Age-related differences in visual encoding and response strategies contribute to spatial memory deficits.

Successful navigation requires memorising and recognising the locations of objects across different perspectives. Although these abilities rely on hippocampal functioning, which is susceptible to degeneration in older adults, little is known about the effects of ageing on encoding and response strategies that are used to recognise spatial configurations. To investigate this, we asked young and older participants to encode the locations of objects in a virtual room shown as a picture on a computer screen. Participants were then shown a second picture of the same room taken from the same (0°) or a different perspective (45° or 135°) and had to judge whether the objects occupied the same or different locations. Overall, older adults had greater difficulty with the task than younger adults although the introduction of a perspective shift between encoding and testing impaired performance in both age groups. Diffusion modelling revealed that older adults adopted a more conservative response strategy, while the analysis of gaze patterns showed an age-related shift in visual-encoding strategies with older adults attending to more information when memorising the positions of objects in space. Overall, results suggest that ageing is associated with declines in spatial processing abilities, with older individuals shifting towards a more conservative decision style and relying more on encoding target object positions using room-based cues compared to younger adults, who focus more on encoding the spatial relationships among object clusters

Age-related changes in memory for object locations across different perspectives.

One important aspect of spatial cognition is the ability to recognize and remember spatial locations across different viewpoints. Previous research has suggested that those abilities decline in older adults. The aim of the current PhD project is to develop a clearer understanding of what may be contributing to age-related declines in recognising object locations from different perspectives. Specifically, focusing on how ageing effects encoding strategies that are used to memorize spatial configurations and the precision with which object/landmark locations are remembered. In Chapter 2, gaze behaviour was recorded during a task in which young and older adults judged whether previously encoded objects have remained in the same position or were displaced following perspective shifts. Ageing was associated with declines in spatial processing abilities. Additionally, older adults displayed a more conservative decision style and relied more on encoding object positions using room-based cues compared to young adults, who focused on the spatial relations among the to-be remembered objects during encoding. In Chapter 3, age-related differences in encoding strategies were further investigated using a modified version of the task used in Chapter 2 in which the availability and utility of the room- based cues was manipulated. Performance accuracy was similar across both age groups, yet, older adults displayed a greater preference towards a more categorical encoding strategy in which they formed spatial relations between objects and room-based cues. In the remaining chapters the focus shifted to investigating the precision with which object locations are remembered across different perspectives. In Chapter 4 participants memorized the position of an object in a virtual room and then judged from a different perspective, whether the object has moved to the left or to the right. Results revealed that participants exhibited a systematic bias in their responses that was termed the reversed congruency effect. Specifically, participants performed worse when the camera and the object moved in the same direction than when they moved in opposite directions. In Experiment 2, it was shown that the presence of additional objects in the environment reduced the reversed congruency effect whilst in Experiment 3 the reversed congruency effect was greater in older adults, suggesting that the quality of spatial memory and perspective-taking abilities are critical in mediating the reversed congruency effect. In Chapter 5, a novel task was used to investigate the systematic bias reported in Chapter 4. In this task participants encoded the position of an object in a virtual room and then estimated the object’s position following a perspective shift. In addition, memory load was manipulated. Overall, participants systematically overestimated the position of the object in the direction of the perspective shift. This bias was present in both memory and perception conditions. In Chapter 6, these results were replicated in an online-based version of the study. Lastly in Chapter 7, the influence of camera translations and camera rotations on the perspective shift related bias was decoupled. Additionally, the study investigated whether adding more information into the scene would reduce the bias and if there are age-related differences in the precision of object location estimates and the tendency to display the bias related to perspective shift. Overall, camera translations led to a greater systematic bias than camera rotations. Furthermore, the use of additional spatial information improved the precision with which object locations were estimated and reduced the bias associated with camera translation. Finally, although older adults were as precise as younger participants when estimating object locations, they benefited less from additional spatial information and their responses were more biased in the direction of camera translations. Overall, by combining eye-tracking and diffusion modelling the current thesis shows that ageing is associated with changes in the type of information that is used to encode object locations across different perspectives. Additionally, ageing was found to be particularly associated with impairments in the formation of fine-grained spatial representations. Furthermore, a novel bias in spatial memory across different perspectives has been identified. It is proposed that the perspective shift related bias is driven by uncertainty about object position following a perspective shift that leads participants to rely on an egocentric anchor when estimating the location of an object

Challenges in introduction of artificial intelligence in medical practice – a review of clinical trials concerning adaptation of artificial intelligence in medicine

An interest in Artificial Intelligence [AI] as science is growing in the last years. It has become gradually more used in the medicine. Methodology of development and testing of AI algorithms is generally well established. Use of AI in medicine requires elaboration of standards of its validation in clinical settings. This paper is a review of literature concerning clinical trials on AI adaptation in medicin

Electrogasdynamic control of separated flow: a feasibility study.

