177 research outputs found
Methods and apparatus for determining cardiac output
The present invention provides methods and apparatus for determining a dynamical property of the systemic or pulmonary arterial tree using long time scale information, i.e., information obtained from measurements over time scales greater than a single cardiac cycle. In one aspect, the invention provides a method and apparatus for monitoring cardiac output (CO) from a single blood pressure signal measurement obtained at any site in the systemic or pulmonary arterial tree or from any related measurement including, for example, fingertip photoplethysmography.According to the method the time constant of the arterial tree, defined to be the product of the total peripheral resistance (TPR) and the nearly constant arterial compliance, is determined by analyzing the long time scale variations (greater than a single cardiac cycle) in any of these blood pressure signals. Then, according to Ohm's law, a value proportional to CO may be determined from the ratio of the blood pressure signal to the estimated time constant. The proportional CO values derived from this method may be calibrated to absolute CO, if desired, with a single, absolute measure of CO (e.g., thermodilution). The present invention may be applied to invasive radial arterial blood pressure or pulmonary arterial blood pressure signals which are routinely measured in intensive care units and surgical suites or to noninvasively measured peripheral arterial blood pressure signals or related noninvasively measured signals in order to facilitate the clinical monitoring of CO as well as TPR
Measuring Decentrality in Blockchain Based Systems
Blockchain promises to provide a distributed and decentralized means of trust among untrusted users. However, in recent years, a shift from decentrality to centrality has been observed in the most accepted Blockchain system, i.e., Bitcoin. This shift has motivated researchers to identify the cause of decentrality, quantify decentrality and analyze the impact of decentrality. In this work, we take a holistic approach to identify and quantify decentrality in Blockchain based systems. First, we identify the emergence of centrality in three layers of Blockchain based systems, namely governance layer, network layer and storage layer. Then, we quantify decentrality in these layers using various metrics. At the governance layer, we measure decentrality in terms of fairness, entropy, Gini coefficient, Kullback-Leibler divergence, etc. Similarly, in the network layer, we measure decentrality by using degree centrality, betweenness centrality and closeness centrality. At the storage layer, we apply a distribution index to define centrality. Subsequently, we evaluate the decentrality in Bitcoin and Ethereum networks and discuss our observations. We noticed that, with time, both Bitcoin and Ethereum networks tend to behave like centralized systems where a few nodes govern the whole network
Regulatory Taking: A Contract Approach
This Article begins by defining the parameters of the fifth amendment\u27s taking clause. The Article then reviews the various tests used in determining whether governmental action constitutes a taking, and discusses the recent Supreme Court decisions within the framework of case law as it has evolved since the Court\u27s 1922 landmark decision, Pennsylvania Coal Co. v. Mahon. Finally, the Article suggests a formula based on well-established contract principles for analyzing the impact of land use regulation on private property interests
On Using Machine Learning to Identify Knowledge in API Reference Documentation
Using API reference documentation like JavaDoc is an integral part of
software development. Previous research introduced a grounded taxonomy that
organizes API documentation knowledge in 12 types, including knowledge about
the Functionality, Structure, and Quality of an API. We study how well modern
text classification approaches can automatically identify documentation
containing specific knowledge types. We compared conventional machine learning
(k-NN and SVM) and deep learning approaches trained on manually annotated Java
and .NET API documentation (n = 5,574). When classifying the knowledge types
individually (i.e., multiple binary classifiers) the best AUPRC was up to 87%.
The deep learning and SVM classifiers seem complementary. For four knowledge
types (Concept, Control, Pattern, and Non-Information), SVM clearly outperforms
deep learning which, on the other hand, is more accurate for identifying the
remaining types. When considering multiple knowledge types at once (i.e.,
multi-label classification) deep learning outperforms na\"ive baselines and
traditional machine learning achieving a MacroAUC up to 79%. We also compared
classifiers using embeddings pre-trained on generic text corpora and
StackOverflow but did not observe significant improvements. Finally, to assess
the generalizability of the classifiers, we re-tested them on a different,
unseen Python documentation dataset. Classifiers for Functionality, Concept,
Purpose, Pattern, and Directive seem to generalize from Java and .NET to Python
documentation. The accuracy related to the remaining types seems API-specific.
