537 research outputs found

    Markers of Discourse Structure in Child-Directed Speech

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    Although the language we encounter is typically embedded in rich discourse contexts, existing models of sentence processing focus largely on phenomena that occur sentence internally. Here we analyze a video corpus of child-caregiver interactions with the aim of characterizing how discourse structure is reflected in child-directed speech and in children’s and caregivers ’ behavior. We use topic continuity as a measure of discourse structure, examining how caregivers introduce and discuss objects across sentences. We develop a variant on a Hidden Markov Model to identify coherent discourses, taking into account speakers ’ intended referent and the time delays between utterances. Using the discourses found by this model, we analyze how the lexical, syntactic, and social properties of caregiver-child interaction change over the course of a sequence of topically-related utterances. Our findings suggest that cues used to signal topicality in adult discourse are also available in child-directed speech and that children’s responses reflect joint attention in communication

    Design and Implementation of Role-based Architectural Event Modules

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    This diploma thesis attempts to improve the language-support for coping with the problem of negative emergence in dynamic Systems-of-Systems (SoS). Negative emergence is understood to be the emergence of unintended behaviour among constituent systems of a SoS in response to certain changes to the composition of constituent systems in the SoS. The architecture description language (ADL) "EventArch 2.0" approaches this problem by allowing the SoS-manager to define certain rules to manipulate the original behaviour of certain constituent systems at certain critical points of execution of the SoS to prevent unintended behaviour ("coordination rules"). This thesis approaches a solution to the following problem: to prevent the introduction of unintended behaviour through overly- or underly-restrictive coordination rules, more- or less-restrictive variants of a coordination rule would have to be applied to the SoS depending on the current composition of constituent systems in the SoS. This thesis has the goal to approach this problem by devising a mechanism to dynamically exchange a coordination rule depending on the current composition of constituent systems in the SoS. To achieve that goal, the ADL "EventArch 2.0" is extended to support the dynamic application of a coordination rule to a System-of-Systems. The dynamic application is achieved by connecting coordinators and constituent systems at runtime. As a special characteristic, each coordinator is dedicated to a specific constituent system and is responsible for achieving compliance of that system with respect to a specific coordination rule. It is shown that this architectural setup can be nicely modeled using concepts from the field of "role-based modeling". The solution does therefore employ concepts that are central to the "role-based modeling"-approach: "Role", "Base", and "Compartment". The applicability of the extended language to practical coordination-problems is shown by applying it to a constructed use case in the field of energy-efficient computing.:1 Introduction 1 1.1 Motivation and Problem Statement 1 1.2 Overview 2 2 Background 4 2.1 System of Systems 4 2.2 EventArch 2.0 8 2.2.1 Concepts 8 2.2.2 Implementation 10 2.2.3 Diagrams 15 2.3 Role-based Modeling 19 2.4 Coupling Strategies 22 3 Related Work 25 3.1 Requirements 25 3.2 Features 28 3.3 OT/J 29 3.4 Other Role-based Languages 31 3.5 Areas of Improvement 35 3.5.1 OT/J 35 3.5.2 Other Role-based Languages 40 4 Concepts of EventArch 3.0 45 4.1 Base, Role, and Compartment 45 4.2 Dynamic Composite AEM and Role-Binder 46 4.3 Inner Roles and Atomic Block 48 4.4 Diagrams 49 5 Internal Design of EventArch 3.0 55 5.1 Implementation of the Concepts 55 5.1.1 Base, Role, and Compartment 56 5.1.2 Dynamic Composite AEM and Role-Binder 58 5.1.3 Inner Roles and Atomic Block 60 5.1.4 Other Concepts 62 5.2 Further Discussion and Design Alternatives 63 6 Evaluation of EventArch 3.0 66 6.1 Advantages 66 6.2 Disadvantages 74 6.3 Reflections on the Fulfillment of the Requirements 77 6.4 Use case 81 6.5 Application to the Example Use case 83 6.5.1 Presentation of the implementation 83 6.5.2 Advantages shown by the implementation 90 7 Conclusion 93 7.1 Future Work 95 8 Appendix 99 8.1 Additional Source-Code 99 8.1.1 OT/J source-code 99 8.1.2 “State”-coordination rule 105 8.2 Internal Design of EventArch 2.0 109 8.2.1 Abstract 109 8.2.2 Detailed 116 8.3 Grammar of EventArch 3.0 . 