In-home and remote use of robotic body surrogates by people with profound motor deficits

By controlling robots comparable to the human body, people with profound motor deficits could potentially perform a variety of physical tasks for themselves, improving their quality of life. The extent to which this is achievable has been unclear due to the lack of suitable interfaces by which to control robotic body surrogates and a dearth of studies involving substantial numbers of people with profound motor deficits. We developed a novel, web-based augmented reality interface that enables people with profound motor deficits to remotely control a PR2 mobile manipulator from Willow Garage, which is a human-scale, wheeled robot with two arms. We then conducted two studies to investigate the use of robotic body surrogates. In the first study, 15 novice users with profound motor deficits from across the United States controlled a PR2 in Atlanta, GA to perform a modified Action Research Arm Test (ARAT) and a simulated self-care task. Participants achieved clinically meaningful improvements on the ARAT and 12 of 15 participants (80%) successfully completed the simulated self-care task. Participants agreed that the robotic system was easy to use, was useful, and would provide a meaningful improvement in their lives. In the second study, one expert user with profound motor deficits had free use of a PR2 in his home for seven days. He performed a variety of self-care and household tasks, and also used the robot in novel ways. Taking both studies together, our results suggest that people with profound motor deficits can improve their quality of life using robotic body surrogates, and that they can gain benefit with only low-level robot autonomy and without invasive interfaces. However, methods to reduce the rate of errors and increase operational speed merit further investigation.Comment: 43 Pages, 13 Figure

Identification of a sex-linked SNP marker in the salmon louse (Lepeophtheirus salmonis) using RAD sequencing

The salmon louse (Lepeophtheirus salmonis (Krøyer, 1837)) is a parasitic copepod that can, if untreated, cause considerable damage to Atlantic salmon (Salmo salar Linnaeus, 1758) and incurs significant costs to the Atlantic salmon mariculture industry. Salmon lice are gonochoristic and normally show sex ratios close to 1:1. While this observation suggests that sex determination in salmon lice is genetic, with only minor environmental influences, the mechanism of sex determination in the salmon louse is unknown. This paper describes the identification of a sex-linked Single Nucleotide Polymorphism (SNP) marker, providing the first evidence for a genetic mechanism of sex determination in the salmon louse. Restriction site-associated DNA sequencing (RAD-seq) was used to isolate SNP markers in a laboratory-maintained salmon louse strain. A total of 85 million raw Illumina 100 base paired-end reads produced 281,838 unique RAD-tags across 24 unrelated individuals. RAD marker Lsa101901 showed complete association with phenotypic sex for all individuals analysed, being heterozygous in females and homozygous in males. Using an allele-specific PCR assay for genotyping, this SNP association pattern was further confirmed for three unrelated salmon louse strains, displaying complete association with phenotypic sex in a total of 96 genotyped individuals. The marker Lsa101901 was located in the coding region of the prohibitin-2 gene, which showed a sex-dependent differential expression, with mRNA levels determined by RT-qPCR about 1.8-fold higher in adult female than adult male salmon lice. This study's observations of a novel sex-linked SNP marker are consistent with sex determination in the salmon louse being genetic and following a female heterozygous system. Marker Lsa101901 provides a tool to determine the genetic sex of salmon lice, and could be useful in the development of control strategies

New neuroimaging methods for clinical neuroscience and neurological disorders

236 p.Clinical neuroscience today makes use of state-of-the-art neuroimaging to study structural and functional brain data to improve diagnosis and prognosis in different neurological disorders.In this thesis dissertation, I focused on Magnetic Resonance Imaging (MRI), a non-invasive neuroimaging modality to study brain functional and structural data. Different new methods for brain connectivity analysis are described and applied to three pathologies: Disorder of Consciousness, Alzheimer's Disease and Traumatic Axonal Injury. This work is at the frontiers between two fields, the Biomedical Engineering of Image Processing and the Clinical Neuroscience

Opportunity cost calculations only determine justified effort-Or, What happened to the resource conservation principle?

We welcome the development of a new model on effort and performance and the critique on existing resource-based models. However, considering the vast evidence for the significant impact of experienced task demand on resource allocation, we conclude that Kurzban et al.'s opportunity cost model is only valid for one performance condition: if task demand is unknown or unspecifie

African swine fever pathogenesis: comparative analysis of immunoregulatory genes in domestic and wild pigs

