953 resultados para epistemic closure


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Purpose: A peripheral iridotomy (PI) is the treatment of choice for pupillary block. In this study we investigated the effect of enlarging the size of a small PI on the anterior chamber angle in patients with angle closure using ultrasound biomicroscopy (UBM). Patients and Methods: Patients who had been treated with laser peripheral iridotomy for angle closure and were identified to have a small patent PI (<100 µm) with still appositionally closed anterior chamber angle were selected prospectively. The anterior chamber angle was assessed using UBM. The angle opening distance 500 µm from the scleral spur (AOD500) as well as the anterior and posterior chamber depth (ACD and PCD) 1000 µm from the scleral spur was measured. In addition, the ACD/PCD ratio was calculated. Afterwards, the PI was enlarged using an Nd: YAG laser and the UBM measurements were repeated as described above. Results: Six eyes of six patients were examined. After the enlargement of the PI the average AOD500 increased from 109 µm (±36) to 147 µm (±40) (p

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Purpose. To evaluate agreement between clinical examination (slit lamp examination and gonioscopy) and ultrasound biomicroscopy (UBM) in characterizing various features of the anterior chamber angle and adjacent structures. Methods. Twenty-eight patients (51 eyes) with open angle glaucoma (14), closed angle glaucoma (4), narrow angle and/or plateau iris (10), who had undergone UBM between March 94 and September 95 were studied. Evaluated parameters included angle width, iris configuration and presence of angle closure. The UBMs were reviewed in a masked fashion. Results. In 87.8% of cases there was agreement (within 10 degrees) between gonioscopic and UBM estimates of angle width. In all cases with greater than 10 degrees difference (12.2%) the angle size estimated by UBM was less than that estimated clinically. Iris configuration was graded identically in 51% of cases; the majority of disagreements (76.1%) occurred in cases graded as "regular" by gonioscopy and as "steep" by UBM. Angle closure was judged to be present more frequently by UBM. Conclusions. UBM and gonioscopy do not necessarily yield identical values for angle width, iris configuration, and presence of angle closure.

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Mineral prospecting and raising finance for ‘junior’ mining firms has historically been regarded as a speculative activity. For the regulators of securities markets upon which ‘junior’ mining companies seek to raise capital, a perennial problem has been handling not only the indeterminacy of scientific claims, but also the social basis of epistemic practices. This paper examines the production of a system of public warrant and associated knowledge practices intended to enable investors to differentiate between ‘destructive’ and ‘productive’ varieties of financial speculation. It traces the use of the notion of ‘disclosure’ in constructing and legitimizing the ‘juniors’ market in Canada. It argues that though the work of ‘economics’ may be necessary in the construction of markets, it is by no means sufficient. Attention must also be given to the ways in which legal models of ‘the free-market’ can be translated and constantly re-worked across the sites and spaces of regulatory practice, animating the geographies of markets.

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Clinical, pathological and experimental studies of radiation retinopathy confirm that the primary vascular event is endothelial cell loss and capillary closure. Pericytes are less susceptible, but typically atrophy as the capillaries become non-functional. The immediate effects of radiation reflect interphase and early mitotic death of injured endothelial cells, whereas later changes may be attributed to delayed mitotic death of compromised endothelial cells as they attempt division in the ordinary course of repair and replacement. Capillary occlusion leads to the formation of dilated capillary collaterals which may remain serviceable and competent for years. Microaneurysms develop in acellular and poorly supported capillaries, predominantly on the arterial side of the circulation and adjacent to regions of poorly perfused retina. Alterations in haemodynamics produce large telangiectatic-like channels which, typically develop a thick collagenous adventitia and may become fenestrated. Limited capillary regeneration occurs, usually evident as recanalisation of arterioles or venules by new capillaries. Vitreo-retinal neovascularisation may occur where retinal ischaemia is widespread. Radiation produces an exaggerated vasculopathy in patients with diabetes mellitus, and five month streptozotocin-induced diabetic rats develop a severe ischaemic retinopathy with vitreoretinal neovascularisation when exposed to 1500 cGy of radiation. Later photocoagulation is useful in containing or reversing microvascular incompetence and vasoproliferation in some patients with advanced radiation retinopathy.

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Freestanding BaTiO3 nanodots exhibit domain structures characterized by distinct quadrants of ferroelastic 90 domains in transmission electron microscopy (TEM) observations. These differ significantly from flux-closure domain patterns in the same systems imaged by piezoresponse force microscopy. Based upon a series of phase field simulations of BaTiO3 nanodots, we suggest that the TEM patterns result from a radial electric field arising from electron beam charging of the nanodot. For sufficiently large charging, this converts flux-closure domain patterns to quadrant patterns with radial net polarizations. Not only does this explain the puzzling patterns that have been observed in TEM studies of ferroelectric nanodots, but also suggests how to manipulate ferroelectric domain patterns via electron beams.

