Discourse Structure and Anaphora: An Empirical Study

ne of the main motivations for studying discourse structure is its effect on the search for the antecedents of anaphoric expressions. We tested the predictions in this regard of theories assuming that the structure of a discourse depends on its intentional structure, such as Grosz and Sidner?s theory. We used a corpus of tutorial dialogues independently annotated according to Relational Discourse Analysis (RDA), a theory of discourse structure merging ideas from Grosz and Sidner?s theory with proposals from Rhetorical Structure Theory (RST). Using as our metrics the accessibility of anaphoric antecedents and the reduction in ambiguity brought about by a particular theory, we found support for Moser and Moore?s proposal that among the units of discourse assumed by an RST-like theory, only those expressing an intentional ?core? (in the RDA sense) should be viewed as constraining the search for antecedents; units only expressing informational relations should not introduce separate focus spaces. We also found that the best compromise between accessibility and ambiguity (?perplexity?) reduction is a model in which the focus spaces associated with embedded cores and embedded contributors remain on the stack until the RDA-segment in which they occur is completed, and discuss the implications of this finding for a stack-based theory

Emergency radiology without the radiologist: the forensic perspective

Purpose. The aim of this paper is to describe two cases from the authors\u27 forensic archive database in which teleradiology was related to unfavourable outcomes. Material and methods. Two patients underwent autopsy after unexpected death following road accidents. In one case, death was caused by multiple cervical fractures following minor neck injury in the presence of diffuse idiopathic skeletal hyperostosis. In the other case, death was due to delayed isthmic aortic rupture occurring after thoracic blunt trauma in a young adult. Both conditions were diagnosed at autopsy only. Results. In both cases, the lethal outcome was due to the failure to obtain radiological reports of the X-rays performed in the emergency department. Radiological diagnoses could have been established by activating the teleradiology service which, according to the hospitals\u27 teleradiology protocols, is available on demand in cases of emergency only, as selected by the physician requesting the service. Conclusions. These cases suggest the high risk of excluding the radiologist from the management of patients whose images are transmitted via a teleradiology system.Obiettivo. Gli autori intendono descrivere due casi tratti dal proprio archivio autoptico medico-legale nei quali l\u27esito sfavorevole ? connesso all\u27uso della teleradiologia. Materiali e metodi. Sono descritte le risultanze dell\u27indagine autoptica eseguita su due soggetti deceduti in maniera inattesa dopo incidente della strada. In un caso la morte ? dipesa da fratture cervicali multiple determinatesi, in soggetto affetto da DISH (iperostosi scheletrica idiopatica diffusa), per un trauma minore del collo. Nel secondo caso un giovane adulto riportava una contusione del torace con "rottura in due tempi" dell\u27istmo aortico. Entrambe le patologie traumatiche sono state diagnosticate solo in sede di esame autoptico. Risultati. La mancata diagnosi in vita ha tratto origine, in entrambi i casi, dalla "non refertazione" degli esami radiologici eseguiti in urgenza; la diagnosi radiologica avrebbe potuto effettuarsi mediante attivazione del sistema di teleradiologia, utilizzabile, secondo il protocollo gestionale della struttura, solo in casi urgenti, selezionati dal medico richiedente la prestazione. Conclusioni. Questi due casi suggeriscono che l\u27esclusione del radiologo dalla gestione dei pazienti le cui immagini sono trasmesse in teleradiologia comporta un rischio molto elevato di prestazioni inadeguate

Photorefractive light needles in glassy nanodisordered KNTN

We study the formation of 2D self-trapped beams in nanodisordered potassium-sodium-tantalate-niobate (KNTN) cooled below the dynamic glass transition. Supercooling is shown to accelerate the photorefractive response and enhance steady-state anisotropy. Effects in the excited state are attributed to the anomalous slim-loop polarization curve typical of relaxors dominated by non-interacting polar-nano-regions

PTP4A1 promotes TGFβ signaling and fibrosis in systemic sclerosis.

Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis of skin and internal organs. Protein tyrosine phosphatases have received little attention in the study of SSc or fibrosis. Here, we show that the tyrosine phosphatase PTP4A1 is highly expressed in fibroblasts from patients with SSc. PTP4A1 and its close homolog PTP4A2 are critical promoters of TGFβ signaling in primary dermal fibroblasts and of bleomycin-induced fibrosis in vivo. PTP4A1 promotes TGFβ signaling in human fibroblasts through enhancement of ERK activity, which stimulates SMAD3 expression and nuclear translocation. Upstream from ERK, we show that PTP4A1 directly interacts with SRC and inhibits SRC basal activation independently of its phosphatase activity. Unexpectedly, PTP4A2 minimally interacts with SRC and does not promote the SRC-ERK-SMAD3 pathway. Thus, in addition to defining PTP4A1 as a molecule of interest for TGFβ-dependent fibrosis, our study provides information regarding the functional specificity of different members of the PTP4A subclass of phosphatases

