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João Guerreiro

Bio: João Guerreiro is an academic researcher from Carnegie Mellon University. The author has contributed to research in topics: Personally identifiable information & Touchscreen. The author has an hindex of 16, co-authored 52 publications receiving 775 citations. Previous affiliations of João Guerreiro include INESC-ID & Technical University of Lisbon.

Papers published on a yearly basis

Papers
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Proceedings ArticleDOI
02 May 2019
TL;DR: An assistive suitcase system for supporting blind people when walking through crowded environments using pre-emptive sound notifications, BBeep, and it is observed that the proposed system significantly reduces the number of imminent collisions.
Abstract: We present an assistive suitcase system, BBeep, for supporting blind people when walking through crowded environments. BBeep uses pre-emptive sound notifications to help clear a path by alerting both the user and nearby pedestrians about the potential risk of collision. BBeep triggers notifications by tracking pedestrians, predicting their future position in real-time, and provides sound notifications only when it anticipates a future collision. We investigate how different types and timings of sound affect nearby pedestrian behavior. In our experiments, we found that sound emission timing has a significant impact on nearby pedestrian trajectories when compared to different sound types. Based on these findings, we performed a real-world user study at an international airport, where blind participants navigated with the suitcase in crowded areas. We observed that the proposed system significantly reduces the number of imminent collisions.

100 citations

Journal ArticleDOI
01 May 2012
TL;DR: Current evidence suggests that human translation of these animal investigations are warranted, as are further studies, to better understand the precise cause-and-effect relationship between flavonoid intake and cognitive outputs.
Abstract: There is considerable interest in the potential of a group of dietary-derived phytochemicals known as flavonoids in modulating neuronal function and thereby influencing memory, learning and cognitive function. The present review begins by detailing the molecular events that underlie the acquisition and consolidation of new memories in the brain in order to provide a critical background to understanding the impact of flavonoid-rich diets or pure flavonoids on memory. Data suggests that despite limited brain bioavailability, dietary supplementation with flavonoid-rich foods, such as blueberry, green tea and Ginkgo biloba lead to significant reversals of age-related deficits on spatial memory and learning. Furthermore, animal and cellular studies suggest that the mechanisms underpinning their ability to induce improvements in memory are linked to the potential of absorbed flavonoids and their metabolites to interact with and modulate critical signalling pathways, transcription factors and gene and/or protein expression which control memory and learning processes in the hippocampus; the brain structure where spatial learning occurs. Overall, current evidence suggests that human translation of these animal investigations are warranted, as are further studies, to better understand the precise cause-and-effect relationship between flavonoid intake and cognitive outputs.

96 citations

Proceedings ArticleDOI
24 Oct 2019
TL;DR: The design of CaBot (Carry-on roBot), an autonomous suitcase-shaped navigation robot that is able to guide blind users to a destination while avoiding obstacles on their path is presented.
Abstract: Navigation robots have the potential to overcome some of the limitations of traditional navigation aids for blind people, specially in unfamiliar environments. In this paper, we present the design of CaBot (Carry-on roBot), an autonomous suitcase-shaped navigation robot that is able to guide blind users to a destination while avoiding obstacles on their path. We conducted a user study where ten blind users evaluated specific functionalities of CaBot, such as a vibro-tactile handle to convey directional feedback; experimented to find their comfortable walking speed; and performed navigation tasks to provide feedback about their overall experience. We found that CaBot's performance highly exceeded users' expectations, who often compared it to navigating with a guide dog or sighted guide. Users' high confidence, sense of safety, and trust on CaBot poses autonomous navigation robots as a promising solution to increase the mobility and independence of blind people, in particular in unfamiliar environments.

