15,350 research outputs found

    iForgot: a model of forgetting in robotic memories

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    Much effort has focused in recent years on developing more life-like robots. In this paper we propose a model of memory for robots, based on human digital memories, though our model incorporates an element of forgetting to ensure that the robotic memory appears more human and therefore can address some of the challenges for human-robot interaction

    Distributed intelligent control and management (DICAM) applications and support for semi-automated development

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    We have recently begun a 4-year effort to develop a new technology foundation and associated methodology for the rapid development of high-performance intelligent controllers. Our objective in this work is to enable system developers to create effective real-time systems for control of multiple, coordinated entities in much less time than is currently required. Our technical strategy for achieving this objective is like that in other domain-specific software efforts: analyze the domain and task underlying effective performance, construct parametric or model-based generic components and overall solutions to the task, and provide excellent means for specifying, selecting, tailoring or automatically generating the solution elements particularly appropriate for the problem at hand. In this paper, we first present our specific domain focus, briefly describe the methodology and environment we are developing to provide a more regular approach to software development, and then later describe the issues this raises for the research community and this specific workshop

    Lines-of-inquiry and sources of evidence in work-based research

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    There is synergy between the investigative practices of police detectives and social scientists, including work-based researchers. They both develop lines-of-inquiry and draw on multiple sources of evidence in order to make inferences about people, trends and phenomena. However, the principles associated with lines-of-inquiry and sources of evidence have not so far been examined in relation to work-based research methods, which are often unexplored or ill-defined in the published literature. We explore this gap by examining the various direct and indirect lines-of-inquiry and the main sources of primary and secondary evidence used in work-based research, which is especially relevant because some work-based researchers are also police detectives. Clearer understanding of these intersections will be useful in emerging professional contexts where the work-based researcher, the detective, and the social scientist cohere in the one person and their research project. The case we examined was a Professional Studies programme at a university in Australia, which has many police detectives doing work-based research, and from their experience we conclude there is synergy between work-based research and lines of enquiry. Specifically, in the context of research methods, we identify seven sources of evidence: 1) creative, unstructured, and semi-structured interviews; 2) structured interviews; 3) consensus group methods; 4) surveys; 5) documentation and archives; 6) direct observations and participant observations; and 7) physical or cultural artefacts, and show their methodological features related to data and method type, reliability, validity, and types of analysis, along with their respective advantages and disadvantages. This study thereby unpacks and isolates those characteristics of work-based research which are relevant to a growing body of literature related to the messy, co-produced and wicked problems of private companies, government agencies, and non-government organisations and the research methods used to investigate them

    Remote and Local Entanglement of Ions using Photons and Phonons

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    The scaling of controlled quantum systems to large numbers of degrees of freedom is one of the long term goals of experimental quantum information science. Trapped-ion systems are one of the most promising platforms for building a quantum information processor with enough complexity to enable novel computational power, but face serious challenges in scaling up to the necessary numbers of qubits. In this thesis, I present both technical and operational advancements in the control of trapped-ion systems and their juxtaposition with photonic modes used for quantum networking. After reviewing the basic physics behind ion trapping, I then describe in detail a new method of implementing Raman transitions in atomic systems using optical frequency combs. Several dierent experimental setups along with simple theoretical models are reviewed and the system is shown to be capable of full control of the qubit-oscillator system. Two-ion entangling operations using optical frequency combs are demonstrated along with an extension of the operation designed to suppress certain experimental errors. I then give an overview of how spatially separated ions can be entangled using a photonic interconnect. Experimental results show that pulsed excitation of trapped ions provide an excellent single photon source that can be used as a heralded entangling gate between macroscopically separated systems. This heralded entangling gate is used to show a violation of a Bell inequality while keeping the detection loophole closed and can be used a source private random numbers. Finally, the coherent Coulomb force-based gates are combined with the probabilistic photon-based gates in a proof of concept experiment that shows the feasibility of a distributed ion-photon network

    Worsening of cerebral hyperemia by the administration of terlipressin in acute liver failure with severe hepatic encephalopathy

