage over RES models by being able to identify relevant variables, incorporate environmental interactions, and provide spatially explicit estimates of model uncertainty. RES models resulted in larger, less refined areas of predicted habitat for all species. Our study highlights the importance of data quality in predicting the distribution and habitat of albatrosses and emphasises the need to consider the pros and cons associated with different levels of data quality when using SDMs to inform management decisions. Furthermore, we examine the overlap in preferred habitat predicted by each SDM with fishing effort. We discuss the influence of data quality on predicting the wide-scale distributions of pelagic seabirds and how these impacts could result in different protection measures

    [In Press] Pushing through the barriers : peer advice to increase physical activity and reduce dementia risk from participants in a massive open online alzheimer's focused course

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    BACKGROUND: Engagement in physical activity is associated with reduced dementia risk but insufficient physical activity is a global trend. OBJECTIVES: We aimed to explore what advice might be offered to others to increase physical activity and to identify enablers and barriers to physical activity for adults interested in dementia prevention and participating in a massive open online course. PARTICIPANTS: Two thousand, one hundred and thirty-two participants contributed to an online discussion forum. DESIGN: Analysis was conducted using Topic modelling analysis followed by thematic analysis. RESULTS: The themes generated from the discussion posts included time constraints, poor health and lack of motivation as barriers to physical activity, and social interaction, incidental activities, and dog ownership as enablers. Peer advice was frequently suggested around scheduling physical activity into the day and joining a friend or organised activity. CONCLUSION: This online discussion forum uniquely captured ideas from a large, diverse group of participants. Future research may benefit from further examining the role of discussion forums and peer advice in dementia risk reduction initiatives

    The BDNF Val66Met Polymorphism Moderates the Effect of Cognitive Reserve on 36-month Cognitive Change in Healthy Older Adults

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    Introduction: Cognitive reserve (CR) and BDNF Val66Met are independently associated with the rate of cognitive decline in preclinical Alzheimer\u27s disease. This study was designed to investigate the interactive effects of these variables on 36-month cognitive change in cognitively intact older adults. Methods: Data for this investigation were obtained from 445 community-residing participants of the Tasmanian Healthy Brain Project, who underwent genetic screening and annual assessment of neuropsychological, health, and psychosocial function. Results: Our main result was that BDNF Val66Met moderated the relationship between baseline CR and change in executive function performance, in that CR-related differences in function decreased across the follow-up period in BDNF Val homozygotes, but became more pronounced in BDNF Met carriers. Similar effects were not observed within the other memory- and language-related cognitive domains. Discussion: Inheritance of BDNF Met may be associated with a detrimental influence on the relationship between CR and cognitive change in cognitively intact older adults, but this effect may be restricted to the executive function domain

    Factors influencing the habitat use of sympatric albatrosses from Macquarie Island, Australia

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    Differences in habitat use of sympatric species are influenced by variability in functional morphology and life history trade-offs and are expected to shape species resilience to environmental change. To determine differences in year-round habitat use and gain insight into how morphological and life history traits influence foraging of an albatross community from subantarctic Macquarie Island, Australia (54.6°S, 158.9°E), we quantified the physical features associated with high residence time for 10 black-browed Thalassarche melanophris; 10 grey-headed T. chrysostoma; 15 light-mantled Phoebetria palpebrata; and 12 wandering albatrosses Diomedea exulans tracked in 1994-2009. Overlap among the 4 species was greatest close to the island during the breeding season, extending north into the Tasman Sea. Nevertheless, black-browed albatrosses ranged more locally than the other species, perhaps because they have a shorter breeding cycle and morphological traits that result in less efficient flight and greater capacity to outcompete other species for prey. Nonbreeding albatrosses showed high variability in habitat use across wide ocean expanses, but all used productive frontal regions and mesoscale eddies. Increased residence times during the breeding and nonbreeding periods were associated with moderate wind speeds for all species (excluding breeding black-browed albatrosses), indicating that birds used areas where aerodynamic performance was enhanced. Given patterns in residence time at sea, and the functional and life history adaptations of each species, we suggest that black-browed albatrosses breeding on Macquarie Island will be more vulnerable to expected future climate-driven changes to wind patterns in the Southern Ocean, and potential latitudinal shifts in the Subantarctic Fron

    Estimating presymptomatic episodic memory impairment using simple hand movement tests: A cross‐sectional study of a large sample of older adults

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    Abstract:-  INTRODUCTION: Finding low-cost methods to detect early-stage Alzheimer's disease (AD) is a research priority for neuroprotective drug development. Presymptomatic Alzheimer's is associated with gait impairment but hand motor tests, which are more accessible, have hardly been investigated. This study evaluated how home-based Tasmanian (TAS) Test keyboard tapping tests predict episodic memory performance. METHODS: 1169 community participants (65.8 ± 7.4 years old; 73% female) without cognitive symptoms completed online single-key and alternate-key tapping tests and episodic memory, working memory, and executive function cognitive tests. RESULTS: All single-key (R2adj = 8.8%, ΔAIC = 5.2) and alternate-key (R2adj = 9.1%, ΔAIC = 8.8) motor features predicted episodic memory performance relative to demographic and mood confounders only (R2adj = 8.1%). No tapping features improved estimation of working memory. DISCUSSION: Brief self-administered online hand movement tests predict asymptomatic episodic memory impairment. This provides a potential low-cost home-based method for stratification of enriched cohorts. Highlights: We devised two brief online keyboard tapping tests to assess hand motor function. 1169 cognitively asymptomatic adults completed motor- and cognitive tests online. Impaired hand motor function predicted reduced episodic memory performance. This brief self-administered test may aid stratification of community cohorts.</p

    Geolocator tagging links distributions in the non-breeding season to population genetic structure in a sentinel North Pacific seabird.

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    We tested the hypothesis that segregation in wintering areas is associated with population differentiation in a sentinel North Pacific seabird, the rhinoceros auklet (Cerorhinca monocerata). We collected tissue samples for genetic analyses on five breeding colonies in the western Pacific Ocean (Japan) and on 13 colonies in the eastern Pacific Ocean (California to Alaska), and deployed light-level geolocator tags on 12 eastern Pacific colonies to delineate wintering areas. Geolocator tags were deployed previously on one colony in Japan. There was strong genetic differentiation between populations in the eastern vs. western Pacific Ocean, likely due to two factors. First, glaciation over the North Pacific in the late Pleistocene might have forced a southward range shift that historically isolated the eastern and western populations. And second, deep-ocean habitat along the northern continental shelf appears to act as a barrier to movement; abundant on both sides of the North Pacific, the rhinoceros auklet is virtually absent as a breeder in the Aleutian Islands and Bering Sea, and no tagged birds crossed the North Pacific in the non-breeding season. While genetic differentiation was strongest between the eastern vs. western Pacific, there was also extensive differentiation within both regional groups. In pairwise comparisons among the eastern Pacific colonies, the standardized measure of genetic differentiation (FꞌST) was negatively correlated with the extent of spatial overlap in wintering areas. That result supports the hypothesis that segregation in the non-breeding season is linked to genetic structure. Philopatry and a neritic foraging habit probably also contribute to the structuring. Widely distributed, vulnerable to anthropogenic stressors, and exhibiting extensive genetic structure, the rhinoceros auklet is fully indicative of the scope of the conservation challenges posed by seabirds
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