89 citations

Proceedings ArticleDOI
19 Oct 2017
TL;DR: Two smartphone-based virtual navigation interfaces are presented: VirtualLeap, which allows the user to jump through a sequence of street intersection labels, turn-by-turn instructions and POIs along the route; and VirtualWalk, which simulates variable speed step-by -step walking using audio effects, whilst conveying similar route information.
Abstract: When preparing to visit new locations, sighted people often look at maps to build an a priori mental representation of the environment as a sequence of step-by-step actions and points of interest (POIs), e.g., turn right after the coffee shop. Based on this observation, we would like to understand if building the same type of sequential representation, prior to navigating in a new location, is helpful for people with visual impairments (VI). In particular, our goal is to understand how the simultaneous interplay between turn-by-turn navigation instructions and the relevant POIs in the route can aid the creation of a memorable sequential representation of the world. To this end, we present two smartphone-based virtual navigation interfaces: VirtualLeap, which allows the user to jump through a sequence of street intersection labels, turn-by-turn instructions and POIs along the route; and VirtualWalk, which simulates variable speed step-by-step walking using audio effects, whilst conveying similar route information. In a user study with 14 VI participants, most were able to create and maintain an accurate mental representation of both the sequential structure of the route and the approximate locations of the POIs. While both virtual navigation modalities resulted in similar spatial understanding, results suggests that each method is useful in different interaction contexts.

82 citations

Proceedings ArticleDOI
02 May 2019
TL;DR: This study presents the first systematic evaluation posing BLE technology as a strong approach to increase the independence of visually impaired people in airports and finds that despite the challenging environment participants were able to complete their itinerary independently.
Abstract: People with visual impairments often have to rely on the assistance of sighted guides in airports, which prevents them from having an independent travel experience. In order to learn about their perspectives on current airport accessibility, we conducted two focus groups that discussed their needs and experiences in-depth, as well as the potential role of assistive technologies. We found that independent navigation is a main challenge and severely impacts their overall experience. As a result, we equipped an airport with a Bluetooth Low Energy (BLE) beacon-based navigation system and performed a real-world study where users navigated routes relevant for their travel experience. We found that despite the challenging environment participants were able to complete their itinerary independently, presenting none to few navigation errors and reasonable timings. This study presents the first systematic evaluation posing BLE technology as a strong approach to increase the independence of visually impaired people in airports.

58 citations


Cited by
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Journal ArticleDOI
TL;DR: How this extended communication system might influence a broad spectrum of diseases, including irritable bowel syndrome, psychiatric disorders and demyelinating conditions such as multiple sclerosis is reviewed.
Abstract: A bidirectional neurohumoral communication system known as the gut–brain axis integrates the activities of the intestine and the brain. In this Progress article, Collins, Surette and Bercik describe recent evidence suggesting that the intestinal microbiota is intimately connected with the gut–brain axis and can influence animal behaviour, development and health. The intestinal microbiota consists of a vast bacterial community that resides primarily in the lower gut and lives in a symbiotic relationship with the host. A bidirectional neurohumoral communication system, known as the gut–brain axis, integrates the host gut and brain activities. Here, we describe the recent advances in our understanding of how the intestinal microbiota communicates with the brain via this axis to influence brain development and behaviour. We also review how this extended communication system might influence a broad spectrum of diseases, including irritable bowel syndrome, psychiatric disorders and demyelinating conditions such as multiple sclerosis.

1,218 citations

01 Jan 2010
TL;DR: In this article, the authors examined the patterns and effects of departmental oversight across 28 ministries in Estonia, Hungary, Poland and Slovenia in relation to transposition planning, legal review and monitoring of deadlines.
Abstract: The extent to which member states transpose EU directives in a timely fashion is often argued to be strongly associated with the general effectiveness of national bureaucracies. But what kind of institutional solutions ensure better performance? This paper examines the patterns and effects of departmental oversight across 28 ministries in Estonia, Hungary, Poland and Slovenia. In mapping the strength of oversight, it relies on around 90 structured interviews regarding the rules-in-use on transposition planning, legal review and monitoring of deadlines. The analysis of the impact of departmental oversight is based on an original dataset of over 300 directives with transposition deadlines between January 2005 and December 2008.