123 8.4 EventArch 3.0 Diagrams 126 Bibliography 134Die vorliegende Diplomarbeit ist mit der Verbesserung der Sprachunterstützung zur Vermeidung negativer Emergenz in dynamischen Systems-of-Systems (SoS) befasst. Negative Emergenz wird dabei als unerwünschtes Verhalten von an einem SoS beteiligten Systemen verstanden, welches auf Grund von Änderungen in der Zusammensetzung des SoS (d.h. auf Grund des Eintritts oder Austritts von konstituierenden Systemen) aufgetreten ist. Die Architekturbeschreibungssprache "EventArch 2.0" unterstützt den SoS-manager bei der Lösung dieses Problems durch die Möglichkeit das Verhalten der beteiligten Systeme in bestimmten Ausführungsmomenten durch die Definition von Koordinationsregeln zu manipulieren und auf diesem Wege das Auftreten negativer Emergenz zu vermeiden. Die Diplomarbeit ist ein Beitrag zur Lösung des folgenden Problems: Um die Einführung von unerwünschtem Verhalten durch übermäßig- oder unzureichend restriktive Koordinationsregeln zu verhindern, müssten unterschiedliche Varianten einer Koordinationsregel, die sich im Grade ihrer Restriktivität unterscheiden, auf das SoS angewendet werden. Diese Anwendung müßte in Abhängigkeit der aktuellen Zusammensetzung des SoS aus konstituierenden Systemen erfolgen. In der vorliegenden Diplomarbeit wird eine Möglichkeit entwickelt um eine Koordinationsregel zur Laufzeit in Abhängigkeit der aktuellen Zusammensetzung des SoS aus konstituierenden Systemen auszutauschen. Sie leistet damit einen Beitrag zur Lösung des vorgenannten Problems. In der Arbeit wird die Architekturbeschreibungssprache "EventArch 2.0" um die Möglichkeit des dynamischen Austausches von Koordinationsregeln erweitert. Dabei werden Koordinationsregeln angewendet durch die gezielte Verbindung von Koordinatoren und konstituierenden Systemen. Die Besonderheit des Ansatzes besteht darin, dass jedem konstituierenden System ein persönlicher Koordinator zugeordnet wird, d.h. ein Koordinator der ausschließlich für die Anpassung des Verhaltens des jeweiligen Systems an eine bestimmte Koordinationsregel verantwortlich ist. In der Arbeit wird gezeigt, dass dieser architektonische Ansatz durch zentrale Konzepte des Modellierungsansatzes "rollenbasierte Modellierung" modelliert werden kann. In der entwickelten Spracherweiterung werden daher die Konzepte "Rolle", "Basis" und "Compartment" verwendet. Die Anwendbarkeit der erweiterten Sprache, wird durch deren Anwendung auf einen konstruierten Anwendungsfall aus dem Bereich der Energie-effizienten Berechnung gezeigt.:1 Introduction 1 1.1 Motivation and Problem Statement 1 1.2 Overview 2 2 Background 4 2.1 System of Systems 4 2.2 EventArch 2.0 8 2.2.1 Concepts 8 2.2.2 Implementation 10 2.2.3 Diagrams 15 2.3 Role-based Modeling 19 2.4 Coupling Strategies 22 3 Related Work 25 3.1 Requirements 25 3.2 Features 28 3.3 OT/J 29 3.4 Other Role-based Languages 31 3.5 Areas of Improvement 35 3.5.1 OT/J 35 3.5.2 Other Role-based Languages 40 4 Concepts of EventArch 3.0 45 4.1 Base, Role, and Compartment 45 4.2 Dynamic Composite AEM and Role-Binder 46 4.3 Inner Roles and Atomic Block 48 4.4 Diagrams 49 5 Internal Design of EventArch 3.0 55 5.1 Implementation of the Concepts 55 5.1.1 Base, Role, and Compartment 56 5.1.2 Dynamic Composite AEM and Role-Binder 58 5.1.3 Inner Roles and Atomic Block 60 5.1.4 Other Concepts 62 5.2 Further Discussion and Design Alternatives 63 6 Evaluation of EventArch 3.0 66 6.1 Advantages 66 6.2 Disadvantages 74 6.3 Reflections on the Fulfillment of the Requirements 77 6.4 Use case 81 6.5 Application to the Example Use case 83 6.5.1 Presentation of the implementation 83 6.5.2 Advantages shown by the implementation 90 7 Conclusion 93 7.1 Future Work 95 8 Appendix 99 8.1 Additional Source-Code 99 8.1.1 OT/J source-code 99 8.1.2 “State”-coordination rule 105 8.2 Internal Design of EventArch 2.0 109 8.2.1 Abstract 109 8.2.2 Detailed 116 8.3 Grammar of EventArch 3.0 . 123 8.4 EventArch 3.0 Diagrams 126 Bibliography 13