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This book investigates why some societies defer the solution of transitional justice issues, such as the disappeared/missing, even after successful democratic consolidation. It also explains why the same societies finally decide to deal with these human rights issues. In short, it considers the interesting and understudied phenomenon of post-transitional justice. The prolonged silences in Spain, Cyprus and Greece contradict the experience of other countries -- such as South Africa, Bosnia, and Guatemala -- where truth recovery for disappeared/missing persons was a central element of the transition to peace and democracy. Despite democratization, the exhumation of mass graves containing the victims from the violence in Cyprus (1963-1974) and the Spanish civil war (1936-1939) was delayed until the early 2000s, when both countries suddenly decided to revisit the past. Cyprus and Spain are not alone: this is an increasing trend among countries trying to come to terms with past violence. Interestingly, despite similar background conditions, Greece is resisting the trend, challenging both theory and regional experience. Truth Recovery and Transitional Justice considers three interrelated issues. First, what factors can explain prolonged silence on the issue of missing persons in some transitional settings? Second, which processes can address the occasional yet puzzling transformation of victims’ groups from opponents of truth recovery to vocal pro-reconciliation pressure groups? Third, under which conditions is it better to tie victims’ rights to an overall political settlement? The book looks at Spain and Cyprus to show how they have attempted to bring closure to deep trauma by exhuming and identifying their missing, albeit under considerably different conditions. It then probes the generalizability of the conclusions on Spain and Cyprus by looking at the Greek experience; oddly, despite similar background conditions, Greece remains resistant to post-transitional justice norms. Interestingly, each case study takes a different approach to transitional justice.

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We describe, for the first time, quantification of in-skin swelling and fluid uptake by hydrogel-forming microneedle (MN) arrays and skin barrier recovery in human volunteers. Such MN arrays, prepared from aqueous blends of hydrolyzed poly(methylvinylether/maleic anhydride) (15%, w/w) and the cross-linker poly(ethyleneglycol) 10,000 Da (7.5%, w/w), were inserted into the skin of human volunteers (n = 15) to depths of approximately 300 μm by gentle hand pressure. The MN arrays swelled in skin, taking up skin interstitial fluid, such that their mass had increased by approximately 30% after 6 h in skin. Importantly, however, skin barrier function recovered within 24 h after MN removal, regardless of how long the MN had been in skin or how much their volume had increased with swelling. Further research on closure of MN-induced micropores is required because transepidermal water loss measurements suggested micropore closure, whereas optical coherence tomography indicated that MN-induced micropores had not closed over, even 24 h after MN had been removed. There were no complaints of skin reactions, adverse events, or strong views against MN use by any of the volunteers. Only some minor erythema was noted after patch removal, although this always resolved within 48 h, and no adverse events were present on follow-up.

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University classroom talk is a collaborative struggle to make meaning. Taking the perspectival nature of interaction as central, this paper presents an investigation of the genre of spoken academic discourse and in particular the types of activities which are orientated to the goal of collaborative ideas or tasks, such as seminars, tutorials, workshops. The purpose of the investigation was to identify examples of dialogicality through an examination of stance-taking. The data used in this study is a spoken corpus of academic English created from recordings of a range of subject discipline classrooms at a UK university. A frequency-based approach to recurrent word sequences (lexical bundles) was used to identify signals of epistemic and attitudinal stance and to initiate an exploration of the features of elaboration. Findings of quantitative and qualitative analyses reveal some similarities and differences between this study and those of US based classroom contexts in relation to the use and frequency of lexical bundles. Findings also highlight the process that elaboration plays in grounding perspectives and negotiating alignment of interactants. Elaboration seems to afford the space for the enactment of student stance in relation to the tutor embodiment of discipline knowledge.

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AgentSpeak is a logic-based programming language, based on the Belief-Desire-Intention (BDI) paradigm, suitable for building complex agent-based systems. To limit the computational complexity, agents in AgentSpeak rely on a plan library to reduce the planning problem to the much simpler problem of plan selection. However, such a plan library is often inadequate when an agent is situated in an uncertain environment. In this paper, we propose the AgentSpeak+ framework, which extends AgentSpeak with a mechanism for probabilistic planning. The beliefs of an AgentSpeak+ agent are represented using epistemic states to allow an agent to reason about its uncertain observations and the uncertain effects of its actions. Each epistemic state consists of a POMDP, used to encode the agent’s knowledge of the environment, and its associated probability distribution (or belief state). In addition, the POMDP is used to select the optimal actions for achieving a given goal, even when facing uncertainty.

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Conventional wisdom has it that the EU is unable to promote viable social integration, which contrasts with its commitments to improving working and living conditions and to social values and goals such as solidarity, social protection and social inclusion. This
article challenges two diff erent standpoints: on the one hand, competitive neoliberalism demands that the EU focuses on economic integration through legally binding internal market and competition rules even if Member States can only maintain a limited commitment to social inclusion, while authors defending the social models unique to the continent of Europe demand that the EU rescinds some of its established legal principles in order to make breathing space for Member States to maintain market correcting social policies. Both positions convene that there should be no genuine social policy at EU level.
This article uses scenarios of widely discussed rulings by the Court of Justice to illustrate that legally enforceable economic integration would prevent most Member States from achieving sustainable health services, labour relations and free university education on the basis of national closure. Since the EU has limited legislative competences to create EU level institutions to balance inequalities, it derives a Constitution of Social Governance from the EU’s values, proposing that the Court of Justice develops its urisprudence into an instrument for challenging European disunion induced by new EU economic governance

