61 research outputs found
Exploring efficacy in personal constraint negotiation: an ethnography of mountaineering tourists
Limited work has explored the relationship between efficacy and personal constraint negotiation for adventure tourists, yet efficacy is pivotal to successful activity participation as it influences people’s perceived ability to cope with constraints, and their decision to use negotiation strategies. This paper explores these themes with participants of a commercially organised mountaineering expedition. Phenomenology-based ethnography was adopted to appreciate the social and cultural mountaineering setting from an emic perspective. Ethnography is already being used to understand adventure participation, yet there is considerable scope to employ it further through researchers immersing themselves into the experience. The findings capture the interaction between the ethnographer and the group members, and provide an embodied account using their lived experiences. Findings reveal that personal mountaineering skills, personal fitness, altitude sickness and fatigue were the four key types of personal constraint. Self-efficacy, negotiation-efficacy and other factors, such as hardiness and motivation, influenced the effectiveness of negotiation strategies. Training, rest days, personal health, and positive self-talk were negotiation strategies. A conceptual model illustrates these results and demonstrates the interplay between efficacy and the personal constraint negotiation journey for led mountaineers
The Effects of Two Types of Sleep Deprivation on Visual Working Memory Capacity and Filtering Efficiency
Sleep deprivation has adverse consequences for a variety of cognitive functions. The exact effects of sleep deprivation, though, are dependent upon the cognitive process examined. Within working memory, for example, some component processes are more vulnerable to sleep deprivation than others. Additionally, the differential impacts on cognition of different types of sleep deprivation have not been well studied. The aim of this study was to examine the effects of one night of total sleep deprivation and 4 nights of partial sleep deprivation (4 hours in bed/night) on two components of visual working memory: capacity and filtering efficiency. Forty-four healthy young adults were randomly assigned to one of the two sleep deprivation conditions. All participants were studied: 1) in a well-rested condition (following 6 nights of 9 hours in bed/night); and 2) following sleep deprivation, in a counter-balanced order. Visual working memory testing consisted of two related tasks. The first measured visual working memory capacity and the second measured the ability to ignore distractor stimuli in a visual scene (filtering efficiency). Results showed neither type of sleep deprivation reduced visual working memory capacity. Partial sleep deprivation also generally did not change filtering efficiency. Total sleep deprivation, on the other hand, did impair performance in the filtering task. These results suggest components of visual working memory are differentially vulnerable to the effects of sleep deprivation, and different types of sleep deprivation impact visual working memory to different degrees. Such findings have implications for operational settings where individuals may need to perform with inadequate sleep and whose jobs involve receiving an array of visual information and discriminating the relevant from the irrelevant prior to making decisions or taking actions (e.g., baggage screeners, air traffic controllers, military personnel, health care providers)
Actioning atrial fibrillation identified by ambulance services in England: a qualitative exploration
Attenuation of Responses of Waterbirds to Repeat Drone Surveys Involving a Sequence of Altitudes and Drone Types: A Case Study
Remotely piloted aircraft systems (RPAS, or ‘drones’ hereafter) have potential for surveying waterbird species and habitats, but there is a risk that the disturbance from drones could compromise count accuracy and bird welfare. We examined the response of 16 waterbird species to repeated up-and-back overhead drone flights (n = 50 flights) at multiple flight heights (80, 60, 40 and 20 m) using three common drone platforms (DJI Matrice 300, DJI Mavic 2 Enterprise Advanced and DJI Phantom 4). A ground observer scored the species’ responses to overhead drone flights, which ranged from no response (no change to initial behavior), vigilance (head turning and tracking), movement within the site (swimming, diving, flight into or on the water) and substantial flight resulting in departure from the pond (fleeing). A total of 280 waterbird encounters with overhead drones were observed. The most common response across all flights was no response (70.7%), followed by vigilance (27.5%), whereas more intense responses were comparatively rare (1.8%). The responses were of higher intensity during earlier overhead drone flights, before moderating substantially during later flights. Thus, our case study provides the first unambiguous evidence of the attenuation of responses of bird species to drones
Alcohol tax reform: now is the time
TO THE EDITOR: Alcohol misuse is one of the leading causes of preventable death, illness and injury in Australia because too many Australians drink too much alcohol too often. The evidence is clear on what are the most effective strategies to curb alcohol misuse at a population level. By far the most effective of these is increasing the price of alcohol by increasing alcohol taxes
An Azobenzene Photoswitch Sheds Light on Turn Nucleation in Amyloid-β Self-Assembly
Amyloid-β (Aβ) self-assembly into cross-β
amyloid
fibrils is implicated in a causative role in Alzheimer’s disease
pathology. Uncertainties persist regarding the mechanisms of amyloid
self-assembly and the role of metastable prefibrillar aggregates.