    Resource Allocation for Outdoor-to-Indoor Multicarrier Transmission with Shared UE-side Distributed Antenna Systems

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    In this paper, we study the resource allocation algorithm design for downlink multicarrier transmission with a shared user equipment (UE)-side distributed antenna system (SUDAS) which utilizes both licensed and unlicensed frequency bands for improving the system throughput. The joint UE selection and transceiver processing matrix design is formulated as a non-convex optimization problem for the maximization of the end-to-end system throughput (bits/s). In order to obtain a tractable resource allocation algorithm, we first show that the optimal transmitter precoding and receiver post-processing matrices jointly diagonalize the end-to-end communication channel. Subsequently, the optimization problem is converted to a scalar optimization problem for multiple parallel channels, which is solved by using an asymptotically optimal iterative algorithm. Simulation results illustrate that the proposed resource allocation algorithm for the SUDAS achieves an excellent system performance and provides a spatial multiplexing gain for single-antenna UEs.Comment: accepted for publication at the IEEE Vehicular Technology Conference (VTC) Spring, Glasgow, Scotland, UK, May 201

    Stroke warning campaigns: delivering better patient outcomes? A systematic review.

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    Background: Patient delay in presenting to hospital with stroke symptoms remains one of the major barriers to thrombolysis treatment, leading to its suboptimal use internationally. Educational interventions such as mass media campaigns and community initiatives aim to reduce patient delays by promoting the signs and symptoms of a stroke, but no consistent evidence exists to show that such interventions result in appropriate behavioral responses to stroke symptoms. Methods: A systematic literature search and narrative synthesis were conducted to examine whether public educational interventions were successful in the reduction of patient delay to hospital presentation with stroke symptoms. Three databases, MEDLINE, CINAHL, and PsycINFO, were searched to identify quantitative studies with measurable behavioral end points, including time to hospital presentation, thrombolysis rates, ambulance use, and emergency department (ED) presentations with stroke. Results: Fifteen studies met the inclusion criteria: one randomized controlled trial, two time series analyses, three controlled before and after studies, five uncontrolled before and after studies, two retrospective observational studies, and two prospective observational studies. Studies were heterogeneous in quality; thus, meta-analysis was not feasible. Thirteen studies examined prehospital delay, with ten studies reporting a significant reduction in delay times, with a varied magnitude of effect. Eight studies examined thrombolysis rates, with only three studies reporting a statistically significant increase in thrombolysis administration. Five studies examined ambulance usage, and four reported a statistically significant increase in ambulance transports following the intervention. Three studies examining ED presentations reported significantly increased ED presentations following intervention. Public educational interventions varied widely on type, duration, and content, with description of intervention development largely absent from studies, limiting the potential replication of successful interventions. Conclusions: Positive intervention effects were reported in the majority of studies; however, methodological weaknesses evident in a number of studies limited the generalizability of the observed effects. Reporting of specific intervention design was suboptimal and impeded the identification of key intervention components for reducing patient delay. The parallel delivery of public and professional interventions further limited the identification of successful intervention components. A lack of studies of sound methodological quality using, at a minimum, a controlled before and after design was identified in this review, and thus studies incorporating a rigorous study design are required to strengthen the evidence for public interventions to reduce patient delay in stroke. The potential clinical benefits of public interventions are far-reaching, and the challenge remains in translating knowledge improvements and correct behavioral intentions to appropriate behavior when stroke occurs