We discuss our results and how they inform the development of tools for
supporting developers sharing and accessing API knowledge. Published article:
https://doi.org/10.1145/3338906.333894
Planar Octilinear Drawings with One Bend Per Edge
In octilinear drawings of planar graphs, every edge is drawn as an
alternating sequence of horizontal, vertical and diagonal ()
line-segments. In this paper, we study octilinear drawings of low edge
complexity, i.e., with few bends per edge. A -planar graph is a planar graph
in which each vertex has degree less or equal to . In particular, we prove
that every 4-planar graph admits a planar octilinear drawing with at most one
bend per edge on an integer grid of size . For 5-planar
graphs, we prove that one bend per edge still suffices in order to construct
planar octilinear drawings, but in super-polynomial area. However, for 6-planar
graphs we give a class of graphs whose planar octilinear drawings require at
least two bends per edge
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Clinical course of acute zonal occult outer retinopathy complicated by choroidal neovascularization
Purpose
To report the clinical course and multimodal imaging features of acute zonal occult outer retinopathy (AZOOR) complicated by choroidal neovascularization (CNV) treated with anti-vascular endothelial growth factor (VEGF) treatment or photodynamic therapy (PDT).
Methods
Observational case series. Retrospective analysis of patients presenting to different institutions with evidence of AZOOR and neovascular lesions. Diagnosis of AZOOR was made on the basis of clinical presentation and multimodal imaging. All patients underwent a comprehensive ophthalmic evaluation and multimodal retinal imaging, including color fundus photos, fundus autofluorescence, fundus fluorescein angiography and spectral-domain optical coherence tomography.
Results
Four patients (three males, mean age 53.5Â years) were included in the study. Mean follow-up was 5.1Â years. Presentation of AZOOR was unilateral in two patients and bilateral in the remainder two patients. One of the patients presenting with unilateral AZOOR developed zonal lesions in the fellow eye during follow-up. All patients presented with unilateral type 2 (subretinal) CNV. Three patients underwent intravitreal anti-VEGF injections and one patient underwent a single PDT. Multimodal retinal imaging showed zonal or multizonal progression during treatment. After treatment, visual acuity and CNV stabilization was observed in all patients.
Conclusions
The presence of CNV expands the clinical spectrum of AZOOR. CNV complicating AZOOR may be effectively treated with intravitreal injections of anti-VEGF, despite progression of the zonal lesions. Further studies are required to define the role of treatment in the progression of the zonal lesions
Ferroxitosis: a cell death from modulation of oxidative phosphorylation and PKM2-dependent glycolysis in melanoma
Reliance on glycolysis is a characteristic of malignancy, yet the development of resistance to BRAF inhibitors in melanoma is associated with gain of mitochondrial function. Concurrent attenuation of oxidative phosphorylation and HIF-1α/PKM2-dependent glycolysis promotes a non-apoptotic, iron- and oxygen-dependent cell death that we term ferroxitosis. The redox cycling agent menadione causes a robust increase in oxygen consumption, accompanied by significant loss of intracellular ATP and rapid cell death. Conversely, either hypoxic adaptation or iron chelation prevents menadione-induced ferroxitosis. Ectopic expression of K213Q HIF-1α mutant blunts the effects of menadione. However, knockdown of HIF-1α or PKM2 restores menadione-induced cytotoxicity in hypoxia. Similarly, exposure of melanoma cells to shikonin, a menadione analog and a potential PKM2 inhibitor, is sufficient to induce ferroxitosis under hypoxic conditions. Collectively, our findings reveal that ferroxitosis curtails metabolic plasticity in melanoma
Declarative Event-Based Workflow as Distributed Dynamic Condition Response Graphs
We present Dynamic Condition Response Graphs (DCR Graphs) as a declarative,
event-based process model inspired by the workflow language employed by our
industrial partner and conservatively generalizing prime event structures. A
dynamic condition response graph is a directed graph with nodes representing
the events that can happen and arrows representing four relations between
events: condition, response, include, and exclude. Distributed DCR Graphs is
then obtained by assigning roles to events and principals. We give a graphical
notation inspired by related work by van der Aalst et al. We exemplify the use
of distributed DCR Graphs on a simple workflow taken from a field study at a
Danish hospital, pointing out their flexibility compared to imperative workflow
models. Finally we provide a mapping from DCR Graphs to Buchi-automata.Comment: In Proceedings PLACES 2010, arXiv:1110.385
SPAM detection: Naïve bayesian classification and RPN expression-based LGP approaches compared
An investigation is performed of a machine learning algorithm and the Bayesian classifier in the spam-filtering context. The paper shows the advantage of the use of Reverse Polish Notation (RPN) expressions with feature extraction compared to the traditional Naïve Bayesian classifier used for spam detection assuming the same features. The performance of the two is investigated using a public corpus and a recent private spam collection, concluding that the system based on RPN LGP (Linear Genetic Programming) gave better results compared to two popularly used open source Bayesian spam filters. © Springer International Publishing Switzerland 2016
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