http://archive.org/details/electrogasdynami00seg

Detection of human finger joints in ultrasound images: structure and optimization

Synovitis is the inflammation of a synovial membrane surrounding a joint. Its assessment is an important step in the diagnosis and treatment of rheumatoid arthritis. Joint detection is the first stage of an automated method of assessment of a degree of synovitis, from an Ultrasound (USG) image of a finger joint and its surrounding area. A joint detector consists of three parts: image preprocessing, feature extraction, and classification. Each part contains adjustable parameters that must be set experimentally to ensure the proper operation of the detector. Both the structure of a joint detector and a procedure for finding a near-optimal configuration of the adjustable parameters are described. The optimization process is based on two evaluation measures: Area Under the Receiver Operating Characteristic Curve (AUC) and False Positive Count (FPC). The optimization process decreases the number of pictures with multiple detections, which was the main point of works presented in this paper. This was achieved by increasing the number of components of the homogeneous mixed-SURF descriptor which has the greatest influence on the final result. Non-SURF descriptors achieve poorer classification results. Our research led to the creation of a better joint detector which could positively influence the final results of inflammation level classification

Opera and poison : a secret and enjoyable approach to teaching and learning chemistry

The storyline of operas, with historical or fictional characters, often include potions and poisons. This has prompted a study of the chemistry behind some operatic plots. The results were originally presented as a lecture given at the University of Minho in Portugal, within the context of the International Year of Chemistry. The same lecture was subsequently repeated at other universities as an invited lecture for science students and in public theaters for wider audiences. The lecture included a multimedia and interactive content that allowed the audience to listen to arias and to watch video clips with selected scenes extracted from operas. The present article, based on the lecture, demonstrates how chemistry and opera can be related and may also serve as a source of motivation and inspiration for chemistry teachers looking for alternative pedagogical approaches. Moreover, the lecture constitutes a vehicle that transports chemistry knowledge to wider audiences through examples of everyday molecules, with particular emphasis on natural products.The author is pleased to express his gratitude to Jorge Calado and Michael John Smith for useful discussions. The author also thanks the reviewers of the manuscript for their helpful comments and suggestions. Thanks are due to the Foundation for Science and Technology (FCT,Portugal), QREN and FEDER/EU for financial support through the research centers, CQ/UM PEst-C/QUI/UI0686/2011. Ciencia Viva, Portugal, is also acknowledged for financial support of the activities organized by the University of Minho during the International Year of Chemistry. The author also expresses his gratitude to Ana Paula Ferreira and Andre Cunha Leal from RTP Antena 2 who contributed immensely to the popularization of the lecture on which this paper is based on

A review of blisters caused by wound dressing components: can they impede post-operative rehabilitation and discharge?

This review highlights that some wound dressings can be the cause of blistering. It also presents the mechanisms by which blisters may be caused by poor choice of dressings. The subsequent impact of the blisters on preventing patient mobility - and hence rehabilitation in terms of physiotherapy – are also identified. The possibility that the clinical sequelae (e.g. delayed wound healing, restricted joint range of motion (ROM), muscle atrophy and increased risk of deep vein thrombosis (DVT)) resulting from this might have a significant and deleterious impact upon patient-related outcomes is discussed. Strategies for the treatment and prevention of blisters are proposed, based upon current knowledge and expertise. The criticality of the wound care specialist and the physiotherapist working together to overcome these challenges and enhance patient care, are underlined. This article is a review of the relevant literature combined with opinions based upon experience and knowledge of the authors

Mindfulness-based stress reduction as supportive therapy in cancer care: systematic review

Aim: This paper reports a systematic review and critical appraisal of the evidence on the effectiveness of Mindfulness-Based Stress Reduction for cancer supportive care. Background: The experience of cancer can have a negative impact on both psychological and physical health and on quality of life. Mindfulness-Based Stress Reduction is a therapy package that has been used with patients with a variety of conditions. In order to draw conclusions on its effectiveness for cancer patients, the evidence requires systematic assessment. Methods: A comprehensive search of major biomedical and specialist complementary medicine databases was conducted. Additionally, efforts were made to identify unpublished and ongoing research. Relevant research was categorized by study type and appraised according to study design. Clinical commentaries were obtained for each study and included in the review. Results: Three randomized controlled clinical trials and seven uncontrolled clinical trials were found. A lack of relevant qualitative research studies was identified. Studies report positive results, including improvements in mood, sleep quality and reductions in stress. A dose-response effect has been observed between practice of Mindfulness-Based Stress Reduction and improved outcome. A number of methodological limitations were identified. Modifications to the traditional Mindfulness-Based Stress Reduction programme make comparison between studies difficult and a lack of controlled studies precludes any firm conclusion on efficacy. Conclusion: Mindfulness-Based Stress Reduction has potential as a clinically valuable self-administered intervention for cancer patients. Further research into its efficacy, feasibility and safety for cancer patients in the nursing context is recommended