Aβ fibrils feature a sheet-turn-sheet motif in the constituent
β-strands; as such, turn nucleation has been proposed as a rate-limiting
step in the self-assembly pathway. Herein, we report the use of an
azobenzene β-hairpin mimetic to study the role turn nucleation
plays on Aβ self-assembly. [3-(3-Aminomethyl)Âphenylazo]Âphenylacetic
acid (AMPP) was incorporated into the putative turn region of Aβ42
to elicit temporal control over Aβ42 turn nucleation; it was
hypothesized that self-assembly would be favored in the <i>cis</i>-AMPP conformation if β-hairpin formation occurs during Aβ
self-assembly and that the <i>trans</i>-AMPP conformer would
display attenuated fibrillization propensity. It was unexpectedly
observed that the <i>trans</i>-AMPP Aβ42 conformer
forms fibrillar constructs that are similar in almost all characteristics,
including cytotoxicity, to wild-type Aβ42. Conversely, the <i>cis</i>-AMPP Aβ42 congeners formed nonfibrillar, amorphous
aggregates that exhibited no cytotoxicity. Additionally, <i>cis</i>-<i>trans</i> photoisomerization resulted in rapid formation
of native-like amyloid fibrils and <i>trans–cis</i> conversion in the fibril state reduced the population of native-like
fibrils. Thus, temporal photocontrol over Aβ turn conformation
provides significant insight into Aβ self-assembly. Specifically,
Aβ mutants that adopt stable β-turns form aggregate structures
that are unable to enter folding pathways leading to cross-β
fibrils and cytotoxic prefibrillar intermediates
The genetic population structure of wild western lowland gorillas (Gorilla gorilla gorilla) living in continuous rain forest
To understand the evolutionary histories and conservation potential of wild animal species it is useful to assess whether taxa are genetically structured into different populations and identify the underlying factors responsible for any clustering. Landscape features such as rivers may influence genetic population structure, and analysis of structure by sex can further reveal effects of sex-specific dispersal. Using microsatellite genotypes obtained from noninvasively collected fecal samples we investigated the population structure of 261 western lowland gorillas (WLGs) (Gorilla gorilla gorilla) from seven locations spanning an approximately 37,000km(2) region of mainly continuous rain forest within Central African Republic (CAR), Republic of Congo and Cameroon. We found our sample to consist of two or three significantly differentiated clusters. The boundaries of the clusters coincided with courses of major rivers. Moreover, geographic distance detoured around rivers better-explained variation in genetic distance than straight line distance. Together these results suggest that major rivers in our study area play an important role in directing WLG gene flow. The number of clusters did not change when males and females were analyzed separately, indicating a lack of greater philopatry in WLG females than males at this scale
The genetic population structure of wild western lowland gorillas (Gorilla gorilla gorilla) living in continuous rain forest
To understand the evolutionary histories and conservation potential of wild animal species it is useful to assess whether taxa are genetically structured into different populations and identify the underlying factors responsible for any clustering. Landscape features such as rivers may influence genetic population structure, and analysis of structure by sex can further reveal effects of sex-specific dispersal. Using microsatellite genotypes obtained from noninvasively collected fecal samples we investigated the population structure of 261 western lowland gorillas (WLGs) (Gorilla gorilla gorilla) from seven locations spanning an approximately 37,000 km(2) region of mainly continuous rain forest within Central African Republic (CAR), Republic of Congo and Cameroon. We found our sample to consist of two or three significantly differentiated clusters. The boundaries of the clusters coincided with courses of major rivers. Moreover, geographic distance detoured around rivers better-explained variation in genetic distance than straight line distance. Together these results suggest that major rivers in our study area play an important role in directing WLG gene flow. The number of clusters did not change when males and females were analyzed separately, indicating a lack of greater philopatry in WLG females than males at this scale
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