858 citations

Journal ArticleDOI
TL;DR: The aim of this body of work is to investigate and review the current literature on anthocyanins, and particularly their pharmacokinetics and any health-promoting properties, in order to summarize existing knowledge and highlight any aspects that require further study and analysis.
Abstract: Anthocyanins belong to the flavonoid group of polyphenolic compounds, which are responsible for the red and blue colors of plant organs such as fruits, flowers, and leaves Due to their frequent presence in plants, particularly berry fruits, vegetables, and grapes, they are key components of the human diet Interest in anthocyanins has increased widely during the past decade Numerous studies have suggested that anthocyanins have a wide range of health-promoting properties These compounds are therefore considered to be a functional food factor, which may have important implications in the prevention of chronic diseases The aim of this body of work is to investigate and review the current literature on anthocyanins, and particularly their pharmacokinetics and any health-promoting properties, in order to summarize existing knowledge and highlight any aspects that require further study and analysis

463 citations

Journal Article
TL;DR: In this paper, the authors present a short bibliography on AI and the arts, which is presented in four sections: General Arguments, Proposals, and Approaches (31 references), Artificial Intelligence in Music (124 references); Artificial AI in Literature and the Performing Arts (13 references), and Artificial Intelligence and Visual Art (57 references).
Abstract: The title of this technical report says almost everything: this is indeed \"a short bibliography on AI and the arts\". It is presented in four sections: General Arguments, Proposals, and Approaches (31 references); Artificial Intelligence in Music (124 references); Artificial Intelligence in Literature and the Performing Arts (13 references), and Artificial Intelligence and Visual Art (57 references). About a quarter of these have short abstracts. Creating a bibliography can be a monumental task, and this bibliography should be viewed as a good and useful start, though it is by no means complete. For comparison, consider the 4,585-entry bibliography Computer Applications in Music by Deta Davis (A-REditions). No direct comparison is intended (or possible), but my point is that many more papers are likely to exist. As a rough check, I looked for several pre-1990 AI and Music articles and books (including my own, of course) in the bibliography. Out of five papers from well-known sources, only one was listed. On the other hand, I discovered a number of papers in this report that were unknown to me, so I am grateful to have a new source of references. In their introduction, the authors acknowledge the need for more references and even offer.a cup of coffee in reward for each new one. I will be sending a number of contributions, so the next time anyone is in Vienna, the coffee is on me. I hope the authors will continue to collect abstracts and publish an updated report in the future.

356 citations

Journal ArticleDOI
TL;DR: The aim of this review is to cover the current literature on anthocyanins, their biological in vitro and in vivo effects and their potential therapeutic applications, as well as their bioavailability and pharmacokinetics, all of which are essential to gain a better understanding of their biological effectiveness and potential toxicity.
Abstract: Anthocyanins are naturally occurring molecules belonging to the flavonoid class characterized by the presence of chromophores. Apart from their well-known antioxidant activity, they show a wide variety of health-promoting properties for human health, ranging from cytoprotective, antimicrobial and antitumour activities to neuroprotective, anti-obesity and lipidomic potential, properties for which anthocyanins have been prescribed as medicines in several countries for thousands of years. Despite this, these phytochemicals have received less attention than other flavonoids, and there is still a gap in the literature, particularly regarding pharmacological and toxicological aspects. Moreover, epidemiological evidence suggests a direct correlation between anthocyanin intake and a lower incidence of chronic and degenerative diseases. In light of this, the aim of this review is to cover the current literature on anthocyanins, their biological in vitro and in vivo effects and their potential therapeutic applications, as well as their bioavailability and pharmacokinetics, all of which are essential to gain a better understanding of their biological effectiveness and potential toxicity. Copyright © 2016 John Wiley & Sons, Ltd.

261 citations