    Systematic review and meta-analysis of the impact of depression on subsequent smoking cessation in patients with chronic respiratory conditions

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    Objective: To systematically review the impact of depression on subsequent smoking cessation in prospective studies of chronic respiratory patients. Method: A systematic search of electronic databases (MEDLINE, Psychinfo, CINAHL) was conducted to identify prospective studies of chronic respiratory patients which measured depression at baseline and smoking status at follow-up, dating from 1st January 1990 to 21st February 2014. The standardised mean difference (SMD) and 95% confidence interval for the association between baseline depressive symptoms and subsequent smoking cessation was estimated from available data using random effects meta-analysis. Results: A total of 1314 citations were retrieved and 197 articles were further evaluated by two reviewers. Seven articles provided sufficient data to estimate the association between depressive symptoms and subsequent smoking cessation. Those with elevated depressive symptoms were significantly less likely to quit smoking at follow-up than those not reporting elevated depressive symptoms (SMD=-.31, 95%CI -.43 to -.19; I2=0%, p=.506). Conclusions: The association between depression and subsequent smoking was poorly reported or omitted in most studies. However, the available evidence suggests depression decreases the likelihood that patients with chronic respiratory conditions will quit smoking. Future research is needed to determine how best to manage depression and smoking cessation in this population

    An ecologic study

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    Background: Vancomycin-resistant enterococci (VRE) are among the most common antimicrobial-resistant pathogens causing nosocomial infections. Although antibiotic use has been identified as a risk factor for VRE, it remains unclear which antimicrobial agents particularly facilitate VRE selection. Here, we assessed whether use of specific antimicrobial agents is independently associated with healthcare-associated (HA) VRE rates in a university hospital setting in Berlin, Germany . Methods: We conducted the study between January 2014 and December 2015 at the Charité-university hospital of Berlin, Germany. From the hospital pharmacy, we extracted data for all antibacterials for systemic use (anatomical therapeutic chemical (ATC)-classification J01) and calculated ward specific antibiotic consumption in defined daily doses (DDDs) per 100 patient-days (PD). We used the microbiology laboratory database to identify all patients with isolation of invasive or non-invasive VRE and calculated HA-VRE incidence as nosocomial VRE-cases per 100 patients and HA-VRE incidence density as nosocomial VRE- cases per 1000 PD. We defined VRE isolates as hospital-acquired if they were identified three days or later after hospital admission and otherwise as community-acquired (CA-VRE). We performed univariable and multivariable regression analyses to estimate the association of the frequency of HA-VRE per month with antibiotic use and other parameters such as length of stay, type of ward or presence of at least one CA-VRE on ward. In a second analysis, we considered only patients with VRE infections. Results: We included data from 204,054 patients with 948,380 PD from 61 wards. Overall, 1430 VRE-cases were identified of which 409 (28.6%) were considered hospital-acquired (HA). We found that carbapenem use in the current month and prior-month use of glycopeptides increased the risk for HA-VRE by 1% per 1 DDD/100 PD and 3% per 1 DDD/100 PD, respectively. However, when only VRE from clinical samples were considered, only glycopeptide use showed a statistically significant association. In both models, detection of at least one patient with CA-VRE on a ward in the current month significantly increased the risk of HA-VRE, thereby indicating nosocomial spread of VRE. Conclusions: Our findings suggest that the risk of HA-VRE is associated with specific antimicrobial agents. Prudent use of these antimicrobial agents might reduce nosocomial VRE rates. That appearance of at least one CA-VRE case on the ward increased the risk of HA-VRE detection highlights the importance of strict hand hygiene practices to interrupt person-to-person transmission of VRE

    Implementation of a Quit Smoking Programme in Community Adult Mental Health Services–A Qualitative Study