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    There is increasing evidence that terlipressin is useful in patients with cirrhosis and hepatorenal syndrome, but there are no data of its use in patients with acute liver failure (ALF) in whom hepatorenal syndrome is common. Although terlipressin produces systemic vasoconstriction, it produces cerebral vasodilatation and may increase cerebral blood flow (CBF). Increased CBF contributes to intracranial hypertension in patients with ALF. The aim of this study was to evaluate the safety of terlipressin in patients with ALF with respect to cerebral haemodynamics. Six successive patients with ALF were electively ventilated for grade IV hepatic encephalopathy. Patients were monitored invasively and CBF was measured (Kety- Schmidt technique). Measurements were made before, at 1, 3 hour and 5 hours after intravenous (single bolus) administration of terlipressin (0.005 mg/kg) )intravenously (single bolus), median 0.25mg (range 0.2-0.3). There was no significant change in heart rate, mean arterial pressure or cardiac output. CBF and jugular venous oxygen saturation both increased significantly at 1 hour (p<0.0=0.016) respectively. Intracranial pressure increased significantly at 21 hours (p<0=.0.031), returning back to baseline values at 42 hours. This study shows that administration of terlipressin, at a dose that did not alter systemic haemodynamicshemodynamics, resulted in worsening of cerebral hyperemia and intracranial hypertension in patients with ALF and severe hepatic encephalopathy. These data suggest the need to exercise extreme caution in the use of terlipressin in these patients in view of its potentially deleterious consequences on cerebral haemodynamics

    Spin-coating on nanoscale topography and phase separation of diblock copolymers

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    CRANN researchers are interested in mathematical modelling of all aspects of the process of spin-coating of diblock copolymers, with the aim of removing expensive trial and error design cycles. Of particular interest is the flow of the polymer during spin-coating, and also during the subsequent annealing process. Also of considerable interest is the chemical process of phase-separation and self-assembly of the diblock copolymer. Existing models in the literature rely heavily on computationally expensive Monte-Carlo simulation methods. The modelling work performed during the study group in summarized in this report. The report is split into four main sections, with discussion and suggestions for experiments in the concluding section. The content of the sections is as follows: Section 0.2: Mathematical modelling of spin-coating onto a flat substrate; no annealing considered. Section 0.3: Modelling of spin-coating onto a substrate with topography (i.e. trenches); no annealing considered. Section 0.4: Flow of polymer during annealing. Section 0.5: Models for self-assembly of polymers into nanostructures. Sections 0.2 to 0.4 are focussed on the fluid flow problems for the polymer, and go some way to providing useful answers to Problem 1. On the other hand, Problem 2 was found to be extremely challenging, and the efforts described in section 0.5 represent only a relatively modest impact on this problem

    Targeting protein–protein interactions within the cyclic AMP signaling system as a therapeutic strategy for cardiovascular disease

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    The cAMP signaling system can trigger precise physiological cellular responses that depend on the fidelity of many protein–protein interactions, which act to bring together signaling intermediates at defined locations within cells. In the heart, cAMP participates in the fine control of excitation–contraction coupling, hence, any disregulation of this signaling cascade can lead to cardiac disease. Due to the ubiquitous nature of the cAMP pathway, general inhibitors of cAMP signaling proteins such as PKA, EPAC and PDEs would act non-specifically and universally, increasing the likelihood of serious ‘off target’ effects. Recent advances in the discovery of peptides and small molecules that disrupt the protein–protein interactions that underpin cellular targeting of cAMP signaling proteins are described and discussed

    Prevalence of Substance Use among Lesbian, Gay, and Bisexual High School Students in 2019 vs. 2021

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    Background: Studies suggest that LGBTQ+ (lesbian, gay, bisexual, transgender, queer/questioning, plus) youth are at increased risk of engaging in alcohol and substance use. The COVID-19 pandemic forced many students to isolate in 2020 and 2021, and the impacts of this have been purported to be detrimental. This study examines the prevalence of alcohol and substance use among lesbian, gay, and bisexual (LGB) U.S. high school students before the pandemic in 2019 versus 2021. Methods: This cross-sectional descriptive study used results from the 2019 Youth Risk Behavior Survey (YRBS) and the 2021 Adolescent Behavior and Experiences Survey (ABES). The 2019 YRBS included 13,677 questionnaires from 136 schools, and the 2021 ABES included 7,705 questionnaires from 128 schools. We selected 15 questions concerning alcohol and substance use common to both surveys and compared results for LGB students in 2019 versus 2021. Results: We found a decrease in prevalence for all 15 alcohol and substance-use-related questions from 2019 to 2021. The most statistically significant differences were observed in E-cigarette use, marijuana use, and obtaining an illegal drug on school property. Conclusions: The results suggest substantial decreases in alcohol and substance use among LGB high school students from 2019 to 2021. These decreases have occurred in the context of the pandemic and reported increases in mental health problems among this population. These outcomes should prompt further research into how social interactions at school (or the lack thereof) among LGBTQ+ youth contribute to patterns of alcohol and substance use
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