The Influence of Volcano Topographic Changes on Infrasound Amplitude: Lava Fountains at Mt. Etna in 2021

Infrasound signals are used to investigate and monitor active volcanoes during eruptive and degassing activity. Infrasound amplitude information has been used to estimate eruptive parameters such as plume height, magma discharge rate, and lava fountain height. Active volcanoes are characterized by pronounced topography and, during eruptive activity, the topography can change rapidly, affecting the observed infrasound amplitudes. While the interaction of infrasonic signals with topography has been widely investigated over the past decade, there has been limited work on the impact of changing topography on the infrasonic amplitudes. In this work, the infrasonic signals accompanying 57 lava fountain paroxysms at Mt. Etna (Italy) during 2021 were analyzed. In particular, the temporal and spatial variations of the infrasound amplitudes were investigated. During 2021, significant changes in the topography around the most active crater (the South East Crater) took place and were reconstructed in detail using high resolution imagery from unoccupied aerial system surveys. Through analysis of the observed infrasound signals and numerical simulations of the acoustic wavefield, we demonstrate that the observed spatial and temporal variation in the infrasound signal amplitudes can largely be explained by the combined effects of changes in the location of the acoustic source and changes in the near-vent topography, together with source acoustic amplitude variations. This work demonstrates the importance of accurate source locations and high-resolution topographic information, particularly in the near-vent region where the topography is most likely to change rapidly and illustrates that changing topography should be considered when interpreting local infrasound observations over long time scales

Combining support vector machines and segmentation algorithms for efficient anomaly detection: a petroleum industry application

Proceedings of: International Joint Conference SOCO’14-CISIS’14-ICEUTE’14, Bilbao, Spain, June 25th–27th, 2014, ProceedingsAnomaly detection is the problem of finding patterns in data that do not conform to expected behavior. Similarly, when patterns are numerically distant from the rest of sample, anomalies are indicated as outliers. Anomaly detection had recently attracted the attention of the research community for real-world applications. The petroleum industry is one of the application contexts where these problems are present. The correct detection of such types of unusual information empowers the decision maker with the capacity to act on the system in order to correctly avoid, correct, or react to the situations associated with them. In that sense, heavy extraction machines for pumping and generation operations like turbomachines are intensively monitored by hundreds of sensors each that send measurements with a high frequency for damage prevention. For dealing with this and with the lack of labeled data, in this paper we propose a combination of a fast and high quality segmentation algorithm with a one-class support vector machine approach for efficient anomaly detection in turbomachines. As result we perform empirical studies comparing our approach to other methods applied to benchmark problems and a real-life application related to oil platform turbomachinery anomaly detection.This work was partially funded by CNPq BJT Project 407851/2012-7 and CNPq PVE Project 314017/2013-

Doing What You\u27re Told: Following Task Instructions in Changing, but Hospitable Environments

The AnimNL project (Anim ation from N atural L anguage) has as its goal the automatic creation of animated task simulations from natural-language instructions. The question addressed in this paper is how agents can perform tasks in environments about which they have only partial relevant knowledge. The solution we describe involves enabling such agents to * develop expectations through instruction understanding and plan inference, and use those expectations in deciding how to act; * exploit generalized abilities in order to deal with novel geometric situations. The AnimNL project builds on an animation system, Jack™, that has been developed at the Computer Graphics Research Lab at the University of Pennsylvania, and draws upon a range of recent work in Natural Language semantics, planning and plan inference, philosophical studies of intention, reasoning about knowledge and action, and subsumption architectures for autonomous agents

Intramedullary non-specific inflammatory lesion of thoracic spine: A case report

<p>Abstract</p> <p>Background</p> <p>There are several non-neoplastic lesions which mimick intramedullary spinal cord neoplasm in their radiographic and clinical presentation. These can be classified as either infectious (TB, fungal, bacterial, parasytic, syphilis, CMV, HSV) and non-infectious (sarcoid, MS, myelitis, ADEM, SLE) inflammatory lesions, idiopathic necrotizing myelopathy, unusual vascular lesions and radiation myelopathy. Although biopsy may be indicated in many cases, an erroneous diagnosis of intramedullary neoplasm can often be eliminated pre-operatively.</p> <p>Case description</p> <p>the authors report a very rare case of intramedullary non-specific inflammatory lesion of unknown origin, without signs of infection or demyelinization, in a woman who showed no other evidence of systemic disease.</p> <p>Conclusions</p> <p>Intramedullary lesions that mimick a tumor can be various and difficult to interpret. Preoperative MRI does not allow a certain diagnosis because these lesions have a very similar signal intensity pattern. Specific tests for infective pathologies are useful for diagnosis, but histological examination is essential for establishing a certain diagnosis. In our case the final histological examination and the specific tests that we performed have not cleared our doubts regarding the nature of the lesion that remains controversial.</p