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    Little is known about the experiences of people with severe mental health difficulties in smoking cessation interventions. This study aimed to review the implementation of a smoking cessation programme across 16 community mental health day services. The aim was to establish the experience from both service user and facilitator perspectives and refine implementation for future groups. In-depth interviews were conducted with 20 service users and four focus groups held with 17 facilitators. Thematic analysis was used to analyse the data for emergent themes in relation to key enablers and barriers to implementation. Data from service users and facilitators revealed that implementation was enabled by an open and engaged recruitment approach; the resourcefulness of facilitators; programme materials and group-based format; combining the cessation programme with other and broader health initiatives; and participants\u27 motivations, including health and money. Barriers included the structure of the service; the lack of a joined-up approach across the health services; literacy issues and the serial/logical process assumed by the programme. Barriers perceived as more specific to those with mental health difficulties included the use of smoking as a coping mechanism, lack of alternative activities/structure and lack of consistent determination. The tobacco free policy, implemented shortly before the programme, interestingly emerged as both a barrier and an enabler. In conclusion, although this group-based cessation programme in community mental health settings was well-received overall, a number of key barriers persist. A joined-up approach which addresses the culture of smoking in mental health settings, inconsistencies in smoking policies, and provides consistent cessation support, is needed. Care needs to be taken with the timing as overall it may not be helpful to introduce a new smoking cessation programme at the same time as a tobacco free policy

    ICONE 14-89120 BUOYANCY DRIVEN COOLANT MIXING STUDIES OF NATURAL CIRCULATION FLOWS AT THE ROCOM TEST FACILITY USING ANSYS CFX

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    ABSTRACT Coolant mixing in the cold leg, downcomer and the lower plenum of pressurized water reactors is an important phenomenon mitigating the reactivity insertion into the core. Therefore, mixing of the de-borated slugs with the ambient coolant in the reactor pressure vessel was investigated at the four loop 1:5 scaled ROCOM mixing test facility. Thermal hydraulics analyses showed, that weakly borated condensate can accumulate in particular in the pump loop seal of those loops, which do not receive safety injection. After refilling of the primary circuit, natural circulation in the stagnant loops can re-establish simultaneously and the de-borated slugs are shifted towards the reactor pressure vessel (RPV). In the ROCOM experiments, the length of the flow ramp and the initial density difference between the slugs and the ambient coolant was varied. From the test matrix experiments with 0 resp. 2% density difference between the de-borated slugs and the ambient coolant were used to validate the CFD software ANSYS CFX. To model the effects of turbulence on the mean flow a higher order Reynolds stress turbulence model was employed and a mesh consisting of 6.4 million hybrid elements was utilized. Only the experiments and CFD calculations with modeled density differences show a stratification in the downcomer. Depending on the degree of density differences the less dense slugs flow around the core barrel at the top of the downcomer. At the opposite side the lower borated coolant is entrained by the colder safety injection water and transported to the core. The validation proves that ANSYS CFX is able to simulate appropriately the flow field and mixing effects of coolant with different densities

    Both systemic and local application of Granulocyte-colony stimulating factor (G-CSF) is neuroprotective after retinal ganglion cell axotomy

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    <p>Abstract</p> <p>Background</p> <p>The hematopoietic Granulocyte-Colony Stimulating Factor (G-CSF) plays a crucial role in controlling the number of neutrophil progenitor cells. Its function is mediated via the G-CSF receptor, which was recently found to be expressed also in the central nervous system. In addition, G-CSF provided neuroprotection in models of neuronal cell death. Here we used the retinal ganglion cell (RGC) axotomy model to compare effects of local and systemic application of neuroprotective molecules.</p> <p>Results</p> <p>We found that the <it>G-CSF receptor </it>is robustly expressed by RGCs <it>in vivo </it>and <it>in vitro</it>. We thus evaluated G-CSF as a neuroprotectant for RGCs and found a dose-dependent neuroprotective effect of G-CSF on axotomized RGCs when given subcutaneously. As stem stell mobilization had previously been discussed as a possible contributor to the neuroprotective effects of G-CSF, we compared the local treatment of RGCs by injection of G-CSF into the vitreous body with systemic delivery by subcutaneous application. Both routes of application reduced retinal ganglion cell death to a comparable extent. Moreover, G-CSF enhanced the survival of immunopurified RGCs <it>in vitro</it>.</p> <p>Conclusion</p> <p>We thus show that G-CSF neuroprotection is at least partially independent of potential systemic effects and provide further evidence that the clinically applicable G-CSF could become a treatment option for both neurodegenerative diseases and glaucoma.</p
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