African swine fever virus (ASFV) poses one of the greatest threats to pig farming worldwide. It is highly infectious and causes rapid haemorrhagic death of domestic pigs and Eurasian wild boar (Sus scrofa). In contrast, native African pig species (bushpigs and warthogs) suffer only a mild, subclinical form of the infection from which they rapidly recover. It is hypothesised that the striking difference in the pathophysiological consequences of ASFV infection may reflect a variable ability of the virus to modulate the host immune response in these species. Alternatively, it may indicate a fundamental evolutionary distinction between the immune responses of these animals.In common with many other DNA viruses, ASFV has evolved a complex strategy for modulating the host-cell immune response. The ASFV-encoded protein, A238L, targets key sites within both the NFkB and NFAT immune-signalling pathways. Furthermore, the ASFV protein, p54, is involved in attachment of virus particles to the microtubule motor complex, cytoplasmic dynein. This may represent a key stage in the infection process. Six host proteins targeted or mimicked by A238L and p54 (light chain dynein, cyclophilin A, calcineurin A, NFAT, p65 (RelA) and IkΒα) have been sequenced in the susceptible domestic pig, resistant warthog and phenotypically unknown babirusa. In addition, the ~1.6kbp promoter driving expression of the proinflammatory cytokine, tumour necrosis factor alpha (TNFα), has also been studied.Despite identifying high levels of nucleotide sequence conservation in these genes, polymorphisms have been identified in the NFkB subunit p65 (RelA) and the TNFα promoter. These may be of functional significance in determining the immune response characteristic of the different pig species studied. These polymorphisms have been further explored using in vitro expression and luciferase-reporter analysis. Furthermore, the identification of these sites has enabled the commercial sponsor of this project, Sygen International, to screen their domestic pig lines for 'warthog-like' sequence, which may confer some degree of disease resistance.These findings provide a valuable insight into potential mechanisms involved in altered host susceptibility to African swine fever. In addition, this study may have wider-reaching implications for understanding issues of both susceptibility and pathogenesis relating to other infectious diseases of both humans and animals

A review of technologies and design techniques of millimeter-wave power amplifiers

his article reviews the state-of-the-art millimeter-wave (mm-wave) power amplifiers (PAs), focusing on broadband design techniques. An overview of the main solid-state technologies is provided, including Si, gallium arsenide (GaAs), GaN, and other III-V materials, and both field-effect and bipolar transistors. The most popular broadband design techniques are introduced, before critically comparing through the most relevant design examples found in the scientific literature. Given the wide breadth of applications that are foreseen to exploit the mm-wave spectrum, this contribution will represent a valuable guide for designers who need a single reference before adventuring in the challenging task of the mm-wave PA design

Structures for Sophisticated Behaviour: Feudal Hierarchies and World Models

This thesis explores structured, reward-based behaviour in artificial agents and in animals. In Part I we investigate how reinforcement learning agents can learn to cooperate. Drawing inspiration from the hierarchical organisation of human societies, we propose the framework of Feudal Multi-agent Hierarchies (FMH), in which coordination of many agents is facilitated by a manager agent. We outline the structure of FMH and demonstrate its potential for decentralised learning and control. We show that, given an adequate set of subgoals from which to choose, FMH performs, and particularly scales, substantially better than cooperative approaches that use shared rewards. We next investigate training FMH in simulation to solve a complex information gathering task. Our approach introduces a ‘Centralised Policy Actor-Critic’ (CPAC) and an alteration to the conventional multi-agent policy gradient, which allows one multi-agent system to advise the training of another. We further exploit this idea for communicating agents with shared rewards and demonstrate its efficacy. In Part II we examine how animals discover and exploit underlying statistical structure in their environments, even when such structure is difficult to learn and use. By analysing behavioural data from an extended experiment with rats, we show that such hidden structure can indeed be learned, but also that subjects suffer from imperfections in their ability to infer their current state. We account for their behaviour using a Hidden Markov Model, in which recent observations are integrated imperfectly with evidence from the past. We find that over the course of training, subjects learn to track their progress through the task more accurately, a change that our model largely attributes to the more reliable integration of past evidenc

Link Scheduling Algorithms For In-Band Full-Duplex Wireless Networks

In the last two decades, wireless networks and their corresponding data traffic have grown significantly. This is because wireless networks have become an indispens- able and critical communication infrastructure in a modern society. An on-going challenge in communication systems is meeting the continuous increase in traffic de- mands. This is driven by the proliferation of electronic devices such as smartphones with a WiFi interface along with their bandwidth intensive applications. Moreover, in the near future, sensor devices that form the Internet of Things (IoTs) ecosystem will also add to future traffic growth. One promising approach to meet growing traffic demands is to equip nodes with an In-band-Full-Duplex (IBFD) radio. This radio thus allows nodes to transmit and receive data concurrently over the same frequency band. Another approach to in- crease network or link capacity is to exploit the benefits of Multiple-Input-Multiple- Output (MIMO) technologies; namely, (i) spatial diversity gain, which improves Signal-to-Noise Ratio (SNR) and thus has a direct impact on the data rate used by nodes, and (ii) spatial multiplexing gain, whereby nodes are able to form concurrent links to neighbors