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This article is based on primary research conducted by the authors in Northern Ireland in Mourne House women’s unit at Maghaberry Prison in 2004 and in Ash House women’s prison unit in Hydebank Wood Young Offender Centre from 2005-2006. It explores the imprisonment of women in prison in the context of a society slowly and unevenly emerging from violent conflict and against a backdrop of the global rise of women’s imprisonment over the past two decades. The history of the gendered punishment of politically motivated prisoners is explored, followed by discussion of the findings of primary research in Mourne House women’s unit and, following its closure, in Ash House. The conclusion analyses how women’s prison experiences in the North contribute to an understanding of the contested terrain of agency and resistance. Finally, the article explores the potential for, and barriers, to change within women’s imprisonment in Northern Ireland.

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Credal networks are graph-based statistical models whose parameters take values in a set, instead of being sharply specified as in traditional statistical models (e.g., Bayesian networks). The computational complexity of inferences on such models depends on the irrelevance/independence concept adopted. In this paper, we study inferential complexity under the concepts of epistemic irrelevance and strong independence. We show that inferences under strong independence are NP-hard even in trees with binary variables except for a single ternary one. We prove that under epistemic irrelevance the polynomial-time complexity of inferences in credal trees is not likely to extend to more general models (e.g., singly connected topologies). These results clearly distinguish networks that admit efficient inferences and those where inferences are most likely hard, and settle several open questions regarding their computational complexity. We show that these results remain valid even if we disallow the use of zero probabilities. We also show that the computation of bounds on the probability of the future state in a hidden Markov model is the same whether we assume epistemic irrelevance or strong independence, and we prove an analogous result for inference in Naive Bayes structures. These inferential equivalences are important for practitioners, as hidden Markov models and Naive Bayes networks are used in real applications of imprecise probability.

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The BDI architecture, where agents are modelled based on their beliefs, desires and intentions, provides a practical approach to develop large scale systems. However, it is not well suited to model complex Supervisory Control And Data Acquisition (SCADA) systems pervaded by uncertainty. In this paper we address this issue by extending the operational semantics of Can(Plan) into Can(Plan)+. We start by modelling the beliefs of an agent as a set of epistemic states where each state, possibly using a different representation, models part of the agent's beliefs. These epistemic states are stratified to make them commensurable and to reason about the uncertain beliefs of the agent. The syntax and semantics of a BDI agent are extended accordingly and we identify fragments with computationally efficient semantics. Finally, we examine how primitive actions are affected by uncertainty and we define an appropriate form of lookahead planning.

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Belief revision studies strategies about how agents revise their belief states when receiving new evidence. Both in classical belief revision and in epistemic revision, a new input is either in the form of a (weighted) propositional formula or a total
pre-order (where the total pre-order is considered as a whole).
However, in some real-world applications, a new input can be a partial pre-order where each unit that constitutes the partial pre-order is important and should be considered individually. To address this issue, in this paper, we study how a partial preorder representing the prior epistemic state can be revised by another partial pre-order (the new input) from a different perspective, where the revision is conducted recursively on the individual units of partial pre-orders. We propose different revision operators (rules), dubbed the extension, match, inner and outer revision operators, from different revision points of view. We also analyze several properties for these operators.

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Retinopathy of prematurity is a sight-threatening complication of premature birth caused by nitrooxidativeinsult to the developing retinal vasculature during therapeutic hyperoxia exposure and laterischemia-induced neovascularization on supplemental oxygen withdrawal. In the vasodegenerativephase, during hyperoxia, defective endothelial nitric oxide synthase (NOS) produces reactive oxygenand nitrogen free radicals rather than vasoprotective nitric oxide for unclear reasons. More important,NOS critically depends on the availability of the cofactor (6R)-5,6,7,8-tetrahydrobiopterin (BH4).Because BH4 synthesis is controlled enzymatically by GTP cyclohydrolase (GTPCH), we used GTPCHdepletedmice [hyperphenylalanaemia strain Q4 (hph1)] to investigate the impact of hyperoxia on BH4bioavailability and retinal vascular pathology in the neonate. Hyperoxia decreased BH4 in retinas,lungs, and aortas in all experimental groups, resulting in a dose-dependent decrease in NOS activityand, in the wild-type group, elevated NOS-derived superoxide. Retinal dopamine levels were similarlydiminished, consistent with the dependence of tyrosine hydroxylase on BH4. Despite greater depletionof BH4, the hphþ/ and hph1/ groups did not show exacerbated hyperoxia-induced vessel closure,but exhibited greater vascular protection and reduced progression to neovascular disease. This vasoprotectiveeffect was independent of enhanced circulating vascular endothelial growth factor (VEGF),which was reduced by hyperoxia, but Q5 to local ganglion cell layerederived VEGF. A constitutively higherlevel of VEGF expression associated with retinal development protects GTPCH-deficient neonates fromoxygen